Soybean Oil-Based Functional Elastomers with Rapid Stress Relaxation: Enabled by Dual Dynamic Interactions

Abstract Developing functional polymeric materials from renewable and biodegradable biobased feedstocks is attractive for alleviating the crisis of energy shortages and achieving sustainable development. In this study, we report a design of a biobased elastomer from renewable soybean oil and biodegradable poly(ε-caprolactone) (PCL), which enables the construction of polymer network systems integrating multiple functional features. Cross-linked networks formed by incorporating multiple hydrogen bonds and reversible boronic ester bonds could tune the elastomer tensile strength to 11.06 MPa and impart observable self-healing properties. The obtained network was observed to have a relatively low relaxation activation energy of 33.41 ± 0.46 kJ/mol and enable fast stress relaxation. Moreover, benefiting from the cooperative contribution of hydrogen bond reformation and dynamic exchange of boronic ester bonds, the elastomer exhibited dual-responsive reprocessability and room-temperature damping properties. Besides, the semi-crystalline nature of PCL and hydrogen bonds within the system support the outstanding shape memory capability of the elastomer. All in all, this work offers a feasible structural design approach for integrating multiple functions into a single biobased elastomer, which can serve as a promising alternative in potential applications.