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Starches were isolated from cocoyam (Xanthosoma sagittifollium), white yam (Dioscorea rotundata) and bitter yam (Dioscorea dumentorum). Starch modification was carried out using acetic anhydride and phthalic anhydride. The native and modified starches were characterized using Fourier Transformed Infra-red Spectroscopy (FTIR) for identification of the functional groups. Functional properties such as water absorption capacities, oil absorption capacity, swelling power, solubility, gelation temperature, least gelation capacity, amylose content and pH were determined using standard procedures. Acetylation increased the water absorption capacity, oil absorption capacity, swelling power, amylose content, and solubility of the starches while phthalation decreased water absorption capacity, oil absorption capacity, swelling power, and solubility of the starches. Native cocoyam starch has the highest gelation temperature (85 °C) while Acetylated bitter yam has the lowest gelation temperature (74 °C). The pH of the native and modified starches was within the range of 4.14 − 6.55. Phthalation and acetylation increased the bulk density of the starches. Native cocoyam, white yam, and bitter yam starches had the lowest gelation concentration (6%). Modification of native starches will improve the usage of starch in food and non-food applications.

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Natural fibres have gained huge attention of researchers in the field of composite manufacturing due to its low cost, biodegradability, availability and high performance. However, due to its high hydroxyl content of cellulose, natural fibre is susceptible to water absorption which invariably adversely affects properties of the composite. Researchers have proved that nano-materials such as nanoclay mixed with the polymer composites can overcome the problem. This study investigates tensile strength and microstructural property of tigernut fibres reinforced polymer composites tailored to automotive application. Tigernut fibres mixed with nanoclay of size 50≤µm, were used to reinforce epoxy in three levels of loading 2, 4, 6 % respectively. The composite was prepared by shear mixing of polymer and the reinforcements, followed by lamination and curing of the composite. The tensile strength and microstructural property of the composites produced were examined. The results show that tensile strength increases as the percentage weight fraction of the reinforcement increases. The microstructures show good interfacial adhesion between reinforcement and polymer matrix. Tigernut fibre show a sustainable material useful for automotive applications.