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  Term / Acronym Definition  
A A Stage Early stage of polymerization of thermosetting resins in which the material is still soluble in certain liquids and is fusible. Also, see B-stage, C-stage   
  ABA Poly(Acrylonitrile Butadiene Acrylate)  
  ABR Acrylate-butadiene rubber  
  Abrasion A The abrasion A in mm³ is the volumetric loss determined in accordance with the test conditions laid down for this test method suffered by a defined test body when this is moved along a defined abrasion path while pressed with a defined pressure against a sheet of emery paper of defined attack strength (reference attack strength).  
  Abrasion Resistance  The ability of a polymer to withstand mechanical action, such as rubbing, scraping or erosion, which tends to remove material progressively from it's surface.    
  ABS  Acrylonitrile Butadiene Styrene (ABS) is a polyphasic material. It has good impact resistance, very good structural strength and has a shiny impervious surface. It possesses high rigidity and impact strength, excellent abrasion resistance, excellent electrical properties, moisture, and creep resistance. ABS is resistant to inorganic salts, alkalies and many acids. It is commonly vacuum formed, molded or extruded. (Working Temperature Range: -25°C to +60°C)  
  ABS  Poly(Acrylonitrile Butadiene Styrene)  
  Absorption (Light) Decrease in directional transmittance of incident radiation (such as light), resulting in a modification or conversion of the absorbed energy, into heat, for example. Light incident on a specimen may be partially reflected, partially transmitted, or partially absorbed.  
  Accelerant Synonym - see "Accelerators"  
  Accelerator Generally used to increase the rate of crosslinking reaction. There are different types of accelerator likes ultra fast accelerator, fast accelerator, semi fast accelerator, slow accelerator, delayed action accelerator, etc. Generally combinations of different types of accelerators are used to get best results.   
  Accelerator activator Generally used to further increase of rate of crosslinking reaction. Common example is zinc stearate.  
  Accelerator: Sulphenamide Class. Delayed action safe and at the same time fast primary accelerators. Used mainly in the manufacture of automobile and cycle tires. Also, used in transmission and conveyor beltings, tire retreading materials, injection molded products, footwear, cable sheathings, etc.  
  Accelerator: Thiazole Class. Semi-ultra accelerators with moderate scorch safety. Used alone or in combination with other accelerators. Used for the manufacture of products like rubber footwear, profiles, hoses, conveyor and transmission beltings, rubber to metal bonded products, bicycle tires, inner tubes, cellular rubber products, etc.  
  Accelerator: Thiuram and Dithiocarbamate Type. Ultra fast accelerators; used alone or as a booster for thiazoles and sulphenamides. Dithiocarbamates are the most widely used accelerators for latex compounding. Used for the manufacture of white and colored products, food contacting and medical goods, footwear, cables, inner tubes, all types of latex based products, etc.  
  Accelerators Organic chemicals of several classes are used to speed the crosslinking process. The amount of accelerator is typically very small compared to the total parts in the compound. The accelerator or accelerator system chosen is critical as it determines to a very large extent how the rubber will cure in the equipment at hand. By changing accelerators, the rubber can be cured slow, cured fast, highly crosslinked, not so highly crosslinked. To measure how a compound cures, the rheometer chart is made with a curemeter. The graph shows a compounder a great deal. The inital dip is the rubber softening under heat. The point at which the line begins to rise is the "scorch time". Usually a longer scorch time is desired to allow the rubber to be safely in the desired equipment position before it begins to cure. A sharply rising line is desirable. The time taken to get the rubber to rise to it's maximum point is the time to cure, and at 90% of this level is T90, the time most compounders consider the stock cured. The shorter time it takes to ge to T90, the sharper the rise is, and the less time the compound spends tied up in equipment, which is of course desirable.   
  ACH Acetone cyanohydrin (ACH)  
  Acid scavenger Additive having the ability to neutralize acidic species from a formulation. It is mainly used to prevent equipment corrosion and to improve the stability of the material. Families of acid scavenger are : Metallic Stearates, Hydrotalcite, Hydrocalumite or Zinc Oxide.   
  ACM  Poly(Acrylic Acid Ester Rubber)   
  ACM  Ethyl acrylate copolymer (ACM)  
  ACM  Poly(Acrylic Acid Ester Rubber)  
  ACN Acetonitrile (ACN)  
  Acrylic based Impact Modifier  Generally core shell particles containing an acrylic core used for impact modification of rigid PVC or impact modification of engineering polymers.  
  Acrylic resin
Family of polymer that refers to large variety of products. They are all made by (co) polymerization of acrylic monomers, such as acrylates (Methyl, Ethyl, Butyl) or acrylic acid. Used in molding and extrusion compounds.   
  ACS  Acrylonitrile-Chlorinated Polyethylene-Styrene Terpolymer  
  ACS  American Chemical Society  
  Addition (or Polyaddition)
Polymerization reaction in which no byproducts are formed.  
  Additive Product introduced into a polymer or applied to its surface in order to modify or to enhance its performances. There are numerous families of additives that can be classified into 3 main categories: property extenders, processing aids and modifiers.  
  Adhesion The bond between a rubber surface and a nonrubber surface (e. g., metal, concrete); the strength of the bond between two uncured rubber surfaces or plies.  
  Adhesion promoter  Adhesion promoters act at the interface to increase the adhesion between two substrates through the reduction of the interfacial tension. When the adhesion promoter is used to increase adhesion between two incompatible polymers it is also called a Compatibilizer. When the adhesion promoter is used to increase adhesion between a polymer and a filler it is called a coupling agent. Compatibilizers or coupling agents can be reactive or non reactive. Syn. Bonding agent.  
  Adhesive Part of a cement system applied over prepared surfaces for bonding them to rubber.  
  Adhesive force The adhesive force in accordance with this standard is the maximum force which arises when the elastomer is peeled off from the rigid plate of a standard test body at an angle of 90 °C (DIN 53531 T1).  
  Adsorption Build up of a molecule at a surface. Not to be confused with absorption. Adsorption generally occurs because different parts of a molecule have an affinity for the two different phases on either side of the interface.   
  AEM Ethylene acrylic terpolymer (AEM)  
  AES  Poly(Acrylonitrile Ethylene Styrene) or Poly(Acrylonitrile Ethylene Propylene Styrene)  
  Age Resistance  The resistance to deterioration by oxygen and ozone in the air, and by heat and light. A variety of anti-oxidants are available which provide protection in differing degrees to these deteriorating factors.    
  Aging [1]. The changing of a material with time under defined environmental conditions, leading to improvement or deterioration of properties. Addition of Antioxidants, UV / Light stabilizers, and so on, allows an improvement of ageing properties. [2]. Deterioration or change of physical and chemical properties of rubber by oxidation, heat, or moisture over a period of time.  
  Air oven aging A means of accelerating a change in the physical properties of rubber compounds by exposing them to the action of air at an elevated temperature at atmospheric pressure.  
  Aliphatic  Any organic compound in which the main structure is a chain of carbon atoms joined to each other is classified as being aliphatic.    
  Alkyd Resin formed by the condensation of polyhydric alcohols with polybasic acids. May be regarded as complex polyester (thermoset).   
  Alternating copolymer  A copolymer consisting of macromolecules comprising two species of monomeric units in alternating sequence.   
  Amide Organic compound that contains a carbonyl group bound to nitrogen. -CON- (C double bonded to O)  
  Amino resin Thermosetting resin manufactured from amino compound and formaldehyde.  
  AMMA  Poly(Acrylonitrile Methyl Methacrylate)  
  AN  Acrylonitrile (AN)  
  Anionic polymerization  An ionic polymerization in which the kinetic-chain carriers are anions    
  Anti-blocking and slip agents  Surface-modifying additives to reduce friction and tackiness of polyolefin films.    
  Antidegradant Compounding material used to retard deterioration caused by oxidation, ozone, light and combinations. Note: Antidegradant is a generic term for such additives as Antioxidants, Antiozonants and UV / Light stabilizers.   
  Anti-fibrillant masterbatch Product that prevents slit-tapes from splitting in machine direction.  
  Antifogging / Antidrip agent  Additive (mostly surface-active compounds) which is added to films or sheets in order to eliminate fogging and/or dripping that is caused by excess humidity.  
  Antioxidant (AO) Used to prevent the oxidation reaction in the product in the presence of air or oxygen. Gives good protection  heat aging and moderate protection against flex cracking. Common examples are acetone-diphenylamine-acetone-amine, N-phenyl-b-napththylamine, 4,4’-dioctyldiphenylamine, etc   
  Antioxidants  A group of substances being able to inhibit radical reactions in the polymer and thus prevent degradation processes. Different types are available: sterically hindered phenols and phosphites as base for polyolefins, sulphur based heat stabilizers and C-radical scavengers for special applications.    
  Antiozonant Additive used to protect a polymer against the effects of ozone-induced degradation and hence used mainly in diene rubbers. Works either by providing a physical barrier to ozone penetration by forming a thin surface film of an ozone-resisting wax or by chemically reacting with ozone or polymer ozonolysis products, as do aromatic diamines such as p-phenylene diamine derivatives. Common example is pera-phenylenediamine  
  Antislip agent Additive used to eliminate the sliding of parallel film surfaces over each other or the sliding of film surfaces over substrates.   
  Antistatic agents   Surface-modifying additives to reduce surface resistance of polyolefins, eliminating charge build-up and dust collection; an example of a widely used antistatic agent is glycerine-monostearate. Additive mainly acting at the surface of a polymer and minimizing static electricity (charge build-up, dust collection) in plastic materials. With external antistatic agents, the plastic is coated by spraying or immersion. Internal antistatic agents are incorporated into the polymer matrix and then migrate to the surface. Conductive fillers can also be used to minimize static electricity. Different types of antistatic agents are used in polymerization reactors to prevent the formed polymer powder from adhering to the reactor wall. Main families of antistatic agents are: Fatty acid esters, Ethoxylated amines, Quaternary ammonium compounds, Alkylsulfonates, Alkylphosphates.     
  Antitack / Antiblock agent Additive used to lessen the adhesion of the surface of products made from the formulation of like or different surfaces. Acts by producing a slight roughening of the surface. Typically finely divided, solid minerals, but some are waxes. Antiblock agents are mainly used in film extrusion. Families of antiblock agents : Natural silica, Synthetic silica, Talc, Calcium carbonate, EBS.  
  AO  Antioxidant  
  APAO Amorphous PolyAlphaOlefin (APAO)  
  APET  Amorphous Polyethylene Terephthalate  
  API  American Petroleum Institute  
  Aromatic  Aromatics are a highly reactive group of hydrocarbons with unsaturated rings of carbon atoms, producing a great variety of products. As their name implies, they have a strong odor, which is not unpleasant.   
  ARP  Poly(Arylterephthalate) Copolyester  
  AS  Antistatic  
  ASA  Acrylate-styrene-acrylonitrile   
  ASA  Poly(Acrylic Styrene Acrylonitrile)  
  ASTM  American Society for Testing and Materials  
  ATH  Aluminum trihydrate   
  Attack strength The attack strength S in mg of the sheet of test emery paper is the loss in mass of a defined test body from the control elastomer that is moved over this sheet under defined test conditions (DIN 53516)   
  Autoclave A heavy steel vessel in which rubber articles are vulcanized by means of steam and/or hot air and under pressure.  
top Autoclave cure The rubber-lined equipment is placed in an autoclave and subjected to steam and/or hot air under controlled temperature and pressure. This method of curing is preferred because it allows better heat transfer and a shorter cure cycle.   
B B Stage Also called resistal. Intermediate stage in the polymerization reaction of thermosets. After B-stage, material softens with heat and is plastic and fusible. The resin of an uncured prepreg or premix is usually B-stage. Also, see A-stage, C-stage.   
  Banbury An enclosed machine for mixing rubber and compounds.  
  BD Butadiene  
  BDMA  Benzyl Dimethyl Amine (Epoxy Cure Accelerator)  
  BDS  Butadiene-styrene block copolymer   
  BGE  Butyl Glycidyl Ether  
  BIIR Brom-isobutene-isoprene rubber (usually designated brombutyl rubber)  
  BIIR Isobutylene isoprene rubber, brominated (bromobutyl rubber) (BIIR)  
  BIIR  Bromobutyl Rubber  
  Biocide / Antibacterial agent Material or additive added to greatly delay or stop the growth of bacteria. They are used to protect the material or for hygienic applications.  
  Bleeding Surface exudation. (also see Bloom)  
  Block copolymer  A copolymer that is a block polymer. In a block copolymer, adjacent blocks are constitutionally different, i.e., each of these blocks comprises constitutional units derived from different characteristic species of monomer or with different composition or sequence distribution of constitutional units    
  Bloom A discoloration or change in appearance of the surface of a rubber product caused by the migration of a liquid or solid to the surface. Examples: sulfur bloom, wax bloom. Not to be confused with dust on the surface from external sources.  
  Blow A soft area caused by porosity below the surface.  
  Blow molding   Extrusion of a parison (hollow melt tube) which is forced to a mold caving by internal pressure and cooled down to form a hollow article. Used for the production of bottles, wide-mouth containers, petrol tanks, etc.   
  Blowing agents Chemical dry powder (azodicarbonamide, bicarbonate/acids, phenyltetrazoles) added to plastics or rubbers. Generates gas or physical (compressed carbon dioxide, nitrogen, air or hydrocarbons) that are already a gas in the polymer melt process and permits the resins to assume a cellular structure. Foam concentrates are formulated with chemical foaming agents. Used to manufacture the micro cellular product. Azocarbonamide, dinitrosopentamethylenetetramine, benzenesulphonohydrazide, etc.  
  Blown film Fabrication of a film by continuously pumping the polymer through a circular die and filling the tube with air. The volume of air contained within the tube stretches the tube out to the desired width and, in conjunction with the rate at which it is being pulled away from the die, the desired thickness is created.   
  BMC  Bulk Molding Compound  
  BMI  Bismaleimide  
  BOPP  Biaxially Oriented Polypropylene (Film)  
  BR Low-cis polybutadiene rubber  
  BR Very high-cis polybutadiene rubber   
  BR  Butadiene rubber (polybutadiene rubber)   
  BR  Polybutadiene Rubber  
  Brightness Aspect of visual perception whereby an area appears to emit more or less light.   
  BRNd High CIS Neodymium Catalyst Polybutadiene (BRNd) rubber  
  Brominated Flame Retardant  Molecule containing high level of Bromine used as flame retardant for polymers.  
  BTX  Abbreviation of the aromatic hydrocarbons, benzene, toluene and xylene    
  Buffing Grinding a surface to obtain dimensional conformance or surface uniformity.  
top Butyl rubber Isobutene-isoprene rubber (IIR), synthetic rubber, soft rubber, chlorobutyl and bromobutyl rubber as variants containing halogens with modified properties, high chemical resistance and high resistance to permeation, resistant to ozone and weathering. Copolymer of isobutene and small amounts of isoprene. Frequently mixed with natural and styrene-butadiene rubbers for obtain special properties like resistance to ageing, initial tack at low temperatures, and good peel-off.     
C C Stage Final step in the cure of a thermoset resin, resulting in irreversible hardening and insolubility. Also, see A-stage, B-stage.   
  CA  Cellulose Acetate  
  CAB  Cellulose Acetate Butyrate  
  Calcium Carbonate Filler widely used in polymer to reduce cost of formulation and to improve stiffness or toughness.  
  Calender A machine equipped with two or more heavy, internally heated or cooled rolls used for the continuous sheeting or "plying up" of rubber compounds.  
  Calendering A process wherein the rubber is compressed in multi-roll process (calender) to produce continuous sheets (solid or sponge) of uniform thickness. Form of extrusion using two or more counter-rotating rolls in which film and sheet is produced by squeezing a hot, viscous material between them.   
