INFLUENCE OF A FINE TALC ON THE PROPERTIES OF COMPOSITES WITH HIGH-DENSITY POLYETHYLENE AND POLYETHYLENE POLYSTYRENE BLENDS/

Fine talc filled high density polyethylene (HDPE) and HDPE/polystyrene (PS) blends were extruded, injection moulded and characterized. Some of the mechanical properties of the talc filled HDPE and talc filled 7 5/25 HDPE/PS blend were deduced from stress-strain measurements. A com parison between the effect of the talc on the properties of the filled HDPE and filled 75/25 HDPE/PS blend showed that the mineral filler ha d the same effect on both systems provided that its array in the organ ic matrix is almost the same in both cases. In fact, the rheological r esults proved that the dispersion of talc in the HDPE matrix was not r eally affected by the presence of PS. The study particularly focused o n the effect of talc on the ultimate tensile strength of the filled HD PE and that of the filled blend. It has been noted that the brittle na ture of PS neutralizes, to a certain extent, the degrading effect of t alc on this property. Furthermore, both PS and talc have a complementa ry effect on the stiffness and the resilience of HDPE/PS/talc blend co mposites.