Properties of in-situ filled polyethylene

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.