Catalytic transformation of epoxy resin into dicyclohexane†

Although thermosetting epoxy resins are widely used high performance polymers in industry, chemical conversion of waste epoxy resins into high value products is hampered by their robust structure. Herein, we developed heterogeneous catalysts containing a hydroprocessing catalyst and solid acid for the chemical transformation of glycidyl end-capped poly(bisphenol A-co-epichlorohydrin) into hydrocarbons (mainly dicyclohexane). The yield of propane-2,2-diyldicyclohexane reached 83.6% at 220 °C after 10 h under the action of cooperative catalysis between Pd/C and HZSM-5. It was proved that Pd/C initiated the reaction and the acidic zeolite assisted further degradation into small oxygen-containing molecules. For the conversion of oxygenates into hydrocarbons, the hydrogenation of unsaturated molecules was achieved using Pd/C, and the acidic zeolite dehydrated the hydrogenation products to remove oxygen. Moreover, the anhydride-cured epoxy resin was converted into propane-2,2-diyldicyclohexane in the presence of Pd/C and HZSM-5 after methanolysis. This work demonstrates that the chemical transformation of waste epoxy resin via heterogeneous catalysis is achievable.