Some catalytic systems based on Ti or Zr compounds and methylalumoxane have been investigated with regard to their ability to promote styrene-ethylene copolymerization. 13C NMR analysis shows that the structure and the composition of the copolymerization products are dependent on the catalytic system and on the transition metal/methylalumoxane mole ratio. Polymers containing phenylethylene units bridging polyethylene sequences are generally obtained in the presence of Ti-based catalysts. In the presence of cyclopentadienyltitanium trichloride/methylalumoxane with high Al/Ti mole ratio one can obtain copolymers of ethylene and syndiotactic polystyrene. Zr-based catalyst don't promote copolymerization at all.
Copolymerization of Styrene and Ethylene In the Presence of Different Syndiospecific Catalysts
LONGO, Pasquale;GRASSI, Alfonso;OLIVA, Leone
1990
Abstract
Some catalytic systems based on Ti or Zr compounds and methylalumoxane have been investigated with regard to their ability to promote styrene-ethylene copolymerization. 13C NMR analysis shows that the structure and the composition of the copolymerization products are dependent on the catalytic system and on the transition metal/methylalumoxane mole ratio. Polymers containing phenylethylene units bridging polyethylene sequences are generally obtained in the presence of Ti-based catalysts. In the presence of cyclopentadienyltitanium trichloride/methylalumoxane with high Al/Ti mole ratio one can obtain copolymers of ethylene and syndiotactic polystyrene. Zr-based catalyst don't promote copolymerization at all.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
