Effect of carbon fiber surface characteristics on the micro-interfacial properties of its reinforced composites

To study the influence of desizing and hygrothermal aging on micro-interface property of composites, interfacial shear strength (IFSS) of carbon fiber T300, T700SC, T800S/epoxy resin monofilament composite before and after desizing and hygrothermal aging were tested by using single fiber fragmentation test (SFFT), and the surface characterization was undertaken by SEM. The results show that IFSS of carbon fibre filament/epoxy composites decreases and birefringence pattern of breakpoints changes from X-shaped to sheath after desizing or hygrothermal aging. After desizing, IFSS of T700SC/epoxy decreases by 70.67%, while that of T300/epoxy decreases by only 6.05%. IFSS of composites with T300 also decreases the least after hygrothermal treatment. Desizing also can accelerate the damage of interface in hygrothermal environment.