Effect of Temperature on the Number of Active Sites and Propagation Rate Constant at Ethylene Polymerization Over Supported Bis(imino)pyridine Iron Catalysts Full article
| Journal |
Journal of Polymer Science, Part A: Polymer Chemistry
ISSN: 0887-624X , E-ISSN: 1099-0518 |
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| Output data | Year: 2008, Volume: 46, Number: 19, Pages: 6621-6629 Pages count : 9 DOI: 10.1002/pola.22972 | ||
| Tags | Activation energy, Bis(imino)pyridine iron catalysts, Kinetics (polym.), Number of active sites, Polyethylene (PE), Propagation rate constant | ||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 07-03-00311 |
Abstract:
The inhibition of ethylene polymerization with radioactive carbon monoxide (14CO) was used to obtain data on the number of active sites (CP) and propagation rate constant (kP) at ethylene polymerization in the temperature range of 35–70 8C over supported catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 (L: 2,6-(2,6-(Me)2C6H3N ¼ CMe)2C5H3N) with activator Al(i-Bu)3. The values of effective activation energy (Eeff), activation energy of propagation reaction (EP), and temperature coefficients of variation of the number of active sites (ECp ¼ Eeff EP) were determined. The activation energies of propagation reaction for catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 were found to be quite similar (5.2–5.7 kcal/mol). The number of active sites diminished considerably as the polymerization temperature decreased, the ECp value being 5.2–6.2 kcal/mol for these catalysts at polymerization in the presence of hydrogen. The reactions of reversible transformations
of active centers to the surface hydride species at polymerization in the presence and absence of hydrogen are proposed as the derivation of ECp.
Cite:
Barabanov A.A.
, Bukatov G.D.
, Zakharov V.A.
Effect of Temperature on the Number of Active Sites and Propagation Rate Constant at Ethylene Polymerization Over Supported Bis(imino)pyridine Iron Catalysts
Journal of Polymer Science, Part A: Polymer Chemistry. 2008. V.46. N19. P.6621-6629. DOI: 10.1002/pola.22972 WOS Scopus РИНЦ ANCAN OpenAlex
Effect of Temperature on the Number of Active Sites and Propagation Rate Constant at Ethylene Polymerization Over Supported Bis(imino)pyridine Iron Catalysts
Journal of Polymer Science, Part A: Polymer Chemistry. 2008. V.46. N19. P.6621-6629. DOI: 10.1002/pola.22972 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Apr 18, 2008 |
| Accepted: | Jul 14, 2008 |
| Published online: | Aug 27, 2008 |
| Published print: | Oct 1, 2008 |
Identifiers:
| Web of science: | WOS:000259589300024 |
| Scopus: | 2-s2.0-54749110253 |
| Elibrary: | 13589966 |
| Chemical Abstracts: | 2008:1204315 |
| Chemical Abstracts (print): | 149:576875 |
| OpenAlex: | W2010636016 |