Реферат: A detailed study of the effect of polymerization conditions at the ethylene polymerization over supported bis(imino)pyridyl Fe(II) complexes (Me2-LFeCl2 and Cl2-LFeCl2 ) and N,N-α-diimine Ni(II) complex (Me3-L(1)NiBr2) on the molecular weight (MW) and molecular weight distribution (MWD) of the produced PE is reported. Silica, modified with alumina in the oxide form (SiO2(Al) was used as a support. The above catalysts show high activity at ethylene polymerization with tri-isobutyl alumina (TIBA) as co-catalyst. Data about the possibility to regulate molecular weight and MWD of polyethylene (PE) produced over the supported catalyst Me2-LFeCl2/SiO2(Al)+TIBA by variation of polymerization temperature, addition of hydrogen and hexene-1 at polymerization as chain-transfer agents, are obtained. The prepared PE samples are characterized by Mw values that varied from 80 to 350 kg/mol and various MWD (Mw/Mn=4.6-11.7). An approach of using of R2-LFeCl2 and L(1)NiBr2 as components of binary catalyst for production of bimodal PE with controlled branching distribution in a single reactor is demonstrated. By grafting on SiO2(Al) support two different bis(imino)pyridyl complexes of Fe(II), producing PE with different MW, bi-component catalyst was prepared. The above system generates linear PE with broad and bimodal MWD (Mw/Mn=33). By grafting on the same support N,N-α-diimine Ni(II) pre-catalyst (Me3L(1)NiBr2), producing branched PE with high molecular weight in ethylene homopolymerization and bis(imino)pyridyl Fe(II) complex (Cl2LFeCl2) that forms PE with low molecular weight, new bi-component catalyst was prepared. PE with broad MWD and high content of branchings, concentrated in the high molecular weight PE fraction was obtained over this catalyst.

Библиографическая ссылка: Matsko M.A. , Semikolenova N.V. , Zakharov V.A.
Design of PE with Broad MWD and Controlled Branching Distribution via Ethylene Homopolymerization over Supported Catalysts on the Base of Fe and Ni Complexes
Asian Polyolefin Workshop 2021 20-21 Dec 2021