| Project/Area Number |
08651042
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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 |
高分子合成
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SAKAMOTO Kenkichi TOHOKU UNIVERSITY,DEPARTMENT OF CHEMISTRY,GRADUATE SCHOOL OF SCIENCE,ASSOCIATE PROFESSOR, 大学院・理学研究科・化学専攻, 助教授 (50187035)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | dendrimer / hyperbranched polymethacrylate / self-condensing polymerization / group transfer polymerization / unimolecular micelle / Solubilization / host-guest chemistry / ケテンシリルアセタール / ポリメタクリル酸エステル / 多分岐高分子 / リビング重合 / 有機ケイ素化合物 / 高分子合成 |
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| Research Abstract |
Dendrimers have recently received much attention as materials with novel physical properties. However, dendrimers are accessible only through multi-step syntheses that limit their availability. Recently, Frechet et al.has described self-condensing vinyl polymerization to produce dendrimer-like hyperbranched polystirene.
In this research project, synthesis of hyperbranched polymethacrylates by the group transfer polymerization was carried out. Thus, 2- (2-methyl-1-triethylsiloxy-1-propenyloxy) ethyl methacrylate 1, which consisted of a methacrylate moiety and a ketene silyl acetal moiety, was prepared for the self-condensing polymerization of methacrylates. The polymerization of 1 was carried out in THF with fluoride ion as a catalyst. The resulting polymers were soluble in various organic solvents. Molecular weights of the polymers were about ten thousand estimated by GPC.The branched structure of the polymers was clearly characterized by ^1H and ^<13>C NMR spectroscopy.
The ketene silyl acetal residues in the polymers were converted to various functional groups. Thus, water-soluble hyperbranched polymethacrylates were synthesized by introduction of ionic functional groups such as carboxylate anion and ammonium cation as the terminal groups of the polymers.
These polymers behaved as unimolecular micelles ; they dissolved in water and incorporated organic molecules (guests) by hydrophobic interaction. Monitoring by UV-Vis and fluorescence spectroscopy revealed that the incorporation was controlled by the electrostatic force between the guests and the host polymers. The cavity size of the polymers depended on the change of their surface charge density. In fact, guest molecules were released when the charge of the polymers neutralized.
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