NEW SYNTHESIS OF A HIGHLY-ACTIVE DELTA-MGCL2 FOR MGCL2 TICL4/ALET(3) CATALYTIC-SYSTEMS/

A good supporting material for Ziegler-Natta type catalysts was obtain ed by reaction between powdered metallic magnesium and 1-chloro-n-CmH2 m+1 (m = 3-9). This reaction affords a highly disordered form of MgCl2 which was characterized by FT-TR spectroscopy and powder X-ray diffra ction (XRD) analysis. This MgCl2 form shows a crystallographic disorde r much higher than that exhibited by the products obtained following t he commercial activation procedures of alpha-MgCl2, either mechanical or chemical. As shown by the XRD spectra, the synthetized MgCl2 is cha racterized 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-Nat ta type catalysts. Thus, by titanation of the obtained delta-MgCl2 we have prepared some supported catalysts which have been tested in the s lurry propene polymerizations, showing high activity (136 000-138 000 gPP/gTi) and good stereoselectivity (82-88 % I.I.).