EFFECT OF SILICA FILLER ON DYNAMIC-MECHANICAL PROPERTIES OF IONIC ELASTOMER BASED ON CARBOXYLATED NITRILE RUBBER

Variation of dynamic mechanical properties like storage modulus (E') a nd loss tangent (tan delta) with temperature show the presence of two transitions in the carboxylated nitrile rubber (XNBR) molded in the pr esence of zinc oxide (ZnO). The low-temperature transition is due to t he glass-rubber transition (T-g) of XNBR, and the high-temperature tra nsition is due to formation of ionic clusters. Incorporation of reinfo rcing silica filler makes the high-temperature transition more promine nt and high filler loading causes a shift of the transition temperatur e to the higher side. It is believed that the rubber-filler interactio n in the cluster region causes striking changes in the variation of E' and tan delta with a double-strain amplitude (DSA). (C) 1995 John Wil ey and Sons, Inc.