An Integrative Chemical Recycling Approach for Catalytic Oxidation of Epoxy Resin and in-situ Separation of Degraded Products.

Abstract

Although many approaches have been proposed to recycling waste epoxy resin (EP), the separation of mixed degraded products remains a challenge due to their similar structures. To address this, we present a catalytic oxidation strategy that enables mild degradation of EP and in-situ separation of degraded products through supramolecular interactions. The oxidative degradation relies on FeIV=O radicals with strong oxidizing properties, which are generated from the electron transfer of FeCl2 with reaction reagents. As the FeIV=O radicals attacked the C-N bonds of EP, EP was broken into fragments rich in active functional groups. Meanwhile, the FeIV=O radicals were reduced to iron ions that can coordinate with the carboxyl groups on the fragments. As a result, the degraded products with different carboxyl content can be effortlessly separated into liquid and solid phase by coordinating with the catalyst. The success of this work lays the foundation for high-value application of degraded products and provides new design ideas for recycling waste plastics with complex compositions.