Kinetic Features of Ethylene Polymerization over Titanium-Magnesium Ziegler-Natta Catalysts: Effect of Monomer Concentration on the Number of Active Centers and Propagation Rate Constant Full article
| Journal |
Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 |
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| Output data | Year: 2015, Volume: 396, Pages: 328-334 Pages count : 7 DOI: 10.1016/j.molcata.2014.10.011 | ||||
| Tags | Ethylene polymerization, Number of active centers, Polymerization kinetics, Propagation rate constant, Ziegler-Natta catalysts | ||||
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| Affiliations |
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Funding (1)
| 1 | The Ministry of Education and Science of the Russian Federation |
Abstract:
It was found that the observed order of the polymerization rate with respect to ethylene concentrationat ethylene polymerization over two titanium-magnesium catalysts of different compositions is signifi-cantly higher than 1 (1.6–2.1). The data on the effect of ethylene concentration on the number of activecenters (CP) and the propagation rate constant (kP) at ethylene polymerization over these catalysts wereobtained by method of polymerization quenching with14CO. An increase in ethylene concentration wasfound to increase the number of active centers. In some cases the increase of ethylene concentration pro-ceeds to the narrowing of the molecular weight distribution of the resulting polyethylene and an increasein the calculated value of propagation rate constant. These effects were shown to be most pronouncedat low ethylene pressure and increased concentration of an activator (AlEt3). Based on the experimen-tal data, we proposed a scheme of reactions to explain the effects of ethylene and AlR3concentrationson the number of active centers, the average values of propagation rate constant and molecular weightdistribution of polymers produced over these multi-site catalysts.
Cite:
Barabanov A.A.
, Sukulova V.V.
, Matsko M.A.
, Zakharov V.A.
Kinetic Features of Ethylene Polymerization over Titanium-Magnesium Ziegler-Natta Catalysts: Effect of Monomer Concentration on the Number of Active Centers and Propagation Rate Constant
Journal of Molecular Catalysis A: Chemical. 2015. V.396. P.328-334. DOI: 10.1016/j.molcata.2014.10.011 WOS Scopus РИНЦ ANCAN OpenAlex
Kinetic Features of Ethylene Polymerization over Titanium-Magnesium Ziegler-Natta Catalysts: Effect of Monomer Concentration on the Number of Active Centers and Propagation Rate Constant
Journal of Molecular Catalysis A: Chemical. 2015. V.396. P.328-334. DOI: 10.1016/j.molcata.2014.10.011 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Aug 20, 2014 |
| Accepted: | Oct 8, 2014 |
| Published online: | Oct 18, 2014 |
| Published print: | Jan 1, 2015 |
Identifiers:
| Web of science: | WOS:000347265200042 |
| Scopus: | 2-s2.0-84910025587 |
| Elibrary: | 24002336 |
| Chemical Abstracts: | 2014:1815007 |
| Chemical Abstracts (print): | 161:682266 |
| OpenAlex: | W2015362777 |