Biobased Biomimetic Adhesive with Underwater Adhesion, Remolding, Degradation, and Closed-Loop Recycling

Underwater adhesives are in urgent demand and hold broad prospects in fields such as marine engineering, underwater wearable devices, and biomedical applications. However, traditional adhesives face challenges in underwater environments, including the disruption of interfacial hydration layers, difficulties in curing, and insufficient long-term stability. Moreover, most rely on nonrenewable petroleum resources. Inspired by the dual biomimetic strategies of mussels and barnacles, this study developed a biobased linear adhesive through the copolymerization of natural rosin derivatives and thiocitic acid. This material integrates the hydrophobic anchoring mechanism of barnacles and the strong interfacial adhesion and dynamic cross-linking strategy of mussels, demonstrating outstanding mechanical properties, room-temperature self-healing capability, exceptional underwater bonding strength (up to 2.13 MPa), and rapid reversible adhesion. PTRG maintains stable adhesion under various extreme conditions (seawater, saline, and acidic environments) and possesses closed-loop recyclability and controllable degradability, offering new insights for designing sustainable, high-performance underwater adhesives.