Physical‐Mechanical and Thermal Properties of Polyethylene Toughened with Submicron BaSO4 Particles

The mechanical and thermal behaviour and the morphology of High‐Density Polyethylene (HDPE), filled with different types of Barium Sulfate (BaSO4) submicron particles have been examined. Composites with a filler content in the range 5‐15 vol% were obtained with a twin screw mixer‐single screw extruder and then analyzed by means of DSC, SEM and tensile and Charpy impact tests. The effect of different surface treatments of filler particles on the composite properties has been studied. The results indicate that the addition of BaSO4 particles leads to slight increase in Young's modulus and to a decrease in the yield stress independently of surface treatment. The fracture resistance tests demonstrated a strong influence of filler content and surface agents on impact parameters. The use of BaSO4 filler appears to induce a good toughening of HDPE, especially at low volume content, while surface agents reduce particle agglomeration and decrease the adhesion between filler and polymer matrix.