PolyAid®

GLOSSARY OF POLYMER TERMINOLOGY

Term / Acronym

Definition

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)

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.

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

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.

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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 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.

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)

Low-cis polybutadiene rubber

Very high-cis polybutadiene rubber

Butadiene rubber (polybutadiene rubber)

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.

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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 Stage

Final step in the cure of a thermoset resin, resulting in irreversible hardening and insolubility. Also, see A-stage, B-stage.

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.

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.

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.

Chlorinated Polyethylene Rubber

Compression Molded

CMC

Carboxymethyl Cellulose

Cellulose Nitrate

Epichlorohydrin homopolymer (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.

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

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

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