国产高清在线观看免费不卡,2020国产一级在线观看,亚洲综合五月天婷婷丁香,亚洲欧美蜜芽tv在线一区

Ethylene-propylene rubber is a copolymer of ethylene, propylene, and a small amount of non-conjugated diene. It is a type of ethylene-propylene rubber. It is represented by EPDM (Ethylene Propylene Diene Monomer), because its main chain is composed of chemically stable saturated hydrocarbons. Only unsaturated double bonds are contained in the side chain, so it has excellent aging resistance such as ozone resistance, heat resistance and weather resistance. It can be widely used in automotive parts, waterproof materials for construction, wire and cable sheaths, heat resistant hoses, tapes, automobiles Seals and other fields.