Ethylene propylene rubber 乙丙橡胶
Ethylene propylene rubber (EPR, sometimes called EPM, the E refers to ethylene, P to propylene and M refers to its classification in ASTM standard D-1418 since the M class includes rubbers having a saturated chain of the polymethylene type) is a type of synthetic elastomer that is closely related to EPDM rubber (EPM is a copolymer of ethylene and propylene whereas EPDM rubber is a terpolymer of ethylene, propylene and a diene-component). Since it began to be produced in the 1960s, production has increased to 870 metric tons per annum, mostly due to advances in polymerization and catalyst technologies which allow polymers to be designed for specific purposes.