Robust and Recyclable Mussel-Inspired Supramolecular Adhesives Enabled by an In Situ Thermoplasticized Cellulose Ester System

Developing sustainable adhesives to replace petroleum-based glues is critical, yet bio-based alternatives are often limited by processing difficulties and an inherent adhesion–cohesion trade-off. To address these challenges, a mussel-inspired cellulose ester supramolecular adhesive (CSA) was prepared through solvent-free thermoplastic processing. Regulation of the hydrogen-bonding network within the cellulose acetate butyrate matrix enabled hot-press processing and facilitated the incorporation of catechol-containing adhesion sites and dynamic metal coordination. The resulting supramolecular network, governed by multiple hydrogen-bonding interactions and dynamic Fe3+–catechol coordination, balanced interfacial adhesion, bulk cohesion, and energy dissipation, yielding a lap-shear strength of 9.43 MPa on Fe substrates. The adhesive maintained effective bonding over a broad temperature range from –196 to 60 °C and exhibited a certain degree of water resistance. Benefiting from the reversible reorganization of its supramolecular interactions, the adhesive retained more than 80% of its initial adhesion strength after four thermal reprocessing cycles. This work provides a practical strategy for developing high-performance, solvent-free, and recyclable bio-based adhesives through multiple hydrogen-bonding interactions and dynamic coordination.