Cure characteristics and mechanical properties of styrene-butadiene rubber/hydrogenated acrylonitrile-butadiene rubber/silica composites

Composites of styrene butadiene rubber (SBR), hydrogenated acrylonitrile–butadiene rubber (HNBR) and silica were prepared. Sulfur (S), dicumyl peroxide (DCP) and a combination of S and DCP (M) were used as curing agents, respectively. The morphology of the composites with different blend ratio was examined to correlate with observations on mechanical properties by scanning electron microscopy. The effects of blend ratio and curing systems on the curing characteristics and mechanical properties, such as stress–strain behavior, tensile strength, elongation at break and hardness of SBR/HNBR/Silica composites, were studied. Composites prepared by M curing systems showed comparatively better mechanical properties, wet traction and rolling resistance than S and D curing systems. The tensile strength, tear strength, and elongation at break were improved by adding HNBR for M curing systems. The wet traction of the vulcanizates containing HNBR was better than that of the vulcanizates without HNBR. A relatively uniform dispersion of silica was observed for SBR/HNBR/silica compositions compared with SBR/silica composites.