Novel Triazine Schiff Base-Based Cationic Gemini Surfactants: Synthesis and Their Evaluation as Antiwear, Antifriction, and Anticorrosive Additives in Polyol

Abstract

Two novel triazine Schiff base-based cationic gemini surfactants namely N,N′-bis{(p-(N,N,N-tetradecyldimethylammonium bromide)- benzylidene} 6-methyl-1,3,5-triazine-2,4-diamine (14-MTR-14) and N,N′- bis{(p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene} 6-phenyl- 1,3,5-triazine-2,4-diamine (14-PTR-14) were synthesized following the two- step reaction. First the intermediate adduct was synthesized by reaction of the 4-(dimethylamino)benzaldehyde with 1-bromotetradecane. In the second step, the germinal surfactants 14-MTR-14 and 14-PTR-14 were synthesized by imine coupling with this intermediate adduct with 6-methyl-1,3,5-triazine-2,4- diamine and 6-phenyl-1,3,5-triazine-2,4-diamine, respectively. Both were characterized using elemental analysis (CHN), infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetry (TG). The compounds were then evaluated as anticorrosive and lubricity improver additive in polyol lube base oil. Both the surfactants show the similar anticorrosive activities. The antiwear and antifriction characteristics were estimated in terms of average wear scar diameter (AWSD) and average friction coefficient using a four ball test following ASTM D4172B. It was found that the 14-MTR-14 is comparatively more effective than 14-PTR-14. 14-MTR-14 reduces the AWSD of the polyol from 690 to 575.83 μm while the average friction coefficient decreases from 0.110 to 0.082 at 4000 ppm doping concentration