Polymerization of 1-hexene catalyzed by bis(cyclopentadienyl)zirconium dichloride/methylaluminoxane; effect of temperature on the molecular weight and the microstructure of poly(1-hexene)

Polymerization of 1-hexene catalyzed with bis(cyclopentadienyl)zirconium dichloride/methyl-aluminoxane revealed increasing molecular weight with decreasing polymerization temperature. The Arrhenius plot (lg M̄n vs. 1/T) shows a sigmoidal curve. These results were interpreted in the sense of a change in the nature of the active species with temperature. In addition it was observed that with decreasing polymerization temperature the concentration of isotactic sequences increases.