ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Polymerization of propene was conducted at 40°C under reduced pressure (0.35 - 1.0 atm) using the C1-Symmetric threo-iPr(3-tBuCp)(3-tBuInd)ZrCl2/MAO and TiCl4/MgCl2/Al(iBu)3 catalyst systems and the effect of propene pressure on the microstructure of the resulting isotactic polypropene was investigated. In the case of C1-symmetric metallocene, the [mmmm]-pentad fraction decreased moderately with decreasing propene pressure, but the magnitude of decrease was much smaller than those reported by Busico et al. using typical C2-symmetric metallocenes. Whereas, the [mmmm]-pentad fraction of isotactic polypropene obtained with the conventional Ziegler-Natta catalyst did not change so much in the pressure range. Thus, epimerization of the growing polymer chain was found to be drastically dependent upon the catalyst system.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1997.021980919
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