The corrosion of mild steel in H 2 SO 4 was studied using gravimetric, gasometric and IR methods. The results indicate that the rate of corrosion of mild steel in H 2 SO 4 increases with increase in the concentration of the acid and that ethanol extracts of the seeds and leaves of Azadirachta indica inhibit the corrosion of mild steel in H 2 SO 4. Inhibition efficiencies of the leaves and seeds extract range from 82.62 to 94.24% and from 60.55 to 84.78%, respectively. The inhibition potential of these extracts is attributed to the presence of tannin, saponin, glycoside, anthraquinone, flavonone and other phytochemicals in the extracts. IR study confirms that the inhibitors are adsorption inhibitors and the adsorption of the inhibitors on mild steel surface is exothermic, spontaneous and consistent with the assumptions of Flory-Huggins adsorption isotherm. Based on the values of the activation, free energy of adsorption and the variation of inhibition efficiency with temperature, a physical adsorption mechanism is proposed for the adsorption of ethanol extract of leaves and seeds of Azadirachta indica on the surface of mild steel.

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The inhibitive and adsorption properties of ethanol extract of Terminalia catappa for the corrosion of mild steel in H 2 SO 4 were investigated using weight loss, hydrogen evolution, and infra red methods of monitoring corrosion. Ethanol extract of T. catappa is a good adsorption inhibitor for the corrosion of mild steel in H 2 SO 4 . The inhibition efficiency of the inhibitor increases with increasing concentration but decreases with increasing temperature. The inhibition potential of ethanol extract of T. catappa is attributed to the presence of saponnin, tannin, phlobatin, anthraquinone, cardiac glycosides, flavanoid, terpene, and alkaloid in the extract. The adsorption of the inhibitor on mild steel surface is exothermic, spontaneous and is best described by Langmuir adsorption model. From the calculated values of activation energy, free energy of adsorption and the trend in the variation of inhibition efficiency with temperature, the mechanism of adsorption of the inhibitor is physical adsorption.

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Effect of acetylation on pretreated wood flour of four different wood species, Boabab (Adansonia digitata), Mahoganny (Daniella oliveri), African locust bean (Parkia biglobosa) and Beech wood (Gmelina arborea), had been investigated. The first batch of wood species were acetylated using acetic anhydride while the second batch were acetylated with commercial vinegar. Both experiments were conducted in the presence of varying amount of CaCl2 as catalyst and at temperature of 120°C for 3 h. The success of acetylation was determined based on Weight Percent Gain for each sample treated with either chemicals used. FT-IR, a veritable tool was used for the analysis of both treated and untreated samples to further investigate the success of acetylation. The results showed the presence of important band such as carbonyl absorptions at 1743, 1744, 1746, 1731, 1718 and 1696 cm−1 as appeared separately in the spectra of acetylated samples, confirming esterification occurred. The purpose of this work was to investigate the applicability of vinegar for acetylation of lignocellulosic fibers. Blends/composites were prepared by solution casting and their kinetics investigated in distilled water. The results indicated they could be used in outdoor applications such as, decking and packaging.