A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4
4'-alkylenedioxydibenzoic acid. The polymers were characterized by using polarized microscopy
DSC and X-ray diffraction. It was realized that all the polymers have nematic thermotropic liquid crystallinecharacteristics. The melting temperature (Tm) and isotropization temperature (Ti) of the polymers change regularly with varying lengths of the alkoxy side group and the length of alkylene group in the main chain in company with an even-odd effect.The mesophase temperature range also varies regularly with the polymer structure.It is shown that the mesophase range has been widened.
Abstract
A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4
4'-alkylenedioxydibenzoic acid. The polymers were characterized by using polarized microscopy
DSC and X-ray diffraction. It was realized that all the polymers have nematic thermotropic liquid crystallinecharacteristics. The melting temperature (Tm) and isotropization temperature (Ti) of the polymers change regularly with varying lengths of the alkoxy side group and the length of alkylene group in the main chain in company with an even-odd effect.The mesophase temperature range also varies regularly with the polymer structure.It is shown that the mesophase range has been widened.
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