Low friction of phytic acid as a water-based lubricant additive

Abstract

Purpose The purpose of this paper is to evaluate naturally occurring phytic acid (PA) as a green-water-based lubricant. Design/methodology/approach Lubrication is studied using a ball-on-disk tribometer with silica glass against silicon nitride contact, and the friction coefficient and wear are measured in the boundary lubrication regimes. Findings Excellent lubrication performance was found by using PA aqueous solutions. After the running-in process, the sliding coefficient of friction could drop to as low as 0.01 with a quite low concentration of 7.5 × 10−4 M. The lubricating performance of PA solution could be further improved by increasing PA concentration. The work suggests that the excellent lubricity of PA in aqueous solution can be mostly contributed to its adsorption on the silica surface. Originality/value The paper shows that the natural products could be used as water-based lubricant additives.