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 primary amine reaction and by 6.6 % for the secondary amine reaction with epoxy groups 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.