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Efficient and tailored polymerization of olefins and styrene by metallocene catalysts
Author(s) -
Kaminsky Walter,
Hopf Andreas,
ArndtRosenau Michael
Publication year - 2003
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200351133
Subject(s) - methylaluminoxane , metallocene , propene , tacticity , polymerization , polymer chemistry , monomer , zirconium , catalysis , post metallocene catalyst , styrene , materials science , melting point , molar mass , molar ratio , chemistry , organic chemistry , copolymer , polymer , composite material , metallurgy
Abstract 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.