以ET为柔性间隔基的嵌段热致液晶共聚酯的合成及表征

SYNTHESIS AND CHARACTERIZATION OF THERMOTROPIC LIQUID CRYSTALLINE BLOCK COPOLYESTER CONTAINING FLEXIBLE ETHYLENE TEREPHTHALATE SEGMENTS

用溶液缩聚法合成了含柔性间隔基的嵌段热致液晶共聚酯。由于在 TCE/ Py溶液中共聚酯溶解度较小及溶液中副反应显著 ,合成的嵌段共聚酯特性粘度都小于 0 .30 d L/ g。 DTA和偏光显微镜对嵌段共聚酯的液晶性和相转变研究结果表明 ,所有嵌段共聚酯都为向列相热致液晶共聚酯。

The thermotropic liquid crystalline block copolyesters with flexible space group in main chain were synthesized via solution polycondensation. Inherent viscosities of the ET block copolymer were always lower than 0.30 dL/g. Formation of low molecular weight ET block copolymer was attributed to:(1)insolubility of the block copolymers in TCE/Py and (2)formation of side products. The block copolymer were characterized by DTA and polarizing optical microscopy. All copolymers exhibited a nematic liquid crystalline texture.