Origin of “Multisite-like” Ethylene Polymerization Behavior of the Single-Site Nonsymmetrical Bis(imino)pyridine Iron(II) Complex in the Presence of Modified Methylaluminoxane
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
ACS Catalysis
ISSN: 2155-5435
|
| Вых. Данные |
Год: 2017,
Том: 7,
Номер: 4,
Страницы: 2868-2877
Страниц
: 10
DOI:
10.1021/acscatal.7b00486
|
| Ключевые слова |
Bis(imino)pyridine, Chain transfer, Ethylene polymerization, MMAO, Molecular-weight distribution, Multisite catalysts |
| Авторы |
Semikolenova Nina V.
1
,
Sun Wen-Hua
2
,
Soshnikov Igor E.
1,3
,
Matsko Mikhail A.
1
,
Kolesova Olga V.
1,3
,
Zakharov Vladimir A.
1,3
,
Bryliakov Konstantin P.
1,3
|
| Организации |
| 1 |
Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
|
| 2 |
Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
|
| 3 |
Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
|
|
Информация о финансировании (2)
|
1
|
Российский фонд фундаментальных исследований
|
16-53-53014
|
|
2
|
Федеральное агентство научных организаций России
|
0303-2016-0009
|
A detailed study of the effect of reaction temperature, time, and cocatalyst composition on the ethylene polymerization performance of 2-[1-(2,6-dibenzhydryl-4-chlorophenylimino)ethyl]-6-(1-mesityliminoethyl)pyridyliron dichloride (1) is reported. In the presence of modified methylaluminoxane (MMAO), 1 behaves like a highly active, “multisite-like” ethylene polymerization catalyst, with the resulting polyethylenes having time-dependent bimodal-like molecular-weight distributions and featuring saturated (n-propyl- and i-butyl-terminated) chain ends. To readily distinguish between bimodal and bimodal-like molecular-weight distributions, we have proposed the use of the dNf/(d log M) – log M representation further to the mainstream dWf/(d log M) – log M one. The consensus mechanism of chain transfer and chain-end formation in the presence of MMAO has been proposed, which explains the composition and amount of terminal alkyl groups in the polymer, and the apparent “multisite-like” nature of the iron catalyst. A comparison between the catalytic behaviors of the “multisite-like” 1/MMAO catalyst system and the truly multisite catalyst system based on Brookhart’s symmetrical bis(imino)pyridine iron catalyst 2 is given.