Ethylene Propylene
ASTM D1418, ISO 1629 Designations: EPM, EPDM
ASTM D2000, SAE J200 Type/Class: AA, BA, CA, DA
Standard Color: Black
Trade Names:
- Buna EP® (Bayer Corp.)
- Keltan® (DSM Copolymer, Inc.)
- Nordel® (DuPont Dow Elastomers)
- Royalene® (Uniroyal, Inc.)
- Vistalon® (Exxon Chemicals)
Relative Cost: Low
General Temperature Range: -65° to +300° F
Ethylene propylene is a copolymer of ethylene and propylene (EPM), or, in some cases, a terpolymer due to the addition of a diene monomer (EPDM). This additional diene monomer can be important because it includes unsaturation to facilitate sulfur crosslinking.
In use since 1961, ethylene propylene is still primarily valued for its outstanding resistance to Skydrol® and other phosphate ester type hydraulic fluids (including Pydraul® and Fyrquel®), as well as for its typical temperature range (-65° F to +300° F, -54° C to +149° C). Ethylene propylene is also known for its good resistance to weathering thanks to saturation within its main backbone.
EPM performs well in:
- Alcohols
- Automotive brake fluids
- Dilute acids and dilute alkalies
- Ketones (MEK, acetone)
- Silicone oils and greases
- Steam (up to 400° F, 204° C)
- Water
EPM does not perform well in:
- Aliphatic and aromatic hydrocarbons
- Di-ester based lubricants
- Halogenated solvents
- Petroleum oils
