1999 Fiscal Year Final Research Report Summary
Control of Branching in Radical Polymerization Based on New Concept
| Project/Area Number |
10650869
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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 | Osaka City University |
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Principal Investigator |
YAMADA Bunichiro Osaka City University, Faculty of Engineering, Professor, 工学部, 教授 (50047198)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Radical Polymerization / Catalytic chain transfer / Branched polymer / Cobaloxime / Addition-fragmentation chain transfer / Cross-linking / Polymerizable chain transfer agent / Bifunctional chain transfer agent |
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| Research Abstract |
A non-polymcrizable dimer of methyl methacrylatc (MMA) is feasible to radical addition to yield an adduct radical which is too stable to react mutually nor to add to monomer. The adduct radical primarily undergoes coupling with propagating radical to link two polymer chains through the dimer unit. The addition and coupling involving the dimer could be employed for gel-free branch formation in radical polymerization. The reactivities of various dimers of α-methyl vinyl compounds such as MMA, metherylonitrile (MAN), α-methylstyrene, and p-substituted α-methylstyrene were examined. Among these, the dimer of MAN participated only in addition/coupling to connect two polymer chains. Polystyrene radical added to the MMA dimer and mainly couple with the adduct radical. However, the adduct radical also yield the polystyrene bearing the unsaturated end group through β-fragmentation of the adduct radical. The dimer structure was introduced into polymer using a polymerizable addition-fragmentation chain transfer agent and a bifunctional addition-fragmentation chain transfer agent. These transfer agents involved one and two α-alkylthiomethylacryloyl groups as chain transferable groups. The polymerization of MMA in the presence of polymerizable transfer gent gave the poly(MMA) with the chain transferable side group which was further involved in addition/fragmentation chain transfer to link poly(MMA) chain. The side chain could also involve branching points. The polymerization of styrene in the presence of the poly(MMA) was found to result in a hyper branched block copolymer. The bifunctional chain transfer agent introduced the carbon carbon double bond to both end of poly(MMA). These double bonds were employed for addition/coupling of polystyrene radical to afford a branched block copolymer without gelation.
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Research Products
(4 results)
