Base Oil Research Articles

Lube Oil Performance Enhancement Using Nano-Polymers Additives during Copolymerization Reaction

Under the parameters of normal engine operation, lubricating oil typically experience periodic shifts in its viscosity. Because of this, engine oils often include polymeric additives that are referred to as viscosity modifiers. The oil is able to give acceptable fluid lubrication at extreme temps due to these additives, which are oil-soluble polymers. The aim of present work to use polymers in form of nano-composites such as Styrene, Octadecyl-methacrylate (ODMC) and Dodecyle-methcrylate (DDMC) for lube oil viscosity index and pour point enhancement during copolymerization reaction. The benzoyl peroxide was used as an initiator. Solubilizes were made using SN-150 mineral base oil from the Al-Dorha refineries in Baghdad, which had a viscosity index of 128, and a viscosity range of 0 to 100°C. Styrene and methacrylate monomer combinations were copolymerized in an SN-150 mineral base oil solution in a nitrogen atmosphere at 60-80°C. A 200 mm3 oil glass reactor fitted with a magnetic stirrer and a reflux condenser was used to conduct the reactions. Five percent by weight of the total monomer was the concentration used. With respect to the monomers, the initiator concentration was 1.0% wt. Seven hours are needed for the whole reaction cycle. The copolymer composition was modified from 5 to 25% wt.% styrene by changing the monomer combination ratio. The advanced statistical analysis is performed to find the optimum conditions by mean of surface response and multiple regression using MINITAB. The optimization finding is obtained at Styrene of 5%, DDMC of 18% and ODMC of 18%, which promotes viscosity index of 197 leading to 51% enhancement in Al-Dora lube oil.

Experimental Study on the Influence of Stearic Acid Additive on the Elastohydrodynamic Lubrication of Mineral Oil 2137

Using an optical elastohydrodynamic lubrication (EHL) test rig, oil film thickness and the coefficient of friction (COF) were measured, and the influence of stearic acid additive on the EHL performance of mineral oil 2137 was investigated. The results showed that 2137 with 0.3 wt% stearic acid (denoted to as 2137s) achieved the same film thickness as 2137, while the COF of 2137s was significantly lower than that of 2137 when the contact was under conditions of a fully lubricant supply. Under conditions of limited lubricant supply, 2137 base oil was prone to oil starvation with the increase of entrainment velocity. On the other hand, 2137s significantly mitigated the oil starvation. This was attributed to the fact that lower surface energy by the adsorption of stearic acid results in discontinuous oil-droplet distribution on the lubrication track and, therefore, early pressure generation. Moreover, it is interesting to find that less 2137s supply quantity can produce higher film thickness when the contact is at high speeds, which is attributed to the fact that a smaller quantity of 2137s gives smaller droplets on the lubrication track, and the resultant small surface area–volume ratio presents oil more resistance to the centrifugal force and results in less oil escaping from the lubrication track. The addition of stearic acid reduced the average COF of 2137 mineral oil by about 13.3%

Deep eutectic solvent intercalation graphene oxide with strong interfacial adsorption capacity towards efficient lubrication

The high-performance lubrication effect of graphene materials is mainly due to the formation of friction film. However, the poor compatibility and interfacial adsorption of graphene oxide restrict the density of the friction film, thus losing the expected lubrication performance. Herein, the novel oil-based lubricant additives were configured by deep eutectic solvents (made of choline chloride and ethylene glycol) intercalation graphene oxide (DES-GOs). The strong hydrogen bonding between deep eutectic solvents (DESs) and graphene oxide nanosheets was detected. Precipitate experiment and UV–vis absorption spectra demonstrated high dispersion stability of DES-GOs1:3 in PEG 200 (no precipitate after 120 days). Significantly, DES-GOs1:3 with excellent electrical conductivity possessed the outstanding lubrication performance, whose average friction coefficient and wear volume decrease by 38.3% and 91.2%, compared with PEG 200, respectively. The proposed reasons to this enhanced performance were the synergistic effect of high dispersion stability, formation of the dense tribo-films and low inter-layers shear effect. Considering the diversity of DESs components and two-dimensional materials, the novel DESs functionalized two-dimensional materials possess great potential in industrial application as lubricant additives for different working conditions and base oils.

