Explore the Tribological Effects of Two N-Containing Functional Groups on O/W Emulsion

Two water-soluble N-containing additives without sulfur and phosphorus, hexanamide with tetraethylenepentamine (EEHA) and benzotriazole amide with diethylenetriamine (BTAA), were synthesized and used as additives in the oil-in-water emulsion to investigate the effect of amino and benzotriazole ring on the tribological properties of the emulsion. The results showed that EEHA/BTAA exhibited wear resistance under all tested conditions. This may be attributed to the basic amino-functional groups in the additives which reduce the corrosive wear of the base emulsion. BTAA-emulsion showed the best friction-reducing and anti-wear performance under the 3 N loading condition, which may be attributed to its benzotriazole ring, which cannot be easily decomposed and could form self-assembled layers through π–π stacking. This π–π stacking may effectively compensate for the low chemical reactivity of the benzotriazole ring, and serve as a better protective film to exert tribological properties.