A recyclable and thermo-responsive adhesive based on ethylene glycol diglycidyl ether and aniline, capable of universal and tunable adhesion

.Polymer-based adhesive with recyclability, thermo-responsivity, universal adhesion prepared via facile ring-opening reaction. • Temperature-regulated adhesion/cohesion balance endows polymer-based adhesive with rapid robust adhesion. • Polymer-based adhesive recycled and reused over five times with well-maintained adhesion in air and underwater. Synthetic polymer-based adhesives have attracted tremendous attention due to their excellent performance during adhesion under dry, wet, and underwater conditions. However, the practical development of such adhesives is hindered by the intricate synthesis of tailored polymers, the inherent challenge of balancing strong adhesion with cohesion, and the prevalent issues of long curing times (typically from tens of minutes to days in the absence of external stimuli). Here, a polymer-based adhesive was synthesized through a facile ring-opening reaction between ethylene glycol diglycidyl ether and aniline. The resulting polymer leverages a backbone rich in hydroxyl and phenyl groups. Heating the polymer-based adhesive to 80 °C for 3 min improves its flowability, promoting intimate contact with the substrate. Subsequent cooling to room temperature restores interactions within the adhesive, resulting in strong cohesion. This dynamic mechanism enables the polymer-based adhesive to achieve impressive adhesion strengths of 4.4 MPa in air and 3.5 MPa underwater on stainless steel. Importantly, the polymer-based adhesive can be recycled and reused over five cycles with well-maintained adhesive strength. This work thus provides a novel and feasible design strategy for next-generation reusable adhesives capable of performing in demanding dry and aqueous scenarios. Download: Download high-res image (245KB) Download: Download full-size image