Synthesis of Novel Polycyclic Alkylated Tetralin Base Oils Catalyzed by Ionic Liquids and Its Lubricating Properties

AbstractA novel polycyclic alkylated tetralin (PAT) similar to the naphthenic oil was successfully synthesized through Friedel‐Crafts alkylation. This was accomplished by reacting coal‐based chemical tetralin with 1,7‐octadiene, using Et3NHCl−AlCl3 ionic liquid as a catalyst. To enhance the selectivity towards dialkylated products (C28−2THN), the reaction conditions were systematically studied. Interestingly, the reaction could proceed well even at a low temperature of 0 °C and the selectivity for C28−2THN products could reach 54.0 %. The primary physicochemical properties of PAT were investigated in detail, it was found that the existence of polycyclic structures contributes to high viscosity, better thermal‐oxidative stability and good polarity. Compared with octyltetralins‐ and commercial alkylnaphthalene‐based oil (AN30), the PAT exhibited superior friction‐reducing and anti‐wear properties under the load of 100 N at 50 °C due to its rigid cycle structures and flexible chain.

Thermal Transport and Rheological Properties of Hybrid Nanofluids Based on Vegetable Lubricants.

Nanofluids based on vegetal oil with different wt.% of carbon nanotubes (CNT), hexagonal boron nitride (h-BN), and its hybrid (h-BN@CNT) were produced to investigate the effects of these nano-additives on the thermal conductivity and rheological properties of nanofluids. Stable suspensions of these oil/nanostructures were produced without the use of stabilizing agents. The dispersed nanostructures were investigated by SEM, EDS, XRD, and XPS, while the thermal conductivity and rheological characteristics were studied by a transient hot-wire method and steady-state flow tests, respectively. Increases in thermal conductivity of up to 39% were observed for fluids produced with 0.5 wt.% of the hybrid nanomaterials. As for the rheological properties, it was verified that both the base fluid and the h-BN suspensions exhibited Newtonian behavior, while the presence of CNT modified this tendency. This change in behavior is attributed to the hydrophobic character of both CNT and the base oil, while h-BN nanostructures have lip-lip "bonds", giving it a partial ionic character. However, the combination of these nanostructures was fundamental for the synergistic effect on the increase of thermal conductivity with respect to their counterparts.

Friction and Wear Characteristics of Fe3O4 Nano-Additive Lubricant in Micro-Rolling

As nanotechnology has developed, some nano-additives have been employed to improve the performance of lubricants. The mechanisms of nano-additives still need to be investigated. The wear characteristics of Fe3O4 nano-additive lubricant were investigated in this study. Different diameters of Fe3O4 nanoparticles were mixed in basic oil using an ultrasonic mixer. The new lubricant was used for analytical tests at room temperature. The results showed that nano-lubricants with 20 nm nanoparticles increase the oil film strength. The coefficient of friction was reduced when 20 nm diameter 8 wt% Fe3O4 nanoparticles were mixed with lubricants. The effect of surfactants and nanoparticles in the base oil was measured using numerical simulation methods. The adsorption capacity of the lubricants was significantly improved by Fe3O4 nanoparticles, particularly when looking at the small relative atomic mass of the metal. The 8 wt% Fe3O4 lubricant exhibited optimal tribological properties when applied in micro-rolling tests. The results showed that the surface quality of the rolled samples was significantly improved, and the rolling force was dramatically reduced. At the same time, the shapes of the samples were effectively controlled in the rolling process. Therefore, Fe3O4 nanoparticles can improve the friction and wear characteristics of lubricants.

Lubricity characteristics of edge and basal functionalized GO as PAO additives

It was studied that the dodecylamine was grafted to the edge (EGO) and basal (BGO) of graphene oxide by amidation and ring-opening reactions to study the effect of different reaction sites on the tribological properties of modified graphite oxide, respectively. The results showed that BGO and EGO were successfully synthesized by a controlled synthesis process. Dispersion experiments showed that GO was dispersed in water and BGO was dispersed in chloroform, while EGO formed a Pickering emulsion and showed amphiphilicity in the water/chloroform two-liquid phase system. Friction experiments showed that both additives improved the friction reduction of the base oil, while BGO showed a better one. The mechanism analysis showed that BGO and EGO participate in the tribochemical reaction, forming a dense carbon film and thus improving the tribological properties. It was also found that BGO and EGO participated in the cracking of base oil as tribocatalysts, which positively impacted the improvement of tribological properties.

