Structural Order Formation and Analysis of Polymers with Dissimilar Moieties

不同组分，特别是不同尺寸或直径的半结晶聚合物的固态结构和有序形成过程有助于阐明聚合物结构设计的基本原理，因为各自的部分或链段相互妥协以实现各自的便利性。在聚合物液晶的研究中，只关注分子的刚性。不仅分子的刚性，而且分子内尺寸的不同也是调节结构条件的主要因素。在本工作中，用X射线衍射法分析了长链烷基侧链梳状聚合物的结构。这些聚合物通常形成具有交替的主链和侧链区域的层状结构。对于具有柔性主链的聚合物，相邻层之间侧链的交错或互穿扩展了主链线圈，因此受主链柔性和分子构型的控制。对于具有刚性主链的梳状聚合物，只有悬挂的侧链通过倾斜侧链取向和变形其构象来适应主链结构，从而实现集体致密堆积。在导电主链的情况下，π共轭部分之间的位置相互作用可能受层状结构的设计控制。

The solid-state structures and the process of order formation in semicrystalline polymers comprising dissimilar components, especially with different size or diameter, are helpful to clarify the fundamental principles of polymer structure design, since the respective moieties or segments compromise with each other to achieve their individually convenience. In the research of polymeric liquid crystals, only the molecular stiffness has been focused. Not only the molecular stiffness but also the intramolecular size dissimilarity is a primary factor to regulate the structural circumstances.In the present work, structures of comblike polymers with long alkyl side chains were analyzed by X-ray diffraction method. These polymers generally form layered structure with alternation main-chain and side-chain regions. For the polymers with flexible backbone chains, the interdigitation or the interpenetration of the side chains between neighboring layers expand the main-chain coil, and is therefore controled by main-chain flexibility as well as the molecular gemometry. For the comb-like polymers with rigid backbone chains, only the pendant side chains accomodated the main-chain structure by tilting the side-chain orientation and also deforming their conformation to achieve the collective dense packing. In the case of electro-conductive backbone chain, the positional interations between the π-conjugate moieties are possibly controled by the design of the layered structure.