Thickness effect on the tensile and dynamic mechanical properties of graphene nanoplatelets-reinforced polymer nanocomposites

Abstract

The thickness effect of graphene nanoplatelets (GNPs) on the morphology, tensile and dynamic mechanical properties of GNPs/PMMA nanocomposites has been studied. Two types of GNPs, G5 (5 nm thick) and G100 (100 nm thick), were incorporated into a poly-methyl methacrylate (PMMA) matrix, each with four weight percentages: 0.1, 0.5, 1.0 and 5.0%. After measured by tensile test and dynamic mechanical analysis, the thinner G5 was found to improve more significantly the reinforcement of nanocomposites than G100. At 5.0 wt%, the Young’s modulus of G5/PMMA was 53.6% greater than that of the pure PMMA as compared to a 26.1% increase for G100/PMMA; the ultimate tensile strength of G5/PMMA was enhanced by 25.5% compared to 3.1% for G100/PMMA; the storage modulus of G5/PMMA was improved by 84.3% compared to 54.1% for G100/PMMA. The fracture toughness of both nanocomposites improved greatly at 0.1 wt%: a 47.9% improvement for G5/PMMA compared with pure PMMA and 20.8% for G100/PMMA, and maintained at the same level up to 1.0 wt%. The advantage of G5 over G100 in terms of tensile and dynamic mechanical properties enhancement was caused by its thinness, to be related to its high specific surface area.