Synergistic Dual-Dynamic Covalent Bonds Enable Robust, Harsh Environment-Resistance, and Structure Evolution Self-Monitoring Polyurethane Adhesives

High adhesive strength and reversible rapid bonding are a long-lasting trade-off in polyurethane adhesives; integrating these advantages remains a key challenge for developing next-generation polyurethane adhesives. Additionally, performance limitations in complex environments and the inability to monitor structural changes in the curing process persist as unresolved issues. Here, a dual-dynamic crosslinking polyurethane adhesive that combines thermally responsive oxime-carbamate bonds and Diels-Alder reactions are presented to achieve both strong reversible adhesion and environmental tolerance. The synergistic effect of dual dynamic bonds yields remarkable adhesive strength under ambient (11.51 MPa) and ultra-low temperature (−196 °C, 9.57 MPa) conditions, with adhesive strength 1.46-fold enhanced in the aqueous environment over 45 days. Through real-time monitoring of electrical property evolution during the curing process, the structural transformations responsible for the adhesive's enhanced performance characteristics are elucidated. This work establishes a robust framework for designing high-performance reversible polyurethane adhesives.