Robust Dynamic Epoxy Adhesives with High Environmental Tolerance Enabled by the Coordination of Small-Molecule Coupling Agents with Boroxine
Haixun Zheng, Song Chen, Yubing Fu, Xinyu Chen, Guoping Zhang, Lan Liu
Abstract
Developing dynamic epoxy adhesives (DEAs) with simultaneously strong adhesion, extreme environmental tolerance, and on-demand detachability is in high demand in the future but remains challenging. In this work, we prepared a robust and dynamic epoxy adhesive cross-linked with boroxines, and a small-molecule coupling agent was introduced to coordinate with boroxines to improve its environmental reliability. Owing to the high exchangeability of boroxines and the coordination of amino group with boroxines, the as-developed adhesive shows simultaneously good mechanical properties (tensile strength of 53.55 MPa, fracture toughness of ∼27.3 MJ m –3 ), excellent lap shear strength (20.5 MPa), good resistance to water (18.8 MPa after soaking in water for 30 days), pH, and high and low temperatures (20.1 MPa at 100 °C, 27.8 MPa at −196 °C), and can be quickly removed and recycled by soaking in specified solvents.