In:
Macromolecular Reaction Engineering, Wiley, Vol. 11, No. 5 ( 2017-10)
Kurzfassung:
SiO 2 ‐supported Cr–V bimetallic catalyst can be used for producing bimodal polyethylene which can be applied for high‐performance pipe material. Alkyl aluminum are used to prereduce the bimetallic catalysts, and the effects of alkyl aluminum for the bimetallic catalyst are fully studied by catalyst characterization, polymerization kinetics, and the properties of polymer product by the comparison with the catalyst without prereduction. The result shows that the optimum polymerization activity is almost double after the catalyst is prereduced by triisobutylaluminum (TIBA), and the needed dosage of alkyl aluminum also is decreased significantly. The alkyl aluminum of the prereduced catalyst can also act as a chain transfer agent, significantly reducing the molecular weight of the polymer. The diethylaluminum chloride (DEAC) is mostly deactivating the Cr species during the ethylene polymerization. The synthesized catalysts, prereduced by TIBA, triethylaluminum (TEA), and DEAC, all exhibited good hydrogen response and comonomer interposition ability, which will be favorable for the further application of the bimetallic catalyst in the industrial field. image
Materialart:
Online-Ressource
ISSN:
1862-832X
,
1862-8338
DOI:
10.1002/mren.201700006
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2017
ZDB Id:
2256713-6