Project/Area Number |
61303012
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Research Category |
Grant-in-Aid for Co-operative Research (A)
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Allocation Type | Single-year Grants |
Research Field |
高分子物性
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Research Institution | Kyoto University |
Principal Investigator |
KATAYAMA Ken-ichi (1988) Institute for Chemical Research, Kyoto University, 化学研究所, 教授 (60027068)
北丸 竜三 (1986-1987) 京都大学, 化学研究所, 教授 (40027016)
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Co-Investigator(Kenkyū-buntansha) |
HORII Fumitaka Institute for Chemical Research, Kyoto University, 化学研究所, 助教授 (70124758)
ITO Taisuke Fac. of Eng. and Design, Kyoto Institute of Technology, 化学研究所, 助教授 (40027769)
TAKAMIZAWA Kanichirou Fac. of Eng., Kyushu University, 工学部, 教授 (10037707)
TANAKA Yasuyuki Fac. of Eng., Tokyo Univ. of Agriculture and Technology, 工学部, 教授 (80015114)
KITAMARU Ryozo Institute for Chemical Research, Kyoto University (Head in 1986 and 1987), 化学研究所, 教授 (40027016)
小川 芳弘 熊本大学, 教養部, 講師 (70149988)
片山 健一 京都大学, 化学研究所, 教授 (60027068)
|
Project Period (FY) |
1986 – 1988
|
Project Status |
Completed (Fiscal Year 1988)
|
Budget Amount *help |
¥17,000,000 (Direct Cost: ¥17,000,000)
Fiscal Year 1988: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1986: ¥11,000,000 (Direct Cost: ¥11,000,000)
|
Keywords | Cycloparaffins / Normal paraffins / Polyethylene / Crystal structure / Solid-solid phase transition / High-resolution solid-state ^<13>C NMR / Electron microscopy / 電子顕微鏡 / 電子顕微鏡観察 / 非晶構造 / 固体高分解能NMR / 分子運動性 |
Research Abstract |
In order to obtain fundamental information about the structures of the crystalline regions and crystalline-amorphous interphase of polyethylene, the crystal structures, solid-solid phase transitions, molecular motions, and diffusional processes have been extensively studied for cyclic and normal paraffins with very high purities by different mothods. Cyclic paraffins can be synthesized by methathesis of cyclododecene, following fractionation by GPC and hydrogenation. Normal paraffins with the odd number of carbons are found to be prepared through ketene-dimerization reactions using esters of fattic acids as starting materials which are highly purified by liquid chromatography. The overlayers of polyethylene single crystals and cycloparaffin crystals, which are epitaxially grown on the (001) face of NaCl crystals, have been examined by high-resolution electron microscopy. It is found that disordered overlayers really exist for polyethylene single crystals, whereas they are devoid for cyc
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loparaffins. The folding direction of the polyethylene single crystals has also been studied by epitaxial xrystallization techniques. The solid-solid phase transitions and characteristic molelular motions in the respective phases have been recealed for n-C<@D227@>D2 H<@D256@>D2 and cyclic C<@D260@>D2 H<@D2120@>D2 crystals by high-resolution solid-state carbon-13 NMR spectroscopy. In particular, it is found that two new solid-solid phase transitions appear for the cyclic paraffin crystale; monoclinic crystals to orthorhombic crystals and orthorhombic crystals to diordered crystals where one kink diffuses along either chain of the two chains of the molecule at a rate more than 10<@D13@>Dd Hz. The diffusion porcess of linear aliphatic esters with different numbers of carbons has been studied in solid polythylene to find the dependence of the diffusion constant on the molecular length. As a result, the activation volume for diffusion appears to well correspond to the value assumed by the reptile diffusion model. Less
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