Kinetic features of ethylene polymerization over titanium-magnesium catalysts with different structures and morphology

Establishing a relationship between structural characteristics of a catalyst system and morphology of polymer particles, on the one hand, and the kinetic characteristics of the catalysts in relation to the molecular weight of the resulting polymer on the other hand, is an important scientific task and has considerable applications. In this paper, for the first time, data on the formation of polyethylene particles with different molecular weights and different morphologies on two samples of highly active supported titanium-magnesium catalysts (TMC) having different textural characteristics (pore structure and crystallite size) are obtained. It is shown that this effect persists with varying polymerization conditions (polymerization temperature, the presence and absence of hydrogen as a polymer chain transfer agent) and titanium content in the catalyst. The discussion of possible causes of the revealed differences in molecular weight of the produced polymers is based on the kinetic data and morphological analysis of the polymer particles formed on TMCs with different structural characteristics and titanium contents. The formation of PE with different molecular weights over these catalysts may be related to different concentrations of ethylene in the subsurface layer of polymer near active sites of the catalysts.

Automated summary

This paper presents experimental data on the formation of polyethylene particles with different molecular weights and morphologies using two samples of highly active supported titanium-magnesium catalysts. The effect of catalyst structural characteristics and titanium content on the molecular weight of the resulting polymers is discussed based on kinetic data and morphological analysis.