Lubrication properties of modified lard and rapeseed oil greases with sodium and lithium thickeners

Abstract

Purpose-The purpose of this paper is to conduct research on the possibility of improving the tribological and utilization properties of lard and rapeseed oil bio-based greases by mixing it with ethanol and selection of thickener and modification with special biological additives. Design/methodology/approach-Rapeseed oil-and lard-based greases with sodium and lithium soap thickeners were mixed with either water or ethanol and modified with a special biological anti-wear additive. Tribological properties of modified lubricants evaluated on a four-ball machine. Findings-Rapeseed oil-and lard-based greases suspended in ethanol and modified with bio-additive have the same wear resistance as the industrial non-biological lubrication grease and much higher wear resistance as bio-based reference grease. The tribological efficiency of the additives is higher in greases of rapeseed oil and less efficient in lard-based greases. Oxidation and wear tests show that investigated bio-based greases have comparatively stable tribological properties also after their aging. Modified greases have sufficient consistence according penetration measurements and high thermal resistance according drop-point temperature measurements. All produced experimental greases pass within the category of the easily degradable materials. Originality/value-The greases mixed with the ethanol make possible to form more homogeneous and stable grease mixture. Modified bio-based greases have significantly higher wear resistance as bio-based reference grease, their lubrication properties are stable also after the aging and are categorized as easily degradable materials.

Tribological and Physiochemical Properties of Greases for Rail Lubrication

“…Aside from that, the influence of base oil and thickener on the grease properties was also being concerned in past studies. Padgurkas et al [5] investigated the physiological and tribological properties of greases made by modified lard and rapeseed oil, and two different types of thickeners; sodiumand lithium-based. The properties were observed in terms of the friction torque, wear scar, oxidation stability, corrosiveness, penetration, drop-point, and biodegradability.…”

Isopropyl‐branched lard and its potential application as a bio‐based lubricant

“…Also, the presence of significant proportion of unsaturated fatty acid chains in its triglyceride structure makes lard susceptible to oxidative degradation. 39,40 To the best of our knowledge, not that much effort has been made to improve the physico-chemical and lubricity properties of lard through chemical transformations directed at the double bond of the unsaturated chains. In this work, we are reporting the introduction of isopropyl groups onto the lard triglyceride structure by reacting with the carbon-carbon double bonds using ethylaluminum sesquichloride (Et 3 Al 2 Cl 3 ), an industrially produced reagent commonly employed to hydro-alkylate non-activated carbon-carbon doubles using alkyl chloroformates as alkylating agents.…”

Chemical, electrochemical and tribological study of various olive oils and their behaviour on steel

“…However, performance issues like oxidation stability, antiwear protection, hydrolytic stability and viscosity are poorly presented in literature [5]. However, less or more comprehensive investigations are carried out on rapeseed oil [6][7][8][9][10].…”