Ring-opening copolymerization of hydroxyproline-derived thiolactones and lipoic acid derivatives

Ring-opening copolymerization is an important means to combine the properties of two or more monomers and fine-tune the properties of polymers. The copolymerization of two different types of monomers with full recyclability, however, has been rare. Here, we copolymerized the rigid 4-hydroxyproline-derived thiolactone with various lipoic acid derivatives that have flexible backbones to prepare poly(thioester-co-disulfide) copolymers with tunable thermal and mechanical properties. Owing to the full recyclability of both types of monomers, the resulting copolymers can be completely depolymerized to recycle both monomers in high monomer yields. This work provides a detailed understanding regarding the kinetics and controllability of the copolymerization system of thiolactone and 1,2-dithiolane, which may facilitate the design, modification, and strengthening of new recyclable polymer materials in the future.

Automated summary

Ring-opening copolymerization is an important method to combine the properties of different monomers and adjust polymer properties. However, the copolymerization of two different monomers with full recyclability is rare. In this study, we successfully copolymerized rigid 4-hydroxyproline-derived thiolactone with various lipoic acid derivatives with flexible backbones to prepare poly(thioester-co-disulfide) copolymers with tunable thermal and mechanical properties. The resulting copolymers can be depolymerized to high monomer yields for full recycling. This research provides a detailed understanding of the kinetics and controllability of the thiolactone and 1,2-dithiolane copolymerization system, which may contribute to the design, modification, and strengthening of new recyclable polymer materials in the future.