1329997-01-4Relevant academic research and scientific papers
Hafnium amidoquinoline complexes: Highly active olefin polymerization catalysts with ultrahigh molecular weight capacity
Fontaine, Philip P.,Klosin, Jerzy,McDougal, Nolan T.
, p. 6244 - 6251 (2012/10/30)
The preparation and characterization of a new class of polyolefin procatalysts is described. Hafnium tribenzyl procatalysts, supported by amidoquinoline ligands, were prepared in two steps from commercially available materials. Solid-state structures, determined by single-crystal X-ray analyses, revealed that all the hafnium complexes display approximate trigonal-bipyramidal geometry around the metal center. The complexes were evaluated in an ethylene/1-octene copolymerization study and were found to be highly active at elevated temperatures (120 °C). The best catalyst, derived from ((2,6-dimethylphenyl)(2,4-dimethylquinolin-8-yl)amino)tribenzylhafnium (6d), compares favorably to previously reported systems supported by bidentate nitrogen-based ligands. In particular, this catalyst exhibits very high molecular weight capacity and high catalytic activity, with a moderate 1-octene response. Alkyl substitution at the carbon ortho to the quinolino nitrogen was found to be an important factor for improving polymer compositional homogeneity, as evidenced by a narrowing of the polydispersity index and a single melting temperature in the resulting copolymer.
PROCESS FOR POLYMERIZING AN OLEFIN MONOMER AND CATALYST THEREFOR
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, (2011/09/16)
The present invention generally relates to a process that polymerizes an olefin monomer, and a precatalyst and catalyst useful in such process.
