Diblock polymeric friction modifier (PFM) in the boundary regime: Tribological conditions leading to low friction

• Published in: Tribology international Vol. 163; p. 107186
• Main Authors: Kossoko, Nasrya F., Dubreuil, Frédéric, Thiébaut, Benoît, Belin, Michel, Minfray, Clotilde
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-11-2021; Elsevier BV; Elsevier
• Subjects: AFM; Boundary lubrication; Coefficient of friction; Engineering Sciences; Friction; Polymer films; Polymer friction modifier; Polymers; Rubbing; Sliding; Substrates; ToF-SIMS; Tribology; AFM; Boundary lubrication; ToF-SIMS; Polymer friction modifier
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2021.107186

The aim of this paper is to investigate the tribological conditions required to obtain low friction with a diblock PIB-PEG polymer friction modifier (PFM) blended in base oil (PAO4 +1% wt PFM) under a severe lubrication regime. Two tribological conditions, rolling/sliding and reciprocating pure sliding, were investigated. A very low friction coefficient (μ ~ 0.035) was obtained at a temperature of 100 °C whatever the tribometer used. ECR measurements, ToF-SIMS characterizations of wear tracks and AFM analysis suggested the presence of an adsorbed polymer film on the rubbing surfaces. ToF-SIMS characterizations showed that the polymer bonds to the steel substrate through polar functions.
•Low CoF were achieved with a diblock PIB-PEG PFM in severe lubricated contacts.•µ obtained with this PFM are slightly lower than with classical MoDTC additive.•Temperature has a strong influence on the friction behavior of the PFM.•The polymer adsorbs on steel surface through ester linker group.