Synthesis and cationic ring-opening polymerization of oxetane monomer containing five-membered cyclic carbonate moiety via highly chemoselective addition of CO2

The bicyclic amidinium iodide effectively catalyzed the reaction of carbon dioxide and the epoxy-containing oxetane under ordinary pressure and mild conditions with high chemoselectivity to give the corresponding oxetane monomer containing five-membered cyclic carbonate quantitatively. The cationic ring-opening polymerization of the obtained monomer by boron trifluoride diethyl ether proceeded to give linear polyoxetane bearing five-membered cyclic carbonate pendant group in high yield. The molecular weight of the polyoxetane was higher than that of polyepoxide obtained by the cationic ring-opening polymerization of epoxide monomer containing five-membered cyclic carbonate. The cyclic carbonate functional crosslinked polyoxetanes were also synthesized by the cationic ring-opening copolymerization of cyclic carbonate having oxetane and commercially available bisoxetane monomers. Analyses of the resulting polyoxetanes were performed by proton nuclear magnetic resonance, size exclusion chromatography, thermogravimetric analysis, and differential scanning calorimetry. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019