Development of super molecular structure during crystallization of rigid rod rod polymers.

刚性聚合物如PBZT、PBZO、PBPZT及其共聚物从稀溶液中结晶，淬火形成纤维状晶体，其中聚合物链平行于纤维。这些原纤维在随后的溶剂中加热处理后变成了烤肉串。等温结晶产生了一组组相同长度的平行棒状晶体，它们看起来像湖上的“木筏”。分子链垂直于棒晶取向。棒状晶体的宽度与平均分子长度密切相关，尤其是在相对分子质量区域。由于分子长度上的分散性，在棒状晶体的边缘以纤毛的形式存在许多定向刚性链。初级核主要由较高分子量组分组成。在木筏组织的早期阶段，生长的棒状晶体(母晶)伴随着碎裂晶体，而碎裂晶体的生长速度比母晶快得多，这是因为母晶提供了定向分子链。生长速度的差异最终使所有的棒状晶体在单独的筏子内变成了相同的长度。测定了成核密度和结晶皱纹速率随温度和相对分子质量的变化，并用X-RAU和高分辨电子显微镜对其晶体结构进行了研究。晶体的晶格像显示了微晶内部的取向起伏和缺陷。等温结晶共聚物的结晶形态取决于共聚物的组成。此外，还讨论了支化刚性聚合物晶体和由共混物结晶而成的混合晶体的形态和结构。

Rigid polymers such as PBZT, PBZO PBPZT and their copolymers were crystallized from dilute solution.Quenching formed fibribrillar crystals in which polymer chains were paralle to the fibril. These fibrils changed into shish-kebabs by subsequent heat treament in the solvent. lsothermal crystallization gave groups of parallel rodlike crystals of the same length, which appeared like "rafts" on a lake. Molecular chains were oriented normal to the rod crystal. The width of the rod-like crystal were closely related to the avarage molecular length, especially in the molecullar weight region. Due to dispersity in molecular length, many oriented rigid chains were present as cilia on the margin of rod crystals. Primary nuclei were mainly composed of higher molecular weight componebt. At early stage of organization of the rafts, the growing rod-like crystals (mother crystals) accompanied fragmental crystals whose growth rate was much faster that of the mother crystals, because of preliminary supply of the oriented molecular chains from the mother crystals. The differnce in the growth rate finally made all the rod-crystals into the same length within the individual raft. Nucleation density and crystal frowth rate were also measured as functions of temperature and molecular weight.Crystal structure was investigated using x-rau and a high resoltion electron microscope. Lattice image of the crystal revealed orientational fluctuation and defects within a crystallite. Crystal morphology of isothermally crystallized copolymers were dependent on the composition of the copolymer. ln addition, morphology and structure of branched rigid polymer crystals and also mixd crystals crystallized from blend were discussed.