Preparation and Emulsification of New Steel Corrosion Inhibitors

H.A. Mohamed, A.A. Farag and B.M. Badran

Department of Polymers and Pigments, National Research Center, Egypt

Abstract

[2-mercaptothiazoline (2-MT), 2-mercaptobenzothiazole (2-MBT), 2-mercapto-5-methyl-1, 3, 4- thiadiazole (2-MMT) and 3-mercapto-4-methyl- 4H- 1, 2, 4- triazole (3-MMT)] had been reacted with epoxidized soybean oil in sealed ampoules at 110°C according to melting point of each compound for 4-6 hours. The reaction products were characterized physically and were evaluated with infra-red spectroscopy (IR) and gel permeation chromatography (GPC). the prepared adducts had been successfully emulsified using Tween 20, Span 20 and Span 80 emulsifiers, HLB 16.7, 8.6 and 4.3, respectively . Surface tension of the prepared emulsions was measured at 20°C using Krüss tensiometer. Emulsion Stability was determined thermally. Effect of pH, solvent, type and concentration of emulsifiers and the prepared thiol adducts on surface tension and stability had been studied. It was found that the reaction between epoxidized soybean oil and thiol compounds had taken place successfully. The reactions products are relatively high molecular weight adducts and have suitable characteristics to inhibit corrosion of steel. Also it was found that the best emulsion stability of 20% oil in water (o/w) was obtained by dissolving adduct with xylene and using Tween 20 and blend of Span 20 and Span 80 emulsifiers by ratio 1:1 at pH ≥ 8.