  CAP  Cellulose Acetate Propionate  
  Capillary rheometry  Actual capillary rheometry gives information about flow properties of polymer melts. Results are given as a viscosity function, that is viscosity as a function of shear rate or shear stress. Compared to MFR measurement the shear rate range is much wider and the rates in processing applications are reached. With many products, however, flow instabilities (melt fracture) at high rates limit the useful range. A capillary rheometer consists of a barrel, piston and die. The sample is put into the barrel, heated and pushed by the piston through the die. The piston is driven by hydraulic pressure which allows more flexible choice of rates compared to MFR measurements. In addition, longer dies can be used to avoid the errors coming from the entrance and exit pressure losses.    
  Carbon Black  Black pigment used in concentrations of about 2.5% in order to ensure excellent UV-resistance. In higher concentrations, 30-40%, Carbon Black is used to obtain semiconductive properties used in Cable applications. The type of CB and the particle size is very important for the end-product properties.    
  Carbon fiber Reinforcing fiber produced by the pyrolysis of an organic precursor fiber, such as PAN. These fibers are mainly used in high performance composites and provide materials with low density and excellent mechanical performances. They can be used chopped in thermoplastics to make reinforced materials with low weight.   
  Cast Film Process that involves the extrusion of polymer melt through a slot or flat die to form a thin, molten sheet or film. This film is "pinned" to the surface of a chill roll (typically water-cooled and chrome-plated) by a blast of air from an air knife or vacuum box.   
  Catalyst  A substance which aids or promotes a chemical reaction without forming part of the final product. It enables the reaction to take place faster or at a lower temperature, and remains unchanged at the end of the reaction.    
  Catalyst: Chromium Catalysts for the production of high and medium density polyethylene grades.  
  Catalyst: Metallocene Structurally defined zirconium-based single-site catalysts metallocene catalysts for polypropylene and polyethylene production.  
  Catalyst: Ziegler Titanium Ziegler catalysts for the production of linear low density and high density polyethylene grades.  
  Catalyst: Ziegler-Natta High yield/high stereospecificity, titanium-based, multi-site Ziegler-Natta catalysts for polypropylene production.  
  Catalysts A substance, generally comprising a mixture of titanium and aluminum compounds that, together with the design of the production process, determines the nature of the polyolefin and the efficiency with which it is produced.  
  CE  Cellulose   
  Cellular Rubber  Low-density rubber products containing a cellular structure. The cells may either be open and interconnecting or closed and not interconnecting; a generic term for materials containing many cells (either open, closed or both) dispersed throughout the mass.    
  Cellulose Complex carbohydrate (C6H10O5)n formed of microfibrils of glucose molecules. Chief constituent of the cell walls of plants, and consequently chief constituent of many fibrous plant products such as paper and board, and cotton, linen and rayon cloth.   
  CF  Cresol Formaldehyde  
  CFR  Code of Federal Regulations (21 CFR has provisions dealing with food contact of polymers)  
  CGE  Cresol Glycidyl Ether  
  Chain extender Additive that "zips-up" the prepolymer molecules, increasing molecular weight and creating the final polymer. They can be used to increase the molecular weight of high polymers (ex: PET, PA, PC) by solid state polymerization or reactive extrusion.   
  Chain polymerization  A chain reaction in which the growth of a polymer chain proceeds exclusively by reaction(s) between monomer(s) and reactive site(s) on the polymer chain such that the reactive site(s) are regenerated on the same polymer chain by the end of each growth step. A chain polymerization consists of initiation and propagation reactions, and may also include termination and chain transfer reactions. The adjective "chain" in "chain polymerization" denotes "chain reaction". In a chain polymerization, the average degree of polymerization remains constant with monomer conversion (e.g., in steady-state, radical polymerizations) or may increase with monomer conversion (e.g., in the formation of living polymers).    
  Chain transfer  A chemical reaction, usually occurring during chain polymerizations, in which the activity of the kinetic-chain carrier is transferred from the growing macromolecule or oligomer molecule to another molecule or another part of the same molecule. Chain transfer to another part of the same molecule is often termed backbiting    
  Chalking The formation of a powdery surface condition due to disintegration of surface binder or elastomer by weathering or other destructive environmental conditions.  
  CHDM  Cyclohexanedimethanol  
  Checking The short, shallow cracks on the surface of a rubber product resulting from damaging action of environmental conditions.  
  Chelating / Complexing agent Family of molecules that can form several bonds to a metal ion, in order to deactivate them. These additives can be used to improve polymer stability particularly for parts in contact with metal (such as Cables). Examples of chelating agents are: EDTA, ethylenediamine, phosphite.   
  Chemical Cure Vulcanization at room temperature activated by chemical agents without the application of heat from an outside source.  
  Chloro-butyl Chloro-isobutene-isoprene rubber (CIIR)  
  Chlorosulfonated polyethylene (CSM) Synthetic rubber (CSM), soft rubber, good resistance to oxidation (usually designated Hypalon)  
  CIIR Isobutylene isoprene rubber, chlorinated (chlorobutyl rubber) (CIIR)  
  CIIR  Chloro-isobutene-isoprene rubber (usually designated chloro-butyl rubber)  
  CIIR  Chlorobutyl Rubber  
  Clarifying agent Additive generally used in polymers like polypropylene or PET, in order to increase the transparency of the parts. As an example, Sorbitol derivatives are excellent clarifying agents for PP.  
  Clarity Characteristic of a transparent body whereby distinct high-contrast images or high-contrast objects (separated by some distance from the body) are observable through the body. Clarity is mainly affected by large irregularities in film, for example, sharkskin.   
  Cling agent Additive that confers adhesiveness to films. They are mainly used in stretch wrap films. An example of cling agent for LLPDE film is PIB. However, some new metallocene resin seems to have natural cling effect.   
  Closed Cell  An expanded structure consisting of a multitude of individual, nonconnecting, gas-tight cells.   
  CM  Chlorinated Polyethylene Rubber  
  CM  Compression Molded  
  CMC  Carboxymethyl Cellulose  
  CN  Cellulose Nitrate  
  CO Epichlorohydrin homopolymer (CO)  
  CO  Epichlorohydrin Rubber (Homopolymer)  
  COC Cyclic Olefin Copolymer (COC)  
  Cocatalyst  Most often an organometallic compound that is used to activate the catalyst.   
  Coextrusion  Process of extruding two or more materials through a single die with two or more orifices arranged so that the extrudates merge and weld together into a laminar structure before chilling.   
  COF  Coefficient of Friction  
  Coinjection  Successive injection into a mould of virgin and recycled polymers. Both materials are molten.   
  Coking  A thermal cracking process to break up large molecules into smaller ones with the generation of quantities of petroleum coke.   
  Color Aspect of object appearance distinct from form, shape, size, position, or gloss that depends upon the spectral composition of the incident light, the spectral reflectance of transmittance of the object, and the spectral response of the observer, as well as the illuminating and viewing geometry.   
  Colorant Dye, pigment, or other agent used to impart a color to a material. Various types of pigments and dyes are used in polymer compounding.  
  Comonomer  Comonomer is a monomer which is used to modify the polymer properties, e.g. to reduce the density of the polymer. Different types of copolymerization processes are possible, leading to different structures and properties of the produced copolymer. In polyethylene, higher a-olefins like butene, hexene or octene are used as comonomers, in polypropylene, mostly ethylene and sometimes butene.    
  Composite Three-dimensional combination of at least two materials differing in form or composition, with a distinct interface separating the components. Composite materials are usually man-made and created to obtain properties that cannot be achieved by any of the components acting alone.   
  Compound A term applied to either vulcanized or unvulcanized mixtures of elastomers and other ingredients necessary to make a useful rubber-like material.   
  Compounding The process of mixing a polymer with all the materials necessary for the finished resin to be shipped to the processor.  
  Compounding  Production of a final homogenized and stabilized product in pellet form. This term is also used for the production of compounds incorporating pigments, reinforcing fibers or fillers as well as blends with other polymers (in the case of polyolefins, frequently elastomers).   
  Compression Molding Technique for molding thermoset plastics in which a part is shaped by placing the fiber and resin into an open mold cavity, closing the mold, and applying heat and pressure until the material has cured or achieved its final form.   
  Compression Set  The residual decrease in thickness of a test specimen measured 30 minutes or 24 hours after removal from a suitable loading device in which the specimen had been subjected for a definite time to compressive deformation under specified conditions of load application and temperature.  Also, The deformation which remains in rubber after has been subjected to and released from a specific compress stress for a definite period of time at a prescribed temperature. Cc Compression set measurements are used to evaluate the creep and stress relaxation properties of rubber.  
  Condensation (polycondensation) Polymerization reaction in which simple byproducts (for example, water) are formed. Polymers like polyester, polyamide are synthesized by polycondensation.   
  Conductive additive Used to increase the conductivity of the material. Common examples are conductive fillers like several types of metallic fillers.  
  Conductive compound Compound providing high mobility for electrical charge. Material that allows electrons to flow easily across its surface or through its mass. Usually the volume resistivity is below 1 E6 ohm.cm. Example of conductive material used in polymers: conductive carbon black, graphite, carbon nanotubes, metallic fibers or films and so on.   
  Conductive Rubber   A rubber with a much lower electrical resistivity than normal. This is achieved by high loadings (e.g. 50phr) of one of the more highly conducting grades of carbon black, e.g. super conduction furnace or acetylene black. A typical resistivity is about 1015¥Øcm compared with about 1015¥Øcm in a normal rubber.  
  Contact Molding  Technique where materials are placed in a mold and cured by hardener, catalyst and/or heat. No additional pressure is used.   
  Contact stain Discoloration of a product by another material or by a rubber article in the area directly touching it.   
  COPA Thermoplastic Copolyamides (COPA)  
  Copolymer  Two monomers polymerized together to form a polymer.   
  Co-stabilizer Additive which augments the protective abilities of other stabilizers (for example: acid scavengers).   
  Coupling agent Substance, which promotes or establishes a stronger bond at the resin matrix/reinforcement interface. Syn. Compatibilizer. See Adhesion promoter   
  Coupling Agents A filler can’t give its best performance unless there is a good adhesion between filler and polymer matrix. One way of improving the adhesion between polymer and filler is to improve the level of wetting of the filler by the polymer. This is done by coating the filler with additives having two active parts. One part is compatible with filler and the other with the polymer matrix. One of the best example is the coating of calcium carbonate with stearic acid. Another way to increase the adhesion between polymer and filler is to link them by covalent bonds using coupling agents. Few examples of coupling agents are trichlorovinylsilane, triethoxyvinylsilane, trichloromethylsilane, trimethoxyethoxysilane, trimethoxyphenylsilane, etc.   
  CP  Cellulose Propionate  
  CPE Chlorinated polyethylene (CPE) can be used as either a thermoplastic or thermoset. It is a tough chemical and oil-resistant material and makes an excellent jacket for industrial control cable. As a thermoset, it can be used as an oil resistant cord jacket. Other outstanding properties include low water absorption and superior crush resistance, which are important attributes in industrial control applications.  
  CPE Chlorinated polyethylene (CPE) resin (i.e. Dow TYRIN™)  
  CPS Compact Polystyrene  
  CPVC  Chlorinated Polyvinyl Chloride  
  CR  Polychloroprene (CR), chloroprene rubber. A rubber-like compound. Manufactured by the emulsion polymerization of 2-chloro-1,3 butadiene monomer. Chloroprene rubber (Polychloroprene Rubber ) / Neoprene rubber (DuPont). Syn. Chlorobutadiene, Neoprene, Polychloroprene   
  CR  Polychloroprene Rubber  
  Cracking  The process of breaking down large molecules of oil into smaller ones. When this process is achieved by the application of heat only, it is known as thermal cracking. If a catalyst is used as well it is known as catalytic cracking. It is known as hydrocracking if the catalytic process is conducted in a hydrogen atmosphere. Cracking causes molecular decomposition and recombination to produce a range of more useful base chemicals.    
  Creep tests  1. Solid-state creep tests are used to measure long term behavior of mechanically loaded material. Creep is time-dependent strain resulting from constant loading. Tensile loading is most common here but flexural loading can be used as well, testing time is typically 1000 hrs. Several loading levels are used to get an overview of creep behavior of the material.  2. Melt creep tests are a type of rheological measurement for the determination of the creep compliance of a polymer melt; they are carried out in the region of linear viscoelasticity.    
  Crosslink  A constitutional unit connecting two parts of a macromolecule that were earlier separate molecules. Note: a network may be thought to consist of many "primary chains" that are interconnected by a number of crosslinks. In the vast majority of cases, the crosslink is a covalent bond but the term is also used to describe sites of weaker chemical interactions, portions of crystallites, and even physical entanglements.   
  Crosslinking Polymerization reaction that branches out from the main molecular chain to form a networked pattern of chemical links. This kind of process has the effect of producing gel in a thermoplastic polymer or converting it into a thermoset polymer.   
  Crosslinking agent  Catalytic or reactive agent which when added to resin causes crosslinking of chains.
Syn. Curing agent, Hardener
  Crosslinking agents Generally used to increase hardness, modulus, stiffness, tensile strength, tear strength, tear resistance, fatigue strength, shear strength, abrasion resistance, ageing resistance, etc and to reduce crack initiation, crack propagation,  etc by chemical reaction (by introducing a covalent bond between the polymer chain). Most common example is sulfur.  
  Crystal Polystyrene (GPPS) Popularly known as general purpose polystyrene (GPPS)  
  Crystallinity  Also designated ¡°degree of crystallinity¡±, it gives the relative fraction of a solid polymer having crystalline regularity. The crystallinity can be determined with various measuring techniques like DSC, density measurement or WAXS, which has the additional advantage that the relative amounts of the different crystal modifications can be determined as well. All crystallinity values are relative and the applied reference values should be quoted.    
  CS  Casein  
  CSA  Canadian Standards Associates  
  CSM Chlorosulphonated polyethylene (CSM)  
  CSM  Chlorosulfonated Polyethylene Rubber (usually designated Hypalon). Also, modified chlorosulphonated polyethylene.   
  CSM  Chopped strand mat   
  CTE  Coefficient of Thermal Expansion  
  CTFE  Chlorortrifluoroethylene  
  CTI  Comparative Tracking Index  
  Cure Changement of the properties of a polymeric system by chemical reaction, which, for example, may be condensation, polymerization, vulcanization or addition; usually accompanied by the action of either heat or catalyst or both, and with or without pressure. Fully cured materials exhibit maximum physical, thermal and chemical properties in use.  Syn. Crosslinking, Hardening   
  Cure chemical Vulcanization is achieved at ambient temperatures by typically applying a liquid vulcanizing agent to the surface of the rubber. Supplementary heat can help to speed up the cure.  
  Curing The act of vulcanization; a description of a definite time and temperature of vulcanization.   
  CVD  Chemical Vapor Deposition  
top Cyanoacrylate Special type of acrylic. Cures through reaction with moisture held on the surfaces to be bonded. Needs close-fitting joints. Usually solidifies in seconds and is suited to small plastics parts, metals and to rubber. Setting times range from 5 to 130 seconds.  
D DAM  Dry As Molded (often applied to nylon)  
  Danbrite™ The PolyAid® brand of Brighteners for polymer applications.  
  Dancel™ The PolyAid® brand of Accelerants for polymer applications.  
  Dancure™ The PolyAid® brand of Curing agents for polymer applications.  
  Dannier® A registered trademark of Dannier Chemical, Inc.  
  Dansof™ The PolyAid® brand of Peptizers for polymer applications.  
  Dansorb™ The PolyAid® brand of Light absorbers and stabilizers for polymer applications.  
