Effect of dynamic vulcanization time on the performance of thermoplastic vulcanizates based on hydrogenated acrylonitrile butadiene rubber/thermoplastic polyester elastomer

Abstract

AbstractThermoplastic vulcanizates (TPVs) are obtained by dynamic vulcanization (DV). Time is a crucial processing parameter. This work aims to develop heat‐ and oil‐resistant TPVs with hydrogenated acrylonitrile butadiene rubber (HNBR) and thermoplastic polyester elastomer (TPEE). It focuses on the effect of DV time on the morphology and properties of the resulting TPVs. The investigation demonstrates that as the DV time increases from 2 to 6 min, the rubber network progressively reinforces and the HNBR domain size decreases under more adequate shearing action, resulting in a more homogeneous morphology. This leads to a significant improvement in tensile properties, elasticity, rheological properties, thermal stability, and oil resistance of the TPV. A further extension in DV time (over 8 min) results in a slight deterioration in elasticity and thermal stability of the TPV because of excessive degradation of the TPEE. Accordingly, an appropriate DV time for HNBR/TPEE‐TPV preparation is between 6 and 8 min under the specified DV conditions.