A Study on Rice-husk/Recycled High Density Polyethylene Composites - Their Physical and Mechanical Properties

This study was undertaken to determine the possibility of using lignocellulosic material as reinforcing filler in wood plastic composite (WPC). Recycled high density polyethylene was used as the matrix and rice-husk flour as the reinforcing filler to prepare a wood-plastic composite. WPC specimens of 45×25×1.6 cm were manufactured using a hot press (T: 200°C, P: 160 bar and t: 7 min). In the sample preparation, high density polyethylene (HDPE) was added at two loadings (40%, 60%) and WPC densities of 0.7 and 0.8 g/cm 3 were tested. In order to examine the compatibility of rice husk with the polymer, maleic anhydride grafted polyethylene (MAPE) was used as a coupling agent and was a variable factor (0%, 3% and 6%). Twelve treatment groups were considered with 3 replicates per treatment, so a total of 36 groups were tested. Water absorption and the thickness of the swelling were measured after 2 and 24 hours. The mechanical properties of the specimens were determined, namely the bending strength, modulus of elasticity and internal bonding strength. According to the results, the optimum treatment with the best physical and mechanical properties was WPC at 0.8 g/cm 3 density, 60% HDPE and 6% coupling agent. Results showed that with an increased content of coupling agent (MAPE), the physical and mechanical properties improved. Having significant differences between the data for water absorption and the thickness of the swelling, the optimum treatment also showed acceptable levels.