Molecular Weight Distributions in Nitroxide-Mediated Living Free Radical Polymerization: Kinetics of the Slow Equilibria between Growing and Dormant Chains
| Autor: | Peter G. Odell, Michael K. Georges, Lora M. Michalak, Richard P. N. Veregin |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Kinetic chain length
Nitroxide mediated radical polymerization Polymers and Plastics Bulk polymerization Chemistry Organic Chemistry Radical polymerization Photochemistry Chain termination Inorganic Chemistry Living free-radical polymerization Polymerization Polymer chemistry Materials Chemistry Living polymerization |
| Zdroj: | Macromolecules. 29:3346-3352 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma951667m |
| Popis: | A kinetic approach, recently developed to calculate the effect of exchange between a dormant and an active species in group transfer polymerization (GTP), has been applied to living free radical polymerization moderated by nitroxide stable free radicals. A general solution for the molecular weight distribution as a function of conversion has been derived. The solution depends only on the rate constants for propagation, the trapping of the growing chains by nitroxide radical, and the release of the growing chain. The general form of the solution is the same in GTP and the stable free radical-mediated polymerization (SFRP), except for the definition of the constants. Using the measured and known experimental rate constants for SFRP and fitting to the only unknown rate constant, that for reversible chain termination by the nitroxide radical, allow a quantitative prediction of the molecular weight distribution with conversion for bulk free radical living polymerization of polystyrene. In this way a good fit t... |
| Databáze: | OpenAIRE |
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