POLY 40 |
| We have developed new methodologies for star polymer synthesis based on polymer-linking reaction with a bifunctional vinyl compound. In-situ micelle formation of living block copolymers induced by UCST-type phase separation was effective for promoting linking reactions of the linear starting living polymers. The resulting star polymers had arm numbers (> 40 arms) larger than those obtained from reactions under normal conditions (10-15 arns). Another method, applicable to linear homopolymers, was reaction in a mixed solvent system, which contains a good and a poor solvent for arm chains (starting living polymers). This system was shown to induce almost quantitative formation of star polymers with many arms (> 40 arms). Furthermore, thermosensitive gold nanoclusters were prepared by a simple reduction method in aqueous solutions of thermosensitive vinyl ether star polymers. A characteristic feature of these polymer-stabilized gold nanoclusters was their highly sensitive thermoresponsiveness and excellent stability during repetitive phase transition cycles. |
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General Papers: Functional Materials
8:00 AM-12:00 PM, Sunday, August 19, 2007 Westin Boston Waterfront -- Douglas, Oral
Division of Polymer Chemistry |