An eco-friendly adhesive with ultra-strong adhesive performance†

With the increasing global attention on energy and environmental issues, there is a growing push towards the eco-friendly transformation of adhesive materials. However, designing and developing eco-friendly adhesive materials with ultra-strong adhesion has always been a significant challenge in the field of adhesion. Herein, we present an eco-friendly adhesive (CBA) derived from bio-based thioctic acid (TA) that combines synergistic covalent and dynamic covalent polymeric segments, demonstrating strong adhesive strength and closed-loop recyclability. Specifically, leveraging the synergistic effects of dynamic covalent and covalent chain segments within the polymer network, the adhesive CBA exhibits ultra-strong adhesive strength (16.1 MPa), exceptional antifreeze performance (11.6 MPa at −196 °C), high reusability with 12.1 MPa retained after ten cycles, and resistance to common organic solvents. Importantly, the main chains of disulfide bonds formed through the solid-phase thermal-induced ring-opening polymerization of TA, combined with robust reversible amide bonds to crosslink into a network, enable closed-loop recyclability. This approach of using bio-based materials with synergistic dynamic covalent and covalent bonds effectively balances adhesive strength with environmental sustainability, offering an excellent solution for designing and developing new adhesive materials.