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Influence of batch reaction conditions on norbornene/ethylene copolymers made using C 2v ‐ and C s ‐symmetric metallocene/MAO catalysts
Author(s) -
Lasarov Harri,
Mönkkönen Kari,
Pakkanen Tuula T.
Publication year - 1998
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19980901)199:9<1939::aid-macp1939>3.0.co;2-f
Subject(s) - norbornene , methylaluminoxane , metallocene , copolymer , ethylene , polymer chemistry , catalysis , post metallocene catalyst , chemistry , monomer , materials science , polymerization , organic chemistry , polymer
The norbornene/ethylene copolymerization was studied using C 2v ‐ and C s ‐symmetric metallocene catalysts in the presence of methylaluminoxane as a cocatalyst. The batch reactions were carried out at four different temperatures copolymerizing a constant amount of ethylene with the appropriate amount of norbornene. The activity decreases for the Cp 2 ZrCl 2 catalyst and increases to a constant level for the [Ph 2 C(Flu)(Cp)]ZrCl 2 catalyst when the norbornene/ethylene ratio in the reaction increased. The highest activities and the highest norbornene contents in the copolymers were achieved using the [Ph 2 C(Flu)(Cp)]ZrCl 2 . The microstructure of the copolymer determined with 13 C NMR was observed to depend on catalyst, temperature and monomer ratio. Cp 2 ZrCl 2 produces more norbornene blocks as a function of norbornene content in the copolymer and longer norbornene sequences than [Ph 2 C(Flu)(Cp)]ZrCl 2 . The correlation between the increasing norbornene content in the copolymer and the increasing glass transition temperature is more obvious for [Ph 2 C(Flu)(Cp)]ZrCl 2 .