Improved tensile and fracture toughness properties of graphene nanoplatelets filled epoxy polymer via solvent compounding shear milling method

Abstract

This paper investigates the effect of graphene nanoplatelets (GNP) on tensile and fracture toughness properties of an epoxy polymer. The GNP filled epoxy nanocomposites were prepared using a combination technique of solution compounding and high-shear milling with three different GNP loadings; 0.1 wt%, 0.2 wt% and 0.3 wt%. The polymer nanocomposites were characterized based on their fracture toughness and tensile properties. In order to evaluate these properties, three points bending and uniaxial tension tests were conducted on single-edge-notch bending (SENB) and dog-bone shape specimens, respectively. It was found that a significant improvement in fracture toughness and tensile properties was obtained without reducing the failure strain values when GNP was added into the epoxy polymer. The addition of 0.3 wt% GNP improved the critical stress intensity factor, critical strain energy release rate and tensile modulus of the epoxy polymer about 64%, 268 J m−2 and 32%, respectively. This can be concluded that the incorporation of GNP increased the fracture toughness as well as the mechanical properties provided a proper fabrication method was implemented. It is also demonstrated that GNP is capable to provide effective toughening mechanisms in epoxy resin as indicated by the SEM micrographs.