Tensile properties of graphene nanoplatelets/epoxy composites fabricated by various dispersion techniques

Abstract

This study investigates the tensile behavior of ductile and brittle epoxy polymers reinforced by graphene nanoplatelets (GNPs) dispersed by various methodologies. Dispersion of GNPs into the epoxy matrix using sonication or sonication in combination with high shear mixing was investigated. Also, the effectiveness of the dispersion of GNPs into epoxy resin or hardener was assessed. Then, the effect of GNP concentration on the tensile properties of GNP/epoxy composites fabricated by three selected dispersion techniques was explored. A large number of specimens were tested under uniaxial tensile loading and the results were analyzed in terms of tensile strength, fracture elongation, and tensile modulus. Finally, scanning electron microscopy imaging was used to assess the fractured surface of the selected specimens. Results indicate that the addition of GNPs into brittle epoxy does not provide significant improvements in tensile properties. On the other hand, up to 41% increase in tensile strength and 19% increase in tensile modulus were observed for ductile epoxy with 1 wt% GNPs. However, the addition of GNPs into either brittle or ductile epoxy reduces the fracture elongation of the developed composites.