Interfacial chain-growth polymerization enables polypropylene-like and circular polythioglycolide
- Yanchao Wang
- Shilong Wu
- Jinlong Chen
- Chenyang Guo
- Maosheng Li
- Hai Wang
- Quan Chen
- Yongfeng Men
- Xianhong Wang
- Youhua Tao
- Eugene Y.-X. Chen
2025-09-24
Much of research on developing chemically circular alternatives to nondegradable/recycle polyolefins has focused on polyethylene-like materials with cleavable bonds, but it is more challenging to create a circular alternative of matched high-performance properties to isotactic polypropylene ( i PP) that accounts for 40% of polyolefins produced worldwide. Here, we introduce high–molecular-weight poly(thioglycolic acid) (PTGA) that exhibits not only closed-loop recyclability but also i PP-like thermal properties, even superior mechanical and barrier properties, and processability well suited for common processing techniques such as blow molding into bottles. To circumvent long-standing challenges of extensive transthioesterification side reactions in the ring-opening polymerization (ROP) of thioglycolide, which typically yielded only oligomers, we developed the interfacial chain-growth ROP occurring at the interface between the semicrystalline polymer surface and the monomer–organocatalyst solution phase, enabling the synthesis of high–molecular-weight PTGA. Overall, we show that PTGA is a scalable circular polymer that provides i PP-like properties and that the interfacial ROP method solves the challenges in typical solution-phase polymerization.