Epoxy resin with exchangeable diselenide crosslinks to obtain reprocessable, repairable and recyclable fiber-reinforced thermoset composites

Abstract

The cross-linked structure of thermosetting carbon fiber composites makes it difficult to degrade and recycle, especially the non-destructive recovery and recycling of high value-added carbon fiber is a major challenge for the sustainable development of carbon fiber composites. The high-efficiency degradation of chemical health and the high performance of materials are mutually restricted and difficult to balance. We report a epoxy resin networks, prepared through ring-opening reaction of epoxy resin with diselenide-labeled diaromatic amine, that can be turned into catalyst-free vitrimer material by exchange of diselenide bonds. When the diselenide bonds are introduced, specific relaxation times and activation energy of the vitrimer have been measured. Based on the dynamic diselenide bonds, this new vitrimer materials can be reprocessed and repaired upon heating via swift metathesis reactions. In addition, the diselenide crosslinks thermoset materials, which have high modulus and high glass transition temperature, exhibit considerable reprocessability, recyclability and reparability. Furthermore, recyclable carbon fiber reinforced composites (CFRC) are prepared using dynamic diselenide covalent network materials as binders.