ASTM - ASTM designation for a copolymers from an acrylate and a small amount of cross linking monomer. (Examples, Hycar 4021,4051,4054 elastomers.)
ABRASION RESISTANCE - The resistance of a material to loss of surface particles due to frictional forces.
ABRASION RESISTANCE INDEX - A measure of the abrasion resistance of a vulcanized rubber part relative to that of a standard under the same conditions.
ACCELERATED AGING - A method in which an attempt is made to produce and measure the effects of natural or in-use again in a short period of time. (Example, 72 hours at 100°C (212°F) in air test tube.)
ACCELERATOR - A chemical used in small amounts to speed up curing or vulcanization of elastomeric compounds. (Example, tetramethyl thiuram monosulfide, 0.5 parts.)
ACRYLATE RUBBER - General term used to describe a class of elastomers based on acrylate esters. (Examples, Hycar 4021, 4051, 4054.) See ACM above.
ACRYLIC RUBBER - See Acrylate Rubber above, which is the preferred usage. Acrylonitrile - A chemical CH2CHCN, also known as vinyl cyanide, manufactured from propylene and copolymerized with butadiene to produce butadiene/acrylonitrile elastomers. (Examples, Hycar 1041,1032.)
ACTIVATOR - A chemical used in elastomer compounding in small quantities to increase the effectiveness of an accelerator. (Example, stearic acid.)
ADHESION - The state in which two surfaces are held together by interfacial forces which may consist of molecular forces or interlocking action, or both.
ADHESION FAILURE - The separation of two materials at the surface interface rather than within one of the materials itself.
ADHESIVE - A substance capable of holding materials together by surface attachment.
ADHESIVE - CONTACT - An adhesive that is apparently dry to the touch but which will adhere to itself upon contact.
ADHESIVE - HEAT ACTIVATED - A dry adhesive film that is rendered tacky or fluid by application of heat or heat and pressure.
ADHESIVE - SOLVENT ACTIVATED - A dry adhesive film that is rendered tacky just prior to use by application of a solvent.
AGE RESISTANCE - The resistance to deterioration by oxygen, heat, light, and ozone or combinations thereof during storage or use.
AGING - a) An irreversible change in material properties after exposure to an environment for an interval of time. b) Exposing materials to a specified environment for an interval of time.
AGING, AIR OVEN - Exposing materials to the action of circulating air in an oven at elevated temperature for a specified period of time. A more severe test than air test tube aging.
AGING, AIR TEST TUBE - Exposing materials to the action of static air within a closed test tube inserted in an oven. Less severe than air oven aging, but more reproducible, as it prevents transfer of volatiles from one set of samples to another.
AIR CHECKS - The surface markings of depressions due to trapping air between the product being cured and the mold or press surface.
AIR-CURING - Curing or vulcanization in air at room or elevated temperatures. Normally at atmospheric pressure.
AMBIENT TEMPERATURE - The temperature of the atmosphere or medium surrounding the object under consideration.
ANILINE POINT - The minimum equilibrium solution temperature for equal volumes of aniline and the liquid in question. The lower the aniline point, the more severe the swelling effect upon nitrile elastomers.
ANTIOXIDANT - Same as Age Register, a chemical used to retard deterioration specifically caused by oxygen. (Example, Age-Rite, Resin D)
ANTIOZONANT - A chemical compounding material used specifically to retard deterioration caused by ozone. (Example, Antozite II).
ANTISTATIC AGENTS - Chemicals which when added to a rubber compound will help dissipate the buildup of electron charges, thereby eliminating a spark or shock risk.
ASH - The residue of mineral matter left when a material is subjected to high heat and all organic material is burned away.
AUTOCLAVE - A pressure vessel used for the curing of vulcanization of rubber parts by means of steam under pressure.
