New synthesis of a highly active d-MgCl2 for MgCl2/TiCl4/AlEt3 catalytic systems

A good supporting material for Ziegler-Natta type catalysts was obtained by reaction between powdered metallic magnesium and 1-chloro-n-CmH2m+1 (m = 3-9). This reaction affords a highly disordered form of MgCl2 which was characterized by FT-TR spectroscopy and powder X-ray diffraction (XRD) analysis. This MgCl2 form shows a crystallographic disorder much higher than that exhibited by the products obtained following the commercial activation procedures of alpha-MgCl2, either mechanical or chemical. As shown by the XRD spectra, the synthetized MgCl2 is characterized by the typical structure of the delta-form. Therefore, this MgCl2 form, in view of its highly disordered structure, appears as a promising material for the preparation of active supported Ziegler-Natta type catalysts. Thus, by titanation of the obtained delta-MgCl2 we have prepared some supported catalysts which have been tested in the slurry propene polymerizations, showing high activity (136 000-138 000 gPP/gTi) and good stereoselectivity (82-88 % I.I.)