INVESTIGADORES
FERREIRA Maria Lujan
artículos
Título:
Effect of Co- and Non-Copolymerizable Lewis Bases in Propylene Polymerization with EtInd2ZrCl2/MAO
Autor/es:
FERREIRA, M. L.; BELELLI, P. G.; DAMIANI, D. E.
Revista:
MACROMOLECULAR CHEMISTRY AND PHYSICS
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Año: 2001 vol. 202 p. 830 - 839
ISSN:
1022-1352
Resumen:
This paper reports the effect of co- and noncopolymerizableLewis bases in propylene polymerizationwith the soluble system EtInd2ZrCl2/MAO. With noncopolymerizableLewis bases, the activity and the molarmass of poly(propylene) are diminished. This result isunusual because there is agreement about the cationic natureof the active site in Zirconocene/MAO systems andthe effect of a Lewis base must be to decrease the terminationconstant versus the propagation constant, consideringthe diminished electrophilicity of Zr. In the case of copolymerizableLewis bases, the negative effect on activity ishigher. An explanation of the data is given, with a newmodel of Lewis bases/cationic Zr interaction, takingaccount of recent reports about the structure of activesites.
