Effect of Silicone Oil on the Mechanical Properties of Highly Filled HDPE Composites

The effects of aluminium and magnesium hydroxide filler, surfacemodifications of the fillers, and silicone oil on the mechanical properties ofhigh density polyethylene (HDPE) composites were studied. The surface modificationsof magnesium hydroxide (Mg(OH) ₂ ) and aluminium hydroxide (Al(OH) ₃ )with coupling agents such as silanes and organotitanate increase the tensilestrength to some extent, and have little effect on elongation at break andnotched Izod impact strength of HDPE composites containing 140 phr fillers. Silicone oil was found to be an effective additive for toughening highly filledHDPE composites, and this, together with an appropriate surface modification ofthe fillers, is an important factor in realizing the change in the highlyfilled HDPE composites from brittle to tough fracture under tensile and impactstress. The plastic deformation of the fracture surfaces of HDPE compositesobserved by scanning electron microscopy is associated with the presence ofsilicone oil.