EFFECT OF WOOD FLOUR AND NANO-CaCO3 CONTENT ON THE PROPERTIES OF NANO-CaCO3/WOOD FLOUR/POLYPROPYLENE INJECTION MOLDED COMPOSITES

This study evaluated the effect of wood flour and nano-CaCO3 contents on some properties of nano-CaCO3/wood flour/polypropylene injection molded composites. The poplar flour content was set at three different levels: 30%, 40% and 50%, the maleic anhydride polypropylene (MAPP) content was constant at 2%, and the nano-calcium carbonate content was set at four different levels: 0%, 1.5%, 3.0% and 4.5%. The materials were mixed in a co-rotating twins-crew extruder. Test samples were made by injection molding. The physical and mechanical properties were studied using X-ray diffraction and scanning electron microscopy. The results showed that the notched impact strength decreased, while the tensile and flexural strength, tensile and flexural moduli, hardness, water absorption and thickness swelling increased when the wood flour content increased from 30 to 50% and the nano-calcium carbonate level was 4.5% after 24 h. The X-ray diffraction spectra showed that an intercalation structure was created in the composite. The scanning electron microscopy images showed that the bonding surface between the matrix and the filler material increased with increasing nano-calcium carbonate and wood flour contents, resulting in stronger connections within the matrixes.