Investigation of Amidoamines Based on Synthetic Oxy- and Petroleum Acids as Inhibitor of Corrosion Steel

Issue 3(81) 2016
Pages 23-28

L.M. Afandiyeva, V.M. Abbasov, L.I. Aliyeva, L.H. Nuriyev, N.I. Mursalov, Sh.Z. Jabrailzadeh

National Academy of Sciences of Azerbaijan the Mamedaliyev Institute of Petrochemical Processes, Baku

Keywords: synthetic petroleum acids, synthetic oxyacids, corrosion inhibitors, amidoamines, adsorption energy

Synthetic petroleum acids (SPA) and oxyacids (OPA) are synthesized on the basis of petroleum hydrocarbons of diesel distillate separated from a mixture of Azerbaijan oils. The acid number of received mixture (SPA+OPA) is 165 mg KOH/g and the yield is 40% mass. A new inhibitor of acid corrosion of steel is prepared on the basis of synthesized acids and polyethylenepolyamine (PEPA). The inhibitory properties of the synthesized compounds in an aqueous solution of 1% NaCl saturated with CO2 is investigated on the surface of steel C 1018. It was found that amidoamine based on synthetic mixed acids at concentrations of 25 and 50 ppm has protective effect from corrosion equaled to 97,9 and 96,7% in medium containing CO2. The values of adsorption constant and Gibbs energy at different concentration have been evaluated. It was shown Gibbs energy of synthesized amidoamines is less –40 kJ/mol which proves the formation of chemically adsorbed film on the steel surface.