Silacyclobutane as "Carbanion Pump" in Anionic Polymerization. 3. Synthesis of Di- and Tri-block Copolymer by "Diphenylsilacyclobutane-Potassium tert-Butoxide System"

• Hyun Jae-Yong

  Graduate School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST)

• Kawakami Yusuke

  Graduate School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST)

書誌事項

タイトル別名

• Silacyclobutane as "Carbanion Pump" in Anionic Polymerization. III. Synthesis of Di- and Tri-block Copolymer by "Diphenylsilacyclobutane-Potassium tert-Butoxide System"

抄録

Efficiency of formation of carbanion from a combination of an alkaline metal tert-butoxide and a silacycle (carbanion pump efficiency) was studied in the presence of diphenylethylene. Combination of a silacyclobutane with potassium counter ion was the most effective among the silacycles studied (1:1 molar ratio). Sodium and lithium counter ions gave low efficiency. When 2-times 1,1-diphenylethylene was used, diphenylsilacyclobutane with potassium counter ion was found superior to dimethylsilacyclobutane–potassium, and produced (tert-butoxy)diphenyl(5,5-diphenylhexyl)silane as the major trapped product of initially formed carbanion. However, (tert-butoxy)diphenylpropylsilane and diphenylpropylsilanol were also formed as non-trapped products in 1 to 27% depending on the reaction conditions, especially when tetrahydrofuran–hexane (9:1) was used. Hydrogen elimination from initially formed intermediate was suggested. With 4-times diphenylethylene, or reaction in tetrahydrofuran–hexane (1:1), (tert-butoxy)(5,5-diphenylhexyl)silane was produced in 95% yield after treatment with methyl iodide, accompanied by only 1–2% (tert-butoxy)diphenylpropylsilane as non-trapped product, and tert-butoxy anion was converted to carbanion in as high as 97% yield. This carbanion pump system was applied in the syntheses of poly(ethylene oxide)-block-polystyrene, poly(ethylene oxide)-block-polystyrene-block-poly(ethylene oxide), poly(ethylene oxide)-block-poly(methyl methacrylate), and poly(ethylene oxide)-block-poly(methyl methacrylate)-block-poly(ethylene oxide).

収録刊行物

• Polymer Journal

  Polymer Journal 36 (10), 856-865, 2004

  The Society of Polymer Science, Japan

キーワード

• Silacycle
• Silacyclobutane
• Alkaline Metal Alkoxide
• Diphenylethylene
• Carbanion Pump
• Anionic Polymerization
• Block Copolymer

詳細情報

• CRID: 1390001206288174848
• NII論文ID: 10013610491
• NII書誌ID: AA00777013
• DOI: 10.1295/polymj.36.856
• ISSN: 13490540
• ISSN: 00323896
• NDL書誌ID: 7111677
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7111677
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可