The impact of usage on the performance of lubricating emulsions in micro-forming

Lubricants are known to change over time, both in terms of aging of the oil and additives, and additive depletion through use. Samples were extracted at intervals from an industrial micro-deep drawing process line to evaluate how the lubricant changes over time. Four-ball testing showed that the tribological performance degraded quickly but stabilised after one million strokes. Measuring of the pH-level and correlation with the oil concentration showed that the emulsion initially becomes more acidic but stabilises after one million strokes, despite changes in oil concentration. Elemental analysis using water inductively coupled plasma (ICP) analysis standard showed that particles in the lubricant could be related to an increasing formation of wear debris. Fourier-transform infrared (FT-IR) analysis was used to evaluate changes in chemical composition of the base oil. Lubricant properties were found to degrade in samples obtained from the onset of the production, while they stabilised for samples that had been in use for a period of more than 1 week. The performance of the used lubricant is therefore different from that of the fresh lubricant, with four-ball wear scars increasing by approximately 30%. These results show that when tribological tests are tailored to industrial tribo-systems, the lubricant that is used in the test should be the steady state lubricant found in the real system rather than fresh lubricant.

Heating repairable superamphiphobic coatings for long-lasting antifouling application

Superamphiphobic materials exhibit broader applications and possess greater potential compared to their superhydrophobic counterparts. Therefore, it is crucial for superamphiphobic coatings to exhibit applications while maintaining a long service life. To address this challenge, the surface of natural clay kaolin particles was modified through the reaction of ethyl orthosilicate and 1 H, 1 H, 2 H, 2 H -perfluorodecyl triethoxysilane to form organic-inorganic cage fluorinated polyhedral oligomeric silsesquioxane (fluoroPOS) modifiers. Subsequently, antimicrobial ZnO nanoparticles were prepared in situ using hydrothermal methods. Finally, a durable superamphiphobic coating was achieved by physical blending of a polydimethylsiloxane (PDMS) solution with the superamphiphobic powder. Experimental results demonstrate that the as-prepared ZnO/kaolin@fluoroPOS/PDMS coatings are resistant to water, milk, coffee, soy sauce, tea, sunflower oil, lubricant base oils, and other everyday liquids at contact angles greater than 150 degrees, demonstrating superior superamphiphobic and self-cleaning properties. Moreover, the coatings can withstand harsh external environments such as strong acid and alkali chemical corrosion, high temperature heating, photo-radiation aging, mechanical friction and wear, and show good durability. More importantly, the low surface energy fluoroPOS can spontaneously migrate from the interior of the coating to the surface when exposed to heat, thus restoring their impaired superamphiphobic properties. The coatings also have good antimicrobial adhesion due to the incorporation of ZnO nanoparticles. In addition, coatings can be fabricated on a variety of soft and hard substrate materials, such as cotton fabrics, sponges, aluminum sheets, and wood. Therefore, the repairable and durable superamphiphobic antifouling coatings constructed in this study are expected to find applications in many areas, such as building coatings, oil and gas pipelines, fluid drag reduction, and biological anti-corrosion.

Insights of nanostructure and nanomechanical properties of the tribofilm derived from CoAl-hexametaphosphate layered double hydroxide on sliding steel surfaces

This study successfully synthesizes CoAl-hexametaphosphate layered double hydroxide (HMP-LDH) via anion exchange. The application of HMP-LDH leads to substantial wear and friction reduction of 88% and 25%, respectively, outperforming the PAO-4 base oil. In-depth characterizations of tribofilms formed on wear scars and tracks were conducted using various techniques, including Raman, X-ray photoelectron spectroscopy, scanning transmission electron microscopy - energy dispersive X-ray spectroscopy, and cryo-electron energy loss spectroscopy. It was found that the predominant composition of the tribofilm consists of mixed oxide and phosphate species. Notably, metallic cobalt is observed near the tribofilm-steel interface. Nanoindentation and nanoscratch were performed on the HMP tribofilm. The relationship between the nanostructure and nanomechanical properties and their influence on friction and wear have been revealed.

Evaluation of tribological properties and sustainability of bio-lubricant developed from neem seed oil for real-life application

The Tribological property of Neem seed oil is evaluated with various proportions of Zinc Dialkyl Dithiophosphate (ZDDP) ranging from 0.5% to 3% by weight and compared with SAE 20W40 oil. The best weight percentage concentration of the additive with the base oil was selected for further property analysis. The formulated bio lubricant is tested on real-life application as engine lubricant on a working motorbike engine to arrive at the feasibility of these oils as a practical engine oil. The biodegradability and toxicity of the best additive concentration were evaluated. The study showed that the addition of 2% ZDDP increased the anti-wear properties of the base oil and it was found comparable to industrial standard oil after the engine run test.

Recycling Waste Lubricants with Different Types of Base Oil into Low Sulfur Fuel with Two Stage Distillation Pyrolysis Process

The intent and purpose of the research is to improve fuel performance by recycling waste lubricants into low sulfur