Antiсorrosion Properties of Quaternary Nitrogen-Containing Derivatives of 2-Allyl-4-isodecylphenol in Aqueous-Salt and Hydrocarbon Systems

The paper presents the results of anticorrosion gravimetric studies of the quaternary nitrogen-containing derivatives of 2-allyl-4-isodecylphenol, namely, the quaternary ammonium salts 2-allyl-4-isodecyl-6-diethylaminomethylphenol (I) and 2-allyl-4-isodecyl-6-piperidinomethylphenol (II) on steel St.3 plates in a system consisting of a 3% aqueous NaCl solution and hydrocarbons (kerosene) at a ratio of 9 : 1 (vol/vol). The influence of the temperature and concentration of the compounds on the corrosion rate, metal surface coverage, and protective effect was studied (test time 5 h). Compounds I and II were found to have high inhibitory properties. The thermodynamic parameters of adsorption (ΔG, ΔH, ΔS) were determined, based on which the chemisorption blocking mechanism of steel St.3 surface protection was proposed. The chemisorption process is described by the Langmuir isotherm.