Detachable, Self-Repairing, and Closed-Loop Recyclable Self-Initiated Light-Curing Adhesives with Controllable Bonding Strength

Light-curing adhesives (LCAs) play an indispensable role in the field of electronic packaging due to their rapid polymerization response under illumination. However, conventional LCAs typically lack detachability and self-healing capability and often encounter challenges related to closed-loop recyclability and bonding strength adjustability. Herein, a self-photosensitive atoxic prepolymer is developed by the simple esterification of natural lipoic acid (TA) with polycaprolactone diol (PCL), enabling complete light-curing within 2 min without additional photoinitiators. The disulfide bond in the prepolymer can endow the green adhesives with detachability (heating at 120 °C for 16 s), dual-stimuli-responsive self-repairing properties (UV radiation for 10 min or heating at 60 °C for 3 h), and efficient closed-loop recycling performance. Moreover, the crystallization behavior of PCL contributes to the versatile adhesives with controllable bonding strength after photocuring, along with a maximum adhesion strength of 5.1 MPa (cured adhesive for 20 min of crystallization). This novel strategy grants the LCA versatility, which opens up an original way for designing electronic packaging adhesives with higher practical value.