Investigating the Nature of the Active Species in Bis(imino)pyridine Cobalt Ethylene Polymerization Catalysts
摘要:
The activation of bis(imino)pyridine cobalt-based catalysts of ethylene polymerization with methylalumoxane (MAO), AlMe3, and AlMe3/[CPh3][B(C6F5)(4)] has been studied by H-1, H-2, and F-19 NMR and EPR spectroscopy. The nature of the active sites of polymerization is discussed. The polymerization kinetics and the polymer properties for the different catalyst/activator systems were correlated with spectroscopic data.