Triethylborane-Assisted Synthesis of Random and Block Poly(ester-carbonate)s through One-Pot Terpolymerization of Epoxides, CO₂, and Cyclic Anhydrides

Poly(ester-carbonate) copolymers were synthesized through triethylborane (TEB)-activated, one-pot copolymerization of epoxides with anhydrides (AH) and CO₂. Depending upon the feeding ratio AH to epoxides, poly(ester-carbonate) random tapered ester structures could be derived due much higher reactivity toward growing oxanions compared Anhydrides like succinic anhydride (SA) phthalic (PA) when tried in terpolymerization propylene oxide (PO) cyclohexene (CHO), CO₂ indeed exhibited such high reactivities comparison that block eventually obtained for ratios PO AH-to-epoxide lower than 10%. Terpolymerization different was thus systematically investigated. In an alternate path, diblock poly(ester-b-carbonate)s prepared by sequential epoxide/anhydride epoxide/CO₂. All characterized ¹H nuclear magnetic resonance (NMR), diffusion-ordered spectroscopy (DOSY), gel permeation chromatography (GPC), differential scanning calorimetry (DSC). The properties terpolymerizations copolymerizations compared.