Ethylene polymerization with catalysts on the base of Zr-cenes and methylaluminoxanes synthesized on zeolite support

Meshkova, I. N.; Ushakova, T. M.; Ladygina, T. A.; Kovaleva, N. Yu.; Новокшонова, Л. А.

doi:10.1007/s002890070066

Cited by 25 publications

(6 citation statements)

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“…Supports such as silica, alumina, and magnesium compounds are in common use [1]. Since Brookhart seminal discovery of Ni(II) and Pd(II) bearing chelating nitrogen-based α-diimine ligands for olefin polymerization, there has been renewed interest in late transition metal-based catalyst usages in industrial scale by immobilizing them on inorganic carriers and some researchers reported maintained high activities without reactor fouling in this case [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Immobilization of α-diimine nickel (II) catalysts on multi-walled carbon nanotube for slurry ethylene polymerization

Talebnezhad

Pourmahdian

2014

Colloid Polym Sci

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Homogeneous α-diimine nickel (II) catalyst complexes, with and without amino para-aryl position functionality, were synthesized. These complexes were immobilized on carboxyl, hydroxyl, and acyl chloride functionalized multiwalled carbon nanotubes to form five novel heterogeneous α-diiminonickel catalysts. Immobilization was performed by covalent or electrostatic bonding via methylaluminoxane (MAO) linker or amide linkage. All the immobilized catalysts were fully characterized and their structures and supporting efficiencies were determined. Both the nature of α-diimine ligands and the kind of interaction between anchored catalyst complexes and multi-walled carbon nanotube surface influenced the catalytic performance, microstructure, and morphology of obtained polyethylenes. Catalysts immobilized by covalent bonds showed higher activities than physisorbed ones with the trend of activity rising versus temperature. Reaction between ligand amino para-aryl position and multiwalled carbon nanotube acyl chloride functionality resulted in immobilization through amide linkage. This procedure prepared catalyst with the lowest relative weight loss in thermogravimetry analysis and highest activities up to 5863 g PE mmol −1 Ni h −1 . The catalyst produced polyethylene with dense botryoidal morphology, highest molecular weight distributions and highest melting points up to 14.1 at 60°C and 133°C at 30°C in polymerization trials, respectively.

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Section: Introductionmentioning

confidence: 99%

Immobilization of α-diimine nickel (II) catalysts on multi-walled carbon nanotube for slurry ethylene polymerization

Talebnezhad

Pourmahdian

2014

Colloid Polym Sci

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“…Due to its Lewis acidity, MAO can produce ligand exchange from the precatalysts and subsequent ligand abstraction from the metallocene complex to form a cationic complex as the active species for the polymerization reaction. However, the exact role of MAO has not yet been fully elucidated, due in part to its complex structure [ 7 , 8 , 9 , 10 ]. Different cocatalysts have been developed to control the activity, selectivity, molecular weight and other olefin polymerization catalytic features [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

“…Different cocatalysts have been developed to control the activity, selectivity, molecular weight and other olefin polymerization catalytic features [ 10 ]. In recent years, clay minerals [ 11 ] or zeolite-supports [ 7 , 8 , 9 , 12 , 13 , 14 , 15 ] have received attention as alternative cocatalysts [ 16 , 17 ] in olefin polymerization reactions.…”

Section: Introductionmentioning

confidence: 99%

Silicoaluminates as “Support Activator” Systems in Olefin Polymerization Processes

et al. 2010

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In this work we report the polymerization behaviour of natural clays (montmorillonites, MMT) as activating supports. These materials have been modified by treatment with different aluminium compounds in order to obtain enriched aluminium clays and to modify the global Brönsted/Lewis acidity. As a consequence, the intrinsic structural properties of the starting materials have been changed. These changes were studied and these new materials used for ethylene polymerization using a zirconocene complex as catalyst. All the systems were shown to be active in ethylene polymerization. The catalyst activity and the dependence on acid strength and textural properties have been also studied. The behaviour of an artificial silica (SBA 15) modified with an aluminium compound to obtain a silicoaluminate has been studied, but no ethylene polymerization activity has been found yet.

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“…For industrial applications, heterogeneous catalyst systems are preferred since the amount of the expensive cocatalyst MAO27–35 can be significantly reduced and “reactor fouling” is avoided. Catalyst precursors for olefin polymerization have been heterogenized on a huge number of different support materials 36–59. Silica gels are the most common supports,36–41 but many other materials like magnesium chloride,42–45 aluminum oxide,46–48 charcoal,49 polypropylene,50 polystyrene,51, 52 zeolites,53–57 starch,58 or even cherry pits59 were applied.…”

Section: Introductionmentioning

confidence: 99%

μ‐Gels as support materials for dinuclear olefin polymerization catalysts

Schilling

Görl

Alt

2008

J of Applied Polymer Sci

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μ‐Gels which consist of poly(organosilicon) networks can be employed as efficient support materials for ethylene polymerization catalyst precursors. Alkylaluminum cocatalysts can be fixed on the μ‐gel surfaces using the PHT (“partially hydrolyzed trimethylaluminum”) method. The influence of different aluminum/water ratios on the ethylene polymerization properties of these heterogeneous systems is investigated. Dinuclear silicon bridged zirconium complexes are used as catalyst precursors yielding polyethylenes with broad or bimodal molecular weight distributions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

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Ethylene polymerization with catalysts on the base of Zr-cenes and methylaluminoxanes synthesized on zeolite support

Cited by 25 publications

References 0 publications

Immobilization of α-diimine nickel (II) catalysts on multi-walled carbon nanotube for slurry ethylene polymerization

Immobilization of α-diimine nickel (II) catalysts on multi-walled carbon nanotube for slurry ethylene polymerization

Silicoaluminates as “Support Activator” Systems in Olefin Polymerization Processes

μ‐Gels as support materials for dinuclear olefin polymerization catalysts

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