Influence of the Nanoclay Concentration and Oil Viscosity on the Rheological and Tribological Properties of Nanoclay-Based Ecolubricants

Abstract

This manuscript describes a rheological and tribological study carried out on eco-friendly lubricants. These ecolubricants were made up of nanoclays as dispersed phase (a layered nanosilicate (montmorillonite Cloisite 15A) and a fiber-like nanoclay (sepiolite Pangel B20)) and vegetable-based oil as continuous phase (castor oil (CO), high oleic sunflower oil (HOSO) and their mixtures). A series of nanoclay-based ecolubricants were prepared by varying both nanoclay concentration and base oil, and thus, its viscosity. Friction and wear behaviors were assessed by using a ball-on-three plates tribometer cell. The results showed that the fiber-like sepiolite Pangel B20 yielded an important reduction in the wear scar diameter, thus revealing its potential as anti-wear and load-carrying additive in ecolubricant formulations, while Cloisite 15A proved to have friction improving properties. These anti-wear and friction reducing properties were found to be influenced by both nanoclay concentration and oil viscosity.

Halloysite Reinforced Natural Esters for Energy Applications

“…Recently, several investigations have been performed by scientists and industry to find sustainable and eco-friendly alternatives [15][16][17][18][19]. The usage of these materials has been emerging and is more common in certain environmentally-sensitive fields [1][2][3][4][20][21][22].…”

Lubrication Performance of Sunflower Oil Reinforced with Halloysite Clay Nanotubes (HNT) as Lubricant Additives

“…Even with these efforts, the use and disposal of mineral or synthetic lubricants and conventional additives which have been used for decades have shown to be harmful to the environment [2]. Recently, studies have been conducted to find new additives and lubricants that are friendly to the environment [2][3][4][5][6][7]. The use of vegetable oils was common until the nineteenth century as they are easily obtainable from natural sources.…”

“…The use of vegetable oils as lubricants offers a wide range of advantages such as a high biodegradability [8,9], low environmental pollution, compatibility with additives, low production cost [10], low toxicity, high flash point, low volatility, and high viscosity indices. Moreover, many food-based biodegradable lubricants have been shown to have good tribological properties [2,6,7]. Vegetable oils are also a source of fatty acids for polyol esters [11,12] and are also base oils for environmentally-friendly lubricants.…”