Reassembled Adhesives Based on Epoxidized Soybean Oil with Dynamic Diels-Alder Bonds: Synthesis, Properties, and Self-Healing Performance

In summary, this study focused on the design and synthesis of a novel adhesive based on epoxidized soybean oil (ESO) with incorporated dynamic covalent bonds (Diels-Alder bonds) for reassembly ability. The synthesis route of ESO-furfuryl (ESOF) was successfully demonstrated, and the chemical structures were confirmed using various characterization techniques. The resulting adhesive films, ESOF-Ix, exhibited excellent solvent resistance and mechanical properties, which could be adjusted by varying the amount of cross-linker (bismaleimide). For instance, ESOF-I1.0 exhibited a higher stress at break (18.45 MPa) compared to ESOF-I0.6 (10.19 MPa). The incorporation of Diels-Alder bonds endowed the adhesive with self-healing capability, as observed from the gradual reduction of surface cracks upon heating. Furthermore, the adhesive demonstrated the ability to undergo recycling without significant changes in properties. The adhesives also exhibited hydrophilicity and low viscosity during the reassembly process, facilitating their practical application. Overall, this study provides valuable insights into the design and synthesis of reassembled adhesives with improved properties, which have great potential in the field of bonding.