The Effect Type of Chemical Treatment of Wood Material on Physical, Mechanical and Morphological Properties of Wood Flour / Polypropylene Hybrid Composite

This study aimed to investigate the effect of chemical treatment of wood material on functional properties of wood flour / polypropylene hybrid composite. For this reason, first of all, mixed hardwood were separately treated by acetic acid, sodium hydroxide and hot water and were compared with control (untreated) samples. After chemical treatment, wood flour and polypropylene with weight ratio of 50 to 50 and 3 phc of compatibilizer combines in the internal mixer and at last the WPC composite were made using injection molding. Then mechanical tests included bending resistance, tension and impact and physical examination, including water absorption and thickness swelling after 2 and 24 hours was performed on specimens according to (ASTM) standard. Also to study the morphology of the composites, scanning electron microscopy (SEM) was used. The results of this study showed that by chemical treatment the mechanical strength increased and physical properties such as water absorption and thickness swelling decreased. So that the highest flexural strength, tensile and flexural modulus is related to alkali treatment and the highest tensile modulus and impact resistance is related to the acid treatment. Also the lowest water absorption and thickness swelling was related to the alkali treatment. In order to ensure chemical treatments, Fourier transform infrared (FTIR) and weight percent gain (WPG) was used on wood flour.