Role of vinyl thiethoxy silane grafted onto fluororubber in compatibilization of fluororubber and silicone rubber blends

Abstract

The blends of fluororubber (FKM) and silicone rubber (MVQ) were prepared by the incorporation of fumed silica using vinyl thiethoxy silane (VTEO) grafted onto FKM (FKM- g-VTEO) as a compatibilizer. The effect of the compatibilizer loading on the curing characteristics, mechanical properties, heat aging properties and oil resistance was investigated. Dynamic mechanical analysis indicates that FKM- g-VTEO acts as a compatibilizer in the FKM/MVQ blends. The tensile properties and oil resistance of FKM/MVQ blends increase with the increasing loading of FKM- g-VTEO up to 9 phr and the heat aging properties increase with the addition of the compatibilizer up to 6 phr. The fracture surfaces of tensile samples were observed by scanning electron microscopy (SEM). SEM of the tensile fracture surface of the blends and rubber–filler interaction studies shows that the presence of FKM- g-VTEO enhances the interfacial interaction of fumed silica and rubber matrix.