Effect of the synthesis conditions of titanium-magnesium catalystson the composition, structure and performance in propylenepolymerization

Supported catalysts synthesized via the interaction of Mg(OEt)2 with TiCl4 in the presence or absence of an internalstereoregulating donor (di-n-butyl phthalate), with different solvents (chlorobenzene, n-undecane, n-heptane) at differenttitanation temperatures have been studied by a set of physicochemical methods. Data on the chemical composition, X-raystructure and pore structure of these catalysts as well as data on their activity and stereospecificity in polymerization of propylenewere obtained. Chemical composition, structure, activity and stereospecificity depend primarily on the presence of an electrondonor stereoregulating component and on the solvent nature and titanation temperature. Activity of the catalysts is determined bytotality of different characteristics: the chemical composition, in particular, the presence of inactive by-products like TiCl3(OEt),the MgCl2 X-ray structure and pore structure. More active catalyst which was synthesized under optimal conditions in thepresence of di-n-butyl phthalate contains the minimal amount of TiCl3(OEt) by-product, and has a more ordered X-ray structureand a homogeneous mesoporous structure with a narrow mesopore size distribution.

Keywords:

Supported Ziegler-Natta catalysts , titanium-magnesium catalysts formation , propylene polymerization