Reza Razavi - Department of Chemistry, University of Zanjan, Zanjan, Iran
Ebrahim Ahmadi - Department of Chemistry, University of Zanjan, Zanjan, Iran
Ali bagheri - Department of Chemistry, University of Zanjan, Zanjan, Iran
Farzad gholami - Department of Chemistry, University of Zanjan, Zanjan, Iran

Different factors affect the activity and Molecular weight of the Philips chromium catalyst. Some of the most important factors including activation and reaction temperature, porosity of catalyst and amount of the co-catalyst. Claiming the catalyst caused to dehydroxylation or annealing of the silica surface and generates the active site population, and thereby the catalyst activity and polymer character. The extent of dehydroxylation during activation depends not only on the calcining temperature, but also on the calcining time, making the two variables seemingly inter-convertible in their effect on catalyst and polymer behavior . In this article we examined the effect of activation temperature range 550-750 °C and time activation from 6 to 18 h on the Molecular weight polyethylene produced and activity catalyst in Ethylene polymerization.

Activation tempreture, Ethylene polymerization, Philips chromium catalyst, Molecular weight polyethylene