Investigating the Effect of Curing Activators on the Cure Kinetics of Acrylonitrile-Butadiene Rubber Filled with Graphene Oxide and Reduced Graphene Oxides Nanocomposites

Abstract

For the first time, acrylonitrile-butadiene rubber (NBR)-graphene oxide (GO) and reduced graphene oxide (rGO) composites were prepared without cure activators: zinc oxide/stearic acid (ZnO/SA) and studied. The vulcanization characteristics of the compounds were systematically studied at 160-190°C, with the aid of rheometer and differential scanning calorimetry (DSC) techniques. NBR revealed rapid curing time (t90) with greater cure rate index compared with NBR-GO/rGO composites for the rheometer measurement. This results were in correspondence with the activation energies Ea (kJ/mol) calculated by Ozawa and Kissinger models of vulcanization kinetics. NBR-rGO obtained reduced t90 and Ea (kJ/mol) than NBR-GO, perhaps due to lower oxygenated groups: epoxide (-C-O-C-), carboxyl (-O-C=O), and hydroxyl (-OH) present. Although, the composites delayed in curing, they significantly recorded high tensile properties with high reinforcing factors than NBR. The order of increasing mechanical properties: NBR < NBR-rGO