Catalytic polymerization of liquid propylene: Effect of low-yield hexene prepolymerization on kinetics and morphology

Abstract

A Ziegler-Natta-catalyst was used in ultra lowyield slurry prepolymerization followed by liquid propylene (main) polymerizations. Complete catalyst disintegration down to 1.5-2 μm particle size is observed at prepolymerization yields of 10 g per g cat. The initial (main) polymerization rate increased up to 55% and the final average particle diameter can be controlled between 50 and 1500 μm at main polymerization yields of 20 kg PP per g cat · hr-1. Tension generation within the particle and the absence of a polymer layer explains these results. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.