Synthesis and mesomorphism of thermotropic liquid crystalline polyurethanes based on meta-diisocyanates with 4,4′-bis(ω-hydroxyalkoxy) biphenyls

研究成果: Article同行評審

17 引文 斯高帕斯(Scopus)

摘要

There are two series of novel thermotropic liquid crystalline polyurethanes (LCPUs), obtained from the polyaddition reaction of 4,4′-bis(ω-hydroxyalkoxy) biphenyls (HBn, n: the number of methylene units in hydroxyalkoxy group) with 1,3-bis(isocyanatomethyl) benzene (XDI) and 1,3-bis(isocyanatomethyl) cyclohexane (H6XDI), respectively. The Fourier transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, polarizing optical microscope and thermogravimetric analysis were used for characterizing these polyurethanes. All of the liquid crystalline polyurethanes exhibited enantiotropism. Except that XDI/HB11 showed trimorphism, all the other polyurethanes presented monomorphism in this study. The H-bonded urethane domain is stronger when the polyurethanes are composed of the benzene ring urethane moiety and longer alkoxy chain, and they show a higher transition temperature associated with the better stability in mesophase. All the thermal degradation of LCPUs are higher than 330°C. The polyurethanes of H6XDI/HB2 and XDI/HB2 show one-step degradation, while the others show two-step degradation.

原文English
頁(從 - 到)1183-1193
頁數11
期刊European Polymer Journal
36
發行號6
DOIs
出版狀態Published - 2000

All Science Journal Classification (ASJC) codes

  • 物理與天文學 (全部)
  • 有機化學
  • 聚合物和塑料
  • 材料化學

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