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

Abstract 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.