Low‐fuel‐permeation thermoplastic vulcanizates prepared from mutually miscible fluoroelastomer and poly(vinylidene fluoride–hexafluoropropylene)

Abstract

AbstractAn oleophobic barrier material is imperative for automotive fuel hose applications to reduce permeation of air‐polluting hydrocarbons. With the increasingly strict exhaust emission regulations, the development of new fluoroelastomer (FKM) materials with enhanced fuel permeation resistance is highly desirable. Herein, we successfully developed a class of all‐fluorinated thermoplastic vulcanizates (TPVs) by dynamic vulcanization from FKM and poly(vinylidene fluoride–hexafluoropropylene) (P(VDF‐HFP)). The mechanical properties, recyclability and fuel resistance of the FKM/P(VDF‐HFP) TPVs were examined. The results show that the FKM/P(VDF‐HFP) blends present high mechanical performance with tensile strength up to 26.3 MPa and strain at break of more than 600% at a high rubber/plastic ratio of 7:3 by weight. Moreover, our FKM/P(VDF‐HFP) TPVs show excellent fuel resistance and recyclability. Such high mechanical properties, recyclability and fuel resistance are correlated with the good miscibility between FKM and P(VDF‐HFP), the strong FKM rubber network and the fine phase morphology of TPVs. This work provides a guidance for the preparation of new TPVs through selecting mutually miscible polymers without any compatibilizer, and demonstrates that these new TPVs can be a good alternative option to replace the traditional thermosetting fluororubbers in the automotive industry as barrier layers for fuel hoses. © 2023 Society of Industrial Chemistry.