Damping Properties of Blends Based on EVM

Key Words:damping; ethylene-propylene-diene copolymer; ethylene-vinyl acetate rubber; nitrile butadiene rubber; polyvinyl chloride

Abstract:The mechanical and damping properties of blends of ethylene-vinyl acetate rubber (VA content >40% wt) (EVM)/ethylene-propylene-diene copolymer (EPDM) and EVM/nitrile butadiene rubber (NBR), both with 1.4 phr BIPB (bis (tert-butyl peroxy isopropyl) benzene) as curing agent, were investigated by dynamic mechanical analysis (DMA). The effect of added polyvinyl chloride (PVC), amido donor N-cyclohexyl-2-benzothiazole sulfonamide (CZ), and dicumyl peroxide (DCP) as a substitute curing agent, on the damping and mechanical properties of both rubber blends were studied. The results showed that in EVM/EPDM/PVC blends, EPDM was immiscible with EVM and could not expand the damping range of EVM at low temperature. PVC was miscible with EVM and dramatically improved the damping property of EVM at high temperature while keeping good mechanical performance. In EVM/NBR/PVC blends, PVC was partially miscible with EVM/NBR blends and remarkably widened the effective damping temperature range (EDTR) from 41.1 degrees C for EVM/NBR to 62.4 degrees C. Curing agents BIPB and DCP had a similar influence on EVM/EPDM blends. DCP, however, dramatically raised the height of tan delta peak of EVM/NBR = 80/20 and expanded its EDTR to 64.9 degrees C. CZ had no obvious influence on the EVM/EPDM blends cured with BIPB. However, a small content of CZ enlarged the tan d peak of EVM/NBR = 80/20 in both height and width, but at the cost of a deterioration of mechanical performance.

Volume:50

Issue:10

Translation or Not:no