SYNTHESIS AND CHARACTERIZATION OF NOVEL CHIRAL SMECTIC C(Sc~*) PHASE SHISH-KEBAB TYPE LIQUID CRYSTALLINE BLOCK COPOLYMERS

A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffraction and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 were in liquid crystal phase at room temperature with low viscosities. The smectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has happened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid crystal block copolymers that form a chiral smectic C(Sc*) phase. The variation of melting and isotropization temperatures with molecular structure was also discussed.

一个含有端基双键的席夫碱型液晶化合物的合成与表征

合成了一个带有端烯基席夫碱型液晶化合物（Ｓｃｈｉｆ＿Ｃ３Ｃ６），通过元素分析、红外光谱、紫外光谱等进行了表征．该化合物的液晶性通过带热台的偏光显微镜进行了表征，初步证明其织态结构为破扇状形态，属于近晶型结构．

手性近晶C相串型液晶共聚物的合成与性能

以对苯二甲酰氯 ,2 ,5 -二 [4 - ((S) - 2 -甲基丁氧基 )苯甲酰氧基 ]对苯二酚和三缩四乙二醇为单体 ,采用低温溶液缩聚的方法 ,合成了一系列新的手性近晶 C相串型液晶共聚物。通过 DSC、偏光显微镜、WAXD和旋光分析等方法 ,发现所有的手性共聚物都有光活性 ,当加热至熔融温度以上时形成近晶 C相。共聚物的熔融温度 (Tm)和各向同性温度 (Ti)随共聚物分子中三缩四乙二醇用量的改变呈规律性变化。

尾链类型对液晶分子近晶相态引入的影响(英文)

研究了分子结构中不同尾链类型对向列相液晶分子液晶相态转变为近晶相的影响。设计合成了两种不同类型的液晶分子,它们的液晶相态采用热台偏光显微镜以及差示扫描量热仪进行研究。结果表明,卤素的引入是使向列相液晶分子相态转变为近晶相的有效方法。