Failure Optimization and Curing Properties of a Passenger Tire Tread Compound

The blending of NR and BR rubber blend with N330 carbon black is studied on curing behavior and the physico-mechanical properties of a SBR rubber based tire tread compound containing N234 carbon black. The effect of sulphur and accelerator contents on different properties of rubber compound is also tested with a wide range of curing agents. Partial substitution of SBR with NR shows significant improvement in cure characteristics, tear resistance, crack growth, resilience and abrasion without much changes in its hardness, dispersion and tensile properties. Partial substituted BR delivers the same results except a considerable increase in the rate of crack growth. A partial substitution of N234 with N330 has a relatively negative effect on the abrasion and tear resistance, but decreases the crack growth rate. The crack growth rate increases with increased level of sulphur and accelerator and the abrasion decreases at certain level of curing agent, although it increases thereafter (crosslink density). The tensile and tear resistance increase first and then decrease with further increase of crosslink density. The study on the governing mechanisms shows that beside rubber chains induced crystallinity, the rubber chain mobility dominates the crack growth rate, while a competition exists between this mechanism and reinforcement mechanism for other failed properties. Finally, an optimized formulation based on SBR/BR/NR and N234/N330 with optimum crosslink density and sulphur/accelerator ratio has been calculated.