Communication: Phenoxycarbonyloxymethyl ethylene carbonate 4 was synthesized from glycerol carbonate and phenyl chloroformate. Polyurethanes with pendant hydroxyl groups were obtained from polycondensation reactions of this AA* monomer with diamines. These polymers contain primary as well as secondary hydroxyl groups. The obtained polyurethanes are amorphous materials. The glass transition temperature decreases with increasing number of methylene groups between the urethane groups.
Summary: Poly(amide urethane)s were prepared from ε‐caprolactam, amino alcohols, and diphenyl carbonate or ethylene carbonate in three steps. Polycondensation was performed either with α‐hydroxy‐ω‐O‐phenyl urethanes or with α‐hydroxy‐ω‐O‐hydroxyethyl urethanes; it was found that the reactivity at 90 °C of the first is much higher than that of the latter. For nearly equal reactivity, the temperature for the polycondensation of α‐hydroxy‐ω‐O‐hydroxyethyl urethanes had to be increased from 90 °C to 150 °C. The microstructure of the resulting poly(amide urethane)s differs by the content of urea groups in the polymer chains, which is 5% for poly(amide urethane)s prepared from α‐hydroxy‐ω‐O‐phenyl urethanes and 15% for poly(amide urethane)s prepared from α‐hydroxy‐ω‐O‐hydroxyethyl urethanes. As a consequence, the thermal properties of the poly(amide urethane)s differ slightly.Synthesis of poly(amide urethane)s.magnified imageSynthesis of poly(amide urethane)s.
Cover: Due to thermodynamical reasons, ethylene carbonate (EC) and 1,2-propylene carbonate (PC) are monomers which cannot be homopolymerized to polycarbonates with uniform microstructure. However, copolymerization of EC and PC with tetramethylene urea (TeU) leads to polyurethanes with randomly distributed TeU-EC/TeU-PC units. It was found that the reactivity of PC is significantly lower than that of EC. The properties of the polyurethanes are determined by the ratio of EC to PC which was deduced from 1 H NMR analysis. This isocyanate-free route to polyurethanes is of ecological importance.
Tetramethylene urea (TeU) is successfully copolymerized with γ-butyrolactone (γBL), leading to an alternating poly(amide urethane) with alternating carbonyl-amino-tetramethylene-amino and carbonyl-trimethylene-oxy repeating units (M h n ) 12 600; M h w ) 21 100; M h n ) 1.67) and with a Tm of 196.5 °C and a Tg of 36.4 °C. Small defects in the microstructure of the alternating poly(amide urethane) arise from the formation of TeU-TeU diads. Furthermore, TeU is successfully copolymerized with mixtures of γBL and ethylene carbonate (EC) or 1,2-propylene carbonate (PC). From NMR spectroscopic data of the terpolymers obtained, it is concluded that the reactivity of the five-membered cycles used increases in the following order: EC . PC ≈ γBL. It is possible to increase the content of γBL repeating units in the poly[(TeU-γBL)-stat-(TeU-EC)] or poly[(TeU-γBL)-stat-(TeU-PC)] by increasing the fraction of γBL in the feed. 13 C NMR spectroscopy reveals that TeU-EC or TeU-PC and TeU-γBL units are randomly distributed in the polymer chain. This conclusion is supported by the thermal properties.
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