Catalyst impregnation and ethylene polymerization with mesoporous particle supported nickel-diimine catalyst

Ye, Zhibin; Alsyouri, Hatem M.; Zhu, Shiping; Lin, Jerry Y S

doi:10.1016/s0032-3861(02)00877-7

Cited by 78 publications

(74 citation statements)

References 43 publications

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“…Similar bimodal melting behavior was also observed for ethylene polymerization using an in situ silica supported nickel-diimine system [22] and nickel-diimine supported on mesoporous silica particles. [24] Conclusion Ethylene polymerization was carried out using MMAOtreated silica supported nickel diimine catalyst (1,4-bis(2,6-diisopropylphenyl) acenaphthene diimine nickel(II) dibromide) in a slurry semibatch reactor. Compared with the homogeneous catalyst, the catalyst activity of the supported catalyst was reduced significantly.…”

Section: Effect Of Catalyst Support On Polymer Propertiesmentioning

confidence: 99%

“…[12,19] One of the techniques which proved to be efficient and is commonly described in the literature is to impregnate the catalyst on MAO-treated silica. [11,19] Nickel diimine catalysts have been supported on different types of inorganic supports, such as silica, [20][21][22][23][24] and polymeric supports. [25] Exxon Chemical has synthesized polyethylene in slurry and fluidized bed gas phase reactors using nickel-diimine catalyst supported on methylaluminoxane (MAO)-treated silica.…”

Section: Introductionmentioning

confidence: 99%

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Ethylene Polymerization with Silica‐Supported Nickel‐Diimine Catalyst: Effect of Support and Polymerization Conditions on Catalyst Activity and Polymer Properties

AlObaidi

Zhu

2003

Macro Chemistry & Physics

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Ethylene was polymerized using both homogeneous and modified methylaluminoxane (MMAO)‐treated silica supported nickel‐diimine catalysts (1,4‐bis(2,6‐diisopropylphenyl) acenaphthene diimine nickel(II) dibromide) in a slurry semibatch reactor. The effects of catalyst support and polymerization conditions (ethylene pressure and reaction temperature) on catalyst activity and polymer properties were systematically investigated. The supported catalyst gave far lower activity than the homogeneous catalyst. The activities of both catalyst systems increased with polymerization temperature with a maximum at 40 °C. Compared with the homogeneous catalyst, the supported catalyst system produced polyethylene with a different microstructure. Due to steric effects, the supported catalyst system exhibited lower chain walking rates than the homogeneous catalyst, producing polymers with less branching content and, thus higher melting points. Depending on polymerization conditions, two active site populations were observed during polymerization using supported catalyst; one population remained fixed on the surface of the support, and the other was extracted from the support, exhibiting the same polymerization behavior as the homogeneous catalyst.DSC thermograms for polyethylene produced with homogeneous and supported catalysts at an ethylene pressure of 50 psig (3.45 · 105 Pa) and reaction temperature 40 °C.magnified imageDSC thermograms for polyethylene produced with homogeneous and supported catalysts at an ethylene pressure of 50 psig (3.45 · 105 Pa) and reaction temperature 40 °C.

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Section: Effect Of Catalyst Support On Polymer Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ethylene Polymerization with Silica‐Supported Nickel‐Diimine Catalyst: Effect of Support and Polymerization Conditions on Catalyst Activity and Polymer Properties

AlObaidi

Zhu

2003

Macro Chemistry & Physics

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“…The supporting method has a great effect on catalyst immobilization and characteristics of supported catalysts. By using the second method, loading amount was found to be much higher and the supported catalysts had a higher catalytic activity for ethylene polymerization [22].…”

Section: Polymerization With Silica Supported Systemmentioning

confidence: 99%

Advances in late transition metal catalysts for olefin polymerization/oligomerizarion

Bahuleyan

Park

et al. 2006

Catal Surv Asia

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In this review article, we have consolidated our recent studies on late transition metal catalysts (mainly Fe, Co) for olefin polymerization/oligomerization. A series of bisiminopyridyl Co(II) and Fe(II) complexes were synthesized. These catalysts when activated with MAO in aromatic or aliphatic hydrocarbon solvents, oligomerize or polymerize ethylene to a-olefins or high molecular weight polymers with exceptionally high activities and selectivities. The electronic and steric effects of allyloxy and benzyloxy substituted bisiminopyridyl Fe(II) and Co(II) complexes were also investigated. The influence of catalyst structure and temperature on the polymerization activity, thermal properties and molecular weight were discussed. The effects of heterogenization of these catalysts on silica and modified SBA-15 were analyzed. The polymerization of polar monomers such as vinyl ethers and methyl methacrylate was tested and no specific trends in activity and polymer molecular weight with changes in steric bulkiness around the metal center were observed with the same catalyst system.

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“…Ni-based diimine catalyst can produce polyethylene with shortchain branches through a chain-walking mechanism [5,[19][20][21][22][23][24]. In 1997, Sumitomo Chemical Company has patented a process of ethylene trimerisation that uses this class of ligands.…”

Section: Introductionmentioning

confidence: 99%

Turning a Cr-based heterogeneous ethylene polymerisation catalyst into a selective ethylene trimerisation catalyst

Nenu

Bodart

Weckhuysen

2007

Journal of Molecular Catalysis A: Chemical

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A Phillips Cr/SiO 2 polymerisation catalyst was converted into an ethylene trimerisation catalyst after assembling new active sites on the silica surface in the presence of TAC (1,3,5-triphenylhexahydro 1,3,5-triazacyclohexane) as ligand and CH 2 Cl 2 as solvent. The reaction conditions play a role in tuning the catalytic activity of this system. It is a true trimerisation catalyst at low ethylene pressures, while, at high pressures, the polymerisation activity becomes dominant. Moreover, at high ethylene pressures, polyethylene characterised by a high crystallinity degree is obtained. Instead, a highly branched heavy oligomer of ethylene characterised by a very narrow molecular weight distribution is obtained at 1 bar. 1-Hexene, formed as the main product in the ethylene trimerisation reaction at low pressures, is partially incorporated into this growing oligomer making redundant the use of a second comonomer feedstock and an expensive catalyst.

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Catalyst impregnation and ethylene polymerization with mesoporous particle supported nickel-diimine catalyst

Cited by 78 publications

References 43 publications

Ethylene Polymerization with Silica‐Supported Nickel‐Diimine Catalyst: Effect of Support and Polymerization Conditions on Catalyst Activity and Polymer Properties

Ethylene Polymerization with Silica‐Supported Nickel‐Diimine Catalyst: Effect of Support and Polymerization Conditions on Catalyst Activity and Polymer Properties

Advances in late transition metal catalysts for olefin polymerization/oligomerizarion

Turning a Cr-based heterogeneous ethylene polymerisation catalyst into a selective ethylene trimerisation catalyst

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