THERMODYNAMIC STUDY OF CORROSION AND INHIBITOR ADSORPTION PROCESSES ONTO C38 STEEL/PIPERAZINES/PHOSPHORIC ACID SYSTEMS
Abstract
This paper describes the inhibition effect of 1-benzyl piperazine (P1) and bis(1-benzyl piperazine) thiuram disulfide (P2) towards the corrosion of C38 steel in 5.5 M H3PO4 solution by potentiodynamic polarization and weight loss methods. The influence of inhibitor concentration and temperature on inhibitory behavior of P2 were investigated. The inhibition efficiency (IE) was found to be dependent on the type of piperazine and its concentration. The IE for 10-3 M P2 in 5.5 M H3PO4 is greater than 98%. Polarization studies clearly revealed that both P1 and P2 act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies ( and
) were evaluated. Kinetic parameters were determined.
An errata has been published. .