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Ethylene polymerization with heterogeneous Ziegler-Natta catalysts
Polymer Bulletin, 1995TiCl4/SiO2, Ti(OC4H9)4/SiO2, MgCl2/TiCl4/SiO2 and MgCl2/Ti(OC4H9)4/SiO2 catalysts were prepared by treating silica gel with TiCl4, Ti(OC4H9)4, MgCl2/TiCl4 or MgCl2/Ti(OC4H9)4 in tetrahydrofuran (THF) solution. Ethylene polymerization was performed with these catalysts activated by common alkylaluminum compounds. The influence of magnesium dichloride on
Luiz Claudio de Santa Maria +3 more
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Stereochemical Control in Ziegler-Natta Catalysts
1987The remarkably high level of stereoselectivity associated with magnesium chloride-based catalysts is realized only in the presence of a selectivity control agent (SCA), frequently an aromatic ester.1 The usual effect of the SCA is to reduce activity while significantly enhancing stereoselectivity.2 Fortunately, the reduction in productivity (65%) is ...
S. E. Wilson, W. L. Callender, R. C. Job
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Particle Control of Supported Ziegler-Natta Catalysts
1987A good catalyst for olefin polymerization should exhibit, among other characteristics, good morphological control of the resulting polymers, as well as high activity, control of the molecular weight and molecular weight distribution. Thus, in regard to the polymer morphology, particles with spherical shape, having an average diameter of about 500 u, no
A. Muñoz-Escalona +3 more
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Stereospecificity of Heterogeneous Ziegler-Natta Catalysts
1985The most prominent feature of heterogeneous Ziegler-Natta catalysts is their ability to produce isotactic olefin polymers exhibiting a combination of outstanding mechanical characteristics. This ability adds a new dimension to the description of the catalysts and the polymerization processes: the study of catalyst and polymerization parameters ...
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