| Project/Area Number |
13650934
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
KAMIGAITO Masami Graduate School of Engineering,Department of Polymer Chemistry,Associate Professor, 工学研究科, 助教授 (00273475)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | living polymerization / radical polymerization / cationic polymerization / water / metal complex / Lewis acid / suspension polymerization / emulsion polymerization |
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| Research Abstract |
This research was directed to development of environmentally friendly precision controlled polymerization, specifically living cationic and radical polymerization in water, both of which have been considered impossible.
(1) Living Cationic Polymerization in Water
Controlled cationic polymerization of various styrene derivatives was achieved in water with the use of an initiating system consisting of R-0H as an initiator and a water-tolerant and highly oxophilic Lewis acid, BF_3. The polymerization proceeded via BF_3-meidated reversible activation of C-OH terminal to give polymers with controlled molecular weights and narrow molecular weight distributions (MWDs). For a suspension system with a large amount of water, p-methoxystyrene was polymerized in a controlled fashion to yield polymers with M._n > 10,000 and M_w/M_n〜 1.5. The initiating system was also applicable for controlled cationic polymerization of p-(chloromethyl)styrene, where the C-OH terminal was selectively activated by BF_3 Without concurrent side-reactions of the chloromethyl functional groups. These are unprecedented results in controlled cationic polymerizations.
(2) Living Radical Polymerization in Water
Water-tolerant iron and ruthenium catalysts induced living radial polymerization of a variety of monomers in water via reversible activation of a carbon-halogen bond. Suspension living radical polymerizations of acrylates and styrene were possible with a half-metallocene type iron complex and gave polymers with controlled molecular weights at least up to M_n. 〜 100,000 and narrow MWDs (M_w/M_n〜 1.2).The use of an ionic phosphine or polyethyleneglycol-based phosphine for ruthenium complexes led to living radical polymerization of methacrylates in water and easy removal of the catalysts from the products.
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