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A mesoporous molecular sieve MCM‐41 supported iron‐based diimine catalyst (MC) was prepared for the first time. The kinetic behavior of ethylene polymerization with MC was studied. The effects of Al/Fe molar ratio and various cocatalysts on the catalytic activity and properties of the polyethylene obtained were investigated. The results showed that good catalytic activities can be reached with cocatalyst methylaluminoxane (MAO) and triethylaluminium (TEA). Ethylene polymerization with MC gave polymers with higher molecular weight, melting temperature and onset temperatures of decomposition (Tonset) and better morphology than those obtained with the corresponding homogeneous catalyst. Copyright © 2004 Society of Chemical Industry

New cobalt catalysts {[2,6-(CH₃C=NAr)₂C₅H₃N]CoCl₂} (Ar=2-methyl-4-methoxyphenyl, 1) and (Ar=2,4-dimethylphenyl,2) were synthesized and found to exhibit good selectivity for α-olefins with methylaluminoxane (MAO) as co-catalyst. With only ethylene as the feed monomer cobalt catalysts 1 or 2 can be coupled with zirconium catalyst Dichloro [rac-ethylenebis(indenyl)]Zirconium (IV) rac-EtInd₂ZrCl₂ (3) to produce linear low density polyethylene by in situ polymerization. Spectra of resulting materials exhibit ethyl, butyl and long-chain branches in the backbone of polyethylene. The ratio of Co/Zr and Δt, which is defined as the interval between introductions of two catalysts into the reactor, influenced catalytic activity and the resulting materials greatly. Compatibility and complementary behaviour of different catalysts proved to be two most important factors for in situ copolymerization. Copyright © 2003 Society of Chemical Industry

A new iron‐based catalyst, 2,6‐bis[(1‐naphthanylimino)ethyl]pyridine iron(II) chloride I, has been successfully synthesized and characterized. Ethylene was polymerized by I/methylaluminoxane to give branched, low‐density polymers with good activity. The result shows that the new diimino ligand has improved the characteristics of the resulting polyethylene.© 2000 Society of Chemical Industry