2. The material is transparent in appearance and light in weight, represented by EPDM. Because its main chain is composed of chemically stable saturated hydrocarbon and its side chain only contains unsaturated double bonds, it has excellent aging resistance such as ozone resistance, heat resistance and weather resistance, and can be widely used in automobile parts, building waterproof materials, wire and cable sheaths, heat-resistant rubber hoses, adhesive tapes, automobile seals and other fields.