The effect of post-processing of carbon fibers on the mechanical properties of epoxy-based composites

Carbon fibers were surface-treated by acid and a titanate coupling agent to improve the interfacial properties of carbon fiber/epoxy composites. The fibers were characterized by SEM, XPS, and single filament tensile testing. The fiber reinforced epoxy composites from as-received and surface-treated carbon were fabricated by the hot-press molding method. The inter–laminar shear strength (ILSS) of the composites was determined by short beam shear test, and the effects of the fiber surface on the mechanical properties were investigated. From the test results, the strength of the composite specimen made from the carbon fiber treated with the titanate coupling agent increased by 34.0% compared to that of untreated one. This result demonstrates the effectiveness of the titanate coupling agent in improving the compatibility and interfacial bonding between the carbon fiber and epoxy resin.