Payne effect of thermo-oxidatively aged isoprene rubber vulcanizates

While many works focus on aging mechanisms and mechanical performances of aged vulcanizates, rare is performed to investigate the influences of aging induced network variation on the Payne effect and energy dissipation. Herein the influence of thermo-oxidative aging on Payne effect of isoprene rubber (IR) gum vulcanized with conventional vulcanization (CV) and efficient vulcanization (EV) systems at similar crosslinking densities was investigated, in order to disclose the roles of the crosslink types and therefore the thermo-oxidative degradation on the Payne effect. The results indicate that the crosslink structure and thus the Payne effect are highly susceptible to the thermo-oxidative aging. The aging induced degradation is more severe in CV than that in EV systems, which greatly improves the dissipation of accompanying the Payne effect. This work is helpful for understanding the contribution of network structure to the Payne effect for design rubber materials with optimized aging and dynamic properties.