ORGN 76 |
| Here we describe a highly crosslinked hyperbranched polymer that rapidly swells and shrinks in dichloromethane solvent in response to the addition of acid or base. The polymer was based on 1,2,3-triazoles units conveniently synthesized under mild conditions in aqueous-organic solvent mixtures using Cu(I) catalyzed [3+2] cycloaddition of a diazide and an amine-containing trialkyne. The insoluble polymer swelled rapidly in trifluoroacetic acid-containing dichloromethane, and absorbed significant amount of solvent. Protonation of the tertiary amine and triazole moieties and concomitant charge-charge repulsion among sites in the polymer is likely to be responsible for the swelling behavior. After washing with dichloromethane, treatment with triethylamine-containing dichloromethane causes the material to retain its expanded architecture but lose most of its trapped solvent mass. Many cycles of acid/base treatment were performed with little or no loss in the measured retention of solvent. Characterization of the polymer before and after swelling showed different morphologies. |
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Materials, Devices, and Switches
1:00 PM-5:00 PM, Sunday, 13 March 2005 Convention Center -- Room 9, Oral
Division of Organic Chemistry |