Precision OrganocatalyticSynthesis of Fluoropolyesterswith Enhanced Degradability and Ionic Conductivity

Extensively as fluoropolymers are studied and utilized, the impacts of fluorinated contents on polyesters are highly under-investigated. In this study, 3,3,3-trifluoropropylene oxide (TFPO) shows significantly higher activity than non-fluorinated epoxides in organocatalytic alternating copolymerization with cyclic anhydrides, which allows synthesis of well-defined fluoropolyesters under mild conditions and one-step construction of partly fluorinated tapered block copolyesters. Thermal stability of the fluoropolyesters rivals that of the non-fluorinated counterparts, while degradation by base-catalyzed methanolysis is remarkably accelerated and shown to occur selectively through cleavage of the CF₃-neighboring ester bond to form a single product. Besides, the fluoropolyesters constitute electrolytes with notably higher Li⁺ conductivity (up to 4.5 × 10^–5 S cm^–1 at 30 °C and 4.6 × 10^–4 S cm^–1 at 80 °C) as well as excellent oxidation stability at high voltage (>4.5 V). Therefore, TFPO can be harnessed to set up a special toolkit for refining the synthesis and properties of polyesters.