67
Crack Growth Improvement with Micronized Rubber Powder in Sidewall Compounds
The use of micronized rubber powder in tread compounds for both improved cost and sustainability is well-established and in use by most major tire companies. This paper will exhibit data that indicates that PolyDyne® micronized rubber powder in sidewall compounds can improve Demattia crack growth dramatically with increasing loadings up to 10% over the base compound formulation. EkoDyne™ functional compound was also evaluated with demonstrated improvements in compound viscosity and physical properties but did not offer an improvement in Demattia crack growth. A plausible hypothesis will be presented on the mechanism for the improvement when introducing micronized rubber powder in the sidewall compound. The hypothesis is supported by both microscopic evidence and the lack of improvement shown using the functional compound.