Toughening and Self‐Healing of Carbon Fiber/Epoxy Composites Interleaved With Meltable/Non‐Meltable Polyamide Nanofiber Veils

ABSTRACT In this study, the effect of interleaved thermoplastic nanofiber veils on the toughening and self‐healing properties of composite laminates was investigated. To achieve this, electrospun meltable and non‐meltable thermoplastic veils and their combinations were introduced into the carbon fiber/epoxy composite laminates and subjected to a series of tests alongside virgin specimens. The results showed that the mode I fracture toughness (G _IC ) of the laminate with interleaved hybrid thermoplastic veils was significantly improved by 85.7%, and the healing efficiency of the laminate under thermal excitation for short beam shear damage and drop hammer impact damage was 91.7% and 36.2%, respectively, which could not be achieved solely by inserting meltable or non‐meltable thermoplastic veils. Furthermore, the addition of low‐melting veils significantly enhanced the compatibility of the thermoplastic nanofibers with the epoxy resin matrix, thus minimizing the negative effect of thermoplastic interleaves on the interlaminar shear strength and flexural strength of the laminates.