Catalytic chain transfer polymerisation (cctp) of methyl methacrylate: Effect of catalyst structure and reaction conditions on chain transfer coefficient
| Autor: | Stuart N. Richards, David M. Haddleton, Darren R. Maloney, Andrew V. G. Muir, Kevin G. Suddaby |
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| Rok vydání: | 1996 |
| Předmět: |
Polymers and Plastics
Organic Chemistry chemistry.chemical_element Chain transfer Activation energy Condensed Matter Physics Photochemistry Catalysis Solvent chemistry.chemical_compound chemistry Polymerization Catalytic chain transfer Polymer chemistry Materials Chemistry Methyl methacrylate Cobalt |
| Zdroj: | Macromolecular Symposia. 111:37-46 |
| ISSN: | 1022-1360 |
| DOI: | 10.1002/masy.19961110106 |
| Popis: | Catalytic chain transfer polymerisation of methyl methacrylate has been investigated by a range of cobalt(I1) complexes. The effect of catalyst structure, reaction temperature and solvent has been examined. At 60°C in the absence of solvent, the chain transfer coefficient, Cs, for MMA and cobaloximes modified by bridging BF2 groups e.g. 3 is found to be 40,900, this is constant over a wide mass range. Cs is lowered when catalysts of larger cross sectional area are used supporting a diffusion controlled process. Co-ordinating solvents suppress Cs by competing for coordination of the Co(I1) effectively reducing the concentration of active species. No conclusions can be drawn regarding the effect of temperature and thus the activation energy of the process. CCTP lowers the observed rate of polymerisation. |
| Databáze: | OpenAIRE |
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