Resumo

MAIA, Alessandra de Souza; QUINI, Josué Garcia; MIOTTI, Renata Diana  e  OLIVEIRA, Wanda de. Styrene polymerization using organolanthanide compounds activated by MAO. Quím. Nova [online]. 2006, vol.29, n.6, pp. 1180-1183. ISSN 0100-4042.  http://dx.doi.org/10.1590/S0100-40422006000600006.

In an attempt to improve the performance of organolanthanide catalysts we investigated the use of the industrially important cocatalyst methylaluminoxane (MAO) to activate organolanthanide compounds in olefin polymerization. The catalytic systems LnBrCp₂(THF)₂/MAO (Cp=cyclopentadienyl) and LnBrCp*₂THF/MAO (Cp*= pentamethylcyclopentadienyl), Ln=Pr and Yb, were active in styrene polymerization but inactive in ethylene and propylene polymerization. These systems produced atactic polystyrene with conversions of up to 8.2% (PrBrCp*₂THF, Al/Ln=200, T=80ºC, t=4 h) in toluene. In the absence of solvent, the conversion is 26.0% (1.5 h) and the molar mass of the atactic polystyrene is almost ten times higher (43 kg/mol).

Palavras-chave : organolanthanide compounds; homogeneous catalysis; olefin polymerization.