Reaction Mechanism Analysis of Photo-retarded Curing Epoxy Adhesives and Their Application to Easy Dismantling

Abstract

We report two topics on photo-retarded epoxy resin–based adhesives using photo-cationic polymerization.The first topic describes the polymerization mechanism of a photo-retarded curing epoxy system, which was analyzed by tracing protons generated from a photoacid generator using 1H-NMR spectroscopy. In particular, we focused on the behavior of crown ethers employed as curing retarders, especially their ability to capture protons.The second topic addresses a material contributing to a sustainable society. We demonstrate that a cationically polymerized epoxy resin can be converted into a dismantlable adhesive through thermal treatment. Upon heating, molecular chains are cleaved, resulting in reduced molecular weight and consequently decreased adhesive strength.We propose an integrated process ranging from bonding to debonding by a series of technologies.