ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The norbornene/ethylene copolymerization was studied using C2v- and Cs-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 Cp2ZrCl2 catalyst and increases to a constant level for the [Ph2C(Flu)(Cp)]ZrCl2 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 [Ph2C(Flu)(Cp)]ZrCl2. The microstructure of the copolymer determined with 13C NMR was observed to depend on catalyst, temperature and monomer ratio. Cp2ZrCl2 produces more norbornene blocks as a function of norbornene content in the copolymer and longer norbornene sequences than [Ph2C(Flu)(Cp)]ZrCl2. The correlation between the increasing norbornene content in the copolymer and the increasing glass transition temperature is more obvious for [Ph2C(Flu)(Cp)]ZrCl2.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
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