新型手性近晶C相液晶共聚酯的设计与合成

DESIGN AND SYNTHESIS OF NOVEL LIQUID CRYSTALLINE COPOLYESTERS WITH CHIRAL SMECTIC C PHASE

以对苯二甲酰氯 ,2 ,5 二 [4 ((s) 2 甲基丁氧基 )苯甲酰氧基 ]对苯二酚和乙二醇、一缩乙二醇、二缩三乙二醇、三缩四乙二醇和聚乙二醇为单体 ,采用低温溶液缩聚方法 ,合成了一系列新的手性近晶C相串型液晶共聚酯 .共聚酯通过GPC、DSC、TG、WAXD、偏光显微镜和旋光仪等方法表征 .发现所有的共聚酯加热至各自的熔点以上都能形成液晶态 ,在液晶态可以观察到近晶相的焦锥织构 ,所有的手性化合物和共聚酯都有较高的旋光性 .通过变温X 射线衍射研究结合偏光显微镜观察和旋光分析证明它们为手性近晶C相 .所有共聚酯的熔融温度 (Tm)和各向同性温度 (Ti)随共聚酯中不同柔性链段长度的增加逐渐降低 。

A series of novel Shish-Kebab type liquid crystalline copolyesters with chiral smectic C phase was synthesized by low temperature solution polycondensation with terephthaloyl chloride, 2,5-bis[4-((s)-2-methylbutoxy) benzoyloxy] hydroqunone, ethylene glycol, diglycol, triethylene glycol, tetraethylene glycol and. polyethylene glycol as the monomers. The copolyester's were characterized by GPC, DSC, TG, WAXD, polarizing macroscope(POM) with a heating stage and rotational analysis instrument. It was found that the copolyesters entered into liquid crystal phase when heated to above their melting temperature. The focal-conic texture was observed. All the chiral compounds and copolyesters showed high optical activity. Temperature-variable X-ray diffraction study together with the POM and polarimetric analysis revealed that the copolyesters synthesized exhibited a chiral smectic C phase. Both T-m and T-i of all the copolyesters decreased with the increase of the length of polyethylene glycol flexible spacers in copolyesters, while the temperature range of the liquid crystal phase of the copolyesters became wider.