Star poly(2‐ethyl‐2‐oxazoline)s—synthesis and thermosensitivity |
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| Authors: | Agnieszka Kowalczuk Juraj Kronek Kornelia Bosowska Barbara Trzebicka Andrzej Dworak |
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| Affiliation: | 1. Centre of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie‐Sklodowskiej 34, 41‐819 Zabrze, Poland;2. Polymer Institute, Slovak Academy of Sciences, Centre of Excellence GLYCOMED, Dubravska cesta 9, 84236 Bratislava, Slovakia;3. University of Opole, Faculty of Chemistry, Oleska 48, 45‐052 Opole, Poland |
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| Abstract: | A series of star‐shaped poly(2‐ethyl‐2‐oxazoline)s was prepared by cationic polymerization. The polymerization was initiated by dipentaerythrityl hexakis(4‐nitrobenzene sulfonate) and a tosylated hyperbranched polymer of glycidol. The polymerization proceeded in a controlled manner. The star structure of the products was determined by nuclear magnetic resonance. The molar mass distributions that were measured by gel permeation chromatography with multiangle laser light scattering were narrow, and the experimental values of the molar masses were close to those predicted. The very compact structure of the polymers obtained (compared with the linear counterparts) confirmed the star formation. The star poly(2‐ethyl‐2‐oxazoline)s show a phase transition temperature in the range 62–75 °C. Comparison of this phase transition temperature with that of the linear poly(2‐ethyl‐2‐oxazoline)s with the same molar masses indicates the influence of molar mass and topological structure of the macromolecule on temperature behavior. The prepared copolymers are spherical, which might be useful for the controlled transport and release of active compounds. Copyright © 2011 Society of Chemical Industry |
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| Keywords: | cationic polymerization star polymers stimuli‐sensitive polymers structure‐property relations |
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