Continuous precipitation polymerization of vinylidene fluoride in supercritical carbon dioxide: molecular weight distribution
| Autor: | Louis M. Wojcinski, Paul A. Charpentier, Manish K. Saraf, George W. Roberts, Karen A. Kennedy, Sylvain Gerard, Joseph M. DeSimone |
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| Rok vydání: | 2002 |
| Předmět: |
chemistry.chemical_classification
Materials science Supercritical carbon dioxide Polymers and Plastics Peroxydicarbonate Organic Chemistry Polymer Condensed Matter Physics chemistry.chemical_compound Monomer chemistry Chemical engineering Polymerization Polymer chemistry Materials Chemistry Precipitation polymerization Molar mass distribution Fluoride |
| Zdroj: | Macromolecular Symposia. 182:119-129 |
| ISSN: | 1521-3900 1022-1360 |
| Popis: | The surfactant-free precipitation polymerization of vinylidene fluoride (VF2) in supercritical carbon dioxide was studied in a continuous stirred autoclave. The polymerization temperature ranged from 65 to 85°C, the average residence time in the reactor varied from 10 to 50 min., and the pressure was between 210 and 305 bar. Diethyl peroxydicarbonate was used as the initiator. The fractional conversion of monomer varied from 7 to 26%, the number-average molecular weight of the polymer was between about 14,000 and 79,000, and the weight-average molecular weight was between about 21,000 and 700,000. In many cases, the polymer exhibited a bimodal molecular-weight distribution, especially at high monomer concentrations. |
| Databáze: | OpenAIRE |
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