Results 31 to 40 of about 6,865 (263)

What do We Know about Reaction Mechanism? The Electrospray Ionization Mass Spectrometry Approach [PDF]

open access: yes, 2011
Santos, LS (reprint author), Univ Talca, Lab Asymmetr Synth, POB 747, Talca, Chile.Man's fascination with chemical reactions goes back to ancient times.
Santos, L.S.
core   +2 more sources

Fragmentable Heterogeneous Cocatalysts for the Metallocene-Catalyzed Polymerization of Olefins, II [1]. Preparation, Characterization and Testing of the Cocatalysts and Microscopic Evaluation of the Polyethylene [PDF]

open access: yes, 2005
Surface modified silica were reacted with different aluminiumalkyls AlR2R’ (R = Me, Et, i-Bu, R’ = H, Me, Et, i-Bu), oligomeric methylaluminoxane (MAO) and combinations of both, to yield heterogeneous cocatalysts.
Lange, Katharina C. H.   +3 more
core   +1 more source

Ti+4 determination in Ziegler–Natta polymerization catalysts via UV‒vis spectroscopy method [PDF]

open access: yesPolyolefins Journal
The determination of Ti+4 in Ziegler–Natta catalysts is highly relevant for industrial plants that use Ziegler–Natta (ZN) catalysts based on TiCl4 as a source of titanium.
Jonas Biagini, Joao Henrique dos Santos
doaj   +1 more source

Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization [PDF]

open access: yesPolyolefins Journal, 2015
Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2  metallocene catalysts using triethylaluminum (TEA) as coupling agent.
Gholam-Reza Nejabat   +7 more
doaj   +1 more source

Protonolysis of Fe-C bonds of a diiminopyridineiron(II) dialkyl complex by acids of different strengths: Influence of monoanionic ligands on the spectroscopic properties of diiminopyiridine-FeY2 complexes [PDF]

open access: yes, 2014
The reaction of the dialkyliron complex [Fe(CH2SiMe 3)2(MesBIP)] (MesBIP = 2,6-bis((N-mesityl)acetimidoyl)pyridine) with protic acids (HY) of different strengths (Y = C6F5O, CF3CO2, Cl, CF3SO3) invariably leads to the cleavage of both Fe-C bonds ...
Cartes Domínguez, María Ángeles   +4 more
core   +1 more source

Ultrasound- and microwave-assisted preparation of lead-free palladium catalysts: effects on the kinetics of diphenylacetylene semi-hydrogenation [PDF]

open access: yes, 2015
The effect of environmentally benign enabling technologies such as ultrasound and microwaves on the preparation of the lead-free Pd catalyst has been studied.
Bonrath, Werner   +6 more
core   +1 more source

Advantages of an Emulsion‐Produced Ziegler‐Natta Catalyst Over a Conventional Ziegler‐Natta Catalyst

open access: yesMacromolecular Materials and Engineering, 2005
AbstractSummary: Self‐supported and MgCl2‐supported Ziegler‐Natta catalysts, produced by two catalyst synthesis methods are compared. Borealis Polymers OY (Finland), who supplied the catalysts, developed the catalyst synthesis methods. The first method (Method One) is based on an emulsion system and consists of an in situ single step preparation.
Mohammed Abboud   +2 more
openaire   +1 more source

Chemical state analysis of magnesium-supported Ziegler-Natta catalyst by soft X-ray emission spectrometer (SXES) after contact with alkyl aluminum [PDF]

open access: yesPolyolefins Journal
This report is on the characterization of active Ti center in heterogeneous Ziegler-Natta catalysts with Soft X-ray Emission Spectrometer (SXES). Since titanium in the catalyst has various chemical bonds, it is important to grasp the chemical bond state.
Masayoshi Saito   +6 more
doaj   +1 more source

Electron Microscopy Transfer System to Protect Atmosphere‐Sensitive Materials for Scanning Electron Microscopy Characterization

open access: yesMicroscopy Research and Technique, EarlyView.
SEM–EDX and XRD characterization confirm that pouches made from readily available aluminum foil, used in combination with a commercial cryo‐EM transfer system, effectively protect highly atmosphere‐sensitive and/or hygroscopic materials from contamination during transfer from inert environments to the SEM vacuum chamber.
Louis G. Corcoran   +8 more
wiley   +1 more source

"Supported Ziegler-Natta catalysts from MgCl2·nROH precursors and its catalytic behaviors for diene copolymerization"

open access: yesHecheng xiangjiao gongye
The precursor MgCl2 · nROH of supported Ziegler Natta catalyst was prepared by chemical activation method, and different pre catalysts TiCl4/MgCl2 (C-Cat) were prepared by loading TiCl4.
FAN Xun-zhang, ZHAO Yuan-jin, LUO Shu-fang, HE Ai-hua?
doaj   +1 more source

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