Study of the effect of physicochemical degradation and contamination of motor oils on their lubricity

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25510%2F21%3A39917061" target="_blank" >RIV/00216275:25510/21:39917061 - isvavai.cz</a>

Result on the web

<a href="https://www.mdpi.com/2079-6412/11/1/60" target="_blank" >https://www.mdpi.com/2079-6412/11/1/60</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/coatings11010060" target="_blank" >10.3390/coatings11010060</a>

Result language

angličtina

Original language name

Study of the effect of physicochemical degradation and contamination of motor oils on their lubricity

Original language description

Internal combustion engine lubrication is essential for unwanted energy and material losses. As part of the experimental work, the lubricity of both new and worn motor oils of Society of Automotive Engineers (SAE) 15W-40 and SAE 10W-40 with different American Petroleum Institute (API) performance classifications, which were taken from various motor trains during maintenance or oil change, was assessed. A total of sixteen lubricant samples were evaluated. Lubricity, i.e., the load capacity of the lubricating film, was evaluated on the basis of the Reichert test. Viscosity, as one of the most important parameters of lubricants, was evaluated by the Stabinger Viscometer. Chemical degradation of motor oils (oxidation, nitration, sulfation), contamination of oils with fuel, soot, water, and loss of antioxidant zinc dialkyldithiophosphate (ZDDP) were monitored by Fourier-transform infrared (FTIR) spectroscopy. Of the fresh motor oils, OMV 10W-40 API SL/CF motor oil had the best lubricity. URANIA LD 15W-40 API CI-4 and M7ADS V 15W-40 API CI-4 CH-4/SL oils showed similar lubricity. M7ADS III 15W-40 API CF-4/SG motor oil showed the highest wear of wear surface, i.e., the lowest lubricity, of the tested new motor oils. Correlation analysis of the experimental data confirmed that the fuel content penetrated the motor oils significantly negatively correlates with the viscosity (R = −0.87). The low water contamination in motor oil does not cause a significant negative effect on lubricity. A significant correlation between the oxidation, nitration, and sulfation products of chemical degradation of the tested oils was confirmed (R ≥ 0.90). These degradation products improve lubricity due to their polarity, i.e., they have caused better lubricity of worn oils compared to new motor oils. Even the depletion of the antioxidant ZDDP did not affect the reduction in lubricity and anti-abrasion properties of chemically degraded motor oils. The experimental results of testing of worn motor oils taken from motor trains showed that current motor oils have excellent lubricity, which they maintain throughout their life.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20506 - Coating and films

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Coatings

ISSN

2079-6412

e-ISSN

—

Volume of the periodical

11

Issue of the periodical within the volume

1

Country of publishing house

CH - SWITZERLAND

Number of pages

18

Pages from-to

—

UT code for WoS article

000610037900001

EID of the result in the Scopus database

2-s2.0-85099647663