Ligands Make the Difference! Molecular Insights into CrVI/SiO2 Phillips Catalyst during Ethylene Polymerization

Insights into the effect of vanadium on chromium-vanadium Phillips catalysts for the ethylene polymerization

The chromium/vanadium bimetallic Phillips catalysts developed by our research group have been proved to be a promising process to produce bimodal polyethylene using a single-reactor process. The vanadium loading of CrV-1/1, CrV-1/2, and CrV-1/3 has a significant effect on the polymerization activity, product molecular weight (MW), as well as th...

Group (IV) Metallocene Complexes with Bulky ω-aryloxyalkyl-Substituted Indenyl Ligands as Catalyst Precursors for Homogeneous Ethylene Polymerization

 A series of seven new complexes of zirconium and hafnium with bulky ω-aryloxyalkyl substituted indenyl ligands were synthesized and characterized by NMR spectroscopy and elemental analysis. These complexes were activated with methylaluminoxane and tested for homogeneous ethylene polymerization. The zirconium catalysts showed higher activities than their hafnium an...

Phillips catalysts synthesized over various silica supports: Characterization and their catalytic evaluation in ethylene polymerization

Ethylene polymerization was carried out using Phillips chromium catalyst based on silica supports such as silica aerogel, SiO2 (Grace 643), and titanium modified SiO2 (G 643), and the results were compared with other catalysts based on SiO2 (Aldrich), SBA-15(Hex), SBA-15(Sp) and MCM-41. A combination of TGA, DSC, XRD, nitrogen adsorption, SEM, ICP, FTIR and other analyses were used to character...

Reaction dynamics during the testing of polymerization catalyst

The olefins polymerization process in a slurry reactor is discussed. The reaction rate dynamics was analyzed and the contributions of feed flow, gas-liquid mass transfer, polymerization reaction, and catalyst deactivation were estimated. The propylene solubility in a solvent mixture “heptane” was calculated using Soave-Redlich-Kwong equation of state. These data were then approximated by Henry-...

Cationic Rhodium Complexes with Hemilabile Phosphine Ligands as Polymerization Catalyst for High Molecular Weight Stereoregular Polyphenylacetylene