Recycling of waste from the rice chain: incorporation of rice husk and rice husk ash in polymeric composites

The high need for polymeric materials and the availability of agro-industrial wastes, such as the rice production chain, demand the development of technologies to obtain polymeric composites based on these waste materials. Therefore, this work aims to develop materials using low density polyethylene (LDPE) as a polymer matrix and rice husk or rice husk ash, prepared by micronization in a whirlwind mill, as reinforcing fillers. The processing was carried out by injection molding, with formulations containing 20%, 30% and 40% of the filler. Tensile strength, hardness and water absorption properties were evaluated. The tensile strength of composites containing rice husk ash was higher than the same parameter for composites containing rice husk as filler. The highest tensile strength of 9.26 N/mm² was found for the material containing 20% of rice husk ash. The shore D hardness of materials containing rice husk ash was slightly higher. Regarding water absorption, the composites containing rice husk ash were those with lower absorption and all developed materials presented water absorption below 1.1%. Based on the results, we concluded that the composites have potential properties for the manufacture of polymeric consumer goods.