Next Article in Journal
Modelling of Frictional Conditions in the Wheel–Rail Interface Due to Application of Top-of-Rail Products
Next Article in Special Issue
The Effects of Energy Efficiency and Resource Consumption on Environmental Sustainability
Previous Article in Journal
Operating Behavior of Sliding Planet Gear Bearings for Wind Turbine Gearbox Applications—Part II: Impact of Structure Deformation
Previous Article in Special Issue
Synthesis of a Lubricant to Mimic the Biorheological Behavior of Osteoarthritic and Revision Synovial Fluid
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Lubricants
Volume 9
Issue 10
10.3390/lubricants9100099
lubricants-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point

by
Andreas Conrad
1,*,
Annika Hodapp
2,
Bernhard Hochstein
2,
Norbert Willenbacher
2 and
Karl-Heinz Jacob
1
1
Nuremberg Institute of Technology, Applied Chemistry, 90489 Nuremberg, Germany
2
Karlsruhe Institute of Technology, Institute of Mechanical Process Engineering and Applied Mechanics, 76131 Karlsruhe, Germany
*
Author to whom correspondence should be addressed.
Lubricants 2021, 9(10), 99; https://doi.org/10.3390/lubricants9100099
Submission received: 30 August 2021 / Revised: 17 September 2021 / Accepted: 2 October 2021 / Published: 6 October 2021
(This article belongs to the Special Issue Green Tribology: New Insights toward a Sustainable World)
Browse Figures
Versions Notes

Abstract

According to the ASTM D97, the pour point is the temperature below which petroleum products cease to flow. To evaluate the relevance of pour point measurements for synthetic lubricating oils, we investigated the crystallization, melting temperature and low-temperature flow behavior of one mineral and five synthetic lubricating oils. The classification of three groups emerged from this process. The formation of paraffin crystals in mineral oils (I) below the crystallization temperature causes shear-thinning behavior and a yield point. The crystallization temperature determined in the thermal analysis and rheology correlates well with the pour point. Synthetic lubricating oils, which solidify glass-like (II), exhibit a steady viscosity increase with falling temperature. The temperature at which viscosity reaches 1000 Pas corresponds well to the pour point. Synthetic oils, especially esters, with complex crystallization behavior (III), exhibit supercooling depending on the shear rate and cooling conditions. For these lubricating oils, the pour point provides no information for low-temperature applicability.
Keywords: lubricating oil; mineral oil; synthetic oil; pour point; low-temperature rheology; DSC lubricating oil; mineral oil; synthetic oil; pour point; low-temperature rheology; DSC

Share and Cite

MDPI and ACS Style

Conrad, A.; Hodapp, A.; Hochstein, B.; Willenbacher, N.; Jacob, K.-H. Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point. Lubricants 2021, 9, 99. https://doi.org/10.3390/lubricants9100099

AMA Style

Conrad A, Hodapp A, Hochstein B, Willenbacher N, Jacob K-H. Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point. Lubricants. 2021; 9(10):99. https://doi.org/10.3390/lubricants9100099

Chicago/Turabian Style

Conrad, Andreas, Annika Hodapp, Bernhard Hochstein, Norbert Willenbacher, and Karl-Heinz Jacob. 2021. "Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point" Lubricants 9, no. 10: 99. https://doi.org/10.3390/lubricants9100099

APA Style

Conrad, A., Hodapp, A., Hochstein, B., Willenbacher, N., & Jacob, K.-H. (2021). Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point. Lubricants, 9(10), 99. https://doi.org/10.3390/lubricants9100099

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop