Vulcanized Eucommia Rubber‐Tung Oil Composite Modified Epoxy Resin: Achieving Enhanced Flexibility and Corrosion Resistance

ABSTRACT This study is dedicated to developing a novel bio‐based flexible epoxy resin composite to address the issues of brittleness and inadequate corrosion resistance in traditional epoxy resins. First, a vulcanized eucommia rubber‐tung oil composite (S‐ERTO) was prepared. This involved a two‐step process: the Diels–Alder (D–A) reaction followed by vulcanization. Subsequently, different contents of S‐ERTO were introduced into the epoxy resin system to obtain modified epoxy resins. After that, a comprehensive evaluation of the epoxy resins was carried out, with a particular focus on their flexibility and corrosion resistance. The results indicated that once the S‐ERTO was cured with the epoxy resin, a distinctive cross‐linked network structure was formed. This structure endowed the system with enhanced comprehensive properties. Specifically, when the S‐ERTO content was 15%, the flexibility of the modified epoxy resin was remarkably improved. The elongation at break reaching 58.04% served as clear evidence of this improvement. Moreover, the electrochemical impedance of the composite reached 2.69 × 10 12 Ω·cm 2 , and the water contact angle increased from 75° to 110.01°. In the neutral salt‐spray test, the composite also demonstrated excellent corrosion‐resistant performance. In conclusion, the epoxy resin modification strategy based on bio‐based materials proposed in this study offers a new approach for preparing high‐performance, flexible, and corrosion‐resistant epoxy resin composites. It holds broad application prospects in fields such as flexible electronics and marine anti‐corrosion.