New Zinc Dicarboxylate Catalysts for the CO₂/Propylene Oxide Copolymerization Reaction: Activity Enhancement Through Zn(II)‐Ethylsulfinate Initiating Groups

Abstract

Summary: A series of zinc dicarboxylates were synthesized by the reaction of diethylzinc with dicarboxylic acids. Zinc monocarboxylate monoalkyl intermediates were obtained by using a defined excess of diethylzinc over dicarboxylic acid. A subsequent insertion reaction of SO2 into these zinc alkyl bonds resulted in a defined number of Zn‐ethylsulfinate groups, which act as active centers for the copolymerization reaction of CO2 and propylene oxide. Corresponding ethylsulfinic acid ester end groups were detected in the poly(propylene carbonate) (PPC) products. The polymerization activity depended strongly on the number of sulfinate groups incorporated and has been significantly increased compared to conventional zinc dicarboxylates. The obtained PPCs have molecular weights ($\overline M _{\rm w}$) exceeding 80 000 g · mol−1 and polydispersities in the range of 2.3 to 3.3.

Atomic Layer Deposition of Zinc Glutarate Thin Films

“…Polymerization : Copolymerization studies were performed according to a method adapted from previous literature . 2 mL of propylene oxide, solvent, and the oven‐dried catalyst were loaded into a 100 mL oven‐dried steel autoclave equipped with a magnetic stirrer.…”

Dinuclear Metal Complex-Mediated Formation of CO2-Based Polycarbonates

“…This species was easily prepared by reaction between zinc oxide and glutaric acid, although several other synthetic methods are also possible [30,32,115,116]. It can also be formed as either a crystalline or amorphous material, with the crystalline structures showing higher activity (~300 g PPC/g Zn) and producing polymers with high molecular weight [117].…”

Syntheses, Crystal Structure, and Properties of Cu(II) and Zn(II) Complexes with 1, 4-phenylenediacetate and 2, 2′-bipyridine

“…The TG-DTG curves of [Zn 2 (PDA) (2, 2 -bpy) 2 Cl 2 ] are shown in Figure 9, which exhibits two decomposition stages. The TGA indicate that the complex loses 67.8% of total weight in the 172-318 • C temperature range (DTG max = 284 • C), corresponding to the removal of two 2, 2 -bipyridine molecules and a PDA ligand (calcd.…”