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

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)1183-1193
Number of pages11
JournalEuropean Polymer Journal
Volume36
Issue number6
DOIs
Publication statusPublished - 2000

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Synthesis and mesomorphism of thermotropic liquid crystalline polyurethanes based on meta-diisocyanates with 4,4′-bis(ω-hydroxyalkoxy) biphenyls'. Together they form a unique fingerprint.

Cite this