Design of polyether modified ester-based epoxy vitrimer with self-healing and recyclable properties

Epoxy resin is difficult to recycle and degrade due to its permanently crosslinked network structure after complete curing. Therefore, the traditional treatment of epoxy resin waste is landfill or incineration, which not only causes environmental pollution and the waste of resources but also limits its secondary applications. To solve this problem, a repairable and recyclable epoxy vitrimer, composed of bisphenol A glycidyl ether, glutaric anhydride, and carboxy-terminated polyether, was prepared in this work. The polyether-modified epoxy vitrimer showed good mechanical properties with a flexural strength of 69.2 MPa and a fracture toughness of 9.17 MJ/m3. Dynamic ester exchange reactions at elevated temperatures enable the epoxy vitrimer to achieve network rearrangement. As a result, the epoxy vitrimer exhibits excellent self-healing (complete healing of cracks within 5 min), shape memory, and recycling properties (75% retention of flexural strength). Furthermore, the prepared carbon fiber-reinforced vitrimer composites can be degraded by ethylene glycol for effective recycling of carbon fibers. Herein, the fracture toughness and reparability of the epoxy vitrimer were effectively improved by introducing the carboxy-terminated polyether into the crosslinked network, which has practical value for extending service life and reducing energy consumption in its engineering applications.