Influence of Graphene Functionalized With Zinc Dimethacrylate on the Mechanical and Thermal Properties of Natural Rubber Nanocomposites

An effective approach is developed to synthesize zinc dimethacrylate functionalized graphene (ZDMA-GE) as reinforcing nanofiller for natural rubber (NR). The morphology and structure of ZDMA-GE were characterized to confirm the exfoliation and functionalization of GE. The as-prepared nanocomposites were investigated by transmission electron microscopy, mechanical analysis, crosslinked network analysis, and the analysis of thermal conductivity. The results demonstrated that there is strong interfacial interaction between GE and rubber matrix due to good dispersion and special two-dimensional structure of GE. The crosslink density of the nanocomposites is greatly improved with the introduction of ZDMA-GE because of the homopolymerization and graft polymerization of ZDMA. It is also noticed that the tensile strength, tear strength, and modulus at 300% elongation of NR nanocomposites with 15 phr ZDMA-GE have been improved by 133, 42, and 174%, respectively. The thermal conductivity of nanocomposites with 40 phr ZDMA-GE is enhanced 1.3 times as that of the pure NR. This remarkable improvement is attributed to the formation of covalent crosslinked network and ionic crosslinked network, good dispersion of GE, and efficient interfacial interaction between GE and NR matrix. This method provides the potential applications of functionalized GE in the polymer composites. (C) 2014 Society of Plastics Engineers