Novel heat and oil-resistant thermoplastic vulcanizates based on ethylene-vinyl acetate rubber/poly(vinylidene fluoride)

Thermoplastic vulcanizates (TPVs) combine the excellent elasticity of conventional vulcanized rubbers and the easy processability and recyclability of thermoplastics. In this study, we successfully prepared novel heat and oil-resistant TPVs based on ethylene-vinyl acetate rubber (EVM) and poly(vinylidene fluoride) (PVDF) by dynamic vulcanization (DV). The phase morphology, morphological evolution, and the properties of the EVM/PVDF TPVs were studied, and the microstructure-property relationship during DV was revealed. Interestingly, a large number of EVM rubber nanoparticles are observed in the EVM/PVDF TPVs during DV, and these nanoparticles assemble into oriented EVM fibers and EVM bundles during DV. As the DV further proceeds, the oriented EVM fibers and EVM bundles agglomerate with one another more densely and further assemble into EVM spherulites, leading to an increase in the thickness of the PVDF ligaments and the deterioration of the rubber network. More importantly, our EVM/PVDF TPVs show good mechanical properties, high elasticity, good processability, excellent heat-and oil resistance, and good recyclability. This study provides guidance for the preparation of new TPVs that can replace the traditional thermosetting rubbers in automotive and oil pipeline areas.