The Effects of Plasticizer and Filler on the Curing Characteristic and Mechanical Properties of (SBR) Styrene Butadiene Rubber and (CR) Chloroprene Rubber Blends

Curing characteristics and mechanical properties of styrene butadiene rubber and chloroprene rubber blends have been studied. Carbon black loading in the range of 50-70 phr and plasticizer in the range of 7.5-12 phr was used. Minimum torque (ML), maximum torque (MH), cure time (Tc 90) and hardness was found to increase, while reduction in scorch time was observed by increasing the carbon black loading in the rubber matrix. Increasing the carbon black quantity in the rubber blends resulted in an enhancement of the tensile strength and tear strength up to 60 phr and then gradually decreased as the filler quantity was increased. The curing characteristics indicate that the rubber filler interaction increases the cure time with increasing filler loading. Tensile strength, tear strength and hardness were found to increases with the increasing plasticizer concentration up to 9 phr in the rubber blends. This property gradually decreases as the plasticizer concentration is increases up to 12 phr while elongation at break increases.