Construction of Polycarbonates with Pendant Multifunctional Groups via a One-Step CO₂/ Diepoxide Copolymerization Approach

Abstract

A "one-step" strategy has been demonstrated for the tunable synthesis of multifunctional aliphatic polycarbonates (APCs) with ethylene oxide (EO), ethylene carbonate (EC), and cyclohexene oxide (CHO) side groups by the copolymerization of 4vinyl-1-cyclohexene diepoxide with carbon dioxide under an aminotriphenolate iron/PPNBz (PPN = bis(triphenylphosphine)iminium, Bz = benzoate) binary catalyst. By adjusting the PPNBz-toiron complex ratio and incorporating auxiliary solvents, the content of functional side groups can be tuned within the ranges of 53−75% for EO, 18−47% for EC, and <1−7% for CHO. The yield and molecular weight distribution of the resulting multifunctional APCs are affected by the viscosity of the polymerization system. The use of tetrahydrofuran as an auxiliary solvent enables the preparation of narrow-distribution polycarbonates at high conversion. This work presents a novel perspective for the preparation of tailorable multifunctional APCs.