Synthesis and Characterization of OH-Terminated Poly(trimethylene carbonate)s by Alcohol-Initiated Ring-Opening Polymerization in Melt Bulk without Using Any Catalyst

Abstract

OH-terminated poly(trimethylene carbonate)s (OH-PTMC) were synthesized by ring-opening polymerization (ROP) of trimethylene carbonate (TMC) in the melt bulk in vacuo at 120 °C using an alcohol such as benzyl alcohol, 1,4-butanediol, ethanol, isopropanol, or tertiary butanol as a respective initiator in the presence or in the absence of acid catalyst (e.g. trifluoroacetic acid (TFA)). The products were characterized by 1H NMR and GPC. Experiments showed that TFA was not indispensable under the polymerization conditions and that the ROP conformed to a pseudoliving polymerization. The molecular weights of products can be predicted based on the monomer conversion and the molar ratio of monomer to initiator practically participating in the polymerization. It was also demonstrated that the alcohol ability to initiate the ROP increased in the following order: ethanol > isopropanol > t-butanol whether using TFA or not. Part of isopropanol or t-butanol did not practically participate in the initiation step and the participating degree further decreased in the absence of TFA catalyst.