Preparation and properties of acrylonitrile-butadiene rubber-graphene nanocomposites

Abstract

The graphene oxide (GO) was prepared by sonication-induced exfoliation from graphite oxide, which was produced by oxidation from graphite flakes with a modified Hummer's method. The GO was then treated by hydrazine to obtain reduced graphene oxide (rGO). On the basis of the characterization results, the GO was successfully reduced to rGO. Acrylonitrile-butadiene rubber (NBR)-GO and NBR-rGO composites were prepared via a solution-mixing method, and their various physical properties were investigated. The NBR-rGO nanocomposite demonstrated a higher curing efficiency and a change in torque compared to the gum and NBR-GO compounds. This agreed well with the crosslinking density measured by swelling. The results manifested in the high hardness (Shore A) and high tensile modulus of the NBR-rGO compounds. For instance, the tensile modulus at a 0.1-phr rGO loading greatly increased above 83, 114, and 116% at strain levels of 50, 100, and 200%, respectively, compared to the 0.1-phr GO loaded sample. The observed enhancement was highly attributed to a homogeneous dispersion of rGO within the NBR matrix; this was confirmed by scanning electron microscopy and transmission electron microscopy analysis. However, in view of the high ultimate tensile strength, the NBR-GO compounds exhibited an advantage; this was presumably due to strong hydrogen bonding or polar-polar interactions between the NBR and GO sheets. This interfacial interaction between GO and NBR was supported by the marginal increase in the glass-transition temperatures of the NBR compounds containing fillers.