Fully Erasable Amphibious Adhesives Derived from Soybean Oil with Record‐High Underwater Adhesion Strength

Abstract Developing amphibious adhesives that combine high adhesion strength with on‐demand erasability in both dry and wet environments remains a significant challenge. In this study, biomass‐derived, amphibious, and erasable adhesives are fabricated by grafting 3‐aminobenzoic acid and 3‐aminobenzeneboronic acid onto epoxidized soybean oil (ESO), yielding ESO‐Am adhesives. These adhesives are dynamically cross‐linked with boroxines, hydrogen bonds, and hydrogen‐bonded hydrophobic nanodomains. ESO‐Am adhesives exhibit strong and durable adhesion to a wide range of substrates under dry conditions, with adhesion strengths comparable to those of commercial counterparts. Remarkably, they also demonstrate exceptional underwater adhesion without the need for post‐curing, achieving an adhesion strength of 5.2 MPa on iron, surpassing previously reported underwater adhesives. This outstanding performance is attributed to the synergistic effect of dynamic boroxine linkages and hydrogen‐bonded hydrophobic nanodomains, which enhance both cohesive strength and interfacial interactions. Importantly, the dynamic cross‐links allow for complete and on‐demand removal of the adhesive by simple ethanol rinsing. In addition, ESO‐Am adhesives are biocompatible, degradable in soil, and reusable, retaining 96% of their original adhesion strength after ten cycles of reuse. The combination of strong amphibious adhesion, full erasability, biodegradability, and reusability makes ESO‐Am adhesives highly promising for a wide range of sustainable and advanced applications.