|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
Retarded anionic polymerization: copolymerization of butadiene and styrene in the presence of alkyllithium and n,s-dibutylmagnesium or triisobutylaluminum derivativesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 12 марта 2014 г.
- Авторы: Carlotti S., Menoret S., Barabanova A., Deffieux A., Desbois P.
- Журнал: Macromolecular Chemistry and Physics
- Том: 205
- Номер: 5
- Год издания: 2004
- Издательство: John Wiley & Sons Ltd.
- Местоположение издательства: United Kingdom
- Первая страница: 656
- Последняя страница: 663
- DOI: 10.1002/macp.200300118
- Аннотация: The influence of Lewis acid additives on the anionic butadiene polymerization using lithium as a counter ion in non-polar solvent is investigated. A decrease of the polymerization rate was always observed. In the presence of n,s-Bu(2)Mg the percentage of 1,2-vinyl units increases with the [Mg]/[Li] ratio. This evolution can be explained by further complexation of lithium with free dialkylmagnesium modifying the nature of the propagating species and/or possible 1,4 to 1,2 isomerization during chain exchanges between lithium and magnesium derivatives. As a result of the transmetallation process, 0.5 to 1 supplementary chains are formed by magnesium depending on the [Mg]/[Li] ratio. In contrast, the (i)Bu(3)Al/RLi system does not yield any modification of polybutadiene microstructure, which remains close to the one observed with s-BuLi alone. The determination of the reactivity ratios in styrene-butadiene copolymerization shows that tapered-like copolymers are obtained in the presence of both n,s-Bu(2)Mg and (i)Bu(3)Al. However the magnesium derivative induces a lesser increase of styrene incorporation in the copolymer than the aluminium additive. The observed microstructure and reactivity ratios support that the monomer insertion proceeds directly into heterocomplexes.
- Добавил в систему: Барабанова Анна Ивановна