Joint work with John Baldwin and David Bauer.
A simple kinetic model has been developed to interpret issues related to accelerated aging of tires. The finite-element model is based on the Basic Autoxidation Scheme and incorporates mass transport limitations related to diffusion of oxygen into the layered elastomer system. The effect of aging on transport properties, such as diffusivity, due to changes in cross-link density is also considered in the model. The extent of oxidation is calculated at different locations within the tire as functions of time, temperature, and inflation media. Approximate changes to physical properties were derived from oxidation histories predicted by the model and compared to experimentally measured data which includes crosslink density and elongation-to-break. Finally, we will examine the effect of temperature on accelerated ageing in the context of accelerated testing.