Ultra‐Robust and Tough Epoxy Resin Enabled by Pulley Mechanism‐Based Curing Agent for Strong and Reversible Adhesion

Abstract Developing sustainable epoxy‐based adhesives that simultaneously possess high strength and toughness is critically important yet remains challenging. In this work, a “pulley‐structured” curing agent is designed featuring rigid covalent anchors and dynamic B─N coordination sliders. This unique architecture enables efficient energy dissipation while maintaining structural integrity and robustness. The resulting epoxy resin (BO2‐EL1) achieves exceptional mechanical properties, of which the tensile strength and Young's modulus reach 67.78 MPa and 2.08 GPa, respectively, comparable to commercial epoxy materials. The toughness (4.63 MJ m ⁻³ ) of BO2‐EL1 is significantly enhanced by the novel crosslinking structure, highly surpassing traditional rigid epoxy counterparts. A convenient solvent‐free in situ curing way is further realized to fabricate epoxy adhesives with superior adhesion strength (16.74 MPa) and toughness. Dynamic B─O/B─N bonds and hydrogen interactions impart recyclability, reprocessability, and multiple debonding‐rebonding ability of the epoxy adhesive. Moreover, the robust epoxy adhesive demonstrates excellent long‐term environmental stability, which can maintain the adhesion strength higher than 10 MPa even at −196 °C. As a result, the produced epoxy resin with exceptional comprehensive performance offers a strong and sustainable adhesive in practical industrial applications.