Synthesis, characterization and evaluation the performance of some novel pyridinone derivatives as corrosion inhibitors in some petroleum applications

In this paper, newly synthesized pyridinone derivatives namely; 6-amino-2-oxo-1-(((1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl) methylene) amino)-4-(thiophen-2-yl)-1,2-dihydropyridine-3,5-dicarbo- nitrile (II) and 6-amino-1-(((2-chloro-7-ethoxyquinnolin-3-yl) methylene) amino)-2-oxo-4-(thiophen-2-yl)-1,2-dihydropyridine-3,5-dicarbonitrile (III) were synthesized in laboratory and their chemical structure were characterized via elemental analysis, FTIR, 1 H- and 13 C -NMR spectroscopic analysis tools. The performance of the newly synthesized pyridinone derivatives as anticorrosion for carbon steel alloys in 2 M HCl aggressive medium were carried out using weight loss measurement as chemical testing method, in addition to PDP and EIS as electrochemical measurements. The collected data revealed that these pyridinone derivatives operated as excellent anticorrosion for metallic structures. PDP results revealed that these pyridinone derivatives behave as mixed type inhibitors. The adsorption isotherm revealed that undertaken compounds obeyed Langmuir adsorption isotherm. EIS data confirmed that the values charge transfer resistance (R ct ) was increased by increasing the concentration of the injected inhibitor molecules, while the electrochemical double layer (C dl ) was dramatically decreased. The work was supported by two surface analysis methods such as SEM and EDX. Finally, a suitable inhibition mechanism was assumed and discussed in details.