  Dantiox™  The PolyAid® brand of Antioxidants for polymer applications.  
  Dantistat™ The PolyAid® brand of Antistatic agents for polymer applications.  
  DAP  Diallyl Phthalate  
  DDS  Diaminodiphenyl Sulfone (Epoxy Cure Agent)  
  Defoamer Chemical which reduces and/or eliminates foam. It pops bubbles when squirted over water surfaces.  
  Density  The density of a material is the quotient from the mass M and the volume V (DIN 53479) ... An important parameter for polyethylene, affecting most end product physical properties like stiffness, impact strength and optical properties. The density is normally given in g/cm3, although the correct SI unit would be kg/m3. Two basic measuring methods are used: (a) Density gradient column is the basic method for density measurement. In it a density gradient is prepared by mixing two liquids of different densities so that density increases uniformly from top to bottom. Small test pieces are immersed into this density gradient, and the density of the polymer is determined based on the equilibrium position of the pieces and calibration floats. (b) Pyknometer measurements rely on calibrated volumes and the density difference to a reference fluid; compression-molded samples are normally used here.   
  Deodorant Chemical additive introduced to remove or make undesired odor to plastics. Examples of Deodorants are: Zeolithe, Active Carbon Black, Fragrance Syn. Odor masking, Fragrance.   
  Design Failure Mode and Effects Analysis (DFMEA) An analytical technique used by a design responsible engineer/team as a means to assure, to the extent possible, that potential failure modes and their associated causes/mechanisms have been considered and addressed.   
  Dessicant Substance which can be used for drying purposes because of its affinity for water.   
  DGEBA  Diglycidyl Ether of Bisphenol A  
  Die C-Tear Strength  The maximum force required to cause a rupture by tearing action of the right angle test specimen; the force divided by the thickness of the specimen. The force acts parallel to the tab ends of the specimen or at 45¡Æ to the 90¡Æ center angle. Refer to ASTM Method D624.    
  Differential Scanning Calorimetry (DSC)  In DSC the sample and a reference material are heated and cooled in a defined manner. DSC provides a rapid method for the determination of the temperature profile of a polymeric material. This includes e.g. measurement of heat capacity, specific heat, melting, crystallization and glass transition temperatures, heat (enthalpy) of fusion, crystallization, study of thermal stability or reaction kinetics and in certain cases identification of the polymer or polymer mixture.    
  Diluent Reactive or non-reactive additive whose primary function is to lower the viscosity and extend the material to which it was added.   
  DIN  Deutches Institut für Normung  
  Dip Coating  Process that consists of applying a coating to a part by simple dipping in a bath. For example, this method is used to coat tools with Plastisol or to produce gloves.  
  Dispersing agent Surface-active substance used to facilitate the suspension of solid compounding materials in a liquid medium and to stabilize the dispersion thereby produced. Syn. Dispersant, Grinding aid, Milling aid.   
Measure, at both the microscopic and macroscopic levels, of how a pigment, filler or additive is completely distributed throughout a polymer matrix. It is probably one of the most fundamentally important properties of any masterbatch.   
  DMC  Dough moulding compound   
  Double-strand polymer  Ladder polymer: a polymer, the macromolecules of which are double-strand chains.    
  Dry-blend Free-flowing dry compound prepared without fluxing or addition of solvent (also called powder blend). Resin mixture composed of a dry, free-flowing mixture of resin, plasticizers, and other additives, which is prepared by blending the components under high shear at temperatures below the fluxing point. Dry blends are often more economical than molding powders and pellets.   
  Dry-blending  Process where materials are blended in dry form without melting.  
  DTUL  Deflection Temperature Under Load  
  Durometer  An instrument for determining the hardness of polymer by measuring it's resistance to the penetration (without puncturing) of a blunt indented point impressed on the rubber surface against the action of a spring. A hand and a special scale indicate the resistance to penetration or "hardness". The scale of the Shore hardness testers reads from 0 to 100, 0 being very soft and 100 being very hard. There are several Shore hardness gauges available and the proper durometer depends on the hardness of the surface being measured (Shore A, D and 00).    
  Durometer hardness An arbitrary numerical value that measures the resistance to indentation of the blunt indenter point of the durometer. Shore hardness, Shore A for soft rubber, Shore D for Ebonite/hard rubber.   
  Dyes Synthetic or natural organic chemicals that are soluble in most common solvents. Dyes exhibit good transparency and high tinctorial strength. They are generally soluble in polymer. One critical property to consider is migration.   
  Dynamic Mechanical Thermal Analysis (DMTA)  Many polymeric materials exhibit time-dependent, reversible viscoelastic properties in deformation. Dynamic mechanical tests are characterized by an application of a small stress in sinusoidal fashion and a continuous scan of resonant frequency of vibration and damping vs. temperature is produced. This is transformed into dynamic storage modulus, dynamic loss modulus and damping factor by the instrument software.    
top Dynamic rheometry  Dynamic rheometry gives information both about flow and elastic properties of polymer melts. In a dynamic measurement the sample is put between two round plates or between a cone and a plate in the oven. The system is heated to a desired temperature and a sinusoidal deformation at different frequencies is applied. As a result we get storage and loss modulus as a function of frequency. Storage modulus is connected with elastic energy, while loss modulus corresponds to viscose energy. From the above parameters we can calculate complex viscosity as a function of frequency.  With most of polyolefin products this is the same as the conventional viscosity function, which is viscosity as a function of shear rate. The dynamic measurements are limited to relatively low shear rates. On the other hand, a benefit compared to capillary rheometry is, that we get reliable information also about elasticity. In addition, the obtained properties are much more sensitive for small differences in polymer structure which play an important role in processing and end-use properties.   
E EAA  Ethylene/Acrylic Acid Copolymer  
  EB Ethylbenzene (EB)  
  EBAC  Poly(Ethylene Butyl Acrylate)  
  EC  Ethyl Cellulose  
  ECN  Epoxy Cresol Novolac  
  ECO Epichlorohydrin copolymer (ECO)  
  ECO  Epichlorohydrin Rubber (Ethylene Oxide Copolymer)  
  ECTFE  Poly(Ethylene Chlorortrifluoroethylene)   
  ECTFE  Ethylene chlorotrifluoro ethylene copolymer   
  ECTFE  Poly(Ethylene Chlorotrifluoroethylene)  
  EEA Ethylene-ethyl acrylate (EEA) copolymer  
  EEA  Poly(Ethylene-Ethyl Acrylate)  
  EEW  Epoxy Equivalent Weight (Also called WPE)  
  Elastic modulus One of several ratios equal to the stress in a material or object divided by its strain. Included are: Young's modulus, the bulk modulus, and the shear modulus.   
  Elasticity Property of materials to recover their original size and shape after deformation.   
  Elastomer Material which at room temperature stretches under low stress to at least twice its length and snaps back to the original length upon release of stress. Possesses deformation and elastic recovery properties like those of natural rubber. Thermosetting elastomers have properties like vulcanized rubber; thermoplastic elastomers are remoldable.   
  Elastomer  A polymer with the properties of rubber. Polymers that can be formulated as elastomers are polyurethane, butyl rubber, silicones and specially treated ethylene-propylene copolymers.    
  Elastomer Types May be characterized into three basic types: General-purpose elastomers, Specialty elastomers and Thermoplastic elastomers.  
  Elastomeric Any of various polymers having the elastic properties of natural rubber.   
  Elastomers Polymeric materials (cured goods) which are solidified in a glasslike manner at temperatures significantly below 0 °C and which do not flow in a viscous manner even at high temperatures but behave elastically in the range between their glass point and their decomposition temperature.   
  Electron Beam (EB) curing Curing of material initiated by Electron Beam. See UV curing.   
  Elongation Fractional increase in length of a material stressed in tension (before break will occur). When expressed as a percentage of the original length, it is called percent elongation.   
  Elongation at tear The elongation at tear is the quotient of the change Lt - L0 of the test length as measured at the moment of tear and the original length L0 of the test body (DIN 53504).   
  EMAAA  Ethylene Acid Terpolymer  
  EMAC  Poly(Ethylene Methyl Acrylate)  
  Embedment/Embedding Process of pressing granules into coating during the manufacture of factory-pre-pared roofing, of inserting a constituent structure into a matrix structure.   
  EMCM  Ethylene Methyl Acrylate Cyclohexene Methyl Acrylate  
  EMI  Electromagnetic Interference  
  Emulsifier Surface-active substance used to facilitate the dispersion of an immiscible liquid compounding material in another liquid and to stabilize the emulsion thereby produced. Syn. Colloïdal stabilizer, Surfactant, Dispersing agent.   
  Encapsulating Process of surrounding, encasing, or enclosing an article in an envelope (a capsule). Often used in the electronic industry to protect sensitive components. Syn. Potting.   
  End-group  A constitutional unit with only one attachment to a chain.    
  Endothermic (blowing agent) Foaming agent's chemistry causing heat to be absorbed when the gas is generated. Most know endothermic blowing agent consists of a mixture of sodium bicarbonate and citric acid.   
  Environmental stress cracking  Under certain conditions of stress and environment like oils, detergents or soaps, ethylene plastics may fail mechanically by cracking. This phenomenon is called environmental stress cracking resistance (ESCR). ESCR properties can be tested in accelerated tests by presence of starter notches, surface active agent, elevated temperature and mechanical loading. Test result is the time when 50 % of the samples have failed.  
  EP Epoxy Resin (EP)  
  EP Ethylene-propylene elastomers (EP elastomers)  
  EP  Epoxy; Epoxide  
  EPA  Environmental Protection Agency (US Government)  
  EPDM  Ethylene-propylene-diene monomer (elastomer)   
  EPDM  Ethylene Propylene Terpolymer Rubber  
  EPDM  EPDM (ethylene-propylene diolefin monomer) Rubber.  Synthetic rubber; a polymer of ethylene and propylene with a small amount of diolefin monomer added to permit vulcanization with sulfur. Possesses excellent resistance to ozone, sunlight and weathering, has good flexibility at low temperatures and good electrical insulation properties.   
  EPM  Ethylene-propylene rubber (EPR)   
  EPM  Ethylene Propylene Copolymer  
  EPN  Epoxy Phenol Novolac  
  Epoxy Curing Agent  Family of curing agent capable of curing epoxy resins. Typical curing agents : Aliphatic Amine, Aromatic Amine, AminoAmide, Anhydrides and so on.  
  Epoxy Resin (EP) (EP) Resin characterized by the presence of the epoxy group (the epoxy or epoxide group is usually present as a glycidyl ether, glycidyl amine, or as part of an aliphatic ring system; the aromatic type epoxy resins are normally used in composites).   
  EPR Ethylene-propylene copolymer (EPR) rubber. A material with good electrical insulating properties.  
  EPR Ethylene - Propylene Rubber ( EPR )  
  EPS  Expanded Polystyrene  
  E-SBR Emulsion-polymerized styrene-butadiene rubber   
  ESCR  Environmental Stress Cracking Resistance  
  ETFE  Poly(Ethylene Tetrafluoroethylene). ETFE is a copolymer of tetrafluoroethylene and ethylene.  
  ETPU  Engineering Thermoplastic Polyurethane  
  EVA  Ethylene vinyl acetate   
  EVAC  Ethylene-Vinyl Acetate Copolymer  
  EVAL  Poly(Ethylene-Vinyl Alcohol)  
  EVM Ethylene vinyl acetate copolymer (EVM)  
  EVOH  Ethylene vinyl alcohol   
  EVOH  Poly(Ethylene Vinyl Alcohol)  
  Exothermic (blowing agent) Foaming agent's chemistry causing heat to be generated when gases are released. Examples of exothermic agents are: Azodicarbonamide, Phenyl tetrazole, Hydrazine derivative.   
  Expanded polymer  Alternative name for cellular polymer, but the term is often restricted to those cases where the material has been produced by allowing a gas to expand within a polymer melt and then cololing the melt, thus trapping the gas bubbles in the now solid polymer. The gas is produced either by the injection under pressure or by the chemical decomposition, usually induced by the high temperatures of melt processing of a blowing agent.  
  Extender Material used to improve polymer properties. Syn. Filler, Reinforcer.   
  Extender It replaces plasticizer to a certain extent in the compound. These are not plasticizers but can be tolerated up to certain extent. It also reduces cost of the product. Refinery oil and chlorinated wax are common example of extender.    
  Extruder A machine for continuous forming of rubber by forcing through a die.   
  Extruder  Equipment for melting, pressurizing and homogenizing plastics by means of a rotating screw. Different configurations are possible; the most simple one being a single screw extruder mainly used for conversion processes like cast film extrusion, fiber spinning, film blowing or pipe and profile extrusion. For more demanding applications like compounding of polymer powder before pelletization or the mixing of polymers, twin screw extruders are used where the two normally intermeshing screws can be moved in a corotating (same direction) or counterrotating (opposite direction) fashion. These machines normally contain different mixing elements, most important being kneading blocks for the local creation of extensional flow.    
  Extruding A process wherein the rubber is continuously forced through a die that forms it to the desired cross-sectional size and shape before curing.    
  Extrusion Process of forming a continuous piece of plastic by forcing it through a shaping orifice with or without the presence of heat. The opening through which the resins are forced gives the product its form, resulting in consistent thickness and gauge control.   
top Extrusion Blow Molding Process that usually uses commodity materials such as PVC, PS, PP, LDPE, HDPE. The extrusion part of the process is continuous and the rest is cyclic. In order to get around the problem, one can either do continuous parison blow molding or intermittent parison blow molding.  
F FDA  Food and Drug Administration (US Government)  
  FEP Fluorinated ethylene-propylene (FEP). A thermo-plastic material with good electrical insulating properties and chemical and heat resistance.  
  FEP  Fluorinated Ethylene Propylene  
  FF  Furan Formaldehyde  
  Fibers Fibers can be used long or short (chopped). For composites, fibers are generally used long or in Mats or fabric. In this case the thermoset resin mainly acts as a binder. In thermoplastics, they are most of the time used chopped (relatively short lengths of very small cross-sections) as reinforcer. Glass fibers are the most used fibers. Syn. Extender, Reinforcer.   
  Filament Winding Process for fabricating a composite structure in which continuous reinforcements (filament, wire, yarn, tape, or other), either previously impregnated with a matrix material or impregnated during the winding, are placed over a rotating and removable form or mandrel in a prescribed way to meet certain stress conditions.  
  Filler Generally used to increase hardness, modulus, stiffness, tensile strength, tear strength, tear resistance, fatigue strength, shear strength, abrasion resistance, ageing resistance, etc and to reduce crack initiation, crack propagation, cost, etc. Fillers are classified into five categories like particulate fillers, rubbery fillers, resins, fibrous fillers, and cork fillers. These are again subdivided into three categories like non-reinforcing fillers, semi-reinforcing fillers and reinforcing fillers. The activity of the fillers depends on the three factors: 1. An extensity factor---the total amount of surface area of filler per unit volume in contact with the polymer. 2. An intensity factor---the specific activity of the filler polymer interface causing chemical and/or physical bonding. 3. Geometrical factors such as structure (aggregation), porosity, average particle size and distribution of the particles.  
  Filler Solid constituent, usually inert, added to the matrix to modify the material properties - such as increasing viscosity, improving appearance or lowering density - or to lowering cost. The particles are usually small, in contrast to those of reinforcements, but there is some overlap between the functions of the two. Example of fillers : Calcium Carbonate, Talc, mica, Wallastonite, Kaolin glass beads. Syn. Reinforcer, Extender.  
  Filler/Fiber conductive Filler or fiber added to increase electrical conductivity. Example of conductive filler is: Graphite. See Conductive Compound.   
