Kinetics of Ethylene Polymerization in the Presence of a Homogeneous Catalyst Based on a bis(Phenoxyimine) Complex of Zirconium(IV) Full article
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Kinetics and Catalysis
ISSN: 0023-1584 , E-ISSN: 1608-3210 |
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| Output data | Year: 2011, Volume: 52, Number: 2, Pages: 217-221 Pages count : 5 DOI: 10.1134/S0023158411020017 | ||
| Tags | Molecular Weight Distribution; Polymerization Time; Ethylene Polymerization; Polymer Chain Growth; Propagation Rate Constant | ||
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 07-03-00311 |
Abstract:
Changes in the molecular-weight characteristics of the product of ethylene polymerization in the course of reaction in the presence of a homogeneous catalytic system and in the number and reactivity of catalyst active sites were studied. The catalytic system consisted of bis[N-(3-tert-butylsalicylidene)anilinato]zirconium dichloride and methylalumoxane as an activator. This catalytic system exhibited the signs of unsteady-state conditions: the rate of polymerization dramatically decreased as the reaction time increased. At the onset of polymerization (to 5 min), the catalyst was single-site, and it produced low-molecular-weight polyethylene with M w = (4–10) × 103 g/mol. The fraction of active sites at the initial point in time was as high as 11% based on the initial amount of the zirconium complex. The reactivity of these centers was very high (the rate constant of polymer chain growth was 5.4 × 104 l mol−1 s−1 at 35°C). As the polymerization time increased, the number of active sites decreased and the molecular-weight distribution of polyethylene broadened because of the decay of a portion of initial centers and the formation of new centers that produced high-molecular-weight polyethylene with M w to 130 × 104 g/mol. The propagation rate constant measured at a sufficiently long polymerization time (20 min) was lower than that at the initial point in time; this fact suggests the much lower reactivity of the new active sites.
Cite:
Barabanov A.A.
, Semikolenova N.V.
, Matsko M.A.
, Echevskaya L.G.
, Zakharov V.A.
Kinetics of Ethylene Polymerization in the Presence of a Homogeneous Catalyst Based on a bis(Phenoxyimine) Complex of Zirconium(IV)
Kinetics and Catalysis. 2011. V.52. N2. P.217-221. DOI: 10.1134/S0023158411020017 WOS Scopus РИНЦ ANCAN OpenAlex
Kinetics of Ethylene Polymerization in the Presence of a Homogeneous Catalyst Based on a bis(Phenoxyimine) Complex of Zirconium(IV)
Kinetics and Catalysis. 2011. V.52. N2. P.217-221. DOI: 10.1134/S0023158411020017 WOS Scopus РИНЦ ANCAN OpenAlex
Original:
Барабанов А.А.
, Семиколенова Н.В.
, Мацько М.А.
, Ечевская Л.Г.
, Захаров В.А.
Кинетические особенности полимеризации этилена в присутствии гомогенного катализатора на основе бис(феноксииминного) комплекса Zr(IV)
Кинетика и катализ. 2011. Т.52. №2. С.225-229. РИНЦ
Кинетические особенности полимеризации этилена в присутствии гомогенного катализатора на основе бис(феноксииминного) комплекса Zr(IV)
Кинетика и катализ. 2011. Т.52. №2. С.225-229. РИНЦ
Dates:
| Submitted: | May 6, 2010 |
| Published print: | Mar 1, 2011 |
| Published online: | Apr 7, 2011 |
Identifiers:
| Web of science: | WOS:000289254900010 |
| Scopus: | 2-s2.0-79953902088 |
| Elibrary: | 16995294 |
| Chemical Abstracts: | 2011:438070 |
| Chemical Abstracts (print): | 155:123746 |
| OpenAlex: | W2110856015 |