Accelerated aging of elastomeric composites with vulcanized ground scraps

摘要

The aim of this work is to study the effect of thermal aging on the mechanical, dynamic-mechanical, and chemical properties of SBR (styrene-butadiene rubber) composites filled with SBR industrial rubber scraps. Eight composites with varying proportions (10-80 phr) of the SBR ground scraps (SBR-r) were prepared and subjected to accelerated aging in an air-oven. The composites were evaluated, and the results were compared with a control sample (base formulation with 0 phr of SBR-r), before and after thermal aging. The accelerated aging led to a decrease in the mechanical properties as a result of an increase in the stiffness of the material, related to an increase in the crosslink density. However, these properties were not affected by the addition of rubber scraps up to 50 phr, either before or after aging. The increase in the glass transition temperature of the composites after aging, measured using dynamic mechanical analysis, confirmed the occurrence of a postcrosslinking process. Fourier transform infrared spectroscopy and crosslink density revealed that the aging mechanism was dependent on the SBR-r content.