Viscoelastic Properties of Carbon/Epoxy Amino-Functionalized Graphene Nanoplatelet Composite

Abstract

A systematic study was conducted on processing and characterizing of the carbon fiber reinforced epoxy polymer (CFRP) composite to enhance its viscoelastic and thermal properties through the integration of an optimized amount of amino-functionalized graphene nanoplatelet (NH2-GNP). Epoxy resin, EPON 828, was modified through the integration of 0.1–0.5 wt% of NH2-GNP as a reinforcing agent. The GNP was infused into the resin using a high intensity ultrasonic processor followed by a three roll milling for better dispersion. Epikure 3223 curing agent was then added to the modified resin and mixed using a high-speed mechanical stirrer. The nanophased epoxy was then used to fabricate CFRP nanocomposites using the compression molding process. Dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA) were performed to analyze viscoelastic and thermal performances of these composites. In all cases, 0.4 wt% GNP-infused epoxy nanocomposite exhibited the best properties. The 0.4 wt% GNP modified carbon fiber/epoxy composites showed 19% and 23% improvement in storage modulus and loss modulus, respectively. Glass transition temperature (Tg) was improved by 16% maximum at 0.4 wt% GNP loading due to better interfacial interaction and effective load transfer between NH2-GNP and epoxy resin. Moreover, there were about 13% and 28% reduction in the coefficient of thermal expansion (CTE) before and after Tg, respectively.