Study on Smectic Liquid Crystalline Structure in Main-Chain Polyester

主链聚酯层列液晶结构的研究

• 批准号: 01550688
• 负责人: WATANABE Junji
• 金额: $ 1.09万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550688/
• 关键词: Thermotropic lqiuid crystal; Polyester; Layer structure; Conformation; Even-odd oscillation; Smectic liquid crystal; 層構造; 光学活性; 強誘電; らせん構造; 高分子液晶; ビベンゾエイト

The thermotropic liquid crystal nature of mainーchain polyesters that can be constructed by an alternative arrangement of the p,p'ーbibenzoate unit as a mesogenic group and the alkanediol as a flexible spacer. The polyesters are designated BB-n where n is the number of methylene units in the diol. This homolog ous series of BB-n (n = 3-9) invariably form smectic mesophases whose isotropization temperatures and entropies exhibit an evenーodd oscillation with the number of intervening methylene units, n. The evenーodd nature of the methylene unit also reflected the thickness of smectic layers, with a larger layer thickness in the even series. Comparing the observed thickness with the calculated ones based on the rotational isomeric state model, we concluded that the evenーodd nature is strongly related to the polymer chain conformations and that the different types of smectic structures can be formed between the two. In even numbered polyesters there is formed a normal smectic A phase in which both axes of the polymer chain and mesogenic group lie perpendicular to the layers. In oddーnumbered ones, in contrast, the smectic structure was found to be a type of smectic C in which the average chain axis of the polymer is perpendicular to the layer, but the mesogenic groups are tilted with respect to the layer normal. Such structural characteristics are also confirmed from the xーray and optical microscopic studies for the oriented smectic phases.

主链聚酯的热致液晶性质可以通过对，对'-联苯甲酸酯单元作为介晶基团和链烷二醇作为柔性间隔基的交替排列来构建，聚酯被指定为 BB-n，其中 n 是BB-n (n = 3-9) 的同系系列总是形成近晶中间相，其各向同性温度和熵随着插入的亚甲基单元的数量 n 表现出奇偶振荡。亚甲基单元的奇偶性质也反映了近晶层的厚度，与观察到的厚度相比，偶数系列中的层厚度更大。根据旋转异构态模型计算的结果，我们得出结论，奇偶性质与聚合物链构象密切相关，并且两者之间可以形成不同类型的近晶结构。在偶数聚酯中，形成正常的近晶A相，其中聚合物链和介晶基团的两个轴都垂直于层，相反，在奇数聚酯中，发现近晶结构是一种近晶C。其中聚合物的平均链轴垂直于层，但介晶基团相对于层法线倾斜，这种结构特征也从x射线和定向近晶相的光学显微镜研究。

项目成果

JUNJI WATANABE and MANABU HAYASHI: "Thermotropic Lequid Crystals of Polyesters Having a Mesogenic Bibenzoate Unit. 1." Macromolecules. 21. 278--280 (1988)

JUNJI WATANABE 和 MANABU HAYASHI：“具有介晶联苯甲酸酯单元的聚酯热致液晶。1。”

"Thermotropic Liquid Crystals of Polyestors Having a Mesogenic p'p'- Bibenzoate Unit.2." Macromolecules. 22. 4083-4088 (1989)

“具有介晶 pp-联苯甲酸酯单元的聚酯的热致液晶。2。”

渡辺 順次: "液晶ー多彩な分子設計と新規機能開発" 高分子. 39. 369-369 (1990)

Junji Watanabe：“液晶 - 多样化分子设计和新功能开发”聚合物 39. 369-369 (1990)

JUNJI WATANABE and MANABU HAYASHI: "Thermotropic liquid crystals of polyesters having a mesogenic Bibenzoate unit. 2." Macromolecules. 22. 4083--4088 (1989)

JUNJI WATANABE 和 MANABU HAYASHI：“具有介晶联苯甲酸酯单元的聚酯热致液晶。2。”

渡辺 順次: "高分子液晶ー高分子効果とその機能化について" 化学工業. 40. 854-860 (1989)

Jun Watanabe：“聚合物液晶 - 关于聚合物效应及其功能化” Kagaku Kogyo。 40. 854-860 (1989)