Homopolymerization of ethylene and copolymerization with 1-butene in the presence of bis(cyclopentadienyl)titanium dichloride and diisobutylaluminum chloride

Ethylene was homopolymerized and copolymerized with 1-butene in benzene at 30°C. with the use of bis(cyclopentadienyl)titanium dichloride and diisobutylaluminum chloride as catalyst. Both freshly prepared catalyst and catalyst which had been aged up to 114 hr. were used. When the catalyst was aged prior to adding the monomer, the yields were lower and the products had higher molecular weights. In the case of copolymers, aging of the catalyst also affected the relative concentrations of the comonomers in the products. 1-Butene was an effective chain transfer agent under all reaction conditions. The data were found to be consistent with the previously suggested mechanism according to which different species initiate polymerizations with freshly mixed and aged catalysts.