An Investigation on the Mechanical and Physical Properties of Hybrid Composite of HDPE/Wood Flour/Nano Silica

In this research, the effect of mineral filler (nano-silica) and cellulosic filler (wood flour) on the physical and mechanical properties of wood plastic composite was examined. Test samples were prepared by injection molding and by using a mix are of wood flour at three levels of 30,40,50%, nano-silica at three levels of 0,3,6% and also 2% maleic anhydride polyethylene as coupling agent. After construction of test samples, physical and mechanical properties such as flexural properties, tensile properties, impact strength, hardness, water absorption and thickness swelling were examined. The results of mechanical tests showed that with increase of nano-silica, flexural modulus, tensile modulus and hardness increased and tensile strength and impact strength decreased. Also with increase of nano-silica up to 3%, flexural strength of composite increased. With the increase of wood flour percent, flexural and tensile strength, flexural and tensile modulus, and hardness of composites increased. Also with increase of wood flour up to 40%, impact strength of wood plastic composite increased and then decreased. The results of physical tests showed that with increase of nano-silica up to 3%, 24-hour water absorption and thickness swelling decreased. With the increase of wood flour percent, 2 and 24-hour water absorption and 24-hour thickness swelling increased.