1994 Volume 51 Issue 10 Pages 663-669
Propene polymerization was conducted with ethylenebis (tetrahydroindenyl) zirconium dichloride combined with methylalumoxane at O, 20, and 40°C. The activity increased linearly with an increase in propene pressure regardless of polymerization temperature. The molecular weights of the polymers obtained at 0°C were independent of the propene pressure, while those at 20 and 40°C slightly increased with an increase in the propene pressure. The polymers obtained at 40°C contained vinylidene end groups addition to a small amount of an internal olefin group, The amount of the vinylidene groups decreased with increasing the propene pressure of decreasing polymerization temperature. On the other hand, the amount of the internal olefins was independent of the propene pressure. The copolymerization of propene with ethylene was also conducted with this catalyst system at 0, 20, and 40°C. The produced polymers had a vinylidene end group exclusively. Moreover, the propene unit also existed at the saturated initiation end. From these results, it was concluded that the chain transfer reaction with this catalyst system was caused mainly by propene monomer when the propagation proceeded via 1, 2-addition.
