Influence of silica addition on mechanical properties of polypropylene/wood powder/silica composite

The influence of different contents (0, 5 and 10% W/W) of silica and poplar wood powder (30, 40 and 50% W/W of total weight of composite) on strength properties of polypropylene/wood powder/silica composite was evaluated. Various compositions of the composite was melt mixed using two screw counter rotating extruder, followed by cooling and granulizing. Composite granules were injected into test samples. The results of strength properties measurements revealed that almost all strength values were improved. At higher content of silica, the MOR increased from 47.9 to 53.3 MPa, flexural MOE from 2625 to 4517 MPa and MOE in tensile increased from initial value of 4525MPa (without silica) to 6884MPa (10% silica in composite). Marginal increase in tensile strength and Izod impact strength was observed, and the hardness of the composite was improved from 66 to 73.77 shoreD. At higher silica content, the density of the composite was higher, as expected