- Synthesis and polymerization of liquid crystals containing vinyl and mercapto groups
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Liquid-crystalline monomers containing two vinyl groups, two mercapto groups, or a 1:1 combination of the two have been synthesized and characterized in terms of their mesomorphic properties. These monomers can be photopolymerized in situ in an appropriate ratio of vinyl and mercapto groups to form highly ordered liquid-crystalline main-chain polymers. During polymerization in the nematic phase the appearance changes from clear in the highly aligned bire-fringent state to opaque. This effect is probably due to scattering which is caused by the disturbance of the macro alignment as a result of the polymerization shrinkage and/or phase separation. In some cases, the reaction mixtures pass from the nematic to the crystalline state which results in a reduction in the degree of conversion and also in a change in the microcrystalline state. Crystallization can be suppressed by promoting asymmetry of the molecular structure which leads to a higher degree of conversion. Wiley-VCH Verlag GmbH, 1997.
- Lub, Johan,Broer, Dirk Jan,Van Den Brock, Nel
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- Synthesis and characterization of block copolymers of polystyrene and thermotropic liquid crystalline polyesters
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A series of block copolymers containing a thermotropic liquid crystalline polymer and an amorphous polystyrene have been synthesized. The block copolymers were prepared by solution polycondensation of α,ω-dicarboxylic acid-terminated polystyrene with 4,4′-dicarboxy-1,6-diphenoxy-hexane and 4,4′-bis(2-hydroxyalkyloxy)biphenyls in a mixture of triphenylphosphine, hexachloroethane, and pyridine. The obtained polymers were fractionated to isolate the pure block copolymer. The block copolymers were characterized by FTIR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, optical polarizing microscopy measurement. Optical polarizing microscopy measurements verify the presence of a smectic liquid crystalline phase for the block copolymers. The block copolymers represent a microphase-separated morphology, i.e., both amorphous and liquid crystalline properties were displayed by the polystyrene and liquid crystalline polyester segments respectively.
- Chen, Cheng-Chih,Lin, Chih-Hung
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p. 125 - 133
(2018/03/21)
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- Bent-core dimesogenic compound and method for preparing thereof
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The present invention refers to nuclear - manufacturing method relates to compounds and their [...] Image frame adjustment equipment of vehicles for farming, more specifically 5 has-substituted benzene two, the substituted with fluorine-substituted benzen
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Paragraph 0102-0104
(2017/04/28)
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- Synthesis and Thermotropic Properties of Twin Mesogens Containing a Polymethylene Spacer
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DSC and microscopic data are presented for a thermotropic twin mesogen series.Deviations from normal trends were observed.
- Aguilera, C.,Ahmad, S.,Bartulin, J.,Mueller, H. J.
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p. 277 - 282
(2007/10/02)
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