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 mixing in the melt. TiO₂ influences the polymerization process. In-situ polymerization was found to be advantageous with respect to encapsulation, dispersion of the filler particles leading to improved mechanical properties, except for TiO₂ containing composites. No significant influence on crystallization was observed.