Preparation and Characterization of Side-Chain Liquid-Crystalline Polyoxetanes Anchoring a Pendant Spacer-Separated Mesogen at the Tertiary-Like C-3 Carbon of the Oxetane Unit
作者:Hiroshi Ogawa、Yasutake Kodera、Shigeyoshi Kanoh、Akihiko Ueyama、Masatoshi Motoi
DOI:10.1246/bcsj.71.433
日期:1998.2
Polyoxetanes anchoring a pendant spacer-separated mesogen at the tertiary-like C-3 carbon of the oxetane unit were prepared by cationic ring-opening polymerization of the corresponding oxetane derivatives. The resulting polymers were liquid-crystalline substances showing textures assignable to the nematic or smectic mesophase over a wide temperature range from about 260 °C to room temperature. These mesogens also behaved in the manner similar to that of the mesogens in the analogous polyoxetanes attached by a methyl side chain at the quaternary C-3 carbon, although the less bulky polymer backbone in the present work indicated a somewhat higher isotropic phase-transition temperature than that of the methyl-substituted analogs. In both types of the polyoxetanes, their mesophase patterns were influenced by the core structure and alkoxy tail length in the pendant mesogen, but not by the bulkiness of the second side chains, H and CH3, attached at the C-3 carbon of the polyoxetane unit.
通过阳离子开环聚合相应的氧杂环丁烷衍生物,制备了在氧杂环丁烷单元的叔碳C-3上锚定由间隔的悬浮剂分离的中介物的聚氧杂环丁烷。所得聚合物是液晶物质,在约260℃到室温的宽温度范围内,其纹理可归因于向列或层状中相。这些中介物也表现出与在季碳C-3上通过甲基侧链连接的类似聚氧杂环丁烷中的中介物相似的行为,尽管本研究中不太笨重的聚合物骨架表明其各向同性相变温度比甲基取代的类似物高一些。在这两种类型的聚氧杂环丁烷中,其中相模式受核心结构和悬垂中介物中的烷氧基尾长的影响,但不受在聚氧杂环丁烷单元的C-3上连接的第二个侧链H和CH3的笨重程度的影响。