Preparation of spherical MgCl2-supported bis(phenoxy-imine) zirconium complex for ethylene polymerization

The spherical MgCl2 supports treated by methylaluminoxane (named MAO-supports) were prepared using MgCl2·2.56C2H5OH adducts as support material subjected to elimination of EtOH by thermal dealcoholization treatments. Then bis(phenoxy-imine) zirconium complex, bis-[N-(3-tert-butylsalicylidence)cyclohexylaminato] zirconium(IV) dichloride (1), was directly impregnated onto these MAO-supports. ICP, EDX, GC, N2-BET, IR and XRD analyses indicated that the texture of the supports and MAO-supports, the elements on solid catalysts, and so on, were greatly relied on dealcoholization temperature. Meanwhile, it was also found that the activities of the supported catalysts for ethylene polymerization and the properties of resultant polymers were strongly dependent on dealcoholization temperature. Finally, PEs with spherical morphology and high bulk density (over 0.35 g/ml) were obtained, without reactor fouling.

Bis-[N-(3-tert-butylsalicylidence)cyclohexylaminato] zirconium(IV) dichloride has been directly impregnated onto MAO modified spherical MgCl2 support. The supported catalyst showed high activity for ethylene polymerization with proper catalytic life-span. Finally, PEs with spherical morphology and high bulk density (over 0.35 g/ml) were obtained, without reactor fouling. SEM image of PE particles produced by supported bis(phenoxy-imine) zirconium catalyst.Figure optionsDownload as PowerPoint slide