Korean Journal of Chemical Engineering, Vol.20, No.1, 22-26, 2003
Influence of Process Parameters on Ethylene-Norbornene Copolymers Made by Using [2,2'-Methylenebis(1,3-dimethylcyclopentadienyl)]-Zirconium Dichloride and MAO
Ethylene-norbornene copolymerization was investigated by using metallocene catalysts, [2,2'-methylenebis(1,3-dimethylcyclopentadienyl)]zirconium dichloride(2,2'-CH2 (1,3-Me2Cp)2ZrCl2, Catalyst A) and racemic-ethylenebis(indenly)zirconium dichloride (rac-Et(Ind)2 ZrCl2, Catalyst B), in the presence of methylaluminoxane as a cocatalyst. The influences of different process parameters such as polymerization temperature and ethylene pressure were studied by using a 56 wt% norbornene solution in toluene. The results show that Catalyst A has a higher activity in copolymerization than Catalyst B. Catalyst A also has a superior norbornene insertion performance to Catalyst B, resulting in polymers with higher glass transition temperatures, by approximately 70 ℃, at similar polymerization conditions, indicative of a great commercial potential of Catalyst A.