Effect of surface treatment on enhancing interfacial strength of carbon fiber/polyimide composites

The practical application of carbon fiber (CF)-reinforced polyimide (PI) resin composite was hampered seriously by the poor interfacial adhesion property. In this work, a novel surface treatment agent was designed and prepared to improve the interfacial strength by covalently bonding CF with PI matrix, which is beneficial to the uniform dispersion and impregnation of PI between CF, thereby improving the mechanical properties of CF/PI composites to some extent. The CF was characterized by high surface roughness, which means better wettability by PI. As a result, the interfacial shear strength and interlaminar shear strength of CF/PI composites were enhanced, benefited mainly from the strong and tough interphase.