Poly(glycidyl Methacrylate) Grafted to Carbon Fiber Surface by RAFT Polymerization for Enhancing Interface Adhesion and Mechanical Properties of Carbon Fiber/Epoxy Composites

In this study, we present a novel approach to graft a large number of poly(glycidyl methacrylate) (PGMA) chains onto the carbon fiber (CF) surface through reversible addition-fragmentation chain transfer (RAFT) polymerization. Characterization results of FT-IR, XPS and TGA demonstrated that PGMA was covalently combined with carbon fibers. The CF/epoxy composites were obtained by addition of pristine CF and CF functionalized with poly(glycidyl methacrylate) (CF-PGMA) into epoxy resin. Experiment results revealed that the grafting of PGMA chains on the CF surface could increase significantly roughness and number of active groups of CF, which enhanced interface and mechanical properties of the composites. The compression strength, tensile strength, flexural strength and interfacial shear strength (IFSS) of CF-PGMA/epoxy composites are enhanced by at least 63.1%, 37.9% 55.6% and 122.5%, respectively, compared to pristine carbon fiber/epoxy composites. This enhancement indicates that surface modification of the carbon fibers by RAFT technique is a potential method to preparing CF-reinforced polymer matrix composites with excellent mechanical properties.