International Science Community Association Research Journal of Chemical Sciences 2231-606X 8 9 2018 09 18 Synthesized Schiff bases from linoleic and benheric acids as inhibitor of mild steel corrosion in HCl medium 12 25 EN Sahira Joshi 1 Department of Engineering Science and Humanities, Institute of Engineering, Pulchowk Campus, Tribhuvan University, Nepal Axel LONTSI TIWA 1 Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 6163, Yaoundé, Cameroon and Department of Organic Chemistry, University of Yaoundé I, P.O Box 812, Yaoundé, Cameroon Emmanuel NNANGA NGA 2 Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 6163, Yaoundé, Cameroon, Department of Organic Chemistry, University of Yaoundé I, P.O Box 812, Yaoundé, Cameroon and Department of Pharmacy, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O Box 812, Douala, Cameroon Alembert TIABOU TCHINDA 3 Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 6163, Yaoundé, Cameroon Ekuma F.K. 1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria Odoemelam S.A. 2 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria Ekanem U.I. 3 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria Okoyeagu A. 4 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria > Research Paper 2018 6 30 2018 09 18 Inhibitory performances of Schiff bases, 2[2-diethylamino) ethyl methyl amino)-4-methy1-5-3 (3-methyl sulfanyl propy1 amino) methylidene cyclohexdien-1-one (DEMS) and [1-(azepan-1-yl)-2-2-[4-(2-tert-butyl sulfanylethyl piperazin-1-yl] ethanone (ATSP) synthesized from linoleic and benheric acids on mild steel corrosion in HCl medium were assessed. Inhibition performances of the Schiff bases under study were assessed by gravimetric and potentiodynamic polarization methods. The inhibitors were characterized by Infrared (IR) spectrophotometry. Results obtained showed pronounced enhancements in efficiencies of the inhibitors as their concentrations gradually increased while a corresponding decline in efficiencies was observed with a rise in temperature of the medium. The measured corrosion data were best described by Langmuir isotherm with R2 values of 0.99. Thermodynamic studies on the inhibition process showed that the mode of adsorption of the Schiff bases followed physisorption. The negative entropy values obtained revealed increased disorderliness at the mild steel-inhibitor interface as concentrations of the Schiff bases gradually build up. Potentiodynamic polarisation results revealed that the inhibitors exhibited a mixed inhibition control Copyright@ International Science Community Association