Polyethylene-filler composites (kaolin, BaSO4, and TiO2) have been prepared
by in-situ polymerization using a metallocene catalyst and by extrusion mi
xing in the melt. TiO2 influences the polymerization process. In-situ polym
erization was found to be advantageous with respect to encapsulation, dispe
rsion of the filler particles leading to improved mechanical properties, ex
cept for TiO2 containing composites. No significant influence on crystalliz
ation was observed.