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

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.