Radical polymerization of miniemulsions induced by compressed gases
| Autor: | Per B. Zetterlund, Yoshi Suzuki, Siming Dong, Noor Hadzuin Nik Hadzir, Frank P. Lucien |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
General Chemical Engineering Radical polymerization technology industry and agriculture Nucleation Emulsion polymerization 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences Miniemulsion chemistry.chemical_compound Monomer Polymerization chemistry Phase (matter) 0210 nano-technology Methyl acrylate |
| Zdroj: | RSC Advances. 6:50650-50657 |
| ISSN: | 2046-2069 |
| DOI: | 10.1039/c6ra08347a |
| Popis: | Generation of miniemulsions (nanoemulsions) comprising hydrophobic vinyl monomers and water by use of the compressed gases carbon dioxide and ethylene, respectively, has been investigated in the absence of high energy mixing. It is proposed that transparent/translucent miniemulsions are formed at the transparency pressure (PT) as a result of the refractive index of the dispersed phase being reduced due to expansion with carbon dioxide/ethylene, resulting in refractive index matched miniemulsions with enhanced stability. Radical polymerization of methyl acrylate at 40 °C in miniemulsions induced by carbon dioxide at PT proceeds as a hybrid miniemulsion/emulsion polymerization system generating particles with diameters less than 100 nm. The experimental data are consistent with particle formation occurring mainly via monomer droplet nucleation (miniemulsion polymerization) but also via secondary nucleation in the aqueous phase (emulsion polymerization). Polymerizations at a range of pressures above and below PT revealed limited pressure effects on the polymerization rate and particle size for both carbon dioxide and ethylene. |
| Databáze: | OpenAIRE |
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