How to Easily Depolymerize Polyurethane Foam Wastes by Superbase Catalysts in Ionic Liquids Below 100 °C

Angew Chem Int Ed Engl. 2024 Dec 23:e202418034. doi: 10.1002/anie.202418034. Online ahead of print.

Abstract

This study introduces a novel and sustainable approach using Ionic Liquids (ILs) as a non-innocent solvent that enhances the performance of the basic catalysts to depolymerize polyurethane foam wastes (PUFWs) through hydrolysis, alcoholysis or aminolysis under mild conditions. The system is stable, fully recoverable, and reusable. Hydrolysis of PUFWs can occur in just 2 minutes at 95-98 °C, producing a white polyol that is easily separated and reused in new polyurethane synthesis. The method was successfully scaled up to depolymerize 200 g of PUFW per batch (1 kg overall depolymerization system). This scalability, combined with the medium's reusability without loss of effectiveness, highlights its strong potential for industrial applications.

Keywords: Polyurethane foam wastes * Ionic Liquid * Hydrolysis * Depolymerization * Superbase catalyst.