Regulation of molecular weight, molecular weight distribution and branching distribution in polyethylene, produced by supported catalysts bearing bis(imino)pyridyl Fe(II) and N,N-α-diimine Ni(II) complexes
| Autor: | Nina Semikolenova, Valentina Panchenko, Mikhail Matsko, Vladimir Zakharov |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Polyolefins Journal, Vol 9, Iss 2, Pp 103-116 (2022) |
| Druh dokumentu: | article |
| ISSN: | 2322-2212 2345-6868 |
| DOI: | 10.22063/poj.2022.3072.1208 |
| Popis: | For preparation of highly active supported catalyst with bis(imino)pyridyl Fe(II) complexes (Fe1, Fe2) and N,N-α-diimine complex of Ni (Ni3), silica modified with alumina (SiO2 (Al)) was used as a support. Data on the possibility to regulate molecular weight (MW) and molecular weight distribution (MWD) of polyethylene (PE), produced over the supported catalyst Fe1/SiO2 (Al)+TIBA by variation of polymerization temperature and the addition of hydrogen and hexene-1, are obtained. The prepared PE samples were characterized by Mw values varied from 80 to 350 kg/mol and various MMD (Mw/Mn=4.6-11.7).By grafting on SiO2(Al) of two different iron bis(imino)pyridyl complexes, producing PE with diverse MW, bi-component catalyst was prepared. This catalyst generates linear PE with broad and bimodal MWD (Mw/Mn=33). Fixation on SiO2(Al) of α-diimine Ni(II) pre-catalyst (Ni3), yielding high molecular weight branched PE at the ethylene homopolymerization, and bis(imino)pyridyl Fe(II) complex (Fe2) that forms lower molecular weight linear PE, affords formation of a new bi-component catalyst. The catalyst produces PE with broad MWD and high content of branches concentrated in high molecular weight PE fraction. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|