Inhibition Of The Corrosion Of Mild Steel In H2SO4 By Daniella Oliveri And Commiphora Africana Gum Extracts:- Onukwube, Nwokocha D

The inhibitive and adsorption characteristics ofDaniella oliveri and Commiphora africana on the corrosion of mild steel have been studied using weight loss, gasometric and thermometric methods. From the results obtained, various concentrations ofDaniella oliveri and Commiphora africana inhibited the corrosion of mild steel in H2SO4 within the temperature range 303 and 333K. The inhibition efficiencies ofthese inhibitors were found to increase as the concentrations ofthese inhibitors increased but decreased with increase in temperature. The inhibition efficiencies at (303K) were relatively higher than those at (333K) and ranged from 64.56% to 90.01% and 59.70% to 90.08% for Daniella oliveri and Commiphora africana respectively. Values of inhibition efficiencies from weight loss method were significantly higher (p < 0.05) than values obtained from gasometric and thermometric methods for the two inhibitors. Also inhibition efficiency values from weight loss method correlated strongly with values obtained from gasometric and thermometric methods. Phytochemical analysis of the inhibitors revealed the presence of alkaloids, tannins, saponins and flavonoids. First order kinetics was observed to favour both the found to be higher for the inhibited reactions than values for the uninhibited systems. Thermodynamically, the inhibitors were found to be adsorbed on mild steel surface spontaneously, and therefore physical adsorption mechanism was proposed as values offree and The inhibitive and adsorption characteristics ofDaniella oliveri and Commiphora africana of mild steel have been studied using weight loss, gasometric and temperature. The inhibition efficiencies at (303K) were relatively higher than those at (333K) and ranged from 64.56% to 90.01% and 59.70% to 90.08% for Daniella oliveri and Commiphora africana respectively. Values of inhibition efficiencies from weight loss method were significantly higher (p < 0.05) than values obtained from gasometric and on the corrosion thermometric methods. From the results obtained, various concentrations ofDaniella oliveri and Commiphora africana inhibited the corrosion of mild steel in H2SO4 within the temperature range 303 and 333K. The inhibition efficiencies ofthese inhibitors were found to increase as the concentrations ofthese inhibitors increased but decreased with increase in inhibited and the uninhibited corrosion of mild steel in H2SO4. Values of half life were energy were negatively lower than the threshold value of -40Kj/mol. Average values of activation energy (Ea) = 59.87Kj/mol and 76.38Kj/mol for Daniella oliveri Commiphora africana respectively of the inhibited corrosion reaction of mild steel were found to be lower than the threshold value of 80Kj/mol required for chemical adsorption.