Recyclable and Reprocessable Tung Oil-Based Epoxy Resin with High Mechanical Strength

In recent years, extensive research has been devoted to the synthesis or modification of epoxy resins from biomass-derived feedstocks. However, realizing closed-loop recyclability, using fully renewable raw materials, and preserving key material properties remain open and persistent challenges in epoxy resin development. Herein, we propose a strategy involving the use of biomass-derived tung oil (TO) as the primary raw material and employing dynamic covalent ester-exchange chemistry to prepare a highly mechanically robust, recyclable, and reprocessable tung oil epoxy resin (ECAT-ME) vitrimer. The ECAT-ME vitrimer consists of a covalent adaptable network based on an associative mechanism, exhibiting tensile and compressive strengths of 11.87 and 17.45 MPa, respectively. Following six pulverization–melting–cooling cycles, the material retained tensile and compressive strengths of 6.99 and 8.92 MPa, respectively. This recyclable, high-performance biobased epoxy resin lays the foundation for the sustainable development of functional composites.