Sustainable Diepoxide Monomers for Polyoxazolidinone-Based High-Performance Thermoplastics

Owing to their outstanding mechanical, thermal, and chemical properties, polyoxazolidinones, which are accessible from the reaction of diepoxides and diisocyanates, have recently gained interest as a new class of high-performance thermoplastic materials. However, mainly bisphenol A diglycidyl ether (BADGE) has thus far served as benchmark for the diepoxide part. Herein, ten bisphenol-free diepoxides that are either bio-based or derived from chemical recycling are presented. All these epoxides selectively resulted in linear polyoxazolidinones using methylene diphenyl diisocyanate (MDI) and p-tert-butyl phenyl glycidyl ether as chain regulators. The new polymers were characterized, and the thermal and mechanical properties were compared to the BADGE-based reference polyoxazolidinone. With three of the new diepoxide monomers, polyoxazolidinones with properties matching or surpassing those of BADGE-based polyoxazolidinone were obtained.