In situ fabrication of graphene oxide supported nano silica for the preparation of rubber composites with high mechanical strength and thermal conductivity

Graphene oxide (GO) supported nano silica (SiO₂), SiO₂‐GO, was synthesized via in situ hydrolysis and condensation of tetraethylorthosilicate (TEOS) on GO surface. It was proved that SiO₂ nanoparticles with an average particle diameter of ca. 30 nm were covalently grafted through Si—O—C bonds and evenly distributed on the surface of GO sheets. Subsequently, SiO₂—GO was incorporated into styrene‐butadiene rubber (SBR) latex to prepare elastomer composite (SBR/SiO₂‐GO). As expected, because of the unique architecture of SiO₂‐GO, the irreversible agglomeration of SiO₂ or GO was eliminated and the nanohybrid was uniformly dispersed in the rubber composites. In addition, the interfacial interaction between SiO₂‐GO and rubber was also significantly improved. Consequently, SBR/SiO₂‐GO composites showed much higher mechanical strength than SBR composites containing equal amount of GO or physical mixture of SiO₂/GO. For example, when the filler content is 6 phr, the tensile strength of SBR/SiO₂‐GO composites is further increased by 21% and 94% compared to those of SBR/GO and SBR/SiO₂/GO composites, respectively. Moreover, SiO₂‐GO nano hybrid can also endow rubber composites with better thermal conductivity than the physical mixture of SiO₂ and GO. Potentially, this unique hybrid architecture synthesized in this work may provide a new method for the preparation of high‐performance elastomer composites. POLYM. COMPOS., 40:E1633–E1641, 2019. © 2018 Society of Plastics Engineers