  Film Blowing Extrusion of the melt through a ring form die, inflating, and cooling to form a thin film. Film blowing is used to produce very thin films of high mechanical strength, mostly from polyethylene.   
  FKM Fluorocarbon Elastomer   
  FKM Fluorocarbon rubber (FKM)  
  FKM Fluorine-based elastomer (FKM)  
  FKM Fluoroelastomer  
  Flame Retardant Additive which inhibits the initiation and/or spread of flame or smoke by inhibiting the combustion reaction in the flame, or by other mechanisms such as suppression of the oxygen flow and the build-up of protecting layers. Syn. Smoke suppressant.  
  Flatting agent Compound added to reduce the gloss without adding color. Syn. Gloss control agent, Matting agent.   
  Flex life The relative ability of a rubber or plastic product to withstand cyclical bending stresses.  
  Flex test A laboratory method used to evaluate the resistance of a rubber product to repeated bending.  
  Flexibilizer Additive incorporated into polymers in order to increase flexibility. In some cases, they can also be called Plasticizers.  
  Flexural test  Like tensile test, flexural test is also used to characterize strength and stiffness of the material. Flexural properties are obtained by placing a specimen horizontally on two supports. A load is applied at a specified rate in the center, normal to specimen longitudinal axis. Measured force - deformation data is used to calculate flexural modulus and flexural strength. Flexural tests can be used if material is too brittle to withstand compressive forces of fixing in tensile grips.    
  Flory-Huggins theory  A thermodynamic theory of polymer solutions, first formulated independently by Flory and by Huggins, in which the thermodynamic quantities of the solution are derived from a simple concept of combinational entropy of mixing and a reduced Gibbs-energy parameter, the `X parameter'. The X parameter is a numerical parameter employed in the Flory-Huggins theory, which accounts in the main for the contribution of the non-combinational entropy of mixing and for the enthalpy of mixing.    
  Flow promoter Used to increase the flow of polymer during the shaping stage. Most common example is low molecular weight resin.  
  FLSR Liquid Fluorosilicone Rubber   
  Fluorescence Process by which radiant flux of certain wavelengths is absorbed and re-radiated nonthermally at other, usually longer, wavelengths. This phenomenon creates colors that show an abnormal color response and are used for packaging and other dramatic effects.   
  Fluorescent pigment By absorbing unwanted wavelengths of light and converting them into light of desire wavelengths, these colors seem to possess an actual glow of their own.   
  Fluorescent whitening agent Additive capable to improve whiteness of polymers. Syn. Optical brightener.  
  Fluorocopolymer Generic term for PVDF.  
  Fluoropolymer Polymer that contains atoms of fluorine. Examples of fluoropolymers are PTFE and PVDF.   
  FMQ Fluoro methyl silicone (FMQ)  
  FMQ  Fluorosilicone Rubber  
  Foam Dispersion of gas bubbles in a solid. Composite foams include syntactic and other foams such as graphite-urethane. Thermoplastic foams are also available for molding large parts. Rigid foams are useful as core materials for sandwich construction.   
  Foaming  Physical process characterized by the continuous formation of bubbles which have sufficiently high surface tension to remain as bubbles beyond the disengaging surface. This formation is due to introduction of a gas in a material.   
  Foaming agent Chemical dry powders (azodicarbonamide, bicarbonate/acids, phenyltetrazoles) that generate gas or physical (compressed carbon dioxide, nitrogen, air or hydrocarbons) that are already a gas in the polymer melt process. Foam concentrates are formulated with chemical foaming agents.   
  Fogging Condensation of water vapor on the surface of a transparent plastic film in the form of small discrete droplets.  
  FPM  Fluorocarbon Rubber  
  FPVC  Flexible Polyvinyl Chloride  
  FR  Flame Retardant  
  Fragrance Natural or synthetic substance or substances used solely to impart or mask an odor.   
  FREP Flame retardant ethylene propylene (FREP) is a special flame retardant version of EPDM rubber. It is designed for use as an industrial control insulation and has excellent electrical characteristics, deformation resistance, and also meets the flame retardant needs of industrial control cables.  
  Fresh keeping agent Additive used in active packaging capable of retarding food degradation and increasing shelf life. See Oxygen absorber.   
  FRP  Fiber reinforced polyester/plastics   
  FR-TPE FR-TPE, flame retarded thermoplastic elastomer, is a rubber-like plastic that has properties similar to rubber yet is processed as a thermoplastic. It is used as the insulation and jacket in an all TPE construction which meets UL 13 and 1277 industrial cable requirements. It has good electrical properties, abrasion resistance, colorability and flame retardancy. This compound is ideal for cold weather applications.  
  FSR Fluorosilicone Rubber (FSR)  
  FTIR Spectroscopy  Infrared radiation induces vibrations of molecules and molecular segments. Absorption of radiation occurs only if the vibration results in the change of the molecular dipole moment. The strength of the vibrating bonds and their dipole moment affect the absorption band intensities and positions which makes FTIR spectroscopy a very useful method in qualitative polymer analysis. Also several fast quantitative FTIR methods have been developed for the structural characterization of polyolefins. Polymer crystallinity and orientation implies a restriction in the movement of some molecules and consequent improvement in polymer mechanical properties. This restriction in the movements reflects also to the FTIR spectrum and thus the amorphous and crystalline polymer phases can be identified.   
  Functional Polymers Polymer containing reactive groups in its backbone. One very important family of functional thermoplastic is Maleic anhydride grafted polyolefins used as compatibilizer, coupling agent, tie layer, and adhesion promoter.  
  Fungi Types of microscopic plant materials that are very numerous and occur in many different forms. Their spores, or reproductive bodies are everywhere and await only proper conditions of moisture and temperature to germinate, grow and reproduce.   
  Fungicide Substance capable of destroying or preventing the growth of fungi. Fungicides do not provide any residual protection from future mould growth. Syn. Preservative, Biocide.  
  FVMQ Fluoro vinyl methyl silicone (FVMQ)  
  FVMQ  Fluorosilicone Rubber  
top FZ  Fluorinated Polyphosphazene Rubber  
G Gas-assist injection molding Plastic molding process in which a high-pressure gas is co-injected along with the plastic part to produce discrete internal hollow sections. It differs from blow molding in that one large hollow product is not created; rather, a solid piece with hollow sections is produced.   
  GECO Epichlorohydrin terpolymer (GECO)  
  Gel inhibitor Substance added to another substance to prevent gelation. Gel inhibitors are generally free radical scavengers and are used to improve shelf-life and storage of monomers and resin's reactivity via a free radical mechanism.  Examples of Gel inhibitor : Hydroquinone, Tertbutylcatechol.   
  Gel Permeation Chromatography (GPC)  GPC is used to separate dissolved polymer molecules according to their coil diameter in solution. The chromatograms can be converted to molar mass distributions, which is an important parameter because it has a significant effect on the physical, mechanical and rheological properties of a polymer. It is also possible to calculate the average molar masses, Mn, Mv, Mw and Mz, and when on-line viscometric detection is used, to study long chain branching (LCB) and its distribution.    
  Gel time Period of time from initial mixing of liquid reactants to the point when gelation occurs as defined by a specific test method.   
  GFR  Glass Fiber Reinforced  
  Glass transition  Reversible change in an amorphous polymer between a viscous condition and a hard, relatively brittle condition.   
  Glass-transition temperature (Tg) Temperature point where a polymer experiences a significant change in properties. The polymer structure turns "rubbery" upon heating and "glassy" upon cooling; a large change in Young's Modulus is experienced. Amorphous polymers are structural below Tg and go through one stage of the change from a glassy to a rubbery consistency with a simultaneous loss in stiffness. Crystalline, materials go through a stage of becoming leathery before becoming rubbery.   
  Gloss Angular selectivity of reflectance, involving surface-reflected light, responsible for the degree to which reflected highlights or images of objects may be seen as superimposed on a surface.  
  GMP Good Manufacturing Practices (GMP)  
  GMT  Glass mat thermoplastic   
  GP  General Purpose  
  GPO  Propylene Oxide Rubber  
  GPPS Polystyrene (General Purpose) GPPS  
  GPPS  General Purpose Polystyrene  
  Grade  The designation given a material by a manufacturer such that it is always reproduced to the same specifications established by the manufacturer.    
  Graft polymer  A substance composed of graft macromolecules.    
  Grain The unidirectional orientation of rubber or filler particles occurring during processing (extrusion, milling, calendering) resulting in anisotropy of a rubber vulcanizate.  
  Green strength (1) The resistance to deformation of a rubber stock in the uncured state. (2) Uncured adhesion between plied or spliced surfaces.  
top GRP  Glass Reinforced Plastics  
H HAI  High Amp Arc Ignition  
  HALS Hindered Amine Light Stabilizer, Additive having a common chemical structure (a piperidine ring) as part of its molecule. This highly effective UV stabilizer protects the polymer by scavenging free radicals.  
  HALS  Hindered Amine Light Stabilizer (HALS)  
  Hand Lay-up Process of placing (and working) successive plies of reinforcing material or resin-impregnated reinforcement in position on a mold by hand.   
  Hardener Substance used to promote or control curing action by participating in and being consumed by the cure reaction, as opposed to a catalyst. Syn. Crosslinking agent, Curing agent.   
  Hardness Resistance of a (polymer) surface to deformation. The different measures of hardness applied for characterizing polymers are:  (a) Shore hardness (two scales, A for softer and D for harder materials).  (b) Ball indentation hardness (also useable on profiled surfaces because of bigger measuring device).  (c) Vickers hardness (normally used for steel).   
  HCR High Consistency Rubber (Heat Cured Rubber)   
  HDPE  High Density Polyethylene  
  HDT  Heat Deflection Temperature or Heat Distortion Temperature  
  Heat deflection temperature (HDT)  Heat deflection temperature (HDT) indicates how loaded material deforms at higher temperatures. Test bars are placed in a heating bath, resting horizontally on two supports. A constant load is applied in the center of the specimen and the bath temperature is raised at a constant rate. The temperature of the bath at which the flexural deflection of the loading point has reached a predefined level is the heat deflection temperature of the material.    
  Heat history The accumulated amount of heat a rubber stock has been subjected to during processing operations, usually after incorporation of the vulcanizing agents. Incipient cure or scorch can take place if heat history has been excessive.   
  Heat stabilizer Additive that increases the ability of the material to withstand the negative effects of exposure to heat. It is used to increase the overall service temperature of the polymer.   
  HEMA  Hydroxyethyl methacrylate polymer   
  Heterophasic copolymers  Heterophasic copolymers also contain ethylene (and possibly higher a-olefins) as comonomer. The production is however carried out in a two-stage process, resulting in a multiphase structure with a homopolymer matrix and inclusions consisting of amorphous EP-copolymer and crystalline PE. Variations of molar mass and composition of the elastomeric phase in relation to the matrix allow a wide variation of properties (stiffness, toughness and transparency).    
  Heveaplus MG  Trade name for a natural rubber methyl methacrylate graft copolymer, obtained by polymerization of methyl methacrylate in the presence of a natural rubber latex. Typically contains 30-50% methyl methacrylate, which confers increased modulus and the ability to stick two unlike surfaces together.    
  HFP  Hexafluoropropylene  
  HFPE Hydrofluoropolyether  
  High density polyethylene (HDPE )  Coming from a low pressure process based on special catalysts (Ti- or Cr-based), HDPE has a linear polymeric chain, combined with a higher density and melting point. To fit special applications, the molar mass distribution can be adjusted in a wide range by means of catalysts or polymerization technology. New applications are opened for HDPE as well as other low pressure PEs by applying metallocene (single-site) catalysts, which allow the production of very narrow molar mass distributions and the better distribution of comonomers.    
  Hindered Amine Light Stabilizer (HALS) Additive having a common chemical structure (a piperidine ring) as part of its molecule. This highly effective UV stabilizer protects the polymer by scavenging free radicals.  
  HIPS  High Impact Polystyrene  
  HMMM Hexamethoxymethylmelamine (HMMM). A crosslinking agent used for coatings.  
  HNBR Hydrogenated acrylonitrile butadiene rubber (HNBR)  
  HNBR  Hydrogenated Nitrile Rubber (Acrylonitrile-Butadiene Rubber)  
  Holiday Test High voltage spark test for the detection of pinholes (vide "spark tester")  
  Homopolymer The result of the polymerization of a single monomer, a homopolymer consists of a single type of repeating unit.  
  Homopolymers  Homopolymers (HOMO) consist only of one monomer units; their properties can be regulated via molar mass distribution and the degree of isotacticity (stereoregular structure).    
  HRE  Rockwell E Hardness Number  
  HRM  Rockwell M Hardness Number  
  HRR  Rockwell R Hardness Number  
  HSBS Hydrogenated Styrenic Block Copolymer  
  HSR Emulsion-polymerized resin-rubber masterbatch   
  HVAR  High Voltage Arc Resistance to Ignition  
  HVTR  High Voltage Tracking Rate  
  HWI  Hot Wire Ignition  
  Hydrocarbon  An organic compound that consists exclusively of the elements carbon and hydrogen. Generally, the term hydrocarbon is used for the chemicals that are derived from natural gas, oil and coal.    
  Hypalon Trade name and the designation usual in the USA for chloro-sulfonated rubber (CSR). A synthetic rubber consisting of chlorosulfonated polyethylene. Provides long life in harsh environments and used in a wide range of industrial and automotive applications that require high performance.   
top Hysteresis The heat generated by rapid deformation of a vulcanized rubber part. It is the difference between the energy of the deforming stress and the energy of the recovery cycle.   
I IBS  Interactive Blowing System  
  IIR Isobutene-isoprene rubber (usually designated butyl rubber)  
  IIR Isobutylene isoprene copolymer (butyl rubber) (IIR)  
  IIR  Butyl Rubber  
  IM Polyisobutylene rubber (IM)  
  IM  Injection Molded  
  Impact modifier Physical material, especially an elastomer or plastic of a different type, which is added to and incorporated in a plastic compound to improve the impact resistance of the finished product (to resist sudden pulls or shocks.) Syn. Toughener.  
  Impact resistance Relative susceptibility of plastics to fracture by shock, as indicated by the energy expended by a standard pendulum type impact machine in breaking a standard specimen in one blow.   
  Impact Strength   Impact Strength characterizes material behavior under high speed loading. Pendulum and falling weight type testers are applied here. Specimen can be either plaques, notched or unnotched bars or parts of finished products. There are several impact methods like Charpy impact test, instrumented puncture test and tensile impact test. Generally impact test shows the energy which is needed to break or puncture specimen under specified conditions. In some tests it is possible to accurately record force - deformation transient curves and calculate specific parameters describing material behavior under impact loading.   
  Impregnation Saturation of reinforcement with liquid resin.   
  IMR  Internal Mold Release  
  Infrared filter Substance introduced into a polymer which absorb IR light. An example of application is in Greenhouse film for a better control of the temperature.   
  Inhibitor Substance that slows down or retards a chemical reaction. Inhibitors are sometimes used in certain types of monomers and resins to prolong storage life or working life. See Gel inhibitor.   
  Injection blow molding Blow molding process by which the plastic parison to be blown is formed by injection molding.   
  Injection Molding Method of forming objects from granular or powdered plastics, most often of the thermoplastic type, in which the material is fed from a hopper to a heated chamber in which it is softened, after which a ram or screw forces the material into a mold. Pressure is maintained until the mass has hardened sufficiently for removal from the mold. After the part cools and solidifies, the mold is opened and the part is ejected. No chemical reaction occurs during the molding process.   
