Silicone Surfactants as Potential Lubricating Substances and Bases

This article presents an assessment of the physicochemical and tribological properties of silicone polyether aqueous solutions. Raw materials used in this research were characterized by different oxyethylation and oxypropylation degrees: PEG/PPG-20/20 dimethicone, bis-PEG/PPG-20/20 dimethicone, and PEG/PPG-25/25 dimethicone. The physicochemical properties were determined by surface tension, wetting angle, and atomic force microscopy images. The tribological properties were characterized by the motion resistance changes and wear in a concentrated ball (steel)-on-disk (steel) contact. The results of physicochemical properties indicate that these compounds are surface active and characterized with good wettability of the steel surface. In addition, it was shown that under the conditions of friction they can form an adsorption layer, which lowers friction and reduces wear of friction couples. In summary, oxyethylated and oxypropylated silicone aqueous solutions, particularly at higher concentrations (60–80%), and pure compounds can be used as potential and effective lubricants.