Regulating Active Sites of <scp>ZnGA</scp> Catalyst for Highly Efficient <scp> CO ₂ </scp> Copolymerization

ABSTRACT Carbon dioxide (CO 2 )‐based copolymers are renewable and biodegradable polymer materials with significant potential. Zinc glutarate (ZnGA) is a commonly used heterogeneous catalyst for its simple preparation, high selectivity, and ability to produce high‐molecular‐weight polymer. However, its catalytic activity is still inferior to that of homogeneous catalysts. Herein, a high‐purity ZnGA catalyst was obtained by using diethylzinc (ZnEt 2 ) as the zinc source. By regulating preparation temperatures and heating rates, ZnGA catalysts with optimal crystallinity and surface area were synthesized, addressing the challenge of low crystallinity of ZnEt 2 ‐based ZnGA in traditional methods. The synthesized catalyst was applied in the alternating copolymerization of propylene oxide (PO) and CO 2 , achieving high‐yield poly(propylene carbonate) (PPC) with a carbonate content exceeding 97%. The molecular weight of PPC reached 160.6–188.4 kg/mol, with the highest yield of 126.5 g PPC /g cat . The resulting PPC exhibited excellent thermal properties, with a high glass transition temperature ( T g ) of 40°C–41°C and a decomposition temperature ( T 5% ) of approximately 250°C. This study provides valuable insights into improving the catalytic performance of ZnEt 2 ‐based ZnGA catalysts and advancing the production of high‐quality CO 2 ‐based copolymers.