ISSN:
0887-624X
Keywords:
propylene polymerization
;
metallocene catalyst
;
methylaluminoxane
;
atactic polypropylene
;
regioselectivity
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Propylene has been polymerized with mono(η5-cyclopentadienyl)titanium tribenzyloxide activated with methylaluminoxane (MAO). It was found that the content of residual trimethylaluminium (TMA) in MAO has a determinative effect on the polymerization. An excess of TMA in the catalyst system reduces the Ti species to inactive lower valent states. The catalyst system gives medium molecular-weight atactic polypropylene (Mv = 2-7 × 104) with narrow molecular weight distribution (Mw/Mn = 1.4-1.8). The polymer has a stereoirregular structure described by Bernoullian statistics. Statistical analysis of the regiotriad distribution of the polypropylene chains indicates a regioblock microstructure. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2051-2057, 1998
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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