abstract |
Polyethylenes are prepared having a density in the range 900-980 kg/m3 and a weight average molecular weight >=375,000 characterized by a fracture toughness at -40° C. >20 kJ/m2 and a dynamic viscosity of <3000 Pa.s at 100 rad/sec. The polymers also having a die swell of 10-80% and show a desirable combination of physical and processing properties. The polymers are prepared by the use of catalysts comprising a metallocene component and a Ziegler component. |