Influence of filler type and loading on cure characteristics and vulcanisate properties of SBR compounds with a novel mixed vulcanisation system

In the present work, the influences of filler type and content on cure characteristics, mechanical and dynamic mechanical properties, and heat aging resistance of filled styrene butadiene rubber (SBR) compounds cured with a mixed vulcanisation system were assessed. A new mixed curing system was developed to obtain vulcanisates with excellent mechanical properties and heat aging resistance compared to those with a commercial EV cure system. The results show that filler has stronger effect on scorch time, cure time and cure rate index with the EV system than with the mixed curing system. The torque difference of filled SBR compounds depends on the filler content. With mixed vulcanisation, it is easier to control the conditions during moulding when the formulation is altered, particularly with a change in filler content. The mixed vulcanisation gave overall improved mechanical properties, heat build-up and heat aging resistance compared to the EV system, even though reinforcing fillers were used in the SBR compounds.