Like the butyls, the EP rubbers are of two types. EPDM is chemically reactive and is capable of sulfur vulcanization. The copolymer must be cured with peroxide. However, property retention is better than that of NR on exposure to heat, oxidation, or ozone. These materials have broad resistance to chemicals but not to oils and other hydrocarbon fluids.
Electrical properties are good.
EPDM sheeting, either unsupported or reinforced, is used in roofing and as liners for water conservation and pollution-control systems.