A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
rac-[ethylenebis(2-(thexyldimethylsiloxy)indenyl)]zirconium dichloride: synthesis, molecular structure and olefin polymerization catalysis
Tekijät: Leino R, Luttikhedde HJG, Lehmus P, Wilen CE, Sjoholm R, Lehtonen A, Seppala JV, Nasman JH
Kustantaja: ELSEVIER SCIENCE SA
Julkaisuvuosi: 1998
Lehti:: Journal of Organometallic Chemistry
Tietokannassa oleva lehden nimi: JOURNAL OF ORGANOMETALLIC CHEMISTRY
Lehden akronyymi: J ORGANOMET CHEM
Vuosikerta: 559
Numero: 1-2
Aloitussivu: 65
Lopetussivu: 72
Sivujen määrä: 8
ISSN: 0022-328X
DOI: https://doi.org/10.1016/S0022-328X(98)00405-7
Tiivistelmä
The synthesis and molecular structure of rac-[ethylenebis(2-(thexyldimethylsiloxy)indenyl)]zirconium dichloride (4), is reported. In combination with methylaluminoxane (MAO), 4 forms an active catalyst system for homogeneous polymerization of ethylene and propylene. The high activity of 4/MAO is retained at low [Al]:[Zr] ratios [(150-250):1]. Decreasing polymerization temperature or the [Al]:[Zr] ratio results in production of polyethylene having a high molecular weight shoulder in its molecular weight distribution (MWD). Deconvolution of the MWDs into a series of calculated Flory-distribution curves indicates that with this catalyst system ethylene is polymerized by three different types of active sites, whereas propylene is predominantly polymerized by two active sites. Complex 4 crystallizes in the indenyl-backward conformation. The ligand backbone adopts the expected C-2 symmetry. (C) 1998 Elsevier Science S.A. All rights reserved.
The synthesis and molecular structure of rac-[ethylenebis(2-(thexyldimethylsiloxy)indenyl)]zirconium dichloride (4), is reported. In combination with methylaluminoxane (MAO), 4 forms an active catalyst system for homogeneous polymerization of ethylene and propylene. The high activity of 4/MAO is retained at low [Al]:[Zr] ratios [(150-250):1]. Decreasing polymerization temperature or the [Al]:[Zr] ratio results in production of polyethylene having a high molecular weight shoulder in its molecular weight distribution (MWD). Deconvolution of the MWDs into a series of calculated Flory-distribution curves indicates that with this catalyst system ethylene is polymerized by three different types of active sites, whereas propylene is predominantly polymerized by two active sites. Complex 4 crystallizes in the indenyl-backward conformation. The ligand backbone adopts the expected C-2 symmetry. (C) 1998 Elsevier Science S.A. All rights reserved.