Properties of in-situ filled polyethylene

Polyethylene-filler composites (kaolin, BaSO 4 , and TiO 2 ) have been prepared by in-situ polymerization using a metallocene catalyst and by extrusion mixing in the melt. TiO 2 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 TiO 2 containing composites. No significant influence on crystallization was observed.