Interfacial adhesion between carbon fibers and nylon 6: Effect of fiber surface chemistry and grafting of nano-SiO2

Abstract In this study, the effect of carbon fiber (CF) surface chemistry and grafting of nano-SiO 2 on CF surface with respect to the interfacial adhesion of CF-reinforced nylon 6 composites was investigated. CFs were oxidized and reacted with poly(oxypropylene) diamines to modify the surface chemistry. The oxidized CFs were modified with 3-aminopropyltriethoxysilane and then grafted with SiO 2 nanoparticles. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microcopy (SEM), and atomic force microscopy (AFM) were used to characterize the chemistry and topographies of the CF surface. The transverse fiber bundle strength of CF oxidized and grafted nano-SiO 2 increased to 31.92 MPa and 39.35 MPa, respectively, from 12.57 MPa for untreated CF. The results indicated that the reaction between the carboxyl group and nylon 6 led to chemical bonding at the interface and it meanwhile was strengthened and toughened by uniformly distributed SiO 2 nanoparticles on the CF surface.