Water Soluble Nonionic Rosin Surfactants As Corrosion Inhibitor of Carbon Steel in 1 M HCl

摘要

Preparation of nonionic surfactants from cheap biomaterials such as rosin and application in the fieldof corrosion inhibitors are the main goal of the present work. In this respect, rosin acids reacted withpoly (ethylene glycol) monomethyl ether has molecular weight 750 g/mol, MPEG 750, to producerosin ester (RMPEG-750). On the other hand, modification of rosin acid with maleic anhydride usingDiles Alder reaction produced adduct (RMA) which esterified with MPEG 750 to produce branchednonionic surfactants to study the effect of rosin modification on both surface activity and corrosioninhibition efficiency in 1 M HCl. The surface activity of the prepared surfactants evaluated indeionized water and 1 M HCl to measure the micellization and adsorption of the prepared surfactantsat water/air interface. The surface tension, critical micelle concentration, and surface activities weredetermined. Surface parameters such as surface excess concentration (max), the area per molecule atinterface (Amin), and the effectiveness of surface tension reduction were determined from theadsorption isotherms of the prepared surfactants. The results of polarization measurements indicatedthat RMPEG750 acts as a mixed type inhibitor in acidic solution. The inhibition efficiency (IE) isdependent upon inhibitor concentration and increases with increasing inhibitor concentration. Thecharge transfer resistance of carbon steel increases with increasing inhibitor concentration and thecorrosion process on CS surface is mainly controlled by charge transfer reaction.