Structure Formation and Relaxation Phenomena in Polymeric Systems

对以下三种聚合物进行了实验和分析。1.等规聚苯乙烯：从小角X射线散射和电子显微镜可以看出，尽管样品的结晶度在30%左右，但晶体厚度比无定形的要大。利用原子力显微镜对晶化薄膜表面的长间距进行了定量测量。在薄膜结晶过程中，晶体形态和位错受衬底的影响，生长速率与薄膜厚度成反比，并用旋转模型对结果进行了解释。2.聚对苯二甲酸乙二酯：同时进行了介电弛豫和X射线散射的实时测量。在观察到晶化之前，介电α松弛转变为另一个α‘松弛，然后伴随着晶化发生介电松弛的变化。这种现象被解释为：晶化前非晶区分子的运动模式发生变化，然后转变为晶片约束的模式。3.聚偏氟乙烯：从熔体结晶过程中的介电松弛和X射线散射的实时测量中可以看出，晶层结构的生长和晶区的松弛是同时发展的。

Experiments and analysis were performed for the following three kinds of polymers.1.Isotactic polystirene : From small-angle x-ray scattering and electron microscopy, it is clarified that the crystal thickness is larger than the amorphous one, although the degree of crystallinity of specimen is about 30%. The long spacing is quantitatively obtained by the atomic force microscopy on the surface of crystallized thin film. In the crystallization in thin film, it is shown that crystal morphology and the dislocations are affected by the substrates and that the growth rate is reciprocally proportional to the film thickness, and the results were interpreted in terms of the reptation model.2.Polyethylene terephthalate : Simultaneous real-time measurements of dielectric relaxation and x-ray scattering was performed. Before crystallization is observed, the dielectric alpha relaxation changes into another alpha'relaxation, then the change in dielectric relaxation occurs accompanying the crystallization. This phenomena are interpreted as follows : the mode of molecular motion in amorphous region changes prior to crystallization and then the mode changes into the one constrained by the crystalline lamellae.3.Polyvinylidene fluoride : From the simultaneous real-time measurements of dielectric relaxation and x-ray scattering during the crystallization process from the melt, it is shown that the growth of lamellar structure and the relaxation the crystalline region are simultaneously developed.