12 ° Congresso Brasileiro de Polímeros ( 12 ° CBPol ) UTILIZATION OF MICROCRYSTALLINE CELLULOSE AND RICE-HUSK CELLULOSE AS REINFORCEMENT IN POLYPROPYLENE COMPOSITES

Rice husk is an important residue from the agro-industry. In this study, pure cellulose was extracted from rice husk and added to polypropylene in a melt mixer. The properties of these PP/RHC composites were compared to the properties of PP/commercial microcrystalline cellulose composites (PP/MMC). The cellulosic fillers were treated with vinyltriethoxysilane (VTES) with the objective of improving adhesion. PP modified with maleic anhydride (PPMA) was also added. In our work, the cellulose was isolated from rice husks using environmental friendly techniques. In composites containing silane, MCC and RHC were first treated with VTES with the objective of promoting filler dispersion and compatibility. Concentrated PP/cellulose masterbatches were prepared using xylene. In the next step, the masterbatches were diluted with PP using a mixer Haake. Dynamic-mechanical analyses showed that the use of 5% cellulose did not show improvements in the storage modulus (E’), even after silanization or PPMA addition. However, increasing the cellulose content to 10% increased E’ was around 250% percent at ambient temperature.