1998 Fiscal Year Final Research Report Summary
Synthesis of Sequential Wholly Aromatic Polyketones Having Terphenyl Moiety in the Main Chain
| Project/Area Number |
09650971
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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 | Tokyo University of Agriculture and Technology |
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Principal Investigator |
YONEZAWA Noriyuki Tokyo University of Agriculture and Technology, Department of Material Systems Engineering, Associate Professor, 工学部, 助教授 (10167033)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Wholly aromatic polyketone / Sequential Polymer / Ring assembly / Terphenyl / Aromatic coupling / Transition metal complex / Electrophilic Aromatic Substitution / Direct condensation |
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| Research Abstract |
The preparation of wholly aromatic polyketones having terphenyl skeleton in the main chain by aromatic coupling reaction of o-terphenyl derivative bearing two chlorobenzoyl moieties (a) and the synthesis and polymerization of novel monomers containing trifluoromethyl side group for sequential polymers having ring-assembly structures (b) were investigated. (a) Two synthetic routes for bis(p-chlorobenzoyl)-o-terphenyl monomer were studied. Cross-coupling synthesis of the monomer was unsuccessful because of the failure of double cross-aromatic coupling of adjacent carbons on the aromatic ring. Synthesis of the o-terphenyl monomer was achieved by chemo- and regioselective direct acylation of o-terphenyl by p-chlorobenzoic acid. Aromatic coupling reaction of the o-terphenyl monomer was carried by use of transition metal (nickel) complex catalyst having triphenylphosphine and bipyridyl ligands in the presence of zinc powder as reducing reagent in an aprotic polar solvent such as dimethylacet
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amide, N-methyl-2-pyrolidone, or dimethylformamide. Because of the precipitation of the product in the early stage of polymerization, high-molecular-weight was not achieved. The highest inherent viscosity of the polyketones obtained was 0.17 dL/g (0.3 g/dL in conc. H_2SO_4, 30ﾟC). The resulting polyketone has glass transition temperature (Tg) at 184ﾟC.The weight loss was not observed till 450ﾟC, and the 10%-weight loss temperature was found to be 570ﾟC.(b) The synthesis of sequential polyketones having ring-assembly skeleton and fluorine-containing side group was undertaken. Three types of monomers were synthesized : 1) self-polymerization type monomer for head-to-tail polymer skeleton having both an acyl cation accepting moiety and an electrophile part with high regioselectivity, 2) a symmetric macro-monomer having three biphenylene units with two carboxyl groups giving head-to-head type polyketone structure by the reaction with 2,2'-dimethoxybiphenyl, and 3) biphenylenedicarboxylic acid monomer bearing one trifluoromethyl group giving random sequenced polyketone molecule. The polymerization was undertaken through direct polycondensation in P_2O_5-MsOH.The resulting three types polyketones have molecular-weights of 2800(head-to-head polyketone), 3300(head-to-tail), and 5800(random) based on the terminating group analysis using ^1H-NMR spectra. Less
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