• Title/Summary/Keyword: x-shaped rigid group

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Synthesis and Properties of Semi-flexible Liquid Crystalline Polyesters with Rigid Lateral Group (강직한 측쇄기를 갖는 반 유연성 액정폴리에스터의 합성 및 성질)

  • Park, Jong-Ryul;Lee, Eung-Jae;Yoon, Doo-Soo;Bang, Moon-Soo;Choi, Jae-Kon
    • Elastomers and Composites
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    • v.48 no.4
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    • pp.306-311
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    • 2013
  • A series of liquid crystalline polyesters containing the 4-chloro benzoate group on the hydroquinone unit of rigid group were synthesized through solution polymerization of 2,5-di(4-chlorobenzoate)hydroquinones and 4,4'-dicarboxy-${\alpha},{\omega}$-diphenoxy alkane. The structure and properties for synthesized polymers were investigated by $^1H$-NMR, FT-IR, DSC, TGA, and POM. As result of investigations, The presence of the methylene group and bulky lateral groups in polymer chain have a great influence on the properties of polymers such as solubilities and thermal transitions. The optical textures of polymers revealed a weak birefringence in the melt and indicated that they form nematic mesophase. All polymers have very narrow mesophase temperature ranges.