| Abstract: | Ethylene and propylene were polymerized by different combinations of metallocenes and aluminoxanes. Ethyl‐iso‐butylaluminoxane (EBAO), which could be easily obtained by direct hydrolysis of Et3Al/iso‐Bu3Al in toluene with water, displayed as good polymerization activity as methylaluminoxane when it was paired with some metallocenes. The UV–visible spectroscopic study on different metallocene/aluminoxane pairs suggests that tightness of the ionic pairs generated from the reaction between metallocene and aluminoxane is different for a fixed metallocenium. The loose ionic pair derived from EBAO prefers the monomer propagation and hinders the interaction between active species, which results in high catalytic activity and molecular weight. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 998–1003, 2003 |
