Materials

Elastomer

An Elastomer is a material that can be, or already is, modified to a state exhibiting little plastic flow and has quick and nearly complete recovery from an extending force.
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Such material before modification is called, in most instances, a raw or crude rubber, and, by appropriate processes, can be converted into a finished product.

When the basic elastomer is converted to an essentially non-plastic state and tested at room temperature, 15° to 30† C (60° to 90† F), it must meet the following test requirements, according to ASTM:

• Capable of being stretched 100%.
• After being stretched 100%, held for 5 minutes and then released, it is capable of retracting to within 10% of its original length within 5 minutes after release.

Neoprene

Neoprene rubber is a homopolymer of chloroprene. It is more resistant than natural rubber to gasoline, sunlight, ozone and oxidation. It is also flame resistant and will not support combustion. It has good resistance to corrosive action of chemicals, bacterial enzymes, and its water resistance is as good as natural rubber. It has good resistance to heat and does not soften as does natural rubber, but where increased resistance to heat, ozone, weathering, gasoline or oil is required. The temperature range is -40° to +135°C (-40° to 275° F)

Buna-S 

Buna-S or SBR is a copolymer of styrene and butadiene and has properties similar to natural rubber. It has greater abrasion resistance than natural rubber, better wear resistance and better low temperature flexibility. Though superior in water resistance to natural rubber, it has about the same resistance to solvents and chemicals. It has better heat resistance and heat-aging qualities than natural rubber, and in excess heat it hardens and becomes brittle instead of softening as does natural rubber. The temperature range of SBR is -55ƒ to +70ƒC (-67ƒ to158ƒF).

Butyl

Butyl (IIR) rubber is a copolymer of isobutylene. It has exceptionally low gas and moisture permeability and outstanding resistance to heat aging, weather, ozone, chemical attack, flexing, abrasion and tearing. It has good resistance to phosphate ester based hydraulic fluids, and has excellent electrical insulation performance. Butyl is not recommended for use when in contact with petroleum oils and fluids. The temperature range is -55ƒ to 120ƒC (-67ƒ to +248ƒF).

EPDM 

Ethylene Propylene (EPDM) rubber is a copolymer of ethylene and propylene and also contains a small amount of a third monomer, diene. It has outstanding resistance to aging, weathering, ozone, oxygen and many chemicals. It has high and low temperature stability, as well as steam and water resistance. Its dynamic and mechanical properties are between those of natural rubber and SBR. It has excellent resistance to phosphate ester based hydraulic fluids, but is not recommended for use in contact with petroleum oils or fluids. The temperature range is -55ƒ to +135ƒC (-67ƒ to +275ƒF).

Hypalon® 

Hypalon is Chlorosulfonated polyethylene. It has outstanding resistance to ozone attack and color retention during light exposure. It has excellent flame and oil resistance, as well as excellent heat, weather, acid, chemical, and abrasion resistance. Hypalon has a temperature range of -40ƒ to+160ƒC (-40ƒ to +320ƒF).

Hypalon® is a Registered Trade Mark of DuPont Dow Elastomers

Natural

Natural rubber is a ready-made organic elastomer. It offers the optimum balance of properties necessary for high performance in demanding mechanical applications. it has high resilience, has very good tensile and tear properties over a wide range of durometers and has excellent resistance to cold flow. The abrasion resistance of natural rubber is good, and it has better low temperature flexibility than most synthetics. However, natural rubber does not age well, nor is it chemically inert. It is inferior to many synthetics in heat aging, resistance to sunlight, oxygen, ozone, solvents and oil. The temperature range of natural rubber is -55ƒ to +50ƒC (67ƒ to +122ƒF).

Silicone 

Silicone (SI) rubber is a semi-organic elastomer made from silicone, oxygen, hydrogen and carbon. It has outstanding resistance to temperature extremes. Under normal operating conditions, temperatures as high as 260ƒ C (500ƒ F) and as low as -75ƒ C (-103ƒ F) have little effect on the physical and electrical properties. At temperatures between -85ƒ C (-121ƒ F) and +260ƒ C (+500ƒ F), it is superior in its resistance to compression set, compared with all other available elastomers. At moderate temperatures, it has poor tensile strength, tear resistance and abrasion resistance. However, at extreme temperatures, where other materials have failed, the physical properties of silicone remain unchanged. Silicone has outstanding resistance to sunlight, ozone, oxygen, gases and moisture. It has a temperature range of -100ƒ to +315ƒ C (-148ƒ to +599ƒ F).

Urethane 

Polyurethane (AU, EU) elastomers are formed from the reaction of isocyanates with hydroxyl compounds. The have outstanding abrasion resistance at moderate temperatures, greater than most rubbers and plastics. Urethanes have exceptionally high tensile strength, tear strength, and load bearing capabilities, higher than any conventional rubbers. They are resistant to oils, solvents, fats, greases, gasoline, ozone, sunlight and weather. A wide range of hardnesses are available to urethane from a soft 15 duro., Shore A to a hard 80 duro., Shore D. Urethane remains flexible at low temperatures or where there is a possibility of heat build-up from friction. The temperature range is -40ƒ to +95ƒ C (-40ƒ to +203ƒ F).

Viton®

Viton rubber is a copolymer of vinylidene fluoride and hexafluoropropylene. It has good resistance to most chemicals and commercial fluids. It has an outstanding ability to retain strength at elevated temperatures and to withstand embrittlement during long-term heat aging. It has outstanding compression set with the ability to recover following deflection at 150ƒ to 230ƒ C (302ƒ to 446ƒ F). The temperature range is -30ƒ to +230ƒ C (-22ƒ to +446ƒ F), but will withstand temperatures up to 315ƒ C (599ƒ F) for short periods of time.

​​​​​​​Viton® is a Registered Trade Mark of DuPont Dow Elastomers