Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/43282
Title: A comparative kinetic study of ethylene polymerization mediated by iron, cobalt and chromium catalysts bearing the same N,N,N-bis(imino)trihydroquinoline
Authors: Huang, C
Zakharov, VA
Semikolenova, NV
Matsko, MA
Solan, GA
Sun, WH
First Published: 5-Nov-2018
Publisher: Elsevier for Academic Press
Citation: Journal of Catalysis, 2019, Volume 369, pp. 1-9
Abstract: The iron(II), cobalt(II) and chromium(III) chlorides, [2-{(2,4,6-Me3C6H2)NCMe}-8-{N(2,4,6-Me3C6H2)}C9H8N]MCln (n = 2, M = Fe LFeCl2, Co LCoCl2; n = 3, M = Cr LCrCl3), each bearing the same N,N,N-bis(imino)trihydroquinoline chelating ligand, have been employed as precatalysts for ethylene polymerization with modified methylaluminoxane (MMAO) as the co-catalyst. The kinetic profiles for these homogeneous polymerizations are reported in addition to the properties of the resultant polymers under comparable reaction conditions. All the experimental data indicate that the active metal center plays a key role on the catalytic performances of the complexes, especially the polymerization activity, thermal stability and lifetime of the active species. Under optimized conditions the iron catalyst displays the highest rate of polymerization but displays this for only a short period, while the chromium catalyst shows a lower maximum polymerization rate but sustains its performance over a longer period and at a higher temperature. In terms of the polymer properties, all three metal catalysts afford highly linear polymers with the metal center influencing the molecular weight and type of end group. Specifically, the cobalt and chromium catalysts produce narrowly dispersed low molecular weight polymers incorporating vinyl end groups, while the iron catalyst affords polymers of higher molecular weight displaying broad molecular weight distributions, with both fully saturated and unsaturated chain ends.
DOI Link: 10.1016/j.jcat.2018.10.028
ISSN: 0021-9517
eISSN: 1090-2694
Links: https://www.sciencedirect.com/science/article/pii/S0021951718304123?via%3Dihub
http://hdl.handle.net/2381/43282
Embargo on file until: 5-Nov-2019
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © Elsevier, 2018. After an embargo period this version of the paper will be an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Description: The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.
Appears in Collections:Published Articles, Dept. of Chemistry

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