Characterization of groundnut shell powder as a potential reinforcement for biocomposites

Abstract

Natural fibers are becoming the right candidate material as a substitute for glass fibers in the reinforcement of plastic polymers for various applications. The ease of their processing with minimal energy consumption and the quest to produce biodegradable plastics with lightweight has given natural fibers comparative advantages over synthetic fibers. In this study, groundnut shell powder (GSP) in different forms (untreated, sodium hydroxide treated and ash) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray fluorescence (XRF), Nuclear magnetic resonance (NMR), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) to evaluate their possible utilization as reinforcement in polymers. GSP was treated with sodium hydroxide for 5 hrs and dried in vacuum for 24 hrs to obtain treated GSP while ash GSP was formed by heating GSP in the furnace at 600 °C for about 3 hrs. The results reveal that sodium hydroxide treatment was very effective in the breaking down of the hydrogen bond with a consequent reduction in the hydrophilicity of the GSP. This would promote GSP bonding with the hydrophobic polymer matrix in the development of natural fiber reinforced plastic polymer composite materials. Ash GSP was found to have the highest crystallinity among the three forms of GSP based on XRD results. Therefore, the result achieved in this work confirmed that treated and ash GSP fibers are good reinforcement material in the production of polymer composites, with the actual choice depending on end-use property requirements of the composite.