Efficient and tailored polymerization of olefins and styrene by metallocene catalysts

Different optimised new c s ‐symmetric ansa zirconocenes were used for the homopolymerization of propene ‐ activated by methylaluminoxane (MAO) with an Al : Zr molar ratio of 2000. In a series of experiments, the polymerisation temperature was varied in a range from 0 to 60°C. The obtained syndiotactic polypropenes show highly isotacticities up to rrrr pentads of 98% and melting points of 150°C. Stereoselectivities are sensitive to the monomer concentration, showing decreasing syndiotacticities with decreasing propene concentration due to increasing amount of skipped insertion which is demonstrated for the zirconium catalyst.