Abstract
Rosin, a robust inexhaustible raw material from pine tree has attracted much attention due to its utilization as a feedstock for the preparation of cationic surfactants. Maleopimaric acid (MPA), one of most important rosin derivative obtained from the Diels-Alder reaction between the gum rosin and maleic anhydride which can be obtained with low cost and high purity and it used as intermediate compound for the preparation of cationic surfactants. MPA was reacted with oxalyl chloride and 2-diethylethanolamine to prepare rosin ester which quaternized with hexadecylbromide to obtain QRMAE cationic surfactant. The structure and properties of these rosin derivatives were characterized by FT-IR, and H-1 NMR. The results showed that MPA and QRMAE was high purity. The surface activity of the prepared QRMAE surfactant was evaluated in water and 1 M HCl to measure the micellization and adsorption of the prepared surfactants at water/air interface. The results showed that cationic derivative inhibited corrosion of carbon steel and the extent of its inhibition was concentration dependent. Potentiodynamic polarization investigations revealed that cationic acted as a mixed-type inhibitor. The inhibition efficiency increases with the concentration of cationic to attain 92 % at 250 ppm.