| Autor: |
Alain Guyot, R. Jerome, T. Hamaide, Pascal Charlier |
| Rok vydání: |
1991 |
| Předmět: |
|
| Zdroj: |
Polymer. 32:1089-1094 |
| ISSN: |
0032-3861 |
| DOI: |
10.1016/0032-3861(91)90597-c |
| Popis: |
Telechelic polystyrene and polyisoprene bearing carboxylatobetaine end groups of various intercharge lengths were prepared and characterized. Dimethylamino telechelic polyisoprene and polystyrene were anionically synthesized and the dimethylamine end groups were reacted with bromoalkyl ethylcarboxylic esters, comprising a methyl and an n-butyl group. After treatment with aqueous NaOH, the end groups were converted into carboxylatobetaine form of various intercharge lengths. Glass transition temperatures of both functionalized polystyrene and polyisoprene were found to increase with respect to the precursor polymers and to depend on the intercharge length. A smaller intercharge length appears to promote stronger interactions. Solubility of the carboxylatobetaine form depends on both the polymeric nature of the backbone and the intercharge length of the betaine end group. Highly viscous solutions were obtained when dissolving the polymers in a low polarity solvent. The viscosity of the zwitterionic polystyrenes in toluene was affected by the intercharge length of the end group. An average aggregation number was calculated from the viscosity data and the results were compared with those of randomly grafted carboxylatobetaines of the same zwitterionic molar fraction. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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