The effects of graphene nanoplatelets and microcrystalline cellulose on the mechanical properties of fiberglass and carbon fiber composites

This study investigated how graphene nanoplatelets (GNP) and microcrystalline cellulose (MCC) affect the mechanical properties of epoxy (EP), carbon fiber (CF), and fiberglass (FG) composites. The tensile and flexural properties of GNP-EP and MCC-EP of varying reinforcement concentrations were examined. Results indicated significant improvements on tensile and flexural properties by GNP and MCC. At 0.1 wt% GNP, tensile and flexural strengths increased by 10% and 21%, while 2.0 wt% improved flexural modulus by 65%. Similarly, 2.0 wt% MCC improved tensile strength, modulus, and flexural modulus by 11%, 11%, and 46%, respectively, and a 26% increase in flexural strength at 1.0 wt%. These concentrations were used to reinforce CF and FG composites. For CF composites, GNP effectively enhanced mechanical properties due to good dispersion and strong interface formation, resulting in a 14% increase in tensile strength and a 32% increase in modulus with 0.1 wt% GNP, while 2.0 wt% improved flexural strength by 36%. However, MCC showed a lesser impact, enhancing tensile modulus by 37% at 2.0 wt% but negatively affecting flexural performance, likely due to property mismatches. In FG composites, both additives had negative impacts, with only minimal improvements in flexural properties at specific concentrations, likely due to materials incompatibility.