SEP is a kind of special EPDM modified by organic silicon, so that the weather resistance and low temperature resistance of EPDM can be improved. In terms of performance between silicone and EPDM, SEP also has excellent resistance to chlorine and sponge foam.
Mechanical strength in high temperature environment, especially tear strength, SEP is better than EPDM when more than 100 ℃, comparable with high strength silicone. In addition, the durability of SEP is better than silicone in steam resistance, hot water resistance, acid resistance and alkali resistance.

SEP is mainly used for high strength rubber parts at high temperatures, such as spark plug protective cover, anode cap, etc.