Monomer-to-Polymer Phase Transition of Diacetylenes with gamma-Rays
| Project/Area Number |
62540239
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUYAMA Tomochika Kyoto Univ., Res. Reactor Institute, Associate Professor, 原子炉実験所, 助教授 (50027463)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAOKA Hitoshi Kyoto Univ., Res. Reactor Institute, Professor, 原子炉実験所, 教授 (80026004)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
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| Keywords | Diacetylene / Polydiacetylene / Topochemical polymerization / Oriented polymers / Color change / Solid state polymerization / Single crystals of polymers / First order phase transition / 放射線重合 / 相転移 / ジアセチセン / DCH / TCDU / 共役系高分子単結晶 |
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| Research Abstract |
1. The monomer crystal of 1,6-di(N-carbazolyl)-2,4-hexadiyne (DCH) has the lattice parameters which predict a low reactivity in solid state polymerization. Despite the prediction, DCH monomer crystals can be converted to fully conjugated polymer crystals upon exposure to gamma-rays. This is due to the transformation of the crystal from a less-reactive phase to a more-reactive phase at the level of about 30% polymerization. This phase transformation is abruptly achieved without destruction of the crystal. The fact implies that a topochemical 1,4-addition reaction leading to the polymerization under gamma-irradiation proceeds homogeneously in both phases by the formation of solid solutions.
2. The crystal of DCH monomer undergoes inherent phase transition (IPT). It has been determined that the temperature and the heat of IPT are 148K and 1.2 kcal/mol in as-grown DCH crystals, respectively. When the crystals were gamma-irradiated at room temperature, it was found that all lattice parameter
… More
s change gradually with gamma-ray dosage in the aforementioned less-reactive phase. In addition to the above fact it was also found in the less-reactive phase that the transition point of IPT is shifted to the temperature side lower than 148K with decreasing the heat of IPT under gamma-irradiation and that the color of the crystal is red below and blue above the temperature of IPT. The temperature shift of IPT, the decrement of heat for IPT and the color change at IPT are interpreted in terms of the concept of strain field induced by the formation of polymers within the monomer columns.
3. The asymmetric monomers of 1-(N-carbazolyl)-6-(4'-methyl terephthaloyl)- 2,4-hexadiyne and 1-(N-carbazolyl)-6-(2',4'-dinitrophenyl ether)-2,4- hexadiyne were synthesized. Their crystal structures were determined with x-ray diffraction analysis. The present crystals showed neither topochemical polymerization nor phase transition. The non-polymerizability of the crystals is explained with monomer packing parameters and is consistent with the Baughman's model. Less
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Report
(4 results)
Research Products
(27 results)