  Injection molding  A repetitive process in which plastic is melted and injected into a mold cavity where the article is cooled down. After cooling, the mould opens and the article is ejected. ). The melt is prepared in a screw setup similar to an extruder; the screw acts in melting and homogenizing the polymer while slowly retracted to build up the melt reservoir necessary for the injection step. Then, the screw is used as a plunger in a forward movement to inject the melt through the runner , a manifold in case of a multiple mould and the gate into the mold. In the injection molding process, filling of the mold and solidification takes place partially at the same time, resulting in a very complex morphology in case of semi crystalline polymers.   
  Inorganic pigment Used to color plastics. Inorganic pigments are Natural or synthetic metallic oxide, sulfide, and other salts, calcined during processing at 1200 to 2100 °F (650 to 1150 °C). They possess outstanding heat- and light-stability, weather resistance, and migration resistance.   
  Internal mixer Mixing unit for the production of rubber mixtures.  
  Interpenetrating Polymer Network (IPN) Combination of two polymers, in network form, of which at least one is synthesized and/or cross-linked in the immediate presence of the other without any covalent bonds between them.  
  Ionic polymerization  A chain polymerization in which the kinetic-chain carriers are ions. Usually, the growing chain ends are ions.    
  IPN Interpenetrating Polymer Network (IPN)  
  IPS Impact-resistant Polystyrene (IPS)  
  IR Isoprene rubber, synthetically manufactured NR   
  IR Ionomer Resin  
  IR Polyisoprene (synthetic) (IR)  
  ISO  International Standards Organization  
top Isotactic Pertaining to a type of polymeric molecular structure containing a sequence of regularly spaced asymmetric atoms arranged in like configurations in a polymer chain, usually used in reference polypropylenes.  
K Kaizen Taken from the Japanese words kai and zen where kai means change and zen means good. The popular meaning is continual improvement of all areas of a company not just quality.   
  Kaolin Hydratized aluminum silicate. Offers various degrees of purity. This mineral possesses a hexagonal, sheetlike crystal structure, a pale color, and has an excellent chemical resistance and good electrical properties. Kaolin is very useful in the rubber industry as a filler, in glass fiber-reinforced thermosets in order to improve surface quality, and in PVC wire coating because of its good electrical properties.   
top K-factor  The thermal conductivity of a solid material. The time rate of steady heat flow, watts (or BTU/hour) through a unit area of m2 (or ft2), per unit temperature gradient in the direction perpendicular to an isothermal surface °C/meter (or °F/inch).    
L Laminating Mechanical process of building a laminate by bonding repeated laminations, or layers, of material onto one another. If the layers have a grain, such as in wood, they are often bonded with their grains at different angles to achieve greater strength in the finished material.   
  LCP  Liquid crystal polymer (SRP)   
  LCP  Liquid Crystal Polymer  
  LDPE Low Density Polyethylene (LDPE)  
  LDPE Low Density Polyethylene (LDPE). A plastic used predominantly in film applications due to its toughness, flexibility and relative transparency. LDPE has a low melting point, making it popular for use in applications where heat sealing is necessary. Typically, LDPE is used to manufacture flexible films such as those used for plastic retail bags and garment dry cleaning and grocery bags. LDPE is also used to manufacture some flexible lids and bottles, and it is widely used in wire and cable applications for its stable electrical properties and processing characteristics.   
  Levelling agent Additive that is able to reduce the surface tension under dynamic and static conditions, which is a requirement to obtain an optimal wetting and leveling effect.   
  LFRT Long Fiber Reinforced Thermoplastics (LFRT)  
  Light stabilizer Synonyms: UV Absorber, UVA, UV Light stabilizer, Light Stabilizer.  
  Linear Low Density Polyethylene (LLDPE) A plastic that is used predominantly in film applications due to its toughness, flexibility and relative transparency. LLDPE is the preferred resin for injection molding because of its superior toughness and is used in items such as grocery bags, garbage bags and landfill liners.   
  Liquid crystalline side chain polymer  A liquid crystalline polymer in which the mesogenic groups are part of the groups attached to the main chain. Ordering of the mesogens, and hence liquid crystalline behavior, is enhanced by distancing them from the main chain with flexible groups.    
  Liquid Injection Molding, LIM Process that involves an integrated system for proportioning, mixing, and dispensing dual-component liquid resin formulations and directly injecting the resultant mix into a mold which is clamped under pressure. See Injection molding.   
  Liquid Rubber  A liquid, usually a viscous low molecular weight polymer (typical molecular weight being a few thousand), which may be readily crosslinked to a product similar in behaviour to that of a normal rubber vulcanizate. The use of a liquid rubber offers the considerable technological advantage over conventional rubbers that expensive compounding and press vulcanization procedures are not required. Some polyurethane elastomers, silicone rubbers and polysulphide rubbers may be processed as liquid rubbers. An early liquid rubber was depolymerised natural rubber and the term originally applied specifically to this material. More recently liquid rubbers based on polybutadiene (of molecular weight about 10000), which may be Crossliked through functional groups on the chain ends(telechelic polymer), have been developed, e.g. carboxy-terminated polybutadiene and hydroxy-terminated polybutadiene and similar nitrile and styrene-butadiene copolymers.    
  Living polymerization  A chain polymerization in which the concentration of kinetic-chain carriers, under the appropriate conditions for synthesis, remains constant for a period many times longer than the duration of the synthetic procedure. Often, the absence of chain transfer is implied in the term "living polymerization".    
  LLDPE Linear Low Density Polyethylene (LLDPE)  
  LMDPE  Linear Medium Density Polyethylene  
  Low temperature flexibility The ability of a rubber product to be flexed, bent, or bowed at low temperatures without loss of serviceability.  
  Lower critical solution temperature (LCST)  The critical solution temperature below which a binary mixture exists as a homogeneous single phase solution at all compositions. Thus when such a mixture existing below the LCST is heated, phase separation occurs. Such behaviour is more unusual than upper critical solution temperature behaviour and is not accounted for by the simple theories of solution, e.g. the Flory-Huggins theory for polymer solutions. However, it does occur for several polymer/solvent pairs and not at all infrequently for polymer/polymer pairs, i.e. polymer blends. This behaviour implies an increase in x(the Flory-Huggins interaction parameter) with temperature, and can be accounted for by the corresponding states theory, as being due to dissimilar thermal expansion coefficients between polymer and solvent. At high temperatures, the more highly expanded solvent must fit into a denser medium and mixing must involve a negative volume change and negative entropy of mixing.    
  LSR Liquid Silicone Rubber   
  Lubricant Additive used to aid in the reduction of friction between the polymer melt and a surface. They are two families of lubricants. Internal lubricants are easily soluble in the polymer and reduces the melt viscosity. External lubricants are nearly insoluble and forms a boundary layer film between the melt and metal surfaces. External lubricants can also be called Processing Aids. Also, Allows quick mould release and prevents the molded object from sticking to the mould. Examples are stearic acid and stearate of calcium, zinc, lead, cadmium, etc.  
top Luminescent pigment Special pigment available to produce striking effects in the dark. Basically there are two types: one is activated by ultra-violet radiation, producing very strong luminescence and, consequently, very eye-catching effects; the other type, known as phosphorescent pigments, does not require any separate source of radiation.  
M Macromolecule  A molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of a number of constitutional units.    
  Macromonomer  A monomer which is a polymer of an oligomer.    
  Magnetic additive Generally used to increase the magnetic properties. Common examples are iron oxides, iron elements, boron elements, neodymium-iron-boron alloy, etc.  
  Masterbatch A preliminary mixture of rubber and one or more compound ingredients for such purposes as more thorough dispersion or better processing, and which will later become part of the final compound in a subsequent mixing operation. Also, Plastic compound which includes a high concentration of an additive or additives. Designed for use in appropriate quantities with the basic resin or mix so that the correct end concentration is achieved. For example, color masterbatches for a variety of plastics are extensively used as they provide a clean and convenient method of obtaining accurate color shades.  
  Matting agent Additive used to reduce the gloss. addition of any defect to the polymer surface can potentially reduce gloss of the material. See Gloss.   
  MBS Methacrylate/butadiene/styrene    
  MBS  methacrylate-butadiene-styrene terpolymer   
  MD  Metal Deactivator  
  MDPE  Medium Density Polyethylene  
  MEKP  Methyl Ethyl Ketone Peroxide (Thermoset Curing Agent)  
  Melamine Flame Retardant  Substance use as flame retardant containing melamine rings. Examples : Melamine cyanurate, Melamine phosphate.  
  Melamine Formaldehyde Resin, MF Amino resin, created from melamine and formaldehyde. It may be a syrup if it has a low molecular weight or a powder if it has a high molecular weight. It can be used for laminating, in leather processing, to make adhesives, and to make plastic items such as tableware.   
  Melt flow rate (MFR)  Melt mass flow rate or melt flow rate (MFR) gives an indication of melt processing properties of a polymer. Shear rate range is, however, narrow and much lower than in the most of processing applications. It gives thus very limited information about melt flow behaviour. The method is a kind of capillary measurement. The equipment consists of a barrel, a piston with a place for loading masses and a die. The sample is charged into the barrel and heated up to a specified temperature. After that the piston is loaded extruding the polymer through the die. Melt flow rate (MFR) is defined as a mass flown through the die in 10 min. The weights mostly used with polyolefins are 2.16 kg, 5 kg, 10 kg and 21.6 kg. In addition to the evaluation of flow properties MFR serves as a rough estimation of molecular weight. Usually also Flow Rate Ratio (FRR) is determined. This ia defined as a ratio of two MFR values obtained with two different weights. FRR can be used as a rough estimation of molecular weight distribution.    
  Melt strength enhancer Additive that enhances the strength or elasticity of the plastic while in the molten state. This is a pertinent factor in extrusion, blow molding, thermoforming, foaming and drawing of molten resin from a die.   
  Metal deactivator Some metal ions may contribute to accelerated degradation. For polyolefins in contact with metals, such as cable insulation of copper wires, metal deactivators are added to passivate the degradation reactions.   
  Metallic pigment Pigment consisting of thin opaque aluminum flakes (made by ball milling either a disintegrated aluminum foil or a rough metal powder and then polishing to obtain a flat, brilliant surface on each particle) or copper alloy flakes (known as bronze pigments). Incorporated into plastics, produces unusual silvery and other metal-like effects.   
  Metallic Stearate  Additive containing an inorganic center with a strong separation of charge and two linear hydrocarbon chains. Used in various applications and bringing numerous effects and benefits in polymer production. Metallic stearate possesses acid scavenging, lubrification/process aid and mold release properties.  
  Metallocene  A catalyst which contains a metallocene compound of a transition metal. Often used as a synonym for single site.    
  MF  Melamine-Formaldehyde  
  MFD  Microfloppy Diskettes  
  MFI  Melt Flow Index  
  Mixing mill Driven pair of rollers for the production of rubber mixtures as well as for the plasticizing, homogenizing, preheating and rough-crushing of rubber.  
  MMA Methyl methacrylate (MMA)  
  Modulus In the physical testing of rubber, the load necessary to produce a stated percentage of elongation. Compression, or shear.  
  Molding A processing method which forms the rubber in the mold by the application of pressure and heat which shapes and cures the parts. Molding methods include: Compression Molding, Injection Molding, and Transfer Molding.  
  Molecular Weight Distribution   The relation between the number of molecules in a polymer and their individual chain length. It is often also called molar mass distribution (MMD). Technical polymers are always polydisperse as a result of the nature of the catalyst and the polymerization conditions. The MWD is often characterized by size exclusion chromatography (SEC), but it can also be calculated approximately from rheological data for purely linear polymers.    
  Monomer A single molecule which can join with another monomer or molecule to form a polymer or molecular chain.  
  Monomer   A molecule capable of reacting with like or unlike molecules to form a polymer.    
  Mooney Test with the shearing disk viscosimeter according to Mooney.   
  Mooney Viscosity Measure of the resistance of raw or unvulcanized rubber to deformation, as measured in a Mooney viscometer.  
  Morphology  Morphology is the internal or external structure of a solid substance. Important sub-definitions include (a)Crystal morphology of a polymer film or part (b)Phase morphology of heterophasic polymer systems (blend, copolymer) (c) Powder morphology of a polymer powder from the polymerization reactor.    
  MPR Melt Processible Rubber   
  Multilayer Combination of several polymer layers, separately manufactured double sided sheets bonded together. This combination provides the final material with a mix of the individual performances of the polymers involved. Multilayer structures are often used in flexible packaging applications requiring barrier properties.  
  MVTR  Moisture Vapor Transmission Rate  
top MWD  Molecular Weight Distribution  
N Nanocomposite A class of plastic compound containing well dispersed and exfoliated nanofiller such as nanoclays. Nanocomposites exhibit unique performance profiles such as stiffness/impact balance or transparent barrier properties.   
  Nanofiller Primary particle compound used as filler or reinforcer in polymers with very small particle size (in the nanometer range). Generally, surface modified Montmorillite clays (also called Nanoclays) are used to provide material with excellent mechanical, barrier or FR performances.   
  Nanotube (or Carbon Nanotubes) Long, thin cylinders of carbon. Nanotubes have a very broad range of electronic, thermal, and structural properties that change depending on the different kinds of nanotube (defined by its diameter, length, and chirality, or twist).   
  NASA  National Aeronautics and Space Administration (US)  
  Natural Rubber (NR) (NR) Natural rubber is a polymer produced in the sap of rubber trees (Hevea Brasiliensis) and some other plants. As a natural product, it is formed as a latex which can be collected and dried. The polymer is cis-polyisoprene. It is not cross-linked in the natural state and only becomes a durable solid when it is cross-linked by, for example, vulcanization.   
  Natural rubber, hard Natural rubber or polymer of isoprene (NR), characterized by good processability and resistance to a wide range of chemical agents, shows duroplastic properties.   
  Natural rubber, soft Natural rubber or polymer of isoprene (NR), lower degree of cross-linking than hard natural rubber, high abrasion resistance, medium chemical resistance.   
  NB  No Break (Applied to Impact Test Results)  
  NBR Acrylnitrile-butadiene rubber (usually designated nitrile rubber)   
  NBR Butadiene-acrylnitrile copolymer (NBR) rubber, a material with good oil and chemical resistance.  
  NBR Acrylnitrile butadiene rubber (NBR)  
  NCR  Acrylnitrile-chloroprene rubber  
  Neoprene Trade name, the usual designation in the USA for chloroprene rubber   
  NHFR  Non-Halogen Flame Retardant  
  NHT  High Temperature Nylon  
  NIR  Acrylnitrile-isoprene rubber  
  Nitrile Nitrile is the common word for acrylonitrile-butadiene rubber (NBR). It is a cheap and cheerful product, best known for its resistance to oil (low-temperature, refined oils, that is). It is commonly used in the vast majority of standard O-ring seals.   
  Nitrile rubber Nitrile rubber is synthetic, as opposed to natural latex. Car tires are made of Nitrile. Although it is not considered to be a "plastic" it can be injection molded. (Working Temperature Range: -30°C to +100°C).   
  NR Natural rubber (latex), plantation rubber.  
  NSF  National Sanitation Foundation (nonregulatory agency)  
top Nucleating agent Substance with the ability to act as substrate for crystal formation by epitaxy, thus increasing the nucleation density. Improves crystallization behavior in processing, i.e., cycle time or line speed, as well as crystallinity and morphology in final product, improving optical and mechanical properties. See Clarifier.   
O OB  Optical Brightener  
  ODP  Ozone Depletion Potential  
  OEM  Original Equipment Manufacturer  
  Olefin  An unsaturated simple hydrocarbon with one double bond per molecule, such as ethylene or butylene. Olefins are chained into polymers such as polyethylene.    
  Olefin Fiber  Generic name for fiber composed of a polymer with at least 85 wt% of ethylene, propylene or other olefin units, excepting amorphous rubbery polymers. Examples are Courlene, Fibralon, Herculon and Vectra.  
