The influence of initiator and macrocyclic ligand on unsaturation and molar mass of poly(propylene oxide)s prepared with various anionic system
| Autor: | Sylwia Golba, Marek Matlengiewicz, Kinga Skrzeczyna, Justyna Jurek-Suliga, Zbigniew Grobelny |
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| Rok vydání: | 2017 |
| Předmět: |
Polymers and Plastics
02 engineering and technology 010402 general chemistry 01 natural sciences anionic polymerization chemistry.chemical_compound Deprotonation Polymer chemistry Materials Chemistry poly(propylene oxide Propylene oxide Degree of unsaturation Ligand Chemistry potassium salts General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics ROP 0104 chemical sciences Anionic addition polymerization Monomer Alkoxide Macrocyclic ligand 0210 nano-technology macrocyclic ligands unsaturation |
| Zdroj: | Polymer Bulletin. 75:1101-1121 |
| ISSN: | 1436-2449 0170-0839 |
| DOI: | 10.1007/s00289-017-2078-z |
| Popis: | Anionic polymerization of propylene oxide was carried out in the presence of two groups of potassium salts activated 18-crown-6 (18C6), e.g. alkoxide salts (CH3OK, i-PrOK, t-BuOK, CH3OCH2CH(CH3)OK, KCH2O) and other salts (CbK, Ph3CK, Ph2PK, Ph3HBK, KK, KH, and [(CH3)3Si]2NK) in THF at room temperature. Application of various initiating systems results in polyethers which are different in level and kind of unsaturation represented by allyloxy, cis- and trans-propenyloxy, as well as vinyloxy starting groups. In the presence of selected initiator, i.e. t-BuO-K? unsaturation increases markedly by addition of 18C6 or C222. During the initiation step oxirane ring-opening and direct deprotonation of the monomer occur simultaneously involving in some cases also the ligand. All initiators opens oxirane ring in the b-position except i-PrOK, which opens it in the b- and a-position. The mechanisms of the reactions were discussed. |
| Databáze: | OpenAIRE |
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