Results 41 to 50 of about 13,033 (225)

Synthesis of (Ind)2ZrCl2 Catalyst for Copolymerization of Ethylene and Propylene: Parameters Effect on Productivity [PDF]

open access: yesعلوم و تکنولوژی پلیمر, 2010
Bis(indenyl)zirconium dichloride as a catalyst was synthesized using a modified method at the room temperature. Polymerization of ethylene and copolymerization of ethylene and propylene were carried out by this metallocene catalyst. Ethylene propylene (P/
S. Ahmadjo   +4 more
doaj   +1 more source

Zirconium and titanium complexes supported by tridentate LX2 ligands having two phenolates linked to furan, thiophene, and pyridine donors: precatalysts for propylene polymerization and oligomerization [PDF]

open access: yes, 2008
Zirconium and titanium complexes with tridentate bis(phenolate)-donor (donor = pyridine, furan and thiophene) ligands have been prepared and investigated for applications in propylene polymerization.
Agapie, Theodor   +4 more
core   +2 more sources

Direct protonation of the W–H bonds of Bis(pentamethylcyclopentadienyl)tungsten dihydride [PDF]

open access: yes, 1989
Protonation of (C_5Me_5)_2 WH_2 to give [(C_5Me_5)_2WH_3]+ is proposed to occur by attack at both W–H bonds rather than by direct attack at the d^2 metal ...
Bercaw, John E., Parkin, Gerard
core   +1 more source

Gas phase polymerization of ethylene with a silica-supported metallocene catalyst: influence of temperature on deactivation [PDF]

open access: yes, 1997
Ethylene was polymerized at 5 bar in a stirred powder bed reactor with silica supported rac-Me2Si[Ind]2ZrCl2/methylaluminoxane (MAO) at temperatures between 40°C and 80°C using NaCl as support bed and triethylaluminium (TEA) as a scavenger for impurities.
Meier, G.B.   +5 more
core   +2 more sources

Electronic structure and magnetic properties of metallocene multiple-decker sandwich nanowires

open access: yes, 2011
We present a study of the electronic and magnetic properties of the multiple-decker sandwich nanowires ($CP-M$) composed of cyclopentadienyl (CP) rings and 3d transition metal atoms (M=Ti to Ni) using first-principles techniques.
C. Morari   +6 more
core   +1 more source

Hybrid materials based on polyethylene and MCM-41 microparticles functionalized with silanes: catalytic aspects of in situ polymerization, crystalline features and mechanical properties [PDF]

open access: yes, 2016
New nanocomposites based on polyethylene have been prepared by in situ polymerization of ethylene in presence of mesoporous MCM-41. The polymerization reactions were performed using a zirconocene catalyst either under homogenous conditions or supported
A. Bento   +70 more
core   +1 more source

The charge percolation mechanism and simulation of Ziegler–Natta polymerizations Part III. Oxidation states of transition metals [PDF]

open access: yesJournal of the Serbian Chemical Society, 2006
The oxidation state of the transition metal (Mt) active centre is the most disputable question in the polymerization of olefins by Ziegler–Natta (ZN) and metallocene complexes.
BRANKA PILIC   +5 more
doaj   +3 more sources

Uranium(III) coordination chemistry and oxidation in a flexible small-cavity macrocycle [PDF]

open access: yes, 2015
U(III) complexes of the conformationally flexible, small-cavity macrocycle trans-calix[2]benzene[2]pyrrolide (L)2–, [U(L)X] (X = O-2,6-tBu2C6H3, N(SiMe3)2), have been synthesized from [U(L)BH4] and structurally characterized. These complexes show binding
Arnold P. L.   +22 more
core   +3 more sources

Influence of the elastomeric polypropylene addition on the properties of commercial metallocenic polypropylene

open access: yesMaterials Research, 2001
Polypropylene with special properties can be obtained by metallocenic catalysts. These catalytic systems represent the beginning of a new age in polyolefins technology. In this work, the influence of the addition of a syndiotactic polypropylene (s-PP) on
Maria de Fátima V. Marques   +2 more
doaj   +1 more source

Preparation of High-Purity Ammonium Tetrakis(pentafluorophenyl)borate for the Activation of Olefin Polymerization Catalysts

open access: yesMolecules, 2021
Homogeneous olefin polymerization catalysts are activated in situ with a co-catalyst ([PhN(Me)2-H]+[B(C6F5)4]− or [Ph3C]+[B(C6F5)4]−) in bulk polymerization media. These co-catalysts are insoluble in hydrocarbon solvents, requiring excess co-catalyst (>3
Hyun-Ju Lee   +7 more
doaj   +1 more source

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