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Title: Investigation of Shear-Thinning Behavior on Film Thickness and Friction Coefficient of Polyalphaolefin Base Fluids With Varying Olefin Copolymer Content

Abstract

This study investigates the rheological properties, elastohydrodynamic (EHD) film-forming capability, and friction coefficients of low molecular mass poly-alpha-olefin (PAO) base stocks with varying contents of high molecular mass olefin copolymers (OCPs) to assess their shear stability and their potential for energy-efficient lubrication. Several PAO-OCP mixtures were blended in order to examine the relationship between their additive content and tribological performance. Gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the molecular masses and structures, respectively. Density, viscosity, EHD film thickness, and friction were measured at 303 K, 348 K, and 398 K. Film thickness and friction were studied at entrainment speeds relevant to the boundary, mixed, and full-film lubrication regimes. The PAO-OCP mixtures underwent temporary shear-thinning resulting in decreases in film thickness and hydrodynamic friction. These results demonstrate that the shear characteristics of PAO-OCP mixtures can be tuned with the OCP content and provide insight into the effects of additives on EHD characteristics.

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE) - Office of Vehicle Technology
OSTI Identifier:
1416012
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Tribology; Journal Volume: 139; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
elastohydrodynamic lubrication; fluid friction (traction); lubricant additives; viscosity

Citation Formats

Zolper, Thomas J., He, Yifeng, Delferro, Massimiliano, Shiller, Paul, Doll, Gary, LotfizadehDehkordi, Babak, Ren, Ning, Lockwood, Frances, Marks, Tobin J., Chung, Yip-Wah, Greco, Aaron, Erdemir, Ali, and Wang, Qian. Investigation of Shear-Thinning Behavior on Film Thickness and Friction Coefficient of Polyalphaolefin Base Fluids With Varying Olefin Copolymer Content. United States: N. p., 2016. Web. doi:10.1115/1.4033716.
Zolper, Thomas J., He, Yifeng, Delferro, Massimiliano, Shiller, Paul, Doll, Gary, LotfizadehDehkordi, Babak, Ren, Ning, Lockwood, Frances, Marks, Tobin J., Chung, Yip-Wah, Greco, Aaron, Erdemir, Ali, & Wang, Qian. Investigation of Shear-Thinning Behavior on Film Thickness and Friction Coefficient of Polyalphaolefin Base Fluids With Varying Olefin Copolymer Content. United States. doi:10.1115/1.4033716.
Zolper, Thomas J., He, Yifeng, Delferro, Massimiliano, Shiller, Paul, Doll, Gary, LotfizadehDehkordi, Babak, Ren, Ning, Lockwood, Frances, Marks, Tobin J., Chung, Yip-Wah, Greco, Aaron, Erdemir, Ali, and Wang, Qian. 2016. "Investigation of Shear-Thinning Behavior on Film Thickness and Friction Coefficient of Polyalphaolefin Base Fluids With Varying Olefin Copolymer Content". United States. doi:10.1115/1.4033716.
@article{osti_1416012,
title = {Investigation of Shear-Thinning Behavior on Film Thickness and Friction Coefficient of Polyalphaolefin Base Fluids With Varying Olefin Copolymer Content},
author = {Zolper, Thomas J. and He, Yifeng and Delferro, Massimiliano and Shiller, Paul and Doll, Gary and LotfizadehDehkordi, Babak and Ren, Ning and Lockwood, Frances and Marks, Tobin J. and Chung, Yip-Wah and Greco, Aaron and Erdemir, Ali and Wang, Qian},
abstractNote = {This study investigates the rheological properties, elastohydrodynamic (EHD) film-forming capability, and friction coefficients of low molecular mass poly-alpha-olefin (PAO) base stocks with varying contents of high molecular mass olefin copolymers (OCPs) to assess their shear stability and their potential for energy-efficient lubrication. Several PAO-OCP mixtures were blended in order to examine the relationship between their additive content and tribological performance. Gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the molecular masses and structures, respectively. Density, viscosity, EHD film thickness, and friction were measured at 303 K, 348 K, and 398 K. Film thickness and friction were studied at entrainment speeds relevant to the boundary, mixed, and full-film lubrication regimes. The PAO-OCP mixtures underwent temporary shear-thinning resulting in decreases in film thickness and hydrodynamic friction. These results demonstrate that the shear characteristics of PAO-OCP mixtures can be tuned with the OCP content and provide insight into the effects of additives on EHD characteristics.},
doi = {10.1115/1.4033716},
journal = {Journal of Tribology},
number = 2,
volume = 139,
place = {United States},
year = 2016,
month = 8
}
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