Nano-sulfur decorated graphene oxide to improve the mechanical properties of natural rubber by interfacial participate in the vulcanization reaction

Abstract

As a new material with excellent comprehensive properties, graphene is an excellent reinforcing agent for natural rubber (NR). However, how to improve the interface performance between graphene and NR, and at the same time be practical, is still a great challenge. In this study, nano-sulfur decorated graphene oxide materials (GO-S) were prepared by in-situ loading nano-sulfur on the surface of graphene oxide (GO). Nano-surface cross-link with NR in the vulcanization process, acts as a bridge to anchor GO and NR molecular chains and improve the interface bonding strength of GO and NR. The AFM results show that the interfacial phase thickness of NR-GO-S composites increased from 135 ± 18 nm to 245 ± 28 nm after in-situ loading modification. The tensile strength and tear property of NR-GO-S composites modified by sulfur loading reach 30.3 MPa and 40.0 kN⋅m−1, respectively, which are 31.1 % and 12.8 % higher than those of NR-GO composite. Nano-sulfur form O–S and C–S covalent bonds with GO, and form more efficient covalent crosslinking networks with NR molecules in the vulcanization process, thus improving the interfacial compatibility between GO and NR and making the load transfer in rubber matrix more effective. This work provides a new idea and method to improve the interface property between rubber and inorganic nanomaterials.