Moringa and Graphite as Additives to Conventional Petroleum-Based Lubricants

Nadiège Nomède-Martyr,Philippe Thomas,Philippe Bilas,Yves Bercion

doi:10.3390/lubricants9070065

Abstract

Many researches are focused on the tribological performances of pure vegetable oil in order to replace the conventional mineral engine oils. This work investigates the influence of local moringa oil (noted VO) on the performances of lubricants formed from a blend of dodecane and graphite particles at ambient temperature. In a first part, a reduction of about 50% of friction properties of dodecane is observed when adding small amounts of moringa oil (VO), which is intended to be used as a bio-base performance additive in lubricant formulations. The friction properties of their blends with graphite, generally employed as solid lubricant additive, showed an adsorption effect of fatty acid molecules. The more promising results were obtained for the blend containing 2 w% of VO. Physicochemical characterizations of the tribofilms evidence the good antiwear properties of the lubricant.

Highlights

Green lubrication presents an increasing interest in world industrial and economic development
If the use of vegetable oils as lubricant base oil is not economically possible, the addition of vegetable oils to conventional mineral oils is interesting to improve the tribological performances of the lubricants and to reduce its environmental impact
Exfoliated graphite particles is used as a solid friction reduction additive (Timcal Society)

Summary

Introduction

Green lubrication presents an increasing interest in world industrial and economic development. Commercial lubricants being petroleum-based are the subject of numerous studies due to the progressive depletion of the world reserves of fossil fuels and owing to concern on their environmental impact. Conventional lubricants are composed of base oil and additives conferring specific properties to the lubricant. Friction reduction additives are used to ensure the lubricating properties in the friction boundary regime [1,2,3,4,5]. Natural oils developed with vegetal or animal biomass, and fats present better friction and wear performances than mineral oils. If the use of vegetable oils as lubricant base oil is not economically possible, the addition of vegetable oils to conventional mineral oils is interesting to improve the tribological performances of the lubricants and to reduce its environmental impact

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Results