Improvement in Tear Resistance and Crack Growth of Tire Tread Compound with Effective Cure Systems and Use of Semi-Reinforcement Fillers

Effect of partial natural rubber replaced with synthetic rubbers, styrene butadiene and cis butadiene, on failure and strength properties of bias tread NR/BR based compound was studied by efficient and conventional sulfur curing systems and mixtures of different carbon black grades. It was observed that failure behavior comprising tear resistance and crack growth in substituted compounds dropped significantly without any change in formulation. The type and crosslinking density were further studied with changes in sulfur/accelerator dosage and ratio. It was observed that tear resistance and crack growth improved with lowering sulfur/accelerator ratio, maintaining the same crosslink density, without any change in hysteresis. Other physico-mechanical properties of substituted NR/BR/SBR compound showed similar behavior as reference compound. The carbon black blends in NR/BR substituted compounds showed that using semi-reinforcing filler instead of the original reinforcing filler could improve crack growth resistance. Therefore, it is possible to decrease NR/BR ratio with modification of curing system and use of N330/N660 filler blends.