Interfacial self-healing performance of carbon fiber/epoxy based on postsynthetic modification of metal-organic frameworks

The interfacial self-healing of fiber/matrix materials is an efficient strategy for extend the service life of composites. Here, we constructed the interfacial self-healing carbon fiber/epoxy composites system based on Diels-Alder reaction. Metal-organic frameworks (MOF) after postsynthetic modification (PSM), i.e., UiO-66-maleimide (UiO-66-M) is not only in-situ grafted on carbon fiber (CF) surface, but also used as nanofillers to disperse epoxy resin to fabricate UiO-66-M/epoxy nanocomposites. After growth MOF, the surface energy of CF enhanced from 38.34 to 58.90 mN m−1, the IFSS and ILSS increased by 39.43% and 16.62%, respectively. UiO-66-M rigid structure plays a key role for strengthening the mechanical interlocking. The interface between UiO-66-M-CF and UiO-66-M-EP can be healed three times and the best self-healing efficiency was 90.60%. In addition, UiO-66-M-EP resin can be reprocessed due to the Diels-Alder bonds.