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

刚性棒棒聚合物结晶过程中超分子结构的发展。

基本信息

批准号：
03403018
负责人：
SHIMAMURA Kaoru
金额：
$ 20.8万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

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.

刚性聚合物如PBZT、PBZO、PBPZT及其共聚物在稀溶液中结晶，淬冷形成纤维状晶体，晶体中聚合物链与原纤平行。这些原纤维通过随后在溶剂中的热处理变成串羊肉串。等温结晶得到一组等长的平行棒状晶体，看起来像湖面上的“木筏”。分子链垂直于棒状晶体取向。棒状晶体的宽度与平均分子长度密切相关，尤其是在分子量区域。由于分子长度的分散性，许多定向的刚性链以纤毛的形式存在于棒状晶体的边缘。初生核主要由高分子量组分组成。在筏体组织形成的早期阶段，生长的棒状晶体（母晶）伴随着碎片晶体，其生长速度远快于母晶，这是由于母晶提供了定向分子链的初步供给。生长速度的差异最终使单个筏内的所有棒状晶体都变成相同的长度。测量了成核密度和晶体生长速率随温度和分子量的变化，用x射线衍射和高分辨电子显微镜研究了晶体结构。晶体的晶格图像显示取向波动和缺陷的微晶。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共混物结晶的混合晶体的形态和结构。