Ethylene polymerization using a novel MgCl₂/SiO₂‐supported Ziegler–Natta catalyst

Abstract

A novel MgCl2/SiO2‐supported Ziegler–Natta catalyst was prepared using a new one‐pot ball milling method. Using this catalyst, polyethylenes with different molecular weight distributions were synthesized. The effects of the [Si]/[Mg] ratio, polymerization temperature and [Al]/[Ti] ratio on the catalytic activity, the kinetic behaviour and the molecular weight and the polydispersity of the resultant polymer were studied. It was found that the polydispersity index of the polymer could be adjusted over a wide range of 5–30 through regulating the [Si]/[Mg] ratio and polymerization temperature, and especially when the [Si]/[Mg] ratio was 1.70, the polydispersity index could reach over 25. This novel bi‐supported Ziegler–Natta catalyst is thus useful for preparing polyethylene with a required molecular weight distribution using current equipment and technological processes. Copyright © 2005 Society of Chemical Industry

The interfacial properties of MgCl2 films grown on a flat SiO2/Si substrate. An XPS and ISS study

“…In other words, the active sites into the pores of each particle are accessible for reaction with precursor solutions of the reactants [6][7][8]. Under proper conditions during catalyst preparation most of the active sites inside the pores of each silica particle are accessible for reaction with the precursor solutions.…”

Solid-state NMR studies of Ziegler–Natta and metallocene catalysts

“…Kashiwa [13] proposed that this is caused by the similarities in crystal structure and ionic radius of MgCl 2 and the titanium catalyst. Other commonly used supports are silicon oxide, SiO 2 , and a hybrid of both MgCl 2 and silicon oxide [14,15].…”

TiCl4 immobilized on a composite support SiO2/MgCl2·x(1,4‐butanediol)/poly[styrene‐co‐(acrylic acid)] for ethylene polymerization: The barrier effect of poly[styrene‐co‐(acrylic acid)]

“…Beside inorganic supports, such as MgCl 2 ,6, 7 silica,8, 9 mixture of MgCl 2 and silica,10, 11 and so on, polymer materials have also been applied as supports for Ziegler–Natta catalysts 12, 13. Polymer supports are able to eliminate some side effects of inorganic supports, such as reduction in ash content 14, 15.…”