Friction and Wear Performance of Oleate-Based Esters With Two-, Three-, and Four-Branched Molecular Structure in Pure Form and Mixture
Document Type
Article
Publication Date
1-1-2020
Abstract
This paper reports the optimization of base oils composition involving oleate-based bio-lubricant that results in minimal wear-scar diameter (WSD) and coefficient of friction (COF) using mixture technique (MT) with simplex-lattice design (SLD). The lubricants used were neopenthylglycol dioleate (NPGDO), trimethylolpropane trioleate (TMPTO), and pentaerythritol etraoleate (PETO), which all are products of transesterification process between oleic acid and different types of alcohols becoming oleate ester. Fourball tester (FBT) was used to evaluate the resulting COF under ASTM-D4172 B testing procedure, while WSD was measured under an optical wear-scar measuring device. A second-order polynomial mathematical model was built and able to statistically predict the resulting WSD and COF of lubricant mixtures. In pure form, PETO exhibited the lowest COF with 0.06555 followed by NPGDO (+5.25%) and TMPTO (+16.97%). Meanwhile, NPGDO recorded the smallest WSD with 0.451 mm, followed by PETO (+4.04%) and TMPTO (+8.89%). Under SLD optimization technique, pure PETO was shown to give out the lowest COF; however, the lowest WSD was recorded by a mixture of 80.661 wt% PETO with 11.603 wt% TMPTO, and 7.736 wt% NPGDO resulting in 0.444 mm WSD; 5.53% lower wear than pure NPGDO. © 2020 by ASME.
Keywords
adhesion, bio-lubricants, boundary lubrication, carbon footprint, effect of friction toward wear, environmental protection, fluid film lubrication, lubricants, plant-based lubricant, stick-slip
Divisions
fac_eng
Funders
Innovative Technology Research Cluster, University of Malaya, Malaysia, for financial support through the Grand Challenge grant project titled “Formulation and Blending of Ester-based Lube Oil for Internal Combustion Engine” [GC001A-14AET],Universiti Teknikal Malaysia Melaka (UTeM),Ministry of Education of Malaysia [RAGS/1/2014/ SG06/FKM/B00067]
Publication Title
Journal of Tribology
Volume
143
Issue
1
Publisher
American Society of Mechanical Engineers