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Effects of Hydrogen for Different Stereospecific Active Sites on Ultra Low TiCl 3 Loading Supported Catalyst
Author(s) -
Kouzai Iku,
Liu Boping,
Wada Tooru,
Terano Minoru
Publication year - 2007
Publication title -
macromolecular reaction engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 32
eISSN - 1862-8338
pISSN - 1862-832X
DOI - 10.1002/mren.200600017
Subject(s) - stereospecificity , hydrogen , active site , catalysis , dissociation (chemistry) , chemistry , polymerization , polymer chemistry , organic chemistry , polymer
The relationship between the stereospecificity of active sites and hydrogen effects on propylene polymerization was investigated for MgCl 2 ‐supported TiCl 3 catalysts at ultra‐low Ti contents. Hydrogen had no effect on the catalyst activities for isospecific sites and for aspecific sites. The efficiency of hydrogen as a chain‐transfer agent was found to depend on the stereospecificity of the active sites. Hydrogen was effective for isospecific sites but was not effective for aspecific sites. From the viewpoint of hydrogen dissociation, isospecific sites should have hydrogen dissociation sites in their surroundings. Therefore, isospecific sites may be in the island to be affected by hydrogen and isolated sites may be aspecific or have low isospecificity.