Structure Formation and Relaxation Phenomena in Polymeric Systems

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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.