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

Epoxy resins (EPs) are important thermosetting plastics and difficult to recycle because of their stable cross-linked structure. In this study, we report a strategy of selectively breaking the C(sp3)-O bonds using commercially available low-cost Lewis acid (LA) and reconstructing the broken C(sp3)-N bonds with NaOH to high-efficiently and fully recycle EPs waste into high-value platform chemicals firstly, that is bisphenol A (BPA) and 4,4'-methylenebis (N, N'-diglycidylaniline) (AG80). 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%. Due to its versatility, simplicity of operation, mild reaction conditions, and recyclability of all solvents and byproducts, this approach shows the potential in solving the current recycling challenges associated with EP waste.