Buna® EP rubbers: saturated molecular backbone

Ethylene and propylene can be polymerized to form either copolymers (EPM) or terpolymers (EPDM) when a non-conjugated diene is added. The polymer backbone is saturated. The remaining double bond of the diene is part of the side group. The saturated backbone results in the high resistance of EPDM to thermo-oxidative degradation as well as a variety of chemicals.

Buna is a registered trademark in many countries of the world.