“甲壳型”液晶高分子研究进展  

PROGRESS IN THE STUDY OF "MESOGEN-JACKETED LIQUID CRYSTAL POLYMERS

作　　者：周其凤[1] 

机构地区：[1]北京大学化学系,北京100871

出　　处：《中国科学基金》1994年第4期256-261,共6页Bulletin of National Natural Science Foundation of China

基　　金：国家自然科学基金

摘　　要：本文介绍作者的研究组通过刚性棒状液晶基元的腰部与分子主链相接,得到腰接型侧链液晶高分子。在这种高分子中,主链热运动对液晶基元产生的作用力矩较小,即使不在液晶基元与主链间插入柔性链段也能产生液晶相;液晶相以向列相为主;在没有柔性段或柔性段足够短的情况下,刚性液晶基元在主链周围形成一鳞片状外壳(甲壳),并迫使主链采取伸直构象,主链运动自由受限,表现出较高的链刚性,有较大的构象保持长度,并能产生刚性半刚性链液晶高分子特有的条带织构;柔性间隔段越短,液晶基元产生的甲壳效应越强,分子链的伸直程度和刚性越大,液晶相热稳定性也越高。这些结果说明,甲壳型液晶高分子虽然在化学结构上属侧链型液晶高分子,它们的性质却更接近刚性链或半刚性链主链型液晶高分子。Main polymer chains may be connected with rod-like mesogenic units via their waist positions to build a new type of liquid crystal polymers. Because of this waist attachment, thermal motions of the main chain will have less interference in the organization of mesogenic units than it would have if the attachment is at one of the ends as is the case in conventional side-chain type liquid crystal polymers. Flexible spacers usually used in side-chain polymers are thus not as necessary for the formation of a liquid crystal phase of these new polymers, although the presence and nature of spacers do have significance on properties of the polymers and their mesophase. Without or with only short enough spacers the rigid mesogenic units would form a jacket about each main chain which is thus forced to take extended conformation of less motional freedom and becomes more rigid. These 'mesogen-Jacketed liquid crystal polymers', though of the side-chain type, thus would show properties of main- chain type liquid crystal polymers of rigid or semirigid chains. Evidences in support of these ideas have been provided by structural and morphological solution property studies. The progress in the study of 'mesogen- jacketed luquid crystal polymers' is reviewed.

关 键 词：液晶 液晶高聚物 甲壳型 

分 类 号：O753.2[理学—晶体学]