Progress on Coupling Modification and Interface Properties of Carbon Fiber in Engineering Materials

ABSTRACT

Carbon fiber serves as an important engineering polymer in aerospace, automotive, sporting goods, and energy applications, featuring exceptional specific strength, high modulus, and superior corrosion resistance. However, the weak interfacial bonding between carbon fiber and the matrices remains a major limitation to the composite performance. To address this issue, various strategies for coupling modification and interface behavior management have been extensively explored. The introduction of coupling agents onto the carbon fiber surface enhances fiber–matrix interfacial adhesion, thereby improving the mechanical strength, thermal stability, and corrosion resistance of the resulting composites. This review systematically summarizes recent advances in coupling agent modification techniques for carbon fibers. It elucidates the mechanisms by which coupling agents strengthen the interfacial bonding between carbon fibers and matrix materials and provides a detailed discussion of various surface modification strategies based on silane, titanate, organic acid, organic amine, and polydopamine coupling agents. Furthermore, the synergistic effects and enhancement mechanisms arising from the combination of coupling agents with surface pretreatment and nanomaterial‐assisted modification are examined. Finally, current challenges and future research directions involving the uniformity of coupling modification, interfacial stability, and long‐term durability are outlined, with a focus on interfacial design and multiscale synergistic regulation for next‐generation high‐performance composites, which aims to provide theoretical guidance for the rational design of high‐performance composite interfaces and offers a methodological foundation for interfacial analysis and performance prediction.