Side-Chain Liquid-Crystalline Polyoxetanes with a Spacer-Separated Azobenzene Moiety. II. Preparation and Characterization of Polyoxetanes Derived from 4-(4-Alkoxyphenylazo)phenyl 4-[7-(3-Methyl-3-oxetanyl)-1,6-dioxaheptyl]benzoates
作者:Hiroshi Ogawa、Tetsuya Hosomi、Toshiaki Kosaka、Shigeyoshi Kanoh、Akihiko Ueyama、Masatoshi Motoi
DOI:10.1246/bcsj.70.175
日期:1997.1
A series of polyoxetanes were prepared by the cationic ring-opening polymerization of 4-(4-alkoxyphenylazo)phenyl 4-[7-(3-methyl-3-oxetanyl)-1,6-dioxaheptyl]benzoates using 0.08 molar amount of THF·BF3 in dichloromethane at 20 to 30 °C. Although the product polymers indicated GPC-average molecular weights of around 9000 to 23000, in most cases, they did not have an unimodal molecular weight dispersity. The liquid-crystalline mesophases of the polymers were examined by differential scanning calorimetry and polarized optical microscopy; these textures were observed due to nematic and/or smectic mesophases over a wide temperature range from about 250 °C to room temperature. The benzoate moiety, the longer p-substituted alkoxy tails, and the oxetane main chain play important roles in maintaining highly ordered, stable mesophases.
在 20 至 30 °C 的二氯甲烷中,使用 0.08 摩尔量的 THF-BF3,通过阳离子开环聚合 4-(4-烷氧基苯基偶氮)苯基 4-[7-(3-甲基-3-氧杂环丁基)-1,6-二氧杂庚基]苯甲酸酯,制备了一系列聚氧杂环丁烷。尽管产品聚合物的 GPC 平均分子量约为 9000 到 23000,但在大多数情况下,它们并不具有单峰分子量分散性。聚合物的液晶介相通过差示扫描量热法和偏振光学显微镜进行了检测;在从约 250 °C 到室温的较宽温度范围内,均可观察到由于向列型和/或胶粘型介相而产生的纹理。苯甲酸酯分子、较长的对取代烷氧基尾端和氧杂环丁烷主链在维持高度有序、稳定的介相方面发挥了重要作用。