Novel epoxy/cyclic olefin copolymer/carbon structural composites with electro-activated self-healing properties

Multifunctional self-healing composites have great potential in several applications, i.e., from automotive to aerospace. This study examines the self-healing behavior of carbon fiber reinforced composites by depositing jet-spun cyclic olefin copolymer (COC) meshes on dry carbon fiber plies before lamination with epoxy resin (EP). Three different laminates were prepared, including neat EP/CF and two composites with 4 wt.% and 8 wt.% of COC in the form of a jet-spun network as a healing agent. The introduction of COC mesh reduced flexural stress by 26% and interlaminar shear strength by 50%. Mode I interlaminar fracture toughness (G(I)) was evaluated and specimens were mended at 110? by resistive heating generated by an electrical current flowing within the samples. The laminates containing 8 wt% COC reported a healing efficiency, evaluated as the ratio between the G(I) and as the ratio of the maximum load (P-MAX) of virgin and healed samples, of 9.4% and 33.7%, respectively. Fractography analysis highlighted the poor adhesion between the COC mesh and EP matrix, and several COC microfibers were trapped inside the epoxy matrix, hindering their diffusion inside the crack zone, which limited the healing capability of the prepared laminates.