Synthesis and tribological properties of bio-inspired green dopamine oil soluble additive

A kind of oil-soluble dopamine-cholesterol compound (DA) is synthesized through molecular design. We performed solubility tests and thermogravimetric analysis (TGA) of PAO 10 and DA composition. The tribological properties of DA were investigated in different concentrations. Tribological results test showed that DA has excellent tribological properties. When the content of DA in PAO 10 reaches 3%, it has the most excellent tribological properties under room temperature (RT). The components of the friction interface was analyzed by the use of time-of-flight secondary spectroscopy (TOF-SIMS), X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectrometer (EDS) in order to have a deeper knowledge of the tribo-chemical reaction mechanism of DA composition. The tribo-chemical film composed of nitrates, hydroxides, cyanides. •We synthesized a new green dopamine-cholesterol lubricant additive (DA).•DA molecules have excellent solubility stability and adsorption properties.•DA significantly enhances tribological performance of steel/steel friction pairs.•Generated protective film provides anti-friction and anti-wear properties.