Systematic investigation on the effect of processing procedures on the performance of oil‐resistant thermoplastic vulcanizates based on HNBR/TPEE

Abstract The unique “sea‐island” phase of thermoplastic vulcanizates (TPVs) dictates an inseparable correlation between micro‐morphology and properties, the studies on the processing procedures in dynamic vulcanization are of great significance for the preparation of TPVs with desirable performance. Herein, a new type of oil‐resistant TPV with superior stretchability, low hardness, and high elasticity has been successfully fabricated based on hydrogenated acrylonitrile butadiene rubber (HNBR) and thermoplastic polyester elastomer (TPEE). The effect of processing procedures on the phase morphology, rubber network strength, mechanical properties, rheological performance, thermal stability, and oil resistance of HNBR/TPEE TPV was systematically investigated. In the masterbatch procedure, the homogeneous dispersion of the cross‐linking agent in the rubber phase contributes to stronger rubber networks and effectively reduces HNBR particle size. TPV prepared by masterbatch procedure exhibits a more comprehensive performance with improved mechanical properties, better rheological performance, enhanced thermal stability and oil resistance. In contrast, excessive dispersion of peroxide in the plastic phase during the pre‐compound procedure is demonstrated to the degradation of TPEE, resulting in large‐sized defective domains, while the deterioration of the rubber network leads to the inferior performance of TPV. This study provides new insights into the selection of the optimal procedure for preparing oil‐resistant TPVs.