Copolymerization of Ethylene with α-Olefins over Supported Titanium–Magnesium Catalysts. I. Effect of Polymerization Duration on Comonomer Content and the Molecular Weight Distribution of Copolymers Full article
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Journal of Applied Polymer Science
ISSN: 0021-8995 , E-ISSN: 1097-4628 |
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| Output data | Year: 2012, Volume: 125, Number: 3, Pages: 2034-2041 Pages count : 8 DOI: 10.1002/app.36334 | ||
| Tags | copolymerization, molecular weight distribution/molar mass distribution, polyethylene (PE), Ziegler-Natta polymerization | ||
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 10-03-00136 |
Abstract:
The data on the effect of polymerization duration on molecular weight (MW), molecular weight distribution (MWD), and content of α-olefin were obtained for ethylene/1-hexene copolymers produced on a supported titanium–magnesium catalyst (TMC) upon polymerization in the absence and presence of hydrogen. An increase in MW, narrowing of the MWD, and a decrease in 1-hexene content in the copolymer takes place with increasing polymerization duration. It was shown by molecular weight fractionation of copolymers obtained at different polymerization duration followed by analysis of narrow fractions to determine the butyl branching content that the decrease comonomer content in copolymers with increasing polymerization duration is accounted for by the decrease in the share of low molecular weight fractions with an increased butyl branch content. These data, in combination with the data concerning the narrowing of the MWD of copolymers and the decrease in activity with polymerization duration allow arriving at conclusion that active sites producing low molecular weight polymer with an increased butyl branching content is predominantly deactivated with polymerization. Active sites producing high molecular weight polymer has a low ability to copolymerize ethylene with α-olefins; however, these sites show higher stability during copolymerization.
Cite:
Nikolaeva M.I.
, Matsko M.A.
, Mikenas T.B.
, Echevskaya L.G.
, Zakharov V.A.
Copolymerization of Ethylene with α-Olefins over Supported Titanium–Magnesium Catalysts. I. Effect of Polymerization Duration on Comonomer Content and the Molecular Weight Distribution of Copolymers
Journal of Applied Polymer Science. 2012. V.125. N3. P.2034-2041. DOI: 10.1002/app.36334 WOS Scopus РИНЦ ANCAN OpenAlex
Copolymerization of Ethylene with α-Olefins over Supported Titanium–Magnesium Catalysts. I. Effect of Polymerization Duration on Comonomer Content and the Molecular Weight Distribution of Copolymers
Journal of Applied Polymer Science. 2012. V.125. N3. P.2034-2041. DOI: 10.1002/app.36334 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jun 24, 2011 |
| Accepted: | Sep 23, 2011 |
| Published online: | Jan 19, 2012 |
| Published print: | Aug 5, 2012 |
Identifiers:
| Web of science: | WOS:000302902200041 |
| Scopus: | 2-s2.0-84860219493 |
| Elibrary: | 17983640 |
| Chemical Abstracts: | 2012:106060 |
| Chemical Abstracts (print): | 157:77104 |
| OpenAlex: | W2083182964 |