Zn­(HMDS)2 as a simple, biocompatible, efficient, and supporting ligand-free metal catalyst has been achieved for polyesters synthesis and degradation. The catalyst not only has a powerful capacity for ring-opening polymerization of various lactones to obtain diverse sustainable polyesters, such as poly­(lactide), poly­(3-hydroxybutyrate), and poly­(caprolactone), etc., with controlled molecular weights and narrow molecular weight distributions, but also can be used to degrade polyesters into valuable depolymerization products with excellent yields and chemoselectivity, demonstrating a truly circular materials economy approach to sustainability.

No abstract

Plastics recycling has become an important issue based on the principle of sustainability and circular economy. Therefore, the development of a valuable chemical recycling method, to achieve the recycling process of end-of-life polylactide (PLA) waste without loss of material properties, meets unprecedented opportunities. In this regard, we propose a “DE–RE polymerization” strategy to achieve the recycling process from end-of-life PLA plastic waste to new virgin-quality PLA materials in a “polymer to polymer” mode. This approach improves the efficiency of PLA recycling and promotes the development of plastics reutilization.