نتایج جستجو برای: ziegler natta catalysis

تعداد نتایج: 28180  

2017
Olga P. Tkachenko Alexey V. Kucherov Leonid M. Kustov Ville Virkkunen Timo Leinonen Peter Denifl

Ziegler-Natta polymerization catalysts were characterized by a complex of surface- and bulk-sensitive methods (DRIFTS, XPS, ESR, and XAS = XANES + EXAFS). A diffuse-reflectance Fourier-transform IR spectroscopy (DRIFTS) study showed the presence of strong Lewis acid sites in different concentrations and absence of strong basic sites in the polymerization catalysts. X-ray photoelectron spectrosc...

Journal: :Journal of Polymer Research 2021

Abstract The scientific and technical advances in the field of polymer science has been abundant recent years. Amongst various polymeric materials available market, synthesis polyolefins forefront since decades. A major challenge this domain remains attaining stereoregular especially polypropylene (PP) significant efforts were carried out by synthesizing internal donors (ID) aiding catalysts in...

Journal: :Journal of the American Chemical Society 2002
Harold W Boone Phillip S Athey Michael J Mullins Dean Philipp Richard Muller William A Goddard

Since the advent of Ziegler-Natta polymerization of ethylene, attempts have been made to extend coordination polymerization to commercially important monomers with polar functionality. In this study we examined the copolymerization of perdeuterated vinyl chloride (VC) and perdeuterated vinyl acetate (VA) with ethylene using a tridentate Fe(II) dichloride pyridine diimine metal catalyst. The res...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2006
Cristiane F Petry Larissa B Capeletti Fernanda C Stedile João H Z Dos Santos Dirce Pozebon

A method for the determination of Ti and V using inductively coupled plasma atomic emission spectrometry (ICP OES) in Ziegler-Natta polymerization catalysts is proposed. The concentrations of both Ti and V are efficiently determined after catalyst acid digestion with a mixture of HNO3 + HCl + HF and heating (160 degrees C for 6 h) or with 10% (v/v) H2SO4 and heating (160 degrees C for 6 h) or w...

Journal: Polyolefins Journal 2016

Mg(OEt)2 with spherical morphology is one of the most important precursors for the preparation of industrial Ziegler-Natta catalysts. In the present article, morphology evolution of Mg(OEt)2 particles is studied in the course of the synthesis. The morphology of Mg(OEt)2 particles is observed throughout the process by SEM. The results show that Mg(OEt)2 particles are formed through i) seed gener...

Journal: :Dalton transactions 2011
Kerstin Unverhau Gerald Kehr Roland Fröhlich Gerhard Erker

Starting from 1,1'-diacetylferrocene the ortho-amino,α-dimethylamino[3]ferrocenophane system 3 was prepared. This was converted to the o-imino,α-Cp-derivative 6. Subsequent treatment with e.g. an excess of methyllithium followed by ZrCl(2)(NMe(2))(2)(thf)(2) and Me(2)SiCl(2) eventually gave the [3]ferrocenophane based Cp-amido zirconium complex 11b. In a similar way the [3]ferrocenophane derive...

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