Grafting Comb-Like Copolymer onto Carbon Fiber by Combination of RAFT and ATRP for Improving Interfacial and Mechanical Properties of Epoxy Composites

A novel strategy based on grafting the comb-like copolymer brushes onto the carbon fiber (CF) surface was presented in this paper to improve the interfacial properties between the CF and epoxy matrix. The comb-like copolymer poly(4-vinylbenzyl chloride)-g-poly(glycidyl methacrylate) (PVBC-g-PGMA) was chemically grafted onto the CF surface by combination of reversible addition-fragmentation chain transfer polymerization (RAFT) and atom transfer radical polymerization (ATRP). FT-IR, TGA, XPS and dynamic contact angles analysis demonstrate that the comb-like copolymer brushes have been successfully grafted onto the CF surface, which can increase the surface energy and wettability of the CF with the matrix. Compressive tests show that the tensile strength, flexural strength and interfacial shear strength (IFSS) of epoxy composites reinforced by CF grafted with PVBC-g-PGMA (CF-PVBC-g-PGMA) have been greatly improved by 39.3%, 51.9% and 143.6%, indicating that the grafting of PVBC-g-PGMA onto the CF surface can effectively enhance the mechanical and interfacial properties of epoxy composites.