A comparison of the mechanical properties and water absorption behavior of white rice husk ash and silica filled polypropylene composites

This paper compares the processability, mechanical properties, and water absorption behavior of polypropylene (PP) composites filled with white rice husk ash (WRHA) and silica. It is shown that preparation of WRHA filled composites requires less energy than silica filled composites. WRHA-PP composites exhibit better impact properties while other mechanical properties are better in silica filled composites. WRHA-PP composites also showed a better resistance to the water absorption in comparison to silica composites. An increase in water uptake with increase in filler loading was observed for both fillers although the difference is not significant for WRHA-PP composites. The study further shows that the area of the specimen cut edges influences the water uptake. The effect of water uptake on tensile properties was also briefly examined.