Ethanol-Promoted Efficient Alcohol-Aminolysis of Poly(bisphenol A carbonate)

Poly(bisphenol A carbonate) (PC) is a widely used engineering plastic that is often disposed of by landfilling or incineration, resulting in severe environmental concerns. Alcohol-aminolysis with ethanolamine can convert PC waste back into its monomer bisphenol A (BPA) and the valuable product 2-oxazolidinone. However, the use of hazardous solvents complicates both the recovery of PC and the synthesis and separation of 2-oxazolidinone. Herein, we developed a sustainable alcohol-aminolysis strategy utilizing the eco-friendly solvent ethanol (EtOH), achieving yields of 93% BPA and 88% 2-oxazolidinone from compact discs in 4 h at 80 °C. Multilinear regression revealed that elevated Kamlet–Taft parameters (β, π*) correlate strongly with enhanced PC alcohol-aminolysis efficiency for most solvents. Conversely, in monohydric alcohols, reactivity exhibits minimal dependence on β- and π*-values but is primarily governed by their steric hindrance. Mechanistic investigation reveals that EtOH enhances the nucleophilicity of ethanolamine, enabling nucleophilic attack on the activated carbonyl group of PC while facilitating cyclization of the intermediate. In gram-scale experiments, we recovered 8.64 g of BPA and 2.96 g of 2-oxazolidinone from 10.16 g of PC using simple filtration and evaporation. Economic assessments show that our innovative process presents a sustainable and economically viable method for upcycling waste polymers into valuable products, eliminating the need for hazardous solvents, harsh conditions, and complex purifications, thereby highlighting its potential for industrial applications.