Thermal and water absorption properties of bio-synthetic hybrid reinforced polypropylene composites

Abstract In this study, cattle bone was processed and utilized as complementing reinforcement for the development of cattle bone/calcium carbonate reinforced polypropylene composites. The processed cattle bone was pulverized, calcined and sieved to obtain 53, 63 and 75 μm sizes that were used for the development of the hybrid composites. The composite consists of hybrid reinforcements amounting to 3, 6, 9, 12, and 15 wt%. Compression moulding machine was used for the production of the composites. The fractured surfaces were examined using scanning electron microscopy. The effect of different reinforcement content and particle sizes on thermal and water absorption capacity of the hybrid composites was investigated. The water absorption test revealed that the control sample absorbed less water due to hydrophobic nature of pure polypropylene polymer. The 53 μm hybrid reinforced composite was found to be less porous with good resistance to water intake compared to other particle sizes and hybrid reinforcements. Similarly, the thermal conductivity of the composite was found to be higher than their corresponding particle sizes; culminating to reduction in the thermal resistance. The Thermo-gravimetric analysis/Derivative Thermo-gravimetric (TGA/DTG) analysis revealed that 15 wt%, 75 μm hybrid reinforced composite samples were more thermally stable in comparison with other particle sizes and the control sample. The SEM images revealed good interfacial adhesion in the morphology of 53 μm hybrid reinforced composite sample compared to other particle sizes.