2003 Fiscal Year Final Research Report Summary
Analysis of internal fine structures of high-speed-spun fibers of PET/PEN blends
| Project/Area Number |
14550847
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
TSUJI Masaki Kyoto University, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (60172003)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAHARA Yutaka Kyoto Institute of Technology, Graduate School, Division of Advanced Fibro-Science, Associate Professor, 工芸科学研究科, 助教授 (10303934)
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| Project Period (FY) |
2002 – 2003
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| Keywords | poly(ethylene terephthalate) / poly(ethylene naphthalate) / poly(butylene terephthalate) / electron microscopy / electron diffraction / dark-field imaging / oriented crystallization / shish-kebab structure |
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| Research Abstract |
1.We tried to establish a suitable technique of structural analysis for the high-speed-spun fibers (HSS-fibers), with which the origin of some properties of the fibers can be straightfowardly elucidated for PET, PEN [poly(ethylene naphthalate)] and PET/PEN blends. (1)Fibrillar texture and a fine network structure consisting of stacked-lamella-like structures were recognized in the alkaline-etched HSS-fibers (spun at 4 km/mm or greater) of PEN. (2)Uniaxially oriented thin films of PET and PEN were prepared by applying shear-strain to the melt, and were examined by TEM. Electron diffraction (ED) of PEN showed a highly uniaxial orientation and was consistent with wide-angle x-ray diffraction (XD) of PEN HSS-fibers. Such thin films of PEN were regarded as a model specimen for the HSS-fibers. ED of PET is in good agreement with XD of PET HSS-fibers. (3)As for uniaxially oriented thin films of PET/PEN blends, ED patterns consisted of the reflections from both homopolymer crystals and also showed a highly uniaxial orientation. By dark-field imaging, it was recognized that PEN can form lamellar crystals in uniaxially oriented thin films and this tendency is more remarked than in PET. Morphology was changed from a PET-type to a PEN-type with increasing PET content, formation of PEN lamellae was depressed by PET, and to the contrary, crystallization of PET was suppressed by PEN.
2.Oriented thin films of PBT [poly(butylene terephthalate)] were prepared and examined by TEM. Although their ED patterns consisted of the arc-shaped reflections attributed only to the α-form and accordingly showed a less-developed uniaxial orientation, stacked-lamellar structures were more clearly observed in PBT than in PEN. It was concluded that the stacked lamellae in each of the structures form a shish-kebab structure. Based on the results obtained from all the oriented thin films of polyesters used here, we proposed an "advanced" model of shish-kebab structure.
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