Enhanced gas barrier properties of graphene oxide/rubber composites with strong interfaces constructed by graphene oxide and sulfur

摘要

Constructing strong interfacial interactions and complex filler networks is crucial to establishing high gas barrier properties in rubber composites. In this research, sulfur-graphene oxide (S-GO) hybrids were prepared by in situ growth of sulfur on the surfaces of GO sheets. The S-GO hybrids were also introduced into butadiene styrene rubber (SBR) using a green method of latex compounding. Results showed that sulfur could melt and spread on the surface of the GO during the crosslinking process at high temperatures. This process prevented the aggregation of GO and resulted in a fine dispersion of GO and complex filler networks in S-GO/SBR composites. More importantly, the sulfur particles on the GO surface not only aided the crosslinking of rubber molecules, but also chemically reacted with the GO radicals generated at high temperatures. This occurred by the homolytic cleavage of oxygen-containing groups, which thereby constructed covalent interfaces between the GO and SBR molecules. Due to these strong interfaces and complex filler networks, the tensile and tear strength of S-GO/SBR composites increased by 66.2% and 26.6%, respectively, when compared with conventional GO/SBR composites. The gas permeability coefficient of S-GO/SBR composites was decreased dramatically by 50.7% and 23.3% by comparison with that of pure SBR and GO/SBR composites, respectively. The apparent improvement demonstrated that the facile and effective method used in this research may open up new opportunities for the development of multifunctional rubber crosslinking agent as well as the fabrication of rubber composites with high performance.