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I. K. Varma 《Journal of Thermal Analysis and Calorimetry》1989,35(4):1065-1066
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Journal of Thermal Analysis and Calorimetry - 相似文献
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Fritz Friedrichs 《Fresenius' Journal of Analytical Chemistry》1912,51(12):760-761
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von Nostitz und Jänkendorf 《Fresenius' Journal of Analytical Chemistry》1907,46(2-3):157-158
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Tim Sluckin 《Liquid crystals》2013,40(10):1259-1260
The synthesis of five new cholesteryl-based monomers (M-1?M-5) and the corresponding smectic comb-like polymers containing cholesteryl groups (P-1?P-5) is presented. The chemical structures were characterised by FT-IR, 1H NMR and elemental analyses. The specific optical rotations were evaluated with a polarimeter. The phase behaviour was investigated by polarising optical microscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. The specific optical rotation values of these monomers and polymers with the same number of phenyl rings and terminal groups were nearly equal; however, they decreased with increasing the aryl numbers in the mesogenic core. The monomers M-1?M-5 showed oily streak and focal conic optical textures, or finger print textures characteristic of the chiral nematic phase. The polymers P-1?P-5 showed the smectic A phase. The melting, clearing, and glass transition temperatures increased, and the mesophase temperature ranges widened with increasing the aryl number in the mesogenic core. However, although the molecular structures of M-4 and M-5 were similar to those of M-3, namely their mesogenic cores contained three phenyl rings, their phase behaviour differed considerably, and T m and T i of M-4 and M-5 were less than those of M-3. In addition, M-4 and M-5 showed a clear glass transition similar to the polymer. Furthermore, the ester linkage bond and aryl arrangement in the mesogenic core also affected the phase behaviour. 相似文献