日本东洋纺公司北河享博士:Preferential Orientation of Molecular Planes of Rigid-Rod Polymers along the Radial Direction Normal to the Fiber Axis
日期:2018-03-12
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报告题目:Preferential Orientation of Molecular Planes of Rigid-Rod Polymers along the Radial Direction Normal to the Fiber Axis
报 告 人:日本东洋纺公司 北河享博士
报告时间:2018年3月12日(星期一)15:30
报告地点:材料学院材料科学研究所(28号楼)604室
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材料科学与工程学院
2018年3月5日报告内容摘要
Fibers made of rigid-rod polymers have been developed to utilize the mechanical properties of the molecules to the utmost; the rigidity gives straightness and toughness in the chemical bonds along the molecular axis aligned along the fiber axis. We have previously proposed an estimation method to predict the preferential orientation of the () crystal planes of PBO (poly-p-phenylenebenzobisoxazole) crystals normal to the fiber axis from the diffraction X-ray intensities in diffraction patterns obtained by a micro-focus X-ray diffraction method. Because the PBO molecule have a thin-planar structure with rigidity, it can rotate freely around the molecular axis in the solution state. It is found that the alignment of the (0) planes of the crystals was determined in fibers prepared by coagulation during the fiber spinning process. In this presentation a calculation method to predict the intensities of the (0) reflections of PBO fibers as a function of the distance from the center of the fiber to the center of the focus point of a micro X-ray beam on the fiber is proposed. The method can estimate the degree of preferential orientation of thealong the radial direction of the fiber. The process of preferential orientations of the PBO crystals forming in the fiber structure induced by coagulation was revealed.
报告人介绍
Dr. T. Kitagawa started his research in analytical research laboratory of Toyobo Co., Ltd. Firstly, he mainly focused on X-ray analyses to make clear the relationship between structures and properties of soft materials including high-performance fibers and membranes. He had joined a PBO project to develop a super fiber Zylon® made from rigid-rod polymers for many years. Then, he leaded a development of micro-filtration membranes to apply them to purify a waste water. He also had joint researches with universities including Professor K. Tashiro of Toyota Technological Institute on structural analyses with synchrotron radiation and Professor R. J. Young in University of Manchester on Raman spectroscopy. Now, he belongs to Corporate R&D Administration Department to search for a new business and research project in China.