| Project/Area Number |
06651028
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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 |
高分子合成
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| Research Institution | Osaka University |
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Principal Investigator |
KITAYAMA Tatsuki Osaka University, Faculty of Engineering Science, Department of Chemistry, Associate Professor, 基礎工学部, 助教授 (60135671)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Stereospecific Living Polymerization / Stereoregular Polymethacrylate / Macromonomer / Anionic Polymerization / Graft Polymer / Comb Polymer / Star Polymer / Dimethacrylate / 立体特異性重合 / 二官能性モノマー / くし形ポリマー / リビング重合 / NMR / 星型ポリマーの融合 / GPC-LALLS / 立体規則性グラフトポリマー / 立体規則性くし形ポリマー / ステレオコンプレックス / 重水素化ポリマー |
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| Research Abstract |
1) Isotactic and syndiotactic PMMA macromonomers having methacryloyl group were prepared from the corresponding living PMMA anions. Anionic copolymerization of the macromonomers with methyl and ethyl methacrylate was successfully carried out by using two living polymerization systems ; 1,1-diphenylhexyllithum in tetrahydrofuran and t-C_4H_9MgBr in toluene. The obtained graft polymers were found stereoregular both in their side chains and main chain. Anionic homopolymerization of the macromonomer was also possible to afford comb PMMA with stereoregular main chain. Owing to the defined end-group structure, 1H NMR analysis allows the determination of several important structural features including number of branches, compositions, and molecular weight.
2) Isotactic and syndiotactic PMMA living anions were reacted with dimethacrylate to obtain star polymers with stereoregular PMMA arms. The reaction with ethylene glycol dimethacrylate proceeded only when the isotactic PMMA anion was used in
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the presence of diamines. The syndiotactic PMMA anion gave a star polymer when reacted with butane-1,4-diol dimethacrylate. The molecular weight of the star polymer reached one million. During the formation of the star polymer, intermolecular star-star linking reaction occurred to form higher molecular weight star polymers, as evidenced from the analysis on the change in the number of arms and molecular weight of the star polymers.
3) Several characteristic properties of stereoregular branched PMMA were examined. Graft PMMA having opposite stereoregularities in its main chain and side chains underwent intramolecular stereocomplex formation in asetone, leading to an unusually large Huggins' coefficient. Moecular-weight dependence of viscosity of comb PMMA exhibited the structural change from star-like conformation to comb-like one at critical molecular weight range, which was affected by the stereoregularity of the comb polymer. Viscosity of star PMMA also showed evidently the tacticity dependence, the isotactic star PMMA having larger viscosity than the syndiotactic one. Less
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