| Abstract: | The polymerization of butadiene in toluene using Co(acac)3–(i-Bu)3Al–H2O catalyst system was studied. Presented are the effects of the addition order, aging time, and composition of catalysts on rates, polymer microstructure, and molecular weights. The polymerization was found to be initiated by the Co(acac)3-hydrolized aluminum alkyl complex. The chain propagation proceeds according to a first-order reaction with respect to monomer and active species and is a strong function of Al/H2O with an optimum ratio of 1.0, but independent of Al/Co. The nature of polymerization seems to change as Al/H2O increases from less than 1 to greater than 1. Transfer reaction is significant. From the kinetic data it was found that the termination reaction is most likely to be by combination. |
