Excellent lubricating performance of a novel polysaccharide lubricant on reducing friction-induced deformation

Abstract

Minimizing the deformation caused by friction on surfaces enabled to maintain a stable friction force and coefficient of friction (COF), and valuable insights could be gained from studying bio-based lubrication systems. A natural polysaccharide was derived from fresh okras in order to enhance the lubricating efficiency of aqueous system. The lubricating performance and mechanism of okra polysaccharide were unveiled through the implementation of multiple wear tests between the steel and PA66. Particular attention was paid to the relationship between the deformation, friction force and COF. The results indicated that the surface fluctuated deformations caused comparable fluctuations in both the friction force and the COF. However, the inclusion of okra polysaccharide at a concentration of 2 wt% significantly diminished the amplitudes of friction force by decreasing surface deformations. As a result, almost 50% decrease in both COF and wear loss were observed. The lubricating mechanism of okra-polysaccharide lubricant could be described as the interaction between the hydrophilic groups and water molecules, which forms a hydration layer on the surfaces in contact, thus reducing shear force. The acquired knowledge in this study was used to develop a green lubricant that addresses the issue of instability in frictional systems caused by friction-induced deformation.