1990 Fiscal Year Final Research Report Summary
Surface-Active Properties and Polymerization Behavior of Amphiphilic Poly (Ethylene Oxide) Macromonomers
| Project/Area Number |
01470111
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | Toyohashi University of Technology |
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Principal Investigator |
ITO Koichi Toyohashi University of Technology, Faculty of Engineering, Professor, 工学部, 教授 (00023119)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUCHI Seigou Toyohashi University of Technology, Faculty of Engineering, Instructor, 工学部, 教務職員 (00204694)
ITSUNO Shinichi Toyohashi University of Technology, Faculty of Engineering, Instructor, 工学部, 助手 (50158755)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Macromonomer / Poly(ethylene oxide) / Amphiphilic / Micelle / Radical polymerization / End-group effect / Chain-length effect / Comb-like polymer |
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| Research Abstract |
Amphiphilic macromonomers having both hydrophilic and hydrophobic segments in their chains are expected to exhibit a variety of conformations and/or aggregations depending on the medium, together with very specific polymerization behaviors. This research has established a micellar organized polymerization in water of poly (ethylene oxide)(PEO) macromonomers by examining their polymerizability and micelle formation as a function of the structure including the effects of the end groups and the chain lengths. Some of the results to be noted are as follows.
(1) PEO macromonomers carrying hydroxy, methoxy, n-butoxy, t-butoxy, n-octyloxy, or n-octadecyloxy group as the omega-end and p-vinylbenzyl, methacryloyl, or p-styrylalkys group as the alpha-end were prepared, primarily based on the anionic living polymerization. The molecular weight distributions were very narrow and the end-group functionalities were satisfactory as confirmed by GPC and NMR. Their nonpolymerizable PEO models with benzy
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l or isobutyloyl groups as the alpha-ends were also prepared.
(2) The homopolymerizations of the PEO macromonomers in water were found to be unusually fast as compared to those in benzene and those of the conventional low-molecular-weight monomers. The polymerizability was affected not only by the polymerizing alpha-end groups, but also significantly by omega-stanging end groups and the PEO chain lengths.
(3) Light-scattering measurements of the nonpolymerizable macromonomer models confirmed the micelle formation in water but not in benzene. The relative molecular density within the micelle, estimated from the aggregation number divided by the micellar volume, was found to parallel with the polymerizability.
(4) These results strongly support a micellar organized polymerization of the PEO macromonomers in water. Thus they polymerize very rapidly as a result of enhanced local concentration and orientation of their polymerizing end-groups which are hydrophobic. The comb polymers obtained are interesting as the models of fixed micelles or star-like polymers and confirmed by GPC, viscosity and light-scattering to assume very compact conformations. Less
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