Intrinsic and extrinsic self‐healing fiber‐reinforced polymer composites: A review

Abstract With their high specific modulus, high specific strength and designability, fiber‐reinforced polymer (FRP) composites have replaced or surpassed traditional metallic materials in a wide range of applications. However, the polymer matrix of commonly used FRP composites is usually a thermosetting polymer that is difficult to rework once formed, which implants a substantial challenge for the repair and recycling of composites. Self‐repair, as an emerging method of repairing polymer‐based materials, has the advantages of simplification, high efficiency and repeatability against traditional repair methods. Research on self‐healing polymer materials is developing rapidly and becoming more systematic. With the development of self‐healing polymer, polymer‐based composites with self‐healing capabilities are becoming possible. This paper reviews the current development of self‐healing polymers in recent years, with specific emphasis on their applications in FRP composites. According to the difference in healing mechanisms, the self‐healing polymer composites are split into two categories, intrinsic and extrinsic ones. The essential concepts and different types of intrinsic and extrinsic self‐healing composites are first introduced. Then, their pros and cons are discussed, respectively. Finally, the perspectives of intrinsic as well as extrinsic self‐healing FRP composites are put forward. Highlights Development of self‐healing fiber‐reinforced polymer composites. Extrinsic and intrinsic self‐healing fiber‐reinforced polymer composites. Pros and cons of self‐healing fiber‐reinforced polymer composites. Perspectives of self‐healing fiber‐reinforced polymer composites.