Study of the adsorption of anti-wear additives on the surface of butosyl in oil dispersions

Abstract

The method for evaluating the adsorption capacity of surfactants for plastic lubricants on inorganic thickener, such as silica gel, bentonite, carbon black, colloidal graphite, and others was proposed. The Gibbs adsorption values were calculated based on surface tension curves of samples in oil media, and the adsorption isotherms for each of the media were plotted based on the calculated data. According to the results of the study of the surface tension and refractive index of DF-11 additive solutions in heptane, it was found that 1% of the mass goes to fill the butosil surface, and the rest of its amount remains in the volume. But for the A-22 additive in the reference medium, the filling of the butosil surface occurs at a concentration of 2 % mass. It is shown that the additive A-22 should be used at higher concentrations than DF-11 to improve tribological parameters of silica gel lubricants. It was found that use of butasil based silica-gel grease the mixture of the industrial oil I-40A and PMS-400 as a dispersion medium, allows to reduce concentration of DF-11 and A-22 additives.