Intramolecular Cooperation and Exchange Driven Ring-Opening Polymerization toward Functionalized Polyhydroxyalkanoates with High Ductility and Robust Adhesion

Polyhydroxyalkanoates (PHAs) have emerged as compelling and sustainable alternatives to conventional polymers, distinguished by their inherent biocompatibility and enzymatic degradability. Nevertheless, the chemosynthetic PHAs face constraints in terms of functional versatility and compromised property tunability. Here, we report a bimetallic ligand platform enabling the yttrium-catalyzed stereoselective ring-opening polymerization of various β-lactones, yielding functionalized PHAs with high activity (TOF up to 21,600 h–1) and syndiotacticity (Pr up to 0.94). Mechanistic insights reveal that the intramolecular cooperation and exchange between the yttrium centers with heterochirality eliminate the less active species during chain propagation. In particular, the syndio-enriched poly(4-(phenoxymethyl)-2-propiolactone) overcomes the inherent brittleness of the corresponding defect-free PHAs, while imparting competitive permeability, mechanical and robust adhesion properties compared to commodity polymers, and superior optical transparency to the prospective biobased plastics.