Kinetic Study of Ethylene Polymerization over Supported bis(Imino)pyridine Iron (II) Catalysts Научная публикация
| Журнал |
Macromolecular Chemistry and Physics
ISSN: 1022-1352 , E-ISSN: 1521-3935 |
||
|---|---|---|---|
| Вых. Данные | Год: 2006, Том: 207, Номер: 15, Страницы: 1368-1375 Страниц : 8 DOI: 10.1002/macp.200600122 | ||
| Ключевые слова | Kinetics (polym.), Molecular mass distribution, Number of active centers, Propagation rate constants, Supported bis(imino)pyridine iron catalysts | ||
| Авторы |
|
||
| Организации |
|
Реферат:
Summary: The number of active centers (CP) and propagation rate constants (kP) for polymerization of ethylene with supported catalysts LFeCl2/SiO2, LFeCl2/Al2O3 and LFeCl2/MgCl2 (L = 2,6-(2,6-(Me)2C6H3N[DOUBLE BOND]CMe)2C5H3N), activated by an Al(i-Bu)3 co-catalyst, were determined by a method of polymerization inhibition with radioactive 14CO. In contrast to homogeneous systems based on LFeCl2, the supported catalysts are highly active and stable in ethylene polymerization at 70–80 °C. In the presence of hydrogen, the activity of the supported catalysts substantially increases (2–4 fold). The data obtained on the effect of hydrogen on the calculated CP and kP values suggests that for ethylene polymerization without hydrogen, the “dormant” active centers are formed in the catalytic systems. A scheme for the formation of these “dormant” centers and their reactivation in presence of hydrogen is suggested. For the investigated supported catalysts the CP values were found to be only 2 to 4% of the total iron complex content in the catalysts. The kP value for the catalysts prepared using different supports (SiO2, Al2O3 and MgCl2) were close (3.2 × 104 to 4.5 × 104 L · (mol · s)−1 at 70 °C). The support composition affects neither the molecular mass (MM) nor the molecular mass distribution (MMD) of the polymers produced. The obtained CP and kP values and data on the polymer MM and MMD lead to conclusion that the nature of the support has almost no effect on the structure of the active centers and the distribution of their reactivity.
Библиографическая ссылка:
Barabanov A.A.
, Bukatov G.D.
, Zakharov V.A.
, Semikolenova N.V.
, Mikenas T.B.
, Echevskaja L.G.
, Matsko M.A.
Kinetic Study of Ethylene Polymerization over Supported bis(Imino)pyridine Iron (II) Catalysts
Macromolecular Chemistry and Physics. 2006. V.207. N15. P.1368-1375. DOI: 10.1002/macp.200600122 WOS Scopus РИНЦ CAPlusCA OpenAlex
Kinetic Study of Ethylene Polymerization over Supported bis(Imino)pyridine Iron (II) Catalysts
Macromolecular Chemistry and Physics. 2006. V.207. N15. P.1368-1375. DOI: 10.1002/macp.200600122 WOS Scopus РИНЦ CAPlusCA OpenAlex
Даты:
| Поступила в редакцию: | 16 мар. 2006 г. |
| Принята к публикации: | 30 мая 2006 г. |
| Опубликована online: | 31 июл. 2006 г. |
| Опубликована в печати: | 2 авг. 2006 г. |
Идентификаторы БД:
| Web of science: | WOS:000239848200007 |
| Scopus: | 2-s2.0-33845275346 |
| РИНЦ: | 13533333 |
| Chemical Abstracts: | 2006:896530 |
| Chemical Abstracts (print): | 145:438924 |
| OpenAlex: | W1983996000 |