A comparison of the cationic ring-opening polymerizations of 3-oxetanol and glycidol

The technologically important polymers poly(3-oxetanol) and polyglycidol (sometimes referred to as polyglycerol) were both synthesized in high yield by a one-pot BF3-catalyzed cationic ring-opening polymerization of the respective monomers in dichloromethane at ambient temperature. The polymerization reactions and the resulting polymers were compared. The polymerization of 3-oxetanol was less exothermic than the polymerization of glycidol under identical reaction conditions, because of the lower ring strain in 3-oxetanol than in glycidol, confirmed by semi-empirical calculations. The resulting polymers were similar, i.e., they had similar Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectra, molecular weights, thermal properties and physical characteristics. However, the poly(3-oxetanol) had a higher ratio of secondary to primary alcohols than did polyglycidol.