In:
Macromolecular Symposia, Wiley, Vol. 260, No. 1 ( 2007-12)
Abstract:
In this work, a combination of experimental and computational approaches on the isospecific role of monoester‐type internal electron donors (ED) such as phenylpropionate (PhP), ethylheptanoate (EH), methylbenzoate (MB), ethylbenzoate (EB) for TiCl 4 /ED/MgCl 2 Ziegler‐Natta catalysts had been performed. The propylene polymerization results revealed that the isospecificity of catalysts increases in the following order: PhP 〈 EH 〈 MB 〈 EB. The subsequent molecular modeling on the electronic properties of the donors and two kinds of cluster model catalysts: TiCl 4 /ED/MgCl 2 and TiCl 4 /ED/(MgCl 2 ) 4 based on density functional theory (DFT) method was carried out. Two kinds of ED coordination on MgCl 2 clusters through either O or O within the monoester‐type ED had been disclosed. A perfect correlation between the dipole moment of ED, the coordination bond length of O … Mg, the competitive coordination from O with Mg ion and the isospecificity of the catalysts had been established.
Type of Medium:
Online Resource
ISSN:
1022-1360
,
1521-3900
DOI:
10.1002/masy.200751429
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
2038549-3