物理化学学报 >> 2012, Vol. 28 >> Issue (02): 399-406.doi: 10.3866/PKU.WHXB201112142
SENTHILKUMAR Annamalai1, THARINI Kumaravel2, SETHURAMAN Mathur Gopalakrishnan3
SENTHILKUMAR Annamalai1, THARINI Kumaravel2, SETHURAMAN Mathur Gopalakrishnan3
摘要: Three synthesized piperidin-4-one oximes, 3-ethyl-2,6-diphenyl-piperidin-4-one oxime (A), 1-methyl-3-isopropyl-2,6-diphenyl-piperidin-4-one oxime (B), and 3-isopropyl-2,6-diphenyl-piperidin-4-oneoxime (C), were tested at different concentrations to determine their ability to inhibit corrosion of mild steelin 1 mol·L-1 H2SO4 and measured by a mass loss method (at various temperatures), polarization andimpedance measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM) with energydispersiveX-ray spectroscopy (EDS), and a quantum chemical method. The synergistic influence ofcompounds A, B and C with iodides has also been evaluated. All three compounds show good inhibitionefficiency in the following order: A>B>C. Compounds A, B and C were found to physically adsorb on thesurface of mild steel while obeying the Temkin isotherm. Polarization measurements indicated that thesecompounds behave as a mixed mode inhibitor. XRD and SEM with EDS studies revealed the formation of aprotective barrier on the mild steel surface by these oximes. The electron donating ability of the studiedmolecules was tested using semi empirical methods. The studies revealed that the oxime nitrogen, thepiperidine moiety, and the phenyl ring assist largely in corrosion control. The studies also showed that thesteric crowding by the alkyl group in the piperidine ring affects the inhibitor efficiency. Further, it isinteresting to note that all of the studied compounds exhibit synergism with iodide ions.