Description:
<jats:title>Abstract</jats:title><jats:p>A heat balance reaction calorimeter was used to obtain information about the typical process parameters such as viscosity and heat transfer properties in polymerizations carried out with Cp<jats:sub>2</jats:sub>ZrCl<jats:sub>2</jats:sub>‐methylaluminoxane catalyst. The rate enhancement upon comonomer addition was of particular interest. The viscosity of the reaction mixture was found to increase dramatically during the homopolymerization of ethylene but to increase only a little in the copolymerization of ethylene and 1‐hexene even though the final slurry concentration was six times as high as in the homopolymerization. The explanation offered for this unexpected result is the much smaller particle size in the copolymerization. In part, this might also explain the higher activity in the copolymerization.</jats:p>