Synthesis and Characterization of Novel Liquid-Crystalline Polyurethanes

Synthesis and Characterization of Novel Liquid-Crystalline Polyurethanes

Novel polyurethanes have been synthesized by the condensation of two rigid diols, biphenyl-4,4'-diol (BPH(4,4')D) and 4-hydroxyphenyl-4-hydroxybenzoate (4HPH4'HB), with the flexible hexamethylene diisocyanate (HDI). Their phase diagrams were established by means of differential scanni...

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Veröffentlicht in:Liquid crystals 1993-02, Vol.13 (2), p.295-300
Hauptverfasser: Cidade, M T, Bordado, J C M, Martins, A F, Figueirinhas, J
Format: Artikel
Sprache:eng
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Zusammenfassung:Novel polyurethanes have been synthesized by the condensation of two rigid diols, biphenyl-4,4'-diol (BPH(4,4')D) and 4-hydroxyphenyl-4-hydroxybenzoate (4HPH4'HB), with the flexible hexamethylene diisocyanate (HDI). Their phase diagrams were established by means of differential scanning calorimetry, nuclear magnetic resonance, and polarizing optical microscopy. Poly(4HPH4'HB/HDI) was found to display a nematic phase from 140-199 deg C; poly (BPH(4,4')D/HDI) also exhibits a mesomorphic phase, but so far the nature of this phase has not been established.
ISSN:0267-8292
DOI:10.1080/02678299308026302