Active sites concentration in ethylene homo- and co-polymerization with 1-hexene using the highly active TiCl4MgH2AlEt3 catalyst system

✍ Scribed by Isam A. Jaber; Gerhard Fink

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 687 KB
• Volume: 98
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(95)00024-0

✦ Synopsis

The determination of active centres concentration, [C * 1, by the 14C0 radio-labelling technique in ethylene homopolymerization and copolymerization with I-hexene using various TiCl,/MgH, catalysts of different Ti contents and surface areas is discussed. The effects of I-hexene/ethylene, AlEt,/Ti mole ratios, the polymerization time and the polymerization temperature on [C * ] are reported. At the same polymerization conditions the activity in copolymerization is higher; however, [C * ] in homoand in copolymerization are found to be more or less the same. For a low Ti-content catalyst, the addition of a small amount of 1 -hexene results in a two-to threefold increase in the rate of ethylene consumption relative to a homopolymerization run. Such an increase in the rate of polymerization is not observed for a high Ti-content catalyst. Interestingly, [C * ] determinations reveal that, for either the low or high Ti-content catalyst, [C* ] in homo-and in co-polymerization are more or less the same. The effect of the polymerization temperature on [C*] for both homo-and co-polymerization is also reported and the activation and propagation energies for the catalytic system under investigation are estimated.