DIENE TERMONOMER TYPE AND EPDM PROPERTIES.

Effects of type of diene termonomer on thermal stability and aging of EPDM terpolymers were investigated. Five different polymers using ethylidene norbornene (ENB), butadiene (BD), dicyclopentadiene (DCPD), methyltetrahydroindene (MTHI), and 1,4-hexadiene (HD) as termonomers were made at equimolar unsaturation. In both gum and filled vulcanizates ENB-EPDM is the fastest curing. In gum stocks HD-EPDM is the slowest curing, but is faster than DCPD-EPDM in filled stocks. At 350 F aging temperature, both ENB and HD polymers have 65 percent mopnosulfidic crosslinks and about the same energy-to-break values (E//b). Thermogravimetric analysis in N//2 shows that these vulcanizates decompose in 800-935 F temperature range.