Ethylene/α‐olefin copolymerization using diphenylcyclopentadienyl‐phenoxytitanium dichloride/Al( i Bu) 3 /[Ph 3 C][B(C 6 F 5 ) 4 ] catalyst systems

Copolymerization of ethylene with 1‐octene and 1‐octadecene using constrained geometry catalysts 2‐(3,4‐diphenylcyclopentadienyl)‐4,6‐di‐ tert ‐butylphenoxytitanium dichloride (1), 2‐(3,4‐diphenylcyclopentadienyl)‐6‐ tert ‐butylphenoxytitanium dichloride (2), 2‐(3,4‐diphenylcyclopentadienyl)‐6‐methylphenoxytitanium dichloride (3), and 2‐(3,4‐diphenylcyclopentadienyl)‐6‐phenylphenoxytitanium dichloride (4) was studied in the presence of Al( i Bu) 3 and [Ph 3 C][B(C 6 F 5 ) 4 ](TIBA/B). The effect of the catalyst structure, comonomer, and reaction conditions on the catalytic activity, comonomer incorporation, and molecular weight of the produced copolymers was also examined. The 1 /TIBA/B catalyst system exhibits high catalytic activity and produces high molecular weight copolymers. The melting temperature and the degree of crystallinity of the copolymers show a decrease with the increase in the comonomer incorporation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008