An Efficiently Reworkable Thermosetting Adhesive Based on Photoreversible [4+4] Cycloaddition Reaction of Epoxy‐Based Prepolymer with Four Anthracene End Groups

Abstract

AbstractThe solid–liquid phase transition is always the key to the design and preparation of reworkable adhesives. However, an efficient photoinduced reworkable thermosetting adhesive at room temperature remains a challenge. Here, a photoinduced reworkable thermosetting adhesive of epoxy‐based prepolymer with four anthracene end groups are prepared. The highly active light‐induced [4+4] cycloaddition and depolymerization, as well as a large number anthracene groups endow this adhesive with high optical activity. Soft segments of polyether amines are used to adjust glass transition temperature of these cross‐linked networks which is significant for highly efficient solid–liquid phase transition of photoinduced reworkable adhesive at room temperature. As a reworkable adhesive, the obtained AER/D2000 exhibits desirable viscosity, lap shear strength up to 2.4 MPa for quartz glass substrate in the cross‐linked state, and ideal reworkable efficiency as high as 91.7%. Therefore, this research provides a strategy for a photoinduced reworkable adhesive, and as an alternative for heat‐induced reworkable adhesives.