| Research Abstract |
The International Symposium on "Polymer Crystallization", which was sponsored by the Present Project, was held from June 9-June 12, 2002, in Mishima. Our research group gave 2 oral and 4 poster presentations at the Symposium. Further, a poster presentation was given at the International Symposium on Polymer Physics, which was held from July 2-6, 2002, in Quindao, China. In addition, 9 poster presentations were given in domestic meetings and symposiums concerning with polymer physics.
Various types of studies on polymer crystallization have been carried and presented at the above meeting, and some of them are continued still. The outstanding and important results in this year are summarized as follows.
1)It was found that when poly(ethylene oxide) was crystallized on alkali halides, the diffusion-limited aggregates (DIA) were formed. It is the first case of DLA, which was identified in polymer crystallization. Diffusion is a very important factor of polymer crystallization, and then it is
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one of main targets on the present project to make clear the role of diffusion on polymer crystallization. The typical diffusion phenomenon, DLA, was realized in this way and proves the diffusion is an important factor on crystallization of polymers.
2)When amorphous poly-1-lactide was crystallized by annealing, the crystals of the βform was formed by annealing at low temperature and ones of the a form at high temperatures. Further, the βform of crystals were transformed into the α form at a temperature just below the melting point. The relationship between the two crystalline forms was ambiguous so far, and it was made clear in the present work.
3)Structural formation in high speed spinning is an important theme from the industrial point of view. The study concerning with the structural development and its formation mechanism is in the undeveloped field of fiber science. In cooperation with members of other groups, we were responsibility for electron microscopy and atomic force microscopy of the poly(naphthalene terephthalate) fiber spun at high speed. The high-speed-spun fiber exhibited the different texture from the fiber obtained at low spinning speed. However, it is room for further studies why the structure and the manner of structural development depend on the spinning speed. Less
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