Development of new graphene/epoxy nanocomposites and study of cure kinetics, thermal and mechanical properties

Abstract

New graphene/polymer nanocomposites were prepared using graphene nanoplatelets (GNPs) and the epoxy system Epilok 60-566/Curamine 32-494. The GNPs were first dispersed into the curamine hardener using bath ultrasonication, followed by the addition of the epoxy resin. The cure kinetics were studied by DSC under non-isothermal and under isothermal conditions. The kinetic parameters of the curing process were determined using the non-isothermal Kissinger and Ozawa-Flynn-Wall models. The degree of curing increased with the addition of GNPs, while the activation energy decreased by 13.7% for the first reaction and by 6.6% for the second as obtained from Kissinger. An increase in thermal stability by the addition of GNPs was identified in the range of 360-580℃ using TGA. In terms of mechanical properties, addition of an optimum amount of 0.5%wt of GNPs in the hardener improved the Young’s Modulus by 37%. Nanoindentation measurements showed 9.4% improvement in hardness at 0.7%wt.