Special Issue "Lubricating Greases"

A special issue of Lubricants (ISSN 2075-4442).

Deadline for manuscript submissions: closed (31 August 2015).

Special Issue Editors

Prof. José M. Franco
E-Mail Website1 Website2
Guest Editor
Chemical Product and Process Technology Research Centre (Pro2TecS-), Department of Chemical Engineering, University of Huelva, Campus de “El Carmen”, 21071 Huelva, Spain
Interests: bio-sourced materials; bio-lubricants, lubricating greases; colloids; biopolymers; rheology; tribology; adhesion and adhesives; gels with emphasis on oleogels and organogels
Special Issues and Collections in MDPI journals
Prof. Dr. Jesús F. Arteaga
E-Mail Website
Guest Editor
CIQSO—Center for Research in Sustainable Chemistry and Department of Chemical Engineering, Physical Chemistry, and Organic Chemistry, University of Huelva, Campus de El Carmen s/n, 21071 Huelva, Spain
Tel. +34 959 219999; Fax: +34 959 219983
Interests: organic synthesis; natural products; lubricating greases; biopolymers; supramolecular chemistry in water media; bioactive compounds; photoactive organic compounds

Special Issue Information

Dear Colleagues,

Although lubricating greases are widely used in many specific applications, their market only constitutes a very low percent of the total amount of lubricants processed in the world. This may be one of the reasons why, up to now, not much attention has been paid to innovation and research on lubricating grease formulations and related functional properties. On the other hand, it is worth mentioning that the mechanical response of greases in a lubricated contact is not yet fully understood. This is due to its complex rheological behavior in comparison with other liquid lubricants. Since lubrication is mainly a deformation and flow problem, the knowledge of the rheological properties of lubricating greases may contribute to elucidate one of the unresolved problems in tribology: the effect of viscoelasticity on lubrication characteristics and, consequently, the way in which a lubricating grease behaves under operating conditions. Suitable structural and physical characteristics may be reached from a proper selection of the ingredients but, also, from a process optimization.

The relationship among composition, microstructure and functional properties is another important issue which deserves more investigation as well as the development of new formulations with improved characteristics. In this sense, mostly in the last two decades, lubricant customers are aware of the negative effects that traditional lubricants exert on the environment and, therefore, are demanding new green products able to reduce this impact.

This special issue aims to collect and disseminate the latest developments and trends in the field of lubricating greases including physical, chemical, microstructural and rheological characterization, tribological response and associated mechanisms, technical information and modeling on grease behavior in lubricated contacts (bearings, seals, etc.), processing of greases and pumpability, development of new formulations including bio-greases and new thickeners agents, etc.

Prof. Dr. José M. Franco
Prof. Dr. Jesús F. Arteaga
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Lubricants is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • lubricating grease
  • rheology
  • tribology
  • bearing
  • thickeners
  • additives
  • biodegradable greases
  • grease composition
  • grease microstructure

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Eco-Friendly Multipurpose Lubricating Greases from Vegetable Residual Oils
Lubricants 2015, 3(4), 628-636; https://doi.org/10.3390/lubricants3040628 - 21 Oct 2015
Cited by 5
Abstract
Environmentally friendly multipurpose grease formulation has been synthesized by using Jatropha vegetable residual oil with lithium soap and multifunctional additive. The thus obtained formulation was evaluated for its tribological performance on a four-ball tribo-tester. The anti-friction and anti-wear performance characteristics were evaluated using [...] Read more.
Environmentally friendly multipurpose grease formulation has been synthesized by using Jatropha vegetable residual oil with lithium soap and multifunctional additive. The thus obtained formulation was evaluated for its tribological performance on a four-ball tribo-tester. The anti-friction and anti-wear performance characteristics were evaluated using standard test methods. The biodegradability and toxicity of the base oil was assessed. The results indicate that the synthesized residual oil grease formulation shows superior tribological performance when compared to the commercial grease. On the basis of physico-chemical characterization and tribological performance the vegetable residual oil was found to have good potential for use as biodegradable multipurpose lubricating grease. In addition, the base oils are biodegradable and non toxic. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessArticle
Influence of Base Oil Polarity on the Transient Shear Flow of Biodegradable Lubricating Greases
Lubricants 2015, 3(3), 611-627; https://doi.org/10.3390/lubricants3030611 - 09 Sep 2015
Cited by 2
Abstract
The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on [...] Read more.
The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on the rheologically-measured mechanical structural degradation in transient shear flow. Due to the high temperature dependence of Keesom forces in the background of polar-active bond mechanisms, the analysis of the transient flow response as a function of temperature allows to attribute the observed influences to differences in base oil polarity. In general, clay-thickened greases show a greater tendency to be rheologically influenced by base oil polarities than soap-thickened lubricating greases. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessArticle
Correlation between System Entropy and Structural Changes in Lubricating Grease
Lubricants 2015, 3(2), 332-345; https://doi.org/10.3390/lubricants3020332 - 24 Apr 2015
Cited by 12
Abstract
Lubricating greases are colloid disperse systems consisting of a base oil and a thickener (additional additives). The lubricant is modeled as a tribological system, and the reaction of a fluid friction stress is investigated. The energetic situation of the volume element is analyzed [...] Read more.
Lubricating greases are colloid disperse systems consisting of a base oil and a thickener (additional additives). The lubricant is modeled as a tribological system, and the reaction of a fluid friction stress is investigated. The energetic situation of the volume element is analyzed and the system entropy described. The description of the structural degradation and the used entropy was realized with the help of rheometer tests. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessArticle
Grease Aging Effects on Film Formation under Fully-Flooded and Starved Lubrication
Lubricants 2015, 3(2), 197-221; https://doi.org/10.3390/lubricants3020197 - 09 Apr 2015
Cited by 16
Abstract
Several film thickness measurements were performed with three fresh and aged lubricating greases, their base and bled oils under a wide range of operating conditions using a ball-on-disc test rig with optical interferometry. The analysis of the film thickness measurements is in agreement [...] Read more.
Several film thickness measurements were performed with three fresh and aged lubricating greases, their base and bled oils under a wide range of operating conditions using a ball-on-disc test rig with optical interferometry. The analysis of the film thickness measurements is in agreement with the observations of several authors and adds some important aspects regarding separate film properties in EHL contacts. At full film lubrication and moderate to high speeds, the bled oil showed a similar behavior of its lubricating greases. At fully-flooded condition, low speeds and thin films, it was observed that the thickener lumps play a major role on film formation, overcoming the bled oil effects. A relationship between thickener type and film formation was evidenced. The same trends were observed under starved lubrication, where the thickener type that contributes the most to locally increase the film thickness follows the order of PP > Ca > Li. The aging process of the greases was shown to change their rheological response in different manners—softening or hardening—depending on the grease formulation. Grease aging increased the film thickness under fully-flooded and starved lubrication, regardless of the level of degradation. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessArticle
Recycled and Virgin HDPEs as Bleed Inhibitors and Their Rheological Influences on Lubricating Greases Thickened with PP and mPP
Lubricants 2014, 2(4), 237-248; https://doi.org/10.3390/lubricants2040237 - 18 Dec 2014
Cited by 6
Abstract
Polypropylene (PP) thickened lubricating grease exhibits high oil bleed tendency at low temperatures, which makes it a promising candidate for low temperature applications. At elevated temperatures, PP thickened lubricating grease exhibits excessive oil bleeding, which limits its use at high temperatures. Excessive oil [...] Read more.
Polypropylene (PP) thickened lubricating grease exhibits high oil bleed tendency at low temperatures, which makes it a promising candidate for low temperature applications. At elevated temperatures, PP thickened lubricating grease exhibits excessive oil bleeding, which limits its use at high temperatures. Excessive oil bleed adversely affects the lubricating performance of the PP thickened grease. The present work is focused on the study of the oil bleed tendency of PP and Maleated Polypropylene (mPP) thickened greases at various temperatures by incorporating virgin and recycled high density polyethylene (HDPE) into the thickener system. Grease containing various percentages of PP and mPP thickeners were prepared and modified with different percentages of virgin and recycled HDPE. Polymers were characterized through differential scanning calorimetry (DSC) techniques. The oil bleed performance of these greases was evaluated by the conical sieve method (ASTM D 6184) at various temperatures. Storage (G′) and loss modulus (G″) of greases was determined by rheometry at 25 °C. Incorporation of HDPE and recycled HDPE in PP thickened grease decreased oil bleeding compared to the base grease. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessCommunication
Detection of Elemental Composition of Lubricating Grease Using Laser Induced Breakdown Spectroscopy
Lubricants 2014, 2(4), 223-236; https://doi.org/10.3390/lubricants2040223 - 18 Dec 2014
Cited by 2
Abstract
The elemental composition of lubricating soft grease used in rail engines are studied using laser induced breakdown spectroscopy (LIBS) technique. LIBS spectra of fresh, partially used and fully used grease samples are recorded using time-gated ICCD spectrometer for verification of compositional degradation of [...] Read more.
The elemental composition of lubricating soft grease used in rail engines are studied using laser induced breakdown spectroscopy (LIBS) technique. LIBS spectra of fresh, partially used and fully used grease samples are recorded using time-gated ICCD spectrometer for verification of compositional degradation of the used grease. LIBS spectra of grease samples are analyzed by comparing with emission spectra of elements published by NIST standard database. Many spectral lines of impurity elements like Fe, Cu, Ba, Mg, Mn, Ni, S, Zn, Si, Pb, Ti, Ca and Al present in the grease in ppm or ppb level in trace level concentrations are observed in excess in the used grease mainly due to wear and tear. On the other hand in fresh grease, spectral lines of Ca, Al and Na are observed predominantly. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Back to TopTop