Effect of microwave heat treatment on physical and mechanical properties of high-Density polyethylene/wood flour/Nano-SiO2 composites

The study aimed at investigating the impact of Microwave Heat Treatment (MHT) on the physical and mechanical properties of wood flour (WF)/Nano-SiO2/High-Density polyethylene composites by varying Nano-SiO2 loading from 0, 1, 2, and 3% wt with a constant WF loading at 50% wt. By milling the materials in which were firstly mixed in a twin-screw extruder (Brabender® Plasti-Corder®), wood-plastic composites ASTM Standard samples were produced by an injection molding machine. Microwave irradiation with a power of 900 W and a temperature of 85°C for 7 min was applied for post-treatment of WPCs. After applying the microwave treatment, samples were subjected to physical and mechanical tests. The results indicated that increased Nano-SiO2 loading up to 3 wt% led to increasing the flexural strength and modulus while decreasing the impact resistance, water absorption, and thickness swelling of samples. As such, morphological analyses revealed that MHT increased the flexural modulus and strength, as well as, decreased the impact strength, water adsorption, and thickness swelling of the samples.