Effectof epoxy functionalized elastomer modified carbon fiber on mechanical properties and interfacial adhesion of chloroprene rubber (CR)/natural rubber (NR) composites

Abstract The carbon fibers were oxidized with concentrated hydrochloric acid, and subsequently modified in two steps. First, the oxidized carbon fibers were grafted with γ‐aminopropyltriethoxysilane (KH550) with the purpose of building a platform on the fiber surface, then the epoxy functionalized elastomer (ethylene‐vinyl acetate‐glycidyl methacrylate terpolymer, EVMG) was grafted on the carbon fiber surface. Chloroprene rubber/natural rubber/carbon fiber (CR/NR/CF) composites were prepared by mechanical blending process. Carbon fibers were characterized by different techniques such as X‐ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The results show that EVMG can enhance the interface adhesion between fiber and rubber. It was observed that the surface of the carbon fiber is covered with a layer of the macromolecular film by EVMG, which increases the surface roughness and introduces epoxy groups. On the one hand, carbon fiber and rubber can be entangled through macromolecular chains, and on the other hand, interfacial bonding can be enhanced by chemical interactions. Furthermore, modification by EVMG impacted tensile strength of CF composite increase by 11.05%, the 300% constant tensile stress increased by 21.87%, and the wear resistance increased by 29.8%, respectively.