Physical and mechanical properties of wood plastic composites produced from hazelnut husk

Agricultural wastes are becoming increasingly important in the manufacture of Wood Plastic Composite (WPC) in Turkey and in the world. Turkey is among the world's leading country in terms of agricultural waste potential. A significant contribution to the national economy will be provided with the possibility of using this potential in WPC production. The aim of this study is to increase usage posssibility of the hazelnut husk (green shell) in the WPC production. The hazelnut husk, beech wood flour and Polypropylene (PP) were used as a agricultural waste and plastic raw material. The hazelnut husk were add to the WPC's at different ratios (10%, 20%, 30%, 40% and 50%). Maleic Anhydride Polypropylene (MAPP) for PP mixtures were add at a rate of 3% in order to provide the bonding effect on the interface of polymer/hazelnut husk flour/beech wood flour mixtures. In order to increase the dimensional stability of the produced WPC's, thermal treatment was applied to hazelnut husk flour at 160 °C and 180 °C. The hazelnut husk flour, wood flour, PP and MAPP mixtures were made into pellets using a single screw extruder. The WPC panels were produced in hot press from these pellets. Physical (density, water absorption and thickness swelling) and mechanical (bending strength, modulus of elasticity in bending, impact resistance, tensile strength, modulus of elasticity in tensile and elongation at break) properties of the produced WPCs were determined. The results showed that the water absorption and thickness swelling values of the WPCs increased with increasing hazelnut husk ratio while the mechanical properties decreased. The addition of MAPP and applying thermal treatment to the husk improved the physical and mechanical properties of the WPCs. The findigs obtained in the study showed that the hazelnut husk was capable of serving as new filler in the manufacturing of WPC.