Full Recovery of Epoxy Resin Wastes into Bisphenol A and Epoxy Monomers via Lewis Acid

Abstract Epoxy resins (EPs) are important thermosetting plastics and difficult to recycle because of their stable cross‐linked structure. In this study, we report a full recovery strategy for the conversion of EPs into high‐value platform compounds, i.e., bisphenol A (BPA) and epoxy monomers such as 4,4′‐methylenebis ( N , N ′‐diglycidylaniline) (AG80), which involves the selective breaking of the C(sp 3 )─O bond using commercially available boron trichloride (BCl 3 ), the reconstruction of the broken C(sp 3 )─N bond and the cyclization of the hydroxy groups. The yield of BPA is 93 wt% with a purity of 99%, and the yield of AG80 is 96 wt% with an epoxy value of 0.43. 100% recovery of EP elements was achieved theoretically, and the actual mass recovery of the EPs is as high as 91%. Because of its versatility, simplicity of operation, mild reaction conditions, and recyclability of all solvents and by‐products, this approach shows the potential in solving the current recycling challenges associated with EP waste.