• Title/Summary/Keyword: 네마틱액정

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Liquid Crystal Polymers (X). Synthesis and Properties of New Thermotropic Main Chain Copolyesters with Either Mixed Polymethylene Spacers or Mixed Mesogenic Units (액정 중합체 (제10보). 혼합폴리에틸렌 격자나 메소젠 단위를 갖고 있는 새로운 주사슬 혼성폴리에스테르의 합성 및 성질)

  • Jung-Il Jin;Robert W. Lenz;S. Antoun
    • Journal of the Korean Chemical Society
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    • v.26 no.3
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    • pp.188-193
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    • 1982

  • Four new thermotropic copolyesters were prepared and their liquid crystal properties were investigated by differential scanning calorimetry and on a hot-stage of a polarizing microscope. Three copolyesters had same mesogenic unit, triad aromatic ester structure, interconnected through a random combination of either odd-even, or odd-odd, or even-even number of methylene groups in the polymethylene flexible spacers. Another random copolyester consisted of mesogenic units of 1 : 1 mixture of central methyl-and bromohydroquinone moieties with two flanking p-oxybenzoate units connected by decamethylene spacer. All of the polyesters formed nematic liquid crystal phase upon melting. The transitions for melting and nematic ${\to}$ isotropic transformations could be reversibly observed by DSC as well as by microscopic study. The thermodynamic properties for their liquid crystal ${\to}$ isotropic phase transitions were discussed in relation to their chemical structures.

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Synthesis and Properties of Liquid Crystal Compounds and Epoxy Resin Based Side Chain Liquid Crystal Polymers II. Linear and Crosslinked Epoxy LC Polymers (방향족 액정동족체 및 Epoxy형 측쇄 액정고분자의 합성 및 성질 II. 선형 및 가교형 측쇄 액정고분자)

  • Ahn, Wonsool;Chang, Jin Gyu;Keum, Chang Dae;Park, Lee Soon
    • Applied Chemistry for Engineering
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    • v.9 no.1
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    • pp.71-75
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    • 1998

  • Liquid crystalline compounds with amine terminal group and related linear and cross-linked liquid crystal polymers with epoxy resin structure were synthesized and characterized to develope matrix materials for polymer dispersed liquid display applications. Both linear and crosslinked side chain type liquid crystal polymers made with aromatic amine mesogens and ethylene glycol diglycidyl ether exhibited nematic texture as shown by polarized optical microscope(POM) and their transition temperatures were determined both by DSC and POM. Liquid crystal polymer samples also showed even-odd effect as the spacer length of aromatic amine mesogens were varied, however, the effect was samller than that of low molecular weight mesogens. Changes of nematic-to-isotropic transition($T_{NI}$) of crosslinked type polymer liquid crystals were also disscussed in relation to the concentration change of crosslinking agent 1,10-diaminodecane.

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