Recyclable and Malleable Epoxy Thermoset Bearing Aromatic Imine Bonds

A method for preparing reprocessable epoxy thermoset is presented. The process is composed of synthesis of a bisphenol monomer bridged by an imine bond, glycidylation of the bisphenol, and cross-linking with a hardener to form thermoset. The resulting epoxy thermoset possesses comparable properties to conventional high-performance thermosets made from bisphenol A. However, when treated by a stimulus like acid, temperature, and/or water, the described thermoset exhibits reprocessability. Degradation and recycling involve hydrolysis and re-formation of imine bonds; reshaping and repairing of the thermoset are realized through imine exchange reactions. All the described processes require no metal catalyst, press heating, or additional monomer, which significantly widens thermoset reprocessing.