Rice-based biocomposites: the influence of the rice husk granulometry on physical and biodegradation properties of rice bran matrix biocomposites

Our study presents an innovative material for application in the construction of biocomposites produced from agro-industrial by-products, constituted by the matrix of 70% raw rice bran, reinforced with 15% of rice husk fibers of different particle sizes (> 1 mm, > 500 µm, > 250 µm and < 250 µm) and 15% glycerol as a plasticizer. The materials were manually mixed and then molded by thermal compression in a hydraulic press with heating using a tray format. The molded parts were submitted to tests of biodegradability, contact angle, water absorption and impact resistance. The obtained results showed the influence of the incorporation of the rice husk fibers in the improvement of the evaluated properties when compared to the biocomposite produced only with rice bran. The different particle sizes of the rice husk fibers used in this study presented minor influence on the evaluated properties. Nevertheless, it should be noted that biocomposites with grain sizes > 250 µm and < 500 µm showed significant improvements, such as greater impact performance, higher initial contact angle and minor mass losses in composting experiments.