writer：Z.F.Li, L.Li, S.Y.Zhang, S.J.Zheng and S. K. Cao,
keywords：T-shaped two-dimensional mesogenic units, Liquid crystal polyester,Synthesis and characterization
source：期刊

A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units were synthesized by melt polycondensation of the diacetates of 2-(4`-alkoxy-phenyl)-hydroquinones with 4,4`-alkylenedioxydibenzoic acid. The polymers were characterized by usin polarized microscopy,DSC and X-ray diffraction.It was relized that all the polymers have nematic thermotropic liquid crystalline characteristics.The melting temperature (T_m) and isotropization temperature (T_i) of the polymers change regularly with varying lengths of the alkoxy side group and the length of the 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.