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RESEARCH PRODUCT
Transition metal complexes of tetradentate and bidentate Schiff bases as catalysts for ethylene polymerization: Effect of transition metal and cocatalyst
Krystyna CzajaMarzena BiałekEwelina Szydłosubject
polyethyleneZiegler‐Natta polymerizationDenticitySchiff basePolymers and PlasticsChemistryLigandOrganic ChemistryVanadiumchemistry.chemical_elementPolyethyleneCatalysischemistry.chemical_compoundpostmetallocene catalystTransition metalPolymerizationPolymer chemistryMaterials ChemistrySchiff basesoligomersdescription
This article compares catalytic performance of ethylene polymerization in similar polymerization conditions of transition metal complexes having two ligands [O,N] (phenoxy-imine) and having one tetradentate ligand [O,N,N,O] (salphen or salen). It is shown that the activity of both complex types as well as the product properties depend in the same way on the type of central metal in the complex and on the cocatalyst used. Although the type of ligand has some effect on the catalyst activity, yet it does not control the properties of the obtained products. The vanadium and zirconium complexes, irrespective of the cocatalyst used, yield linear polyethylene with high molecular weight (a few hundred thousand g/mol). Similar products are formed when titanium complexes activated with MAO are employed. On the other hand, the same titanium complexes in conjunction with Et 2 AlCl, yield low molecular weight polyethylene (of a few thousand) and additionally a mixture of oligomers.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-01-15 | Journal of Polymer Science. Part A : Polymer Chemistry |