Precise synthesis of UCST-type amphiphilic diblock copolymers with pendant imidazolium ionic liquid segments and their thermosensitive physical gelation at extremely low concentrations in water
| Autor: | Daichi Yokota, Sadahito Aoshima, Arihiro Kanazawa |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Aqueous solution
Polymers and Plastics Organic Chemistry Bioengineering 02 engineering and technology Vinyl ether 010402 general chemistry 021001 nanoscience & nanotechnology Living cationic polymerization 01 natural sciences Biochemistry Micelle 0104 chemical sciences chemistry.chemical_compound chemistry Upper critical solution temperature Ionic liquid Amphiphile Polymer chemistry medicine Copolymer 0210 nano-technology medicine.drug |
| Zdroj: | Polymer Chemistry. 9:5080-5085 |
| ISSN: | 1759-9962 1759-9954 |
| DOI: | 10.1039/c8py01139g |
| Popis: | Amphiphilic diblock copolymers with an upper critical solution temperature-type thermosensitive segment ([Me2Im][BF4]) were synthesized by living cationic polymerization and subsequent chemical modifications and they exhibited thermosensitive physical gelation behavior at very low concentrations in water. Precise synthesis of precursor diblock copolymers of isobutyl vinyl ether and 2-chloroethyl vinyl ether was achieved by suppressing side reactions using an initiating system consisting of Et1.5AlCl1.5, SnCl4, and di-tert-butylpyridine at 0 °C. An aqueous solution of IBVE50-b-[Me2Im][BF4]400 was demonstrated to undergo thermosensitive physical gelation at a 1 wt% concentration. Interestingly, a block copolymer with 800 units of [Me2Im][BF4] exhibited physical gelation at 0.2 wt% in water. The formation of large micelles with extended corona chains based on electrostatic repulsion and hydration of the ionic [Me2Im][BF4] segment is most likely responsible for physical gelation via micelle packing at a very low concentration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|