Carbonylative Polymerization of Epoxides Mediated by Tri-metallic Complexes: A Dual Catalysis Strategy for Synthesis of Biodegradable Polyhydroxyalkanoates

Polyhydroxyalkanoates (PHAs) are a unique class of commercially manufactured biodegradable polyesters with properties suitable for partially substituting petroleum-based plastics. However, high costs and low volumes of production have restricted their application as commodity materials. In this study, tri-metallic complexes were developed for carbonylative polymerization of epoxides via a dual catalysis strategy, affording 17 products of novel PHAs with up to 38.2 kg/mol M n values. The polymerization proceeds in a sequential fashion, which entails the carbonylative ring expansion of epoxide to β -lactone and its subsequent ring-opening polymerization that occurs selectively at the O- alkyl bond via carboxylate species. The wide availability and structural diversity of epoxide monomers provide PHAs with various structures, excellent functionalities, and tunable properties. This study represents a rare example of the preparation of PHAs using epoxides and carbon monoxide as raw materials.

Dual-site catalysis for sustainable polymers to replace current commodity polymers – carbonylative copolymerization of ethylene, ethylene oxide, and tetrahydrofuran

Thermoplastic elastomers and plastics have been produced via nickel-catalyzed COP of cyclic ethers, ethylene, and CO using a one-pot procedure.