New Approach to Fabricate Novel Fluorosilicone Thermoplastic Vulcanizate with Bicrosslinked Silicone Rubber-Core/Fluororubber-Shell Particles Dispersed in Poly(vinylidene Fluoride): Structure and Property

Abstract

Herein, we report a new method, core–shell dynamic vulcanization, to prepare a poly(vinylidene fluoride) (PVDF)-based thermoplastic vulcanizate (TPV) with cross-linking-controlled silicone rubber (SR)/fluororubber (FKM) core–shell particles. The bicrosslinked SR-core/FKM-shell structure effectively stabilized the blending morphology of TPV, avoiding the direct contact of PVDF and SR. Results of transmission electrom microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier transform-infrared (FT-IR) confirmed the formation of core–shell structure. In the PVDF/FKM/SR (40/30/30) TPV, the size of core–shell particle was ∼2 μm, and the thickness of the FKM shell was ∼400 nm. The cross-link density of SR-core and FKM-shell could be controlled to tailor the properties of the TPV. It was found that the tan δ value of core–shell bicrosslinked TPV could be maintained at around 0.3 in range of 1–1000 cpm. The TPV exhibited good mechanical properties in which its tear strength was as high as 58 kN m–1. The new PVDF/SR/FKM TPV can be an idea potential alternative for expensive fluorosilicone rubbers in some applications.