Electrophoretic Deposition of Chitosan-modified Carbon Fiber to Enhance Hygrothermal and Mechanical Properties of Carbon Fiber/Polyamide 6 Composites

Abstract

The surface of carbon fiber (CF) was modified by the electrophoretic deposition of cationic chitosan (CS), which is expected to enhance the hygrothermal and mechanical properties of carbon fiber/polyamide 6 (CF/PA 6) composites. Carbon fiber in various treatment stages was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The studies demonstrate that the chitosan-modified carbon fiber (CS-CF) increases the surface chemical activity and roughness of carbon fiber, which enhances the chemical bonding and mechanical interlocking of carbon fiber with PA 6. Compared with desized carbon fiber (D-CF), the O/C composition ratio of CS-CF increased from 20.34 % to 50.86 %, and the tensile strength and flexural strength of the CS-CF/PA 6 composites were enhanced by 50.31 % and 43.88 %, respectively. In addition, the hygrothermal properties of CS-CF/PA 6 were also improved. Fracture observation of the composite cross-sections further elucidates the mechanism of interfacial strengthening.