Degradation of Anhydride-Cured Epoxy Thermosetting Resins Promoted by Two-Phase Water-Ionic Liquid Mixtures

Water and ionic liquids (ILs) are attractive candidates for the chemical recycling of plastic materials. In addition, ILs can enhance the reactivity of nucleophiles in organic synthesis. Herein, we report that a two-phase water-IL mixture prepared using water and trioctylmethylammonium salts, which are water-insoluble phase-transfer catalysts, in the presence of sodium hydroxide can promote the degradation of anhydride-cured epoxy thermosetting resins derived from 2,2-bis(4-glycidyloxyphenyl)propane at 120°C into the corresponding alcohol and dicarboxylic acid. The degradation products can be separated via extraction before quenching. Therefore, the two-phase medium serves as an effective degradation field and allows separating the obtained products while circumventing the need for dissolving the resin and using a specific resin shape. In addition, different decomposition products can be selectively obtained by tuning the reaction temperature.