Self‐healing interface of carbon fiber reinforced composites using a thermally reversible sizing agent

Abstract A thermally reversible sizing agent was prepared by directly mixing the furfurylamine‐modified epoxy resin (FAE) and the maleimide‐functionalized Jeffamine T403 (MAT), and it was used to impart self‐healing ability at interface based on the reversible Diels–Alder reaction for potential application in carbon fiber composites. The surface characteristics of FAE/MAT‐modified carbon fibers were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and dynamic contact angle meter and tensiometer. The initial interfacial shear strength of modified carbon fiber composites and the multiple healings of the interface were investigated via a microbond test. The results demonstrated that the healing efficiency of the continuous and uniform FAE–MAT sizing layer functionalized carbon fiber composites was up to 93.8% for the first healing cycle. Furthermore, it is expected that the interface self‐healing of carbon fiber reinforced composites can be achieved from research laboratory to industrial applications by this strategy.