Homogeneous polymerization of ethylene using an iron-based metal catalyst system

Abstract

An iron-based catalyst of 2,6-bis-[1-(2-methylphenylimino)ethyl]pyridine iron dichloride was prepared. The ligand was prepared using 2,6-diacetylpyridine as the starting chemical under controlled conditions. The preparation procedure was followed using 13C-NMR, 1H-NMR, FT-IR, MS (mass spectroscopy), and elemental analysis methods. The homogeneous polymerization of ethylene was carried out using the prepared catalyst in toluene media. Methyl aluminoxane (MAO) was used as a cocatalyst. The effect of the [Al] : [Fe] molar ratio, polymerization temperature, and monomer pressure of 202,000 to 454,500 Pa on the polymerization behavior were studied. The highest activity of the catalyst was obtained at 30°C, the activity decreased with increasing temperature, while increasing pressure linearly increased its activity. The molecular weight distribution of the polyethylene obtained was 1.25 to 1.72. A weight average molecular weight of 7.1 × 104 and 1.5 × 103 were obtained. The crystallinity of the polymer was about 19% and its melting point was about 65°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1517–1522, 2007