Enhanced mechanical and gas barrier properties of rubber nanocomposites with surface functionalized graphene oxide at low content

In the present work, we report for the first time the use of surface functionalized graphene oxide (SGO) with bis(triethoxysilylpropyl)tetrasulfide (BTESPT) as a multi-functional nanofiller for natural rubber (NR). Through a facile approach BTESPT molecules are successfully grafted onto the surface of graphene oxide. The resulting SGO can be finely dispersed in NR via solution mixing. It is found that SGO is prominent in improving the mechanical and gas barrier properties of NR at significantly low filler loading. The percolation point of SGO in the nanocomposites takes place at a content of less than 0.1 wt%. With incorporation of as low as 0.3 wt% of SGO, a 100% increase in the tensile strength, a 66% improvement in the tensile modulus and a 48% reduction in the air permeability are achieved without sacrificing the ultimate strain. This remarkable improvement in the mechanical and gas barrier properties of NR nanocomposites at such low filler loading is attributed to the strong interfacial interaction and the molecular-level dispersion of SGO in the NR matrix.