Interface Strengthening of Carbon Fiber/Epoxy Resin Composites via Chemical Grafting: Mechanisms and Applications

ABSTRACT The interfacial properties of carbon fiber‐reinforced epoxy resin composites (CFRP) are critical to their macroscopic mechanical performance and service reliability. This review focuses on chemical grafting as the core technique for CFRP interfacial modification. It first analyzes the intrinsic issues of the CFRP interface (e.g., internal stress, uneven wetting, brittleness) and outlines multi‐scale innovative characterization technologies enabling interfacial property quantification and mechanism investigation. The key emphasis is on constructing functional interfacial transition layers via chemical grafting of organic molecules or nanoparticles onto carbon fibers (CF), which enhances CF‐epoxy compatibility through chemical bonding, mechanical interlocking, and stress buffering—significantly improving interfacial shear strength (IFSS) and interlaminar shear strength (ILSS). Further, the review elaborates on interfacial bonding, strengthening, and failure mechanisms, clarifying how chemical grafting optimizes load transfer efficiency and induces failure mode transformation from “interfacial debonding” to “matrix cohesive failure,” thereby suppressing interfacial failure. Finally, future research directions are prospected, focusing on fiber‐resin synergistic modification, multi‐technique combination, and interfacial design for industrial production and harsh service environments, aiming to promote CFRP's wide application in high‐end equipment.