Metallocene Catalyzed Homopolymerization of Propylene with a <i>C</i><sub>2</sub> Symmetric Isospecific Zirconecene/MMAO Catalysts under Different Polymerization Conditions

Morphology control of clay-mineral particles as supports for metallocene catalysts in propylene polymerization

Spray dry granulation of clay minerals was studied to obtain clay mineral base support material for metallocene supported olefin polymerization catalysts. The morphology of the granules was strongly influenced by the nature of the clay mineral itself. Because of swelling characteristics of montmorillonite, its water dispersion was highly viscous even in the low slurry concentration (< 4 wt %). ...

Endowing aspecific, unbridged-metallocene propylene-polymerization catalysts with isospecificity: the unprecedented role of MAO.

IN SITU SILICA SUPPORTED METALLOCENE CATALYSTS FOR ETHYLENE POLYMERIZATION

Bis(2-R-ind)ZrCl2 (R: H or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. In this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, TiBA) cocatalyst was used instead of expensive methyl aluminiumoxane (MAO) cocatalyst in the polymerization. The effect of surface ...

Polymerization of propylene in a minireactor: Effect of polymerization conditions on particle morphology

Gas phase polymerization of propylene was carried out in a semi-batch minireactor using a commercially supported Ziegler–Natta (ZN) catalyst. The influence of variables including monomer partial pressure, external electron donor, reaction temperature and time on the particle morphology and size distribution was investigated. Generally, more uniform fragmentation and particle densities were obta...

Developments of chiral metallocenes as polymerization catalysts.

This review article describes developments in chiral metallocenes as polymerization catalysts focusing on C2 symmetric ansa-zirconocene complexes. Selective synthesis of rac-isomers of ansa-zirconocenes are surveyed. Isospecific polymerizations of propylene catalyzed by chiral zirconocenes are summarized. Advanced series of polymerizations by chiral metallocenes such as asymmetric polymerizatio...