Research on electrospinning thermosetting-thermoplastic core-shell nanofiber for rapid self-healing of carbon fiber/epoxy composites

This work fabricated rapid self-healing carbon fiber/epoxy composites based on the thermosetting-thermoplastic core-shell nanofiber to improve the healing efficiency and healing responsiveness of self-healing composites. The core-shell nanofiber was prepared by coaxial electrospinning on the premise that the melting temperature of thermoplastic copolyamide (PA) shell matched the curing temperature of encapsulated epoxy healing agent. Upon interlaminar fracture, the melting PA shell ruptured and released all core at healing temperature. The thermal expansion of PA provided an additional driving force for healing. Therefore, the core-shell acted together as healing agent and rapidly fill the damaged region, realizing the full healing potential. The incorporation of core-shell nanofiber enhanced the bending strength by 16.11%, and the damaged composites achieved 89.96% recovery after healing for 20 min at 130 °C. The delamination surfaces showed the toughening and healing mechanisms of core-shell nanofiber. Moreover, the effect of deposition time on healing efficiency was discussed in detail.