Structural Order Formation and Analysis of Polymers with Dissimilar Moieties

由不同组分组成的半晶聚合物的固态结构和有序形成过程，特别是不同尺寸或直径的聚合物，有助于阐明聚合物结构设计的基本原理，因为各自的部分或段相互妥协以实现各自的方便。在聚合物液晶的研究中，只关注分子刚度。分子刚度和分子内大小的差异是调节结构环境的主要因素。本文用x射线衍射法分析了具有长烷基侧链的梳状聚合物的结构。这些聚合物通常形成层状结构，主链和侧链区域交替存在。对于具有柔性主链的聚合物，相邻层间侧链的互指或互穿使主链线圈膨胀，因此受主链柔韧性和分子几何结构的控制。对于具有刚性主链的梳状聚合物，只有垂侧链通过侧链取向的倾斜和构象的变形来容纳主链结构，从而实现集体致密堆积。在导电主链的情况下，π共轭基团之间的位置相互作用可能由层状结构的设计来控制。

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.