SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTAL POLYESTERS WITH T-SHAPED TWO-DIMENSIONAL MESOGENIC UNITS(Ⅲ)

作     者：周其凤 

作者机构：Department of Polymer Science and Engineering the College of Chemistry Peking University Beijing 100871 China 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：1999年第17卷第5期

页      面：483-490页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：This work was supported by the National Natural Science Foundation of China 

主　　题：T-shaped two-dimensional mesogenic units Liquid crystal polyester Synthesis and characterization 

摘      要：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 (T_m) and isotropization temperature (T_i) of the polymers changeregularly with varying lengths of the alkoxy side group and the length of the alkylene group in the main chainin company with an even-odd effect. The mesophase temperature range also varies regularly with the polymerstructure. It is shown that the mesophase range has been widened.