Multi-Functional Organofluoride Catalysts for Polyesters Production and Upcycling Degradation

The production and degradation of polyesters are two crucial processes in polyester materials' life cycle. In this work, multi-functional organocatalysts based on fluorides for both processes are described. Organofluorides were developed as catalysts for ring-opening polymerization of lactide (lactone). Compared with a series of organohalides, organofluoride performed the best catalytic reactivity because of the hydrogen bond interaction between F- and alcohol initiator. The Mn values of polyester products could be up to 72 kg mol-1. With organofluoride catalysts, the ring-opening copolymerization between various anhydrides and epoxides could be established. Furthermore, terpolymerization of anhydride, epoxide, and lactide could be constructed by the self-switchable organofluoride catalyst to yield a block polymer with a strictly controlled polymerization sequence. Organofluorides were also efficient catalysts for upcycling polyester plastic wastes via alcoholysis. Mixed polyester materials could also be hierarchically recycled. Multi-functional organofluoride catalysts were employed for the production of polyesters via either ring-opening polymerization of lactone (lactide) or ring-opening copolymerization between anhydrides and epoxides. Terpolymerization of anhydride, epoxide, and lactide was accomplished. The upcycling of polylactide by alcoholysis could be catalyzed by organofluoride catalysts. Moreover, hierarchical degradation of polyester blend was investigated.image

Automated summary

In this study, multi-functional organocatalysts based on fluorides were used for the production and degradation of polyesters. The organofluoride catalysts showed excellent reactivity due to the hydrogen bond interaction between fluoride (F-) and alcohol initiator. They were effective in producing high molecular weight polyesters and enabling various polymerization reactions. Additionally, the organofluoride catalysts facilitated the upcycling of polyester plastic wastes via alcoholysis. The hierarchical degradation of polyester blend was also investigated.