Rosin-Modified Polyurethane Elastomers with Room-Temperature Self-Healing Ability, High Strength, and Recyclability Based on Oxime Dynamic Bonds

Rosin, with a rigid hydrogenated phenanthrene ring, is a widely available biomass, but its high-value utilization needs to be enhanced. Inspired by sustainable development strategies, the design of polymer elastomers with a room-temperature self-healing capability has been a hot focus topic. However, designing elastomers that combine the conflicting properties of high mechanical performance and room-temperature self-healing is a significant challenge. The hydrogenated phenanthrene ring of rosin provides a superior solution to this problem. In this work, the polyurethane elastomer (BPU-X% AP) based on rosin-hydrogenated phenanthrene ring structure, dynamic oxime, and hydrogen bonding was reported. The BPU-X% AP exhibits high tensile strength (37.8 MPa), and good toughness (126.9 MJ m^–3). Due to the rosin structure that promotes the movement of the elastomer chain segments, the elastomers have fast room-temperature self-healing and recyclability. Benefiting from their excellent mechanical strength and self-healing properties, BPU-X% AP as adhesives exhibits a strong lap shear strength of 5.5 MPa, and they can be used as hot melt binders. Corresponding to the cycling of the elastomer, the adhesive strength of BPU-10% AP remains almost the same after three cycles of adhesion to the iron and aluminum plates. This work provides a viable approach for the preparation of high-performance biomodified polyurethanes.