Polymerization of olefins through heterogeneous catalysis. XIV. The influence of temperature in the solution copolymerization of ethylene

The influence of temperature variation on the kinetics and the polymer properties in the homo‐ and copolymerization of ethylene in a solution reactor is discussed. The Polymerization is conducted in a semibatch mode at 320 Psig total reactor pressure for 10 min polymerization time. Temperature variations in the range 145–200°C in both home‐and copolymerization of ethylene with 1‐octene shows that the highest catalyst yield was obtained at temperature of 165–175°C. At the optimal temperature, a high initial maximum in the rate of ethylene consumption is attained in a few seconds followed by a relatively slow decay when compared with polymerization conducted at higher temperatures. Polymerization at temperatures ≥ 185°C resulted in a lower peak in the consumption rate of ethylene accompanied by a rapid decay with time. In the case of ethylene/1‐Octene copolymerization, a rather low comonomer incorporation level is obtained at the conditions employed; the 1‐octene incorporated was only 0.2–0.7 mol %. Higher Mw values, of about 350,000 at 145°C, are obtained in homopolymerization in comparison to Mw values obtained in copolymerization, of about 195,000 at the same temperature. Over the temperature range of 145–200°C, both Mw and Mn values vary by about 40%.