Determination of the Number of Active Centers and of the Propagation Rate Constant for Ethylene Polymerization on Supported Ni-Containing Catalysts by Using 14CO Full article
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Macromolecular Chemistry and Physics
ISSN: 1022-1352 , E-ISSN: 1521-3935 |
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| Output data | Year: 1998, Volume: 199, Number: 11, Pages: 2473-2476 Pages count : 4 DOI: 10.1002/(SICI)1521-3935(19981101)199:11<2473::AID-MACP2473>3.0.CO;2-W | ||
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| Affiliations |
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Funding (1)
| 1 | International Science Foundation | RBF300 |
Abstract:
Ethylene polymerization on supported Ni-containing catalysts was studied using 14CO as the inhibitor and as a label for determining the number of active centers (AC). The polymerization rate decreases sharply after introducing a mole ratio 14CO/Ni = 0.5 ÷ 1 and recovers after the removal of 14CO. The number of labels in the polymer and in the liquid phase (hexane) increases with the amount of 14CO introduced and with 14CO contact time (τco). In the absence of ethylene the number of labels in the polymer does not increase with τco and the number of labels in the liquid phase is essentially less than in the presence of ethylene. The rate of the label accumulation in the polymer during short contact times (τco = 5 min) is essentially higher than that during the following periods of time (τco = 5–135 min). Fast label accumulation occurs through first 14CO molecule insertion into the Ni-polymer bond, and the slower one through copolymerization of 14CO with ethylene, i.e. when the second and more 14CO molecules insert into the polymer chain. Catalyst activity and the number of AC (in the range of 1.5 to 6% of Ni content) decrease with polymerization time. For both catalysts the values of the propagation rate constant are maximum at short polymerization time (5 to 15 min) and equal to (3 ± 0.8) · 103 L/(mol · s) at 65°C.
Cite:
Bukatov G.D.
, Goncharov V.S.
, Panchenko V.N.
, Zakharov V.A.
Determination of the Number of Active Centers and of the Propagation Rate Constant for Ethylene Polymerization on Supported Ni-Containing Catalysts by Using 14CO
Macromolecular Chemistry and Physics. 1998. V.199. N11. P.2473-2476. DOI: 10.1002/(SICI)1521-3935(19981101)199:11<2473::AID-MACP2473>3.0.CO;2-W WOS РИНЦ ANCAN OpenAlex
Determination of the Number of Active Centers and of the Propagation Rate Constant for Ethylene Polymerization on Supported Ni-Containing Catalysts by Using 14CO
Macromolecular Chemistry and Physics. 1998. V.199. N11. P.2473-2476. DOI: 10.1002/(SICI)1521-3935(19981101)199:11<2473::AID-MACP2473>3.0.CO;2-W WOS РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jan 12, 1998 |
| Accepted: | May 4, 1998 |
| Published print: | Nov 1, 1998 |
| Published online: | Dec 16, 1998 |
Identifiers:
| Web of science: | WOS:000076888000015 |
| Elibrary: | 21268939 |
| Chemical Abstracts: | 1998:747783 |
| Chemical Abstracts (print): | 130:25391 |
| OpenAlex: | W1992159486 |