Nonisocyanate polyurethanes from six-membered cyclic carbonates: Catalysis and side reactions

We present a detailed investigation of the aminolysis of six-membered cyclic carbonates to form (poly)hydroxyurethanes. Model reactions between hexyl amine and trimethylene carbonate were performed under different conditions where we surveyed the effects of temperature and the presence of catalyst on the rate of reaction. Increased temperatures and the presence of catalyst lead to significant increases in the rate of reaction and overall conversion depending on the structure of the catalyst. Similar observations were also made in model polymerization between a carbonate derivative of di(trimethylolpropane) and diaminopentane. However, the increased rates of reaction and conversion only lead to modest gains in molecular weight. In addition, gelation of the polymerization mixture often occurred as well. Nominal and High resolution mass spectrometry were used to identify side products which formed during the reaction between trimethylene carbonate and hexyl amine which explained the gelation of polymerization mixture and lower than expected molecular weights. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 133, 44941.