| Project/Area Number |
12127204
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Kyoto University |
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Principal Investigator |
MIYAJI Hideki Kyoto University, Graduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (90025388)
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| Co-Investigator(Kenkyū-buntansha) |
TANZAWA Yasutoshi Nagoya Institute of Technology, Faculty of Engineering, Lecturer, 工学部, 講師 (60236776)
MIYAMOTO Yoshihisa Kyoto University, Faculty of Integrated Human Studies, Professor, 総合人間学部, 教授 (00174219)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥10,900,000 (Direct Cost: ¥10,900,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2001: ¥8,400,000 (Direct Cost: ¥8,400,000)
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| Keywords | polymer crystals / entropic barrier / poly(vinylidene fluoride) / diffusion / morphology / crystal growth rate / polyisoprene rubber / エントロピー障壁 / イソプレンゴ / ポリスチレン / 薄膜 / 結晶成長 |
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| Research Abstract |
In the last two years (2000 to 2001), we performed the experiment on crystal growth of polymers in thin films to obtain the following results. 1)The super-cooling (ΔT) dependence of the growth rate G of polymer crystals does not depend on the morphology and film thickness : G is proportional to exp(-K/TΔT).2) The lamellar thickness is determined by crystallization temperature ; the thickness is independent of morphology and film thickness. 3) In the crystal growth for a crystal with a finite width of the growth surface, is observed the ratio of the maximum growth rate to the minimum one to be inconsistent with that predicted by the standard nucleation theory.
In 2002, we investigated thermal roughening in poly(1, 4 trans-butadiene) crystals arid kinetic roughening in poly(butene-1) crystals respectively, and established that result 1) holds universally in polymer crystallization. We confirmed result 3)for poly(vinylidene fluoride) crystals as well as for poly(para-phenylene sulfide) by observing the radial growth rate of their spherulites. On the basis of these observations, we have proposed a new model for polymer crystallization ; in the model a polymer segment experiences an activated free energy barrier due to an entropy loss before adhesion to the crystal surface.
We also investigated the effect of diffusion on polymer crystallization by observing the crystallization of cross-linked polyisoprene rubber through stress-strain curve and X-ray measurement; thermodynamic analysis of these data could reproduce well the strain rate dependence of crystallization rate depending on crystallization temperature.
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