Design and Fabrication of Recyclable Epoxy Vitrimers From Epoxidized Soybean Oil: Dynamic Ester Networks With Tunable Mechanical Properties and Shape Memory Functionality

ABSTRACT The escalating environmental pollution and the critical depletion of fossil resources have underscored the urgent need for sustainable material innovations. This study pioneers a novel, eco‐friendly strategy to design recyclable epoxy vitrimers endowed with shape memory functionality by synergistically integrating epoxidized soybean oil (ESO) with dynamic ester bond chemistry. A groundbreaking multifunctional curing agent (ESOEM) was engineered through sequential epoxy‐amine ring‐opening anhydride modification, thereby establishing a robust cross‐linked network capable of thermally activated transesterification. By modulating the carboxyl/zinc/tertiary amine ratios, we achieved materials with tunable properties, including glass transition temperatures (67.8°C–81.3°C), tensile strength (14.8–42.4 MPa), and elongation at break (5.4%–60.9%). The dynamic network exhibited excellent reprocessability maintaining mechanical integrity over four reprocessing cycles, and demonstrated exceptional solvent resistance. The synergistic catalysis of zinc acetylacetonate and tertiary amine facilitated efficient bond exchange, enhancing the material's dynamic properties. A particularly innovative feature of this system was its rapid (70 s) and complete shape recovery at 60°C, driven by the unique mechanism of stress storage in frozen molecular chains and subsequent thermally triggered stress release via an aliphatic soft‐segment. This research provides a green and sustainable strategy for designing multifunctional and environmentally adaptable thermosets, which can serve as one of the measures to address the end‐of‐life challenges of thermosets.