Polystyrene End-Labeled with 2,7-Dibromofluorene Synthesized Using an Adaptation of Reverse Atom Transfer Radical Polymerization
| Autor: | Eric S. Tillman, Bellamarie Ludwig |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Atom-transfer radical-polymerization Organic Chemistry Solution polymerization Polymer Fluorene Condensed Matter Physics Photochemistry Gel permeation chromatography End-group chemistry.chemical_compound chemistry Cobalt-mediated radical polymerization Polymer chemistry Materials Chemistry Radical initiator Physical and Theoretical Chemistry |
| Zdroj: | Macromolecular Chemistry and Physics. 206:2143-2152 |
| ISSN: | 1521-3935 1022-1352 |
| DOI: | 10.1002/macp.200500296 |
| Popis: | Polystyrene with high amounts of end-labeling was synthesized using initiating systems comprised of conventional radical initiators and 2,7-dibromofluorene or other fluorene derivatives in an adaptation of reverse atom transfer radical polymerization (RATRP). Benzoyl peroxide (BPO) or 2,2'-azoisobutyronitrile (AIBN) were decomposed and allowed to react with 2,7-dibromofluorene, 2-bromofluorene, or fluorene in the presence of ligand-bound CuX 2 allowing for abstraction of the 9-H from the fluorenyl species and the establishment of an equilibrium between the subsequent active radical and the dormant alkyl halide. Gel permeation chromatography (GPC) traces indicated CuCl 2 -catalyzed reactions produced polymers possessing narrow polydispersity index (PDI) values 1.7). Analysis of the polymers using UV-vis spectroscopy and UV-GPC demonstrated competition between initiation from both the conventional radical initiator and fluorenyl species generating polymers end-labeled with both the 2,7-dibromofluorene and isobutyronitrile groups. Fluorene or 2-bromofluorene as co-initiators led to lowered amounts of end-labeling, but the polymers generally possessed lower PDI values compared to 2,7-dibromofluorene systems. |
| Databáze: | OpenAIRE |
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