Bis [N-(3-tert-butylsalicylidene) cyclooctylamine] titanium dichloride activated with MAO for ethylene polymerization

Bis [N-(3-tert-butylsalicylidene) cyclooctylamine] titanium dichloride (C8 FI; complex 1) was synthesized by the Schiff base reaction and formed complex with TiCl4. This catalyst is highly active for producing polyethylene having high molecular weight (1.1 × 106–1.97 × 106 g/mole) and narrow polydispersity (1–2) in the presence of MAO as co-catalyst under atmospheric pressure. Comparing with the bis[N-(3-tert-butylsalicylidene) cycloheptylamine] titanium dichloride (C7 FI; complex 2), complex 1 exhibits higher activity upon the same polymerization condition over the temperature from 20 °C to 60 °C. Polyethylene obtained from the complex 1 has molecular weight lower than that obtained from the complex 2 due to steric bulky congestion. Additionally, the molecular weight of polymer obtained from the complex 1 increased with increasing the polymerization time from 10 to 60 min. It is evident that the complex 1 has a living fashion in ethylene polymerization.