Polimerização de estireno utilizando compostos organolantanídeos ativados por MAO

• Main Authors: Alessandra de Souza Maia, Josué Garcia Quini, Renata Diana Miotti, Wanda de Oliveira
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2006-12-01
• Series: Química Nova
• Subjects: organolanthanide compounds; homogeneous catalysis; olefin polymerization
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422006000600006&lng=en&tlng=en

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).