  Oleoresin  The initial exudation from certain trees when the bark is wounded. An oleoresin consists of a resinous component together with an essential oil. The latter usually evaporates, leaving the hard resin. Best studied is pine oleoresin, from which the resin rosin and the essential oil turpentine are obtained.  
  Oligomer  A substance composed of oligomer molecules.    
  Opacity Ability to prevent the transmission of light; the reciprocal of the transmittance factor.  
  OPS  Oriented Polystyrene (Film)  
  Optical brightener  Additive (dye or pigment) imparting pure to bluish brightness to polymers and intensifying the degree of whiteness; its function is based on the fluorescence effect. It absorbs near-ultraviolet radiant flux and re-emits it as violet-blue visible light causing a whiter appearance, especially when added to a yellowish-white material. Syn. Fluorescent whitening agent.  
  Organic chemicals These are based on carbon compounds and form the backbone of the petrochemicals industry, while inorganic chemicals are non-carbon chemicals, such as mineral acids, alkalis, chlorine, hydrogen peroxide and various salts.  
  Organic Peroxide  Molecule containing at least two Oxygen atoms, single bonded together. These molecules are unstable and are used as source of free radicals. They are used in : rubber crosslinking, polymerization initiation, curing of unsaturated polyester, controlled degradation of PP.  
  Organic pigment  Colorate organic molecules (polycyclic, azo and metal complexes) used for the coloration of plastics. Organic pigments are used for applications needing high tinting strength and brilliant tones.  
  OSHA  Occupation Safety and Health Administration (US Government)  
  Overlay The addition of another layer of lining over an in-place lining construction before vulcanization.   
  Oxygen absorber  Molecule absorbing Oxygen that can be used in active packaging applications to improve shelf life or minimize oxidation.  
top Oxygen induction time (OIT)  A relative measure of a level or a degree of stabilization (amount of remaining active antioxidant).   
P PA  Polyacrylate  
  PA  Polyamide (Nylon)  
  PA 11  Nylon 11  
  PA 12  Nylon 12   
  PA 46  Nylon 46   
  PA 6  Nylon 6  
  PA 610  Nylon 610   
  PA 66  Nylon 66   
  PA 66/610  Nylon 66/610 copolymer   
  PAA  Polaryl amide   
  PAEK  Polyarylether  
  PAEK  Polyaryletherketone  
  PAI  Polyamide-Imide  
  PAMS  Poly(Alpha Methylstyrene)  
  PAN  Polyacrylonitrile  
  PARA  Polyarylamide (polyaramide)  
  PAS  Polyarylsulfone  
  PASA  Polyamide, Semi-Aromatic (Nylon)  
  PASU  Polyarylsulfone  
  PB  Polybutadiene  
  PB  Polybutene-1  
  PB-1 Polybutene. Polybutene (PB-1), like polyethylene and polypropylene, is a polyolefin or saturated polymer that is expressed as CnH2n. PB-1 combines the typical properties of conventional polymers with some characteristics of technical polymers. PB-1 is used as a pure resin at the expense of metal, rubber and Engineering Polymers, it is also used synergistically as a blend component to improve and differentiate the properties of other polyolefins.  
  PBC Propylene-butene copolymer  
  PBGA  Plastic Ball Grid Array  
  PBI  Polybenzimidazole  
  PBLH Hydroxylated polybutadiene (PBLH) rubber  
  PBT  Polybutylene Terephthalate  
  PC  Polycarbonate  
  PCB  Printed Circuit Board  
  PCP  Post-Consumer Plastic  
  PCR  Post-Consumer Resin  
  PCT  Polycyclohexylenedimethylene Terephthalate  
  PCTFE  Polychlorortrifluoroethylene  
  PCTG  Glycol-Modified PCT  
  PCU  Polycarbonate Urethane  
  PDAP  Poly(Diallyl Phthalate)  
  PDSM  Polydimethylsiloxane (Silicone)  
  PE  Polyethylene  
  Pearlescent pigment Colorant exhibiting various colors depending on the angles of illumination and viewing, as observed in mother-of-pearl. Pearlescent pigments are also called nacreous pigments.   
  PEBA  Polyether Block Amide  
  PEC Propylene-ethylene copolymer  
  PEEK  Polyetheretherketone  
  PEEL  Polyester elastomer   
  PEF  Process Engineered Fuel  
  PEG  Polyethylene Glycol  
  PEI  Polyetherimide  
  PEK  Polyetherketone  
  PEKEKK  Polyetherketoneetherketoneketone  
  PEKK  Polyetherketoneketone  
  Pelletized Performance Additive Products (PPAP) Describes PolyAid® pellet-form additive products which minimize occupational hazards and optimize process improvements by maintaining stabilized dispersion during blending, pressing and molding operations.  
  Pelletizing  A process where the polymer powder is homogenized, addiviated and made to pellets. The polymer melt coming from the extruder is pressed through dies in a die plate and cut to pellets by knives under water (underwater pelletizing) or cooled to solid strands and then cut to pellets (strand pelletizing).    
  PEN  Polyethylene Naphthalate  
  PEO  Poly(Ethylene Oxide)  
  PEOX  Poly(Ethylene Oxide)  
  Peptizer Generally used to increase the efficiency of mastication (means reduction of molecular weight) of the polymer. This helps to reduce the viscosity of the polymer matrix. The effectiveness of a peptizer increases with an increase of processing temperature.  Common examples are zinc salt of pentachlorothiophenol  (such as Dansof™ Z), pentachlorothiophenol of with activation and dispersing additives, metal complex of an organic carrier, etc.  
  Peptizer Compound ingredient used in small proportions to accelerate by chemical action the softening of rubber under the influence of mechanical action, heat or both.   
  Permeability  Material constant characterizing gas penetration, like water vapor, oxygen or carbon dioxide.    
  Peroxide  Peroxides are a group of compounds that contain the O2- ion. It is used to initiate the polymerization for high-pressure free radical polymerization processes.    
  PES  Polyethersulfone  
  PESU  Polyethersulfone  
  PET  Polyethylene Terephthalate  
  PETG  PET copolymer   
  PETG  PET Modified with CHDM  
  PETP  Polyethylene Terephthalate   
  PEX  Cross-linked Polyethylene  
  PF  Phenol Formaldehyde   
  PF  Phenol Formaldehyde (Phenolic)  
  PFA  Perfluoro alkoxyl alkane   
  PFA  Perfluoroalkoxy  
  PFPE  Polyperfluoropolyether (PFPE)  
  PFPE  Perfluorinated Fluids (PFPE)  
  PHB  Polyhydroxybutyrate   
  Phenol Formaldehyde Resin, PF Thermosetting phenolic resin manufactured by the reaction of phenol and formaldehyde. Offers low cost, strength and chemical resistance. Used in moldings for electrical and mechanical parts.   
  Phenolic Any of various synthetic thermosetting resins, obtained by the reaction of phenols with simple aldehydes and used to make molded products and as coatings and adhesives. Also called phenolic resin.   
  Phenolic Resin, P Thermosetting resin produced by the condensation of phenol with an aldehyde (particularly of with formaldehyde). Used in high-temperature applications with various fillers and reinforcements.   
  Photoinitiator Agent which when exposed to a specific wavelength of energy forms a reactive element which starts the chain reaction to cause polymer formation. Most commercial photo-initiators for radical curing reactions contain benzoil groups, which are mainly responsible for the absorption of energy from light. Aryl sulfonium salts can generate both radical type and cationic active centers. Syn. Photo-curing material.   
  PI  Polyimide  
  PIB  Polyisobutylene  
  Pigment Colorant, usually an insoluble powdered substance used to produce a desired color or hue. Note: In contrast, a dye is soluble.   
  PIR  Polyisocyanurate rigid (foam)   
  PIR  Polyisocyanurate Foam  
  PISU  Polyimidesulfone  
  Plastic A material that, in its finished state, contains a synthetic polymer of high molecular weight, is a flexible or rigid solid but not an elastomer in its finished state, and at some stage in its manufacture or processing can be shaped by flow or by in-situ polymerization or curing.  
  Plasticizer Used to lower the melt viscosity and to change the physical properties of the product such as to increase softness and flexibility and to decrease the cold flex temperature (a measure of the temperature below which the polymer compound loses its flexibility). The most effective plasticizers are those plasticizers whose solubility parameter close to that of the polymer. Common examples are dioctyl phthalate (DOP), diisooctyl phthalate (DIOP), dibutyl phthalate(DBP), dioctyl sebacate (DOS), etc. This plasticizers are generally used in plastic industry.  
  Plasticizer Compounding material used to enhance the deformability of a polymeric compound. A plasticizer is soluble in the polymer and decreases the glass transition temperature (Tg) value, softens and adds flexibility to the product. Syn. Flexibilizer.   
  PMMA Polymethylmethacrylate (PMMA)  
  PMP  Polymethylpentene  
  PMPAP Pre-Measured Performance Additive Products (PMPAP).   
  PMQ ASTM standard for extreme low temperature service silicone rubber;  also known as PVMQ   
  PMQ Phenyl methyl silicone (PMQ)  
  PNR  Polynorborane Rubber  
  PO  Polyolefin  
  POB  Poly(p-Oxybenzoate)  
  Polyacrylic Material composed of various clear, thermoplastic resins obtained from acrylic acid and its derivatives, and from raw natural sources such as petroleum and natural gas. The effect is achieved by the polymerization of the esters of amides in acrylic acid or methacrylic acid.   
  Polyaddition  A polymerization in which the growth of a polymer chain proceeds by addition reactions between molecules of all degrees of polymerization, not accompanied by the formation of low-molar-mass by-product(s).    
  PolyAid® A registered trademark of Dannier Chemical, Inc. PolyAid® is Dannier's brand of Polymer Performance Additives (PPAs) comprising: Dancel™ Accelerants, Dantiox™ Antioxidants, Dantistat™ Antistatic agents, Dansof™ Peptizers, Dansorb™ Light absorbers and stabilizers, Dancure™ Curing agents, and Danbrite™ Brighteners.  
  Polyamide (PA) Polymer formed by the reaction of a diamine and a diacid. Nylons are commercial polyamides characterized by toughness, solvent resistance, and sharp melting point. Nylon comes in many and varied forms. It generally has excellent structural and impact strength, great working temperature range and is resistant to petrol, oils and solvents. It is subject to attack by acids. It is commonly injection molded and extruded. (Working Temperature Range: varies with polymer type).   
  Polybutadiene (BR) A type of synthetic rubber often blended with other synthetic rubbers to improve their properties. A synthetic rubber that has a high resistance to wear and is used especially in the manufacture of tires.  
  Polybutene Polybutene (PB-1)  
  Polybutene The family of polymers of isobutene, butene-1, and butene-2. Depending on molecular weight, they range from oils through tacky waxes, crystalline waxes, and rubbery solids.  
  Polycarbonate Engineering thermoplastic resin. Polycarbonate is a transparent material with an incredibly high resistance to impact. For this reason it is a major component in bullet-proof "glass" and commonly used for beer jugs and conservatories. Its ability to handle high temperatures sees it used in microwave cookware. Subject to attack from solvents. It is commonly injection molded, extruded, and blow molded. (Working Temperature Range: -25°C to +110°C).   
  Polychloroprene Chloroprene rubber (CR), synthetic rubber, polymer of 2-chlorobutadiene, can be vulcanized to soft rubber, shows good chemical resistance as well as resistance to ageing, weathering and abrasion, and has medium resistance to oils.   
  Polycondensation  A polymerization in which the growth of a polymer chain proceeds by condensation reactions between molecules of all degrees of polymerization accompanied by the formation of low-molar-mass by-products(s). The growth steps are expressed by P_x+P_y -> P_x+y + L {x} element of {1, 2, ... ¡Ä}; {y} element of{1, 2, ...¡Ä} where P_x and P_y denote chains of degree of polymerization x and y, respectively, and L a low-molar-mass by-product. In a polycondensation where the total amounts of the monomers are present from the beginning of the polymerization, the average degree of polymerization increases with conversation of reactive groups.   
  Polyester Polymer in which the structural units are linked by ester grouping. See Saturated Polyesters, SP, Unsaturated Polyester, UP, PET and PBT.   
  Polyether Polymer containing ether linkages. Polyethers used in polyurethane technology contain reactive hydroxyl end groups.   
  Polyethylene (PE) A family of resins prepared from the polymerization of ethylene gas using a variety of catalysts. Density, melt index, crystallinity, degree of branching and cross-linking, molecular weight and molecular weight distribution can be regulated over wide ranges. Further modifications are obtained by copolymerization, chlorination, and compounding additives.  
  Polyethylene terephthalate (PET) (PET) Polyethylene terephthalate has a repeating unit: -(CH2)2-O-CO-C6H4 -CO-O- and a melting temperature of approximately 260°C. Examples of applications are: soda bottle, fibers, tapes.   
  Polyethylene: High density polyethylene (HDPE) Polymers with densities ranging from 0.941 to 0.965 grams per cubic centimeter.  
  Polyethylene: Linear low density polyethylene (LLDPE) Polymers with densities ranging from 0.900 to 0.939 grams per cubic centimeter.  
  Polyethylene: Low density polyethylene (LDPE) Polymers with densities ranging from about 0.910 to 0.925 grams per cubic centimeter.  
  Polyethylene: Medium density polyethylene (MDPE) Polymers with densities ranging from 0.926 to 0.940 grams per cubic centimeter.  
  Polyisoprene Isoprene rubber (IR), synthetic version of natural rubber, is used instead of or mixed with natural rubber, can be processed to hard or soft rubber.   
  Polyketone Type of organic compound having a carbonyl functional group (C=O) attached to two alkyl groups.   
  Polymer Large organic molecule formed by combining many smaller molecules (monomers) in a regular pattern.   
  Polymer  A substance consisting of molecules characterized by the repetition (neglecting ends, branch junctions and other minor irregularities) of one or more types of monomeric units.    
  Polymeric Fiber Polymer whose chains are stretched out straight (or close to straight) and lined up next to each other, all along the same axis.   
  Polymerization Chemical reaction that links monomers to form polymers.   
  Polymerization inhibitor Substance that slows down or retards a polymerization. See Gel inhibitor.   
  Polymerization initiator Additive that helps the monomer to become a polymer. The initiator causes the monomers to link up to each other forming a hard substance. Among the various families of initiators, organic peroxides are used in free radical polymerization.  
  Polyolefin  Family of polymers made from olefin monomers. This is the collective name given to those polymers that are made from the lower olefins: ethylene, propylene, butylene and isoprene. The polyolefins are thermoplastic polymers.    
  Polyolefins The generic term used to describe a family of polymers derived from a particular group of base chemicals known as olefins. The polyolefins family includes polypropylene and polyethylene. Polyolefins are made by joining together small molecules (monomers) to form long chains (polymers) with thousands of individual links.  The base monomers  propylene and ethylene  are gases at room temperature, but when they are linked together they become long chains of molecules called polymers. As polymers, they form tough, flexible plastic materials with a large variety of uses.  
  Polypropylene (PP) (PP) A tough; lightweight, rigid-plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst at relatively low pressures and temperatures.  
  Polypropylene (PP) Polyolefin. Isotactic polypropylene (PP) has a less polar backbone with the repeating unit: -CH2-CH(CH3)- and a melting temperature of approximately 160°C.   
  Polysulfone Synthetic structural thermoplastic resin having the properties of high-temperature, arc-resistance, and low-creep. Often used in paint, polish, rubber, and other products.  
  Polyurethane (PUR) Polymer made by the reaction of polyols with a multi-functional isocyanate. Its molecular structure may cross-link and become a thermosetting plastic, or stay linear and remain thermoplastic.   
  Polyvinyl Resin formed by polymerizing various vinyl monomers.  Examples include polyvinyl chloride, polyvinyl acetate, and polyvinyl alcohol.   
  Polyvinylchloride (PVC) Thermoplastic resin produced by the polymerization of the gas vinyl chloride [CH2CHCl]. Used in soft, flexible films for food packing. Also used in rigid products such as pipes or window profile.   
  POM  Polyoxymethylene (Acetal)  
  POP  Point of Purchase (Marketing Displays)  
  Potting Syn. Encapsulating   
  Powder Coating 100% solid coating generally applied by an electrostatic process as a fine, dry powder. Subsequently transformed by heating into a continuous film.   
  PP Polypropylene  
  PPA Polymer Performance Additive (PPA)  
  PPA  Polyphthalamide  
  PPAP Pelletized Performance Additive Products (PPAP)  
  PPE  Polyphenylene Ether  
  PPF  Phenol-Furfural  
  PPG  Polypropylene Glycol  
  PPO  Polyphenylene Oxide  
  PPOX  Polypropylene Oxide  
  PPS  Polyphenylene Sulfide  
  PPSS  Polyphenylene sulphide sulphone   
  PPSU  Polyphenylsulfone  
  Precipitated Calcium Carbonate Advanced mineral providing various effects to materials such as : process aid, gloss, impact resistance for PVC. In thermosets it can be used as a rheology modifier.  
  Pre-Measured Performance Additive Products (PMPAP).  Describes PolyAid® pre-measured polymer performance additives and customer-specific chemicals and blends produced using in-batch inclusion / dispersible bags to protect workers’ direct contact and conveniently pre-measured to meet exacting target fill weight, dispersion temperature and batch mix specifications.  
  Prepolymerization  A process where polymerization is started to increase the activity of the catalyst getting over the induction time of the catalyst and not to overheat the catalyst particle by to sudden onset of polymerization. Prepolymerization will also help in ensuring more even polymerization on the catalyst particles reducing the probability of creating a high fraction of fines in the later reaction steps.   
  Preservative Substance added to protect, prevent, or retard decay, discoloration, or spoilage under conditions of use or storage. See Biocide, Fungicide.   
  Prevulcanization time t35  The prevulcanization time is the time in minutes from the start of the measurement up to the point in time at which the Mooney viscosity has risen by 35 Mooney units above the viscosity minimum (DIN 53523 T4).  
  Prevulcanization time t5 The prevulcanization time is the time in minutes from the start of the measurement up to the point in time at which the Mooney viscosity has risen by 5 Mooney units above the viscosity minimum. It is also termed the precuring or scorch time (DIN 53523 T4).  
  PRF  Plastics Recovery Facility  
  Primary colorants Small number (pallet) of colorants (dyes or pigments) that may be mixed to produce a large gamut of colors.   
  Process Aid A widely applied term is "process aids". It can mean any material which helps to mix, disperse, or process the mixed compound. Generally when the term process aid is used today, it refers to various fatty acid products or hydrocarbon homogenizers.  
  Process Aid  Compounding material that improves the processability of a polymeric compound. Note: Examples of improvements attributable to processing aids include reduced nerve, better dispersion of dry materials, increased extrusion rates, reduced powder consumption during mixing, smoother surfaces on calendered and extruded products and improved knitting.  
  Processability  A concept to describe the behavior of the polymer in a converting process, such as blow molding machine and film line. A good processability means a stable behavior in the process and a high processing speed.   
  PS  Polystyrene  
  Pseudo-copolymer  An irregular polymer, the molecules of which are derived from one species of monomer but for which one finds it convenient to use copolymer terms. Where appropriate, adjectives specifying the types of "copolymer" may be applied to "pseudo-copolymer". The term statistical pseudo-copolymer, for instance, may be used to describe an irregular polymer in the molecules of which the sequential distribution of configurational units obeys known statistical laws.   
  PSU  Polysulfone  
  PTFE Polytetrafluoroethylene (PTFE)  
  PTMG  Polytetramethylene Glycol  
  PTMT  Polytetramethylene terephthalate (PBT)   
  PTT  Polytrimethylene Terephthalate  
  PU  Polyurethene  
  Pultrusion Continuous process for manufacturing composites in rods, tubes and structural shapes having constant cross sections. After the reinforcement is passed through the resin-impregnation bath, it is drawn through a shaping die to form the desired cross section; curing takes place before the laminate is removed from that cross section.  
  PUR  Polyurethene  
  PVA  Polyvinyl acetate   
  PVAC  Poly(Vinyl Acetate)  
  PVAL  Poly(Vinyl Alcohol)  
  PVB  Polyvinyl butytral (butyrate)   
  PVB  Poly(Vinyl Butyral)  
  PVC  Polyvinyl Chloride  
  PVCA  Poly(Vinyl Chloride-Acetate)  
  PVCC  Chlorinated polyvinyl chloride   
  PVCP  Polyvinyl chloride plasticized   
  PVCU  Polyvinyl chloride unplasticized   
  PVDC  Polyvinylidene Chloride (PVDC)  
  PVDF Polyvinylidene Fluoride (PVDF). PVDF is a polymer of vinylidenefluoride.   
  PVF  Polyvinylflouride   
  PVFM  Poly(Vinyl Formal)  
  PVK  Polvinylcarbazole  
  PVMQ ASTM standard for extreme low temperature service silicone rubber   
  PVMQ Phenyl vinyl methyl silicone (PVMQ)  
  PVOH  Polyvinyl Alcohol  
  PVP  Polyvinylpyrrolidone  
top PZ  Polyphosphazene Rubber  
R Random Copolymer A copolymer consisting of alternating segments of two monomeric units of random distribution, including single molecules. A random copolymer usually results from copolymerization of two monomers in the presence of a free-radical initiator.  
  Random Copolymer Random copolymers are produced by statistical insertion of units of ethylene or higher a-olefins (mostly butene, also in combination with ethylene to give terpolymers). Through this, the glass transition temperature and melting point are lower than in homopolymers, allowing better sealability and application at temperatures below zero degree.    
  Reaction Injection Molding (RIM) (RIM) Process for molding polyurethane, epoxy, and other liquid chemical systems. A mixture of two to four components in the proper chemical ratio is accomplished by a high-pressure impingement-type mixing head, from which the mixed material is delivered into the mold at low pressure, where it reacts (cures).   
  Rebound resilience The rebound resilience R is the ratio of the energy recovered to the energy expended (DIN 53512).   
  Reclaimed Rubber  The product resulting from the treatment of vulcanized scrap rubber in various operations, such as grinding, defibering and devulcanizing by heating with aqueous alkali or with a metallic chloride solution and reclaiming agents, and refining, whereby the fabric is destroyed and the rubber compound is recovered and made suitable for use in the manufacture of rubber goods; the fiber may also be removed mechanically, followed by devulcanization of the rubber.    
  Reinforced Reaction Molding (RRIM) (RRIM) Reaction injection molding with a reinforcement added. See Reaction Injection Molding.   
  Release agent  Additive used to prevent the molded object from sticking to the surface of the mold. Release agent can be directly cooled into mold cavities (external release agent) or it can be introduced into the polymer (internal release agent). Examples of release agents are: silicone, PTFE, waxes, fatty acid esters.   
  Resin Polymer with indefinite and often high molecular weight and a softening or melting range that exhibits a tendency to flow when subjected to stress. Resin mainly refers to thermoset. As composite matrices, resins bind together reinforcement fibers. Also, Any of a class of solid or semi-solid organic products of natural or synthetic origin, generally of high molecular weight with no definite melting point. Most resins are polymers.  
  Resin Transfer Molding (RTM) (RTM) Molding process in which catalyzed resin is pumped into a two-sided, matched mold where fibrous reinforcement has been placed. The mold and/or resin may or may not be heated. RTM offers the ability to consolidate structural parts. Its major drawback is the high cost of the initial, two sided mold.   
  Retarder Used to reduce the rate of crosslinking reaction at the early stage means at the pre-processing stage, means at the mixing stage or at the shaping stage. Phthalic anhydride, N-nitroso diphenylamine are common example of retarder.  
  Reversion (1) A deterioration of physical properties that may occur upon excessive vulcanization of some elastomers, evidenced by a decrease in hardness and tensile strength, and an increase in elongation; (2) A similar change in properties after air aging at elevated temperatures. Natural rubber, butyl, polysulfides and epichlorobydrin polymers exhibit this effect (extreme reversion may result in tackiness). Most other polymers will harden and suffer loss of elongation on hot air aging.   
  RH  Relative Humidity  
  RIM  Reaction Injection Molding  
  Ring-opening polymerization  A polymerization in which a cyclic monomer yields a monomeric unit which is acyclic or contains fewer cycles than the monomer. If the monomer is polycyclic, opening of one ring is sufficient to classify the reaction as ring-opening polymerization.    
  Roller-Head-Anlage High performance extruder with wide extrusion head and two-roller calender.  
  Rotational Molding Cost-effective way to produce large parts. Plastic resins are loaded into a mold that is heated as it is rotated slowly on both the vertical and the horizontal axis. This simultaneous heating and rotation distributes the material on the inner surfaces of the mold and fuses it.   
  Rotomoulding Rotomoulding Process - The process consists of melting raw material inside a sealed hollow mould. This mould is then rotated for a calculated period around two perpendicular axis so as to distribute the melted material in the desired fashion. The heat is turned off while the mould continues to rotate. When cool enough the product is released from the mould, and the process starts again for the next product. Different rotating patens achieve variations in such things as wall thickness as required.   
  RPVC  Rigid Polyvinyl Chloride  
  RRIM  Reinforced Reaction Injection Molding  
  RTI  Relative Thermal Index (UL test)  
  RTPU  Rigid Thermoplastic Polyurethane  
  RTV  Room Temperature Vulcanizing (Silicone)  
  Rubber Natural rubber or any synthetic, elastomeric material with physical properties similar to those of natural rubber.  
  Rubber The term rubber is a very nebulous one. Polymers are materials consisting of long chains of molecules and includes plastics, rubber, and fibers. What distinguishes rubber from plastic is viscoelasticity, that is, it has both elastic and viscous properties. "Rubber" can be any of several different materials. Although usually one thinks of rubber coming from trees somewhere in the jungle ("natural rubber"), it can also be man made in a variety of fashions. Some of the more common types of rubber are SBR (styrene butadiene rubber), PBD (polybutadiene), isoprene (manmade "natural rubber"), nitrile, butyl, EPDM (ethylene propylene diene monomer), polychloroprene, silicone, fluoroelastomers, urethane, ECO (epichlorohydrin), and polyacrylate. There are others.  
  Rubber Tough, elastic polymer, mostly of hydrocarbons. Crosslinked or vulcanized material that is capable of recovering from large deformations quickly and forcibly, and can be modified to a state in which it is essentially insoluble in boiling solvent. See Natural Rubber (NR).  
  Rubber sheets - calendered Several plyers of thin rubber foils of the same or different qualities applied to one rubber sheet.  
  Rubber sheets - extruded Continuous extrusion of rubber sheets or hoses in one layer.  
top Rubber sheets - precured Rubber sheets, partially or completely cured in an autoclave prior application.  
S (SI)n Radial styrene-isoprene block copolymer  
  SAN Styrene-acrylonitrile (SAN)   
  SAN  Styrene acrylonitrile (copolymer)   
  SAN  Poly(Styrene Acrylonitrile)  
  SB  Styrene-Butadiene  
  SBC  Styrene-Butadiene Copolymer  
  SBL Styrene butadiene latex (SBL)  
  SBR Styrene-butadiene rubber  
  SBR A copolymer of styrene and butadiene. Also GR-S or Buna-S. Most commonly used type of synthetic rubber. Because of its excellent abrasion resistance, it is widely used in automobile and truck tires, as well as for carpet backing and paper coating. Other applications are in belting, flooring, wire and cable insulation, and footwear.  
  SBS Styrene-butadiene-styrene (SBS). A thermoplastic elastomer.  
  SBS  Styrene-butadiene-styrene (block copolymer)   
  SBS  Poly(Styrene Butadiene Styrene)  
  Scanning Electron Microscopy (SEM)  In Scanning Electron Microscopy (SEM) a focused beam of electrons scans across the surface of the sample. It is detected synchronously to the position of the scanning electron beam and recorded in an image storage device. Differences in the topography of the sample give rise to the differences in the intensities of the signals formed by the secondary electrons in the detector resulting in a three dimensional image. Scanning electron microscopy is suited to most types of surface morphology studies. Rough topographic features, void content and particle agglomerations are easily revealed as well as the compositional differences within material. Energy Dispersive X-ray Spectroscopy (EDS) or Wavelength Dispersive X-Ray Spectroscopy (WDS) in conjunction with SEM allows elemental analyses to be performed directly over the surface of the sample.    
  Scorch Premature vulcanization of rubber caused by excessive heat during processing. Scorched compounds will not mold satisfactorily, nor develop satisfactory adhesive properties.  
  SEBS Styrene-ethylene-butadiene-styrene (SEBS) rubber.   
  SEBS  Poly(Styrene-Ethylene-Butadiene-Styrene) Elastomer.  
  Self-curing Term applied to rubber mixtures that cure and cross-link on their own at room temperature or at elevated temperatures.  
  Self-Vulcanization Vulcanization of rubber at room temperature or above, and activated by chemical agents without the application of heat from an outside source.  
  SEPS Styrene-ethylene, propylene-styrene copolymer (SEPS).  
  Shear thinning  A behavior where the viscosity decreases when the shear stress increases. Typically broadening of the molecular weight distribution increases shear thinning.   
  Shore Hardness  Resistance of a (polymer) surface to deformation. The different hardness measures applied for characterizing polymers are: (a) Shore hardness (two scales, A for softer and D for harder materials) (b) Ball indentation hardness (also useable on profiled surfaces because of bigger measuring device). Also, Shore hardness is the resistance exercised by the test material to a body of defined shape being pressed into it under a defined spring pressure (DIN 53505), Shore A for soft rubber, Shore D for Ebonite/hard rubber.   
  SI Styrene-isoprene diblock copolymer   
  SI  Silicone  
  SI  System International (a subset of metric units)  
  Single Site Catalysts  Produces stereospecific polymers having very narrow MWD, very uniform comonomer distribution. Usually cocatalyst required.    
  SIS Styrene-isoprene-styrene (SIS). A thermoplastic elastomer.  
  SIS  Poly(Styrene-Isoprene-Styrene) Elastomer.  
  SMA  Styrene maleic anhydride   
  SMA  Poly(Styrene Maleic Anhydride)  
  SMC  Sheet Molding Compound  
  SMMA  Styrene Methyl Methacrylate Copolymer  
  Smoke sheets Plantation natural rubber sheets that, after passing through a mill that puts the conventional ribbing design on them, are washed and hung on racks in a smoke house where they undergo a combined smoking and drying process.  
  SMS  Styrene-a-Methylstyrene  
  Softeners - process aids Replaces plasticizer to a certain extent in the compound. These are not plasticizers but can be tolerated up to certain extent. It also reduces cost of the product. Refinery oil and chlorinated wax are common example of extender.    
  Solution Viscometry  In Solution Viscometry the rate at which a dilute polymer solution flows through a capillary is measured. Temperature and concentration of the polymer are carefully controlled. The parameter most often determined by dilute solution viscometry is intrinsic viscosity. Intrinsic viscosity is related to molar mass through a semi-empirical relationship called Mark-Houwink's equation.   
  Specific gravity The ratio of the mass of a unit volume of a material to that of the same volume of water at a specified temperature.  
  Sponge Rubber  Vulcanized rubber having a porous or cellular structure like that of a sponge, made by incorporating gasifying substances or blowing agents such as sodium bicarbonate and ammonium carbonate in the mixing, and then vulcanizing in a mold cavity larger than the piece of rubber to be vulcanized. Gas is generated from the dispersed particles of the blowing agent, producing the porous structure and inflating the rubber to the size of the mold cavity.  
  SPS  Syndiotactic Polystyrene  
  SPU  Segmented Polyurethane  
  S-PVC S-PVC or suspension PVC is produced as its name indicates by the suspension process and has a coarser particle size than paste PVC (> 50 microns).   
  SRP  Self reinforcing polymer (LCP)   
  SRS Substance Registry System (SRS). The Substance Registry System provides information on substances and how they are represented in the Environmental Protection Agency (EPA) regulations and information systems. See http://www.epa.gov/srs/  
  SRS Silicone Rubber Sheet (SRS)  
  SSBR Solution Styrene-Butadiene Rubber (SSBR)  
  S-SBR Solution-polymerized styrene-butadiene rubber   
  Star macromolecule  A macromolecule containing a constitutional unit from which more than two chains (arms) emanate. A star macromolecule with n linear chains (arms) attached to the central unit is termed an n-star, e.g., five-star.    
  Styrene Monomer Styrene Monomer is a colorless liquid with a distinctive sweet aroma. Styrene monomer is used extensively in the manufacture of plastics, resins, rubbers and latexes such as polystyrene (PS), expandable polystyrene (EPS), acrylonitrile butadiene styrene (ABS), Styrene Acrylonitrile (SAN), butadiene rubber (SBR), and styrene butadiene latex (SBL). Products produced from styrene include packaging, electrical and thermal insulation, fiberglass, pipes, automobile parts, carpet backing, drinking cups and other food-use items.  
  Styrene-ethylene-butadiene-styrene SEBS rubber   
  Sulfur This basic chemical element is the foundation of vulcanization identified by Charles Goodyear many, many years ago. Today, sulfur is still used widely to crosslink ("cure") rubber. Sulfur may also be made available to curing systems by chemicals called "sulfur donors". Uniform dispersion of sulfur in the compound is necessary for uniform curing. This can be best accomplished by use of an elastomeric bound sulfur.   
  Supercritical state  The critical state of a fluid is when the liquid and gas phase both have the same density. The fluid is then at its critical temperature, critical pressure, and critical volume. When the pressure or temperature exceeds this, the fluid is in its supercritical state. The loop reactor in the BORSTAR process is operated in supercritical state for some products.    
  Swelling  The property of a raw or vulcanized rubber of absorbing organic liquid, such as benzene and gasoline, and swelling to many times it's original volume; the property is also shown by other colloids in contact with other liquids; in a general sense, it may be any increase in volume in a solid substance caused by the absorption of a liquid.    
top Syndiotactic macromolecule  A macromolecule comprising alternating enantiomeric configurational base units. Note: in a syndiotactic macromolecule, the configurational repeating unit consists of two configurational base units that are enantiomeric    
T Tackifier Compounding material used to enhance the property that causes contacting surfaces to adhere to each other.   
  Tacticity  The orderliness of the succession of configurational repeating units in the main chain of a regular macromolecule (or oligomer or block).    
  TAIC  Triallyl Isocyanurate  
  Tear Resistance  The force required to tear completely across a specifically nicked rubber test specimen, or right angle test specimen, by elongating at a specific rate. See ASTM Method D 624.   
  Tear strength  Film must have certain resistance to tear loading. Tear strength indicates the average force required to propagate tearing through a specified length of the film sample. This test is suitable for investigation of orientation balance of the film. Normally tear strength is measured in two directions, parallel and transverse to the extrusion direction of the film.   
  TEEE  Ether Ester Block Copolymer (Thermoplastic Elastomer).  
  TEEE  Thermoplastic Elastomer Ether Ester Block Copolymer.  
  Telomer  A substance composed of macromolecules or oligomer molecules having few, usually terminal, reactive functional groups enabling, under appropriate conditions, the formation of larger macromolecules.    
  TEO  Olefinic Thermoplastic Elastomer  
  TES  Thermoplastic Styrenic Elastomer  
  TFE Tetrafluoroethylene. A thermoplastic material with good electrical insulating properties and chemical and heat resistance.  
  TFE  Polytetrafluoroethylene  
  Thermoforming Process of forming a thermoplastic sheet into a three-dimensional shape by clamping the sheet in a frame, heating it to render it soft and flowable. Then applying differential pressure to make the sheet conform to the shape of a mold or die positioned below the frame.   
  Thermoforming, Solid Phase Press. Form Process generally used for forming Polypropylene (PP). See Thermoforming   
  Thermogravimetry (TG, TGA)  Thermogravimetry (TG, TGA) can be used to measure any reaction involving mass change. TG analysis is often complementary test to DSC, the weight loss curve giving a picture of the make-up of the material by showing the temperatures at which individual components volatilize.    
  Thermomechanical Analysis (TMA) Thermomechanical Analysis (TMA) is  a technique for monitoring changes of physical dimensions (expansion, shrinkage, penetration) while the temperature of the sample is changed.   
  Thermoplastic Material that will repeatedly soften when heated and harden when cooled. Typical of the thermoplastics family are the styrene polymers and copolymers, acrylics, cellulosics, polyethylenes, vinyls, nylons, and the various fluorocarbon materials.   
  Thermoplastic A material which will soften, flow, or distort appreciably when subjected to sufficient heat and pressure. Examples are polyvinyl chloride and polyethylene.  
  Thermoplastic Copolyamides Acronym: COPA  
  Thermoplastic elastomers (TPE) Family of polymers that resemble elastomers in that they can be repeatedly stretched without distortion of the unstressed part shape, but are true thermoplastics and thus do not require curing.   
  Thermoplastic Rubber Rubber that does not require chemical vulcanization and will repeatedly soften when heated and stiffen when cooled; and which will exhibit only slight loss of its original characteristics.  
  Thermoplastics Resins or plastic compounds which, in their final state as finished articles, are capable of being repeatedly softened by an increase of temperature and hardened by a decrease of temperature.  
  Thermoset Material that will undergo or has undergone a chemical reaction by the action of heat, catalysts, ultra-violet light, etc., leading to a relatively infusible state. Typical of the plastics in the thermosetting family are the aminos (melamine and urea), most polyesters, alkyds, epoxies, and phenolics.   
  Thermosetting Rubber Chemically vulcanized rubber that cannot be remelted or remolded without destroying its original characteristics.   
  Thickening agent Substance used to raise or control the viscosity without the necessity for major changes in the total solids content. Organic or inorganic, generally considered as being either pseudoplastic or thixotropic in nature. Syn. Rheology modifier, Viscosity modifier.   
  Thixotropic agent Additive that brings thixotropy to a product.   
  Thixotropy Property of certain materials, such as gels, to soften or liquify upon agitation (viscosity decreases upon application of shear), and to stiffen to its original state when allowed to rest (viscosity increases). A product that possesses thixotropy can resist the pull of gravity.   
  Tin stabilizer Organic molecule containing tin atom used to improve heat stability of PVC. These organotin compounds can also be used for catalysis or some crosslinking reactions (ex: silanes hydrolysis).  
  Titanium dioxide Naturally derived from a mineral. Used chiefly as a white pigment, and as an opacifier. Reflects light, so (when stated as such) can be considered as a natural sun block.  
  TM  Transfer Molded  
  TP  Thermoplastic  
  TPE Thermoplastic elastomers. TPEs provide similar functional performance and properties as conventional thermoset rubber products, but can be processed with the speed, efficiency and economy of thermoplastics.   
  TPE Thermo Plastic Elastomer (TPE)  
  TPE-A Thermoplastic Elastomer Amide. TPE-A are copolymers of polyamide with either polyether, polyester or polyether ester.   
  TPEE Thermoplastic copolyesters   
  TPE-E Thermoplastic Elastomer Ester. Ester based thermoplastic elastomer, is a copolymer of polyether-esters or polyester-esters.  
  TPE-U Thermoplastic Elastomer Urethane. TPE-U is a group of polymers often referred to as PUR, with a very wide range of properties. The two main types of TPE-U are either polyester or polyether based.   
  TPI  Thermoplastic Polyimide  
  TPO Thermo Plastic Olefin  
  TPO Thermoplastic Polyolefin Elastomers (TPOs)   
  TPO  Thermoplastic olefin (rubber)   
  TPO  Thermoplastic Polyolefin (often applied to elastomers)  
  TPPE Thermo Plastic Ester Elastomer  
  TPR  Thermoplastic rubber   
  TPS Thermo Plastic Styrenics     
  TPS  Toughened polystyrene (see: HIPS)   
  TPU Thermoplastic Polyurethanes  
  TPU  Thermoplastic polyurethane (rubber) see: TPUR   
  TPU  Thermoplastic Polyurethene (often applied to elastomers)  
  TPUR  Thermoplastic polyurethane (rubber) see: TPU   
  TPUR  Thermoplastic Polyurethene (often applied to elastomers)  
  TPV Thermo Plastic Vulcanate  
  TPV  Thermoplastic Vulcanizate  
  TPX*  Polymethyl pentene copolymer   
  TS  Thermoset  
top TYS  Tensile Yield Strength  
U UF  Urea Formaldehyde  
  UHMW  Ultra High Molecular Weight (often applied to polyethylene)  
  UHMWPE  Ultra high molecular weight polyethylene (PE)   
  UL  Underwriters Laboratory  
  ULDPE  Ultra Low Density Polyethylene  
  Ultraviolet absorber Used to prevent the oxidation reaction in the product in the presence of ultraviolet light.  Common examples are benzophenone and its derivative, phenyl salicylates, benzophenone, etc. Synonyms: UV Absorber, UVA, UV / Light stabilizer.  
  Unsaturated Polyester (UP) Resin that exhibits greater shrinkage during curing and poorer chemical resistance than epoxy. The Unsaturated Polyester generally cure in presence of styrene, also acting as a solvent.   
  Unsaturated Polyester Curing Agent Organic Peroxides are used to initiate the curing reaction between polyester and styrene.  
  UP  Unsaturated Polyester (Thermoset)  
  Urea Formaldehyde Resin (UF) Amino resin made from urea and formaldehyde. Hardens when heated and in the presence of certain chemicals (catalysts or hardeners ); this hardening can be rapid and at moderate temperatures. Used to make plastic tableware and insulation, among others.   
  USDA  United States Department of Agriculture  
  UTS  Ultimate Tensile Strength  
  UV  Ultraviolet  
  UV Absorber Compounding material which, through its ability to absorb ultraviolet radiation and render it harmless, retards the deterioration caused by sunlight an other UV light sources. Screens the most harmful UV portion of light and thereby protects films and sensitive substrates from the photo-destruction. Examples of UV absorbers are: benzophenone and benzotriazole.  
  UV Curing Process during which the liquid application changes under UV / Electron Beam exposure within seconds into a completely cured product.   
top UV Light stabilizer Additive which stabilizes organic materials against UV radiation. Chemical compound which, when admixed with a thermoplastic resin, selectively absorbs UV rays.  
V Vacuum Forming Method of forming plastic sheets or films into three-dimensional shapes, in which the plastic sheet is clamped in a frame suspended above a mold, heated until it becomes softened, drawn down into contact with the mold by means of a vacuum, and cooled while in contact with the mold. Syn. Thermoforming.   
  VC  Vinyl chloride (see: VCM)   
  VCE  Poly(Vinyl Chloride-Ethylene)  
  VCEMA  Poly(Vinyl Chloride-Ethylene-Methyl Acrylate)  
  VCM  Vinyl Chloride Monomer (see: VC)   
  VCMA  Poly(Vinyl Chloride-Methyl Acrylate)  
  VCVAC  Poly(Vinyl Chloride-Vinyl Acrylate)  
  VCVDC  Poly(Vinyl Chloride-Vinylidene Chloride)  
  VHMW  Very High Molecular Weight (often applied to polyethylene)  
  Vicat softening temperature  Vicat softening temperature shows heat softening characteristics of thermoplastics. Flat specimen are placed in a temperature regulated heating bath, a needle type, loaded penetrator is set on the specimen surface and bath temperature is raised at a constant rate. The temperature of the bath at which the penetration of the needle has reached a predefined level is the Vicat softening temperature of the material.   
  Viscosity Resistance to flow or degree of thickening of a fluid. Usually expressed in poise (or centipoise) and in Pascals.seconds (Pa.s).   
  Viscosity modifier Additive modifying rheological behavior of a polymeric composition. Syn. Rheology modifier, Thickener.   
  Vitrification  Point at which a system becomes a glassy solid, and its molecules become immobilized, except for vibrations. At vitrification, the reaction rate (kinetics) drops off quickly.    
  VMQ ASTM standard for general purpose and high strength silicone rubber.  
  Vulcanization Vulcanization consists of creating a sulphur crosslink that is a bridge formed by one or more sulphur atoms between adjacent polymer chains. This chemical reaction induces extensive changes in the physical properties of an elastomer and is brought about by reacting the elastomer with sulphur and/or other suitable agents.   
  Vulcanization  An irreversible process during which a rubber compound, through a change in it's chemical structure (for example, cross-linking), becomes less plastic and more resistant to swelling by organic liquids and elastic properties are conferred, improved or extended over a greater range of temperature.  
  Vulcanization accelerator Molecule that permits the acceleration of vulcanization. It also permits the simplification of the network formed by reducing the length of the intermolecular bonds and by avoiding the formation of cycles. Families of vulcanization accelerator are: Dithiocarbamates, Thiurams, Thiazoles, Amines, Guanidines, and Thioureas.   
top Vulcanizing agent Compounding material that produces vulcanization.  
W Wax Solid or semi-solid, light-colored, more-or-less translucent crystalline mass, slightly greasy to the touch, consisting of a mixture of solid hydrocarbons in which paraffin series predominates. Waxes are used as lubricants or processing aids in many polymers and applications.   
  Wetting Thorough impregnation of a material by a liquid.   
  Wetting Agent Substance used to reduce the surface tension and thereby facilitate spreading or impregnation of a surface. Additives that belong to the group of surfactants. Syn. Dispersing agent , Dispersant, Grinding aid, Milling aid.   
  Whiteness Attribute of color perception by which object's color is judged to approach the preferred white.   
  Wollastonite White calcium metasilicate filler providing materials good dimensional stability and scratch resistance. Wollastonite also imparts excellent mechanical performance and increases HDT (Heat Deflection Temperature).  
top WPE  Weight per Epoxide (also called EEW)  
X XLPE Crosslinked polyethylene is a thermoset and is crosslinked by radiation, thermally, or by moisture. XLPE offers a wide range of operating temperatures, excellent deformation, abrasion, and flame resistance. XLPE can be formulated with halogenated or non-halogenated flame retardant packages. Some grades are also rated XHHW-2 which offers excellent wet electrical properties.  
  XLPE  Cross-linked Polyethylene  
  XNBR Carboxylated acrylonitrile butadiene rubber (XNBR)  
  XPE-PVC Expanded Polyethylene-Polyvinyl Chloride.  Fire retardant.  
top XPS Extruded polystyrene (XPS)   
Y Yellowness Attribute of color perception by which object's color is judged to depart from colorless or a preferred white toward yellow.   
  Young's modulus Elasticity modulus equal to the ratio of applied tension or compression to the resulting strain in a material.  
  Ziegler-Natta Catalyst  Ziegler-Natta Catalyst produces polymer having relatively narrow MWD. Aluminum alkyl cocatalyst required.  
Z Zinc Borate Flame Retardant Molecule used as a flame retardant synergist in order to reduce smoke emissions.