Identifying the Nature of the Active Species in the Polymerization of Methacrylates: Inhibition of Methyl Methacrylate Homopolymerizations and Reactivity Ratios for Copolymerization of Methyl Methacrylate/n-Butyl Methacrylate in Classical Anionic, Alkyllithium/Trialkylaluminum-Initiated, Group Transfer Polymerization, Atom Transfer Radical Polymerization, Catalytic Chain Transfer, and Classical Free Radical Polymerization
| Autor: | David M. Haddleton, Clare Topping, Martin C. Crossman, Kirsty H. Hunt, Carl Waterson, Kevin G. Suddaby |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Polymers and Plastics
Chemistry Organic Chemistry Radical polymerization Chain transfer Photochemistry Inorganic Chemistry Living free-radical polymerization Cobalt-mediated radical polymerization Polymer chemistry Materials Chemistry Living polymerization Reversible addition−fragmentation chain-transfer polymerization Ionic polymerization Living anionic polymerization |
| Zdroj: | Macromolecules. 30:3992-3998 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma970303m |
| Popis: | Reactivity ratios have been determined for the monomer pair methyl methacrylate and n-butyl methacrylate under a range of polymerization conditions. The value of using reactivity ratios as a mechanistic probe is discussed. Reactivity ratios determined where M1 = MMA and M2 = n-BMA are 1.04, 0.81, classical anionic; 1.10, 0.72 , alkyllithium/trialkylaluminum initiated; 1.76, 0.67, group transfer polymerization; 0.98, 1.26, atom transfer radical polymerization; 0.75, 0.98, catalytic chain transfer; and 0.93, 1.22, classical free radical polymerization. The data suggest ATRP and CCTP proceed via radical type propagation. Li/Al-initiated polymerization undergoes an anionic mechanism, while strong evidence is found for an associative, catalyst dependent mechanism for GTP. Galvinoxyl is demonstrated to inhibit GTP as well as free radical polymerization, and it is suggested that neither the use of inhibition nor polymer stereochemistry can be used to distinguish between anionic and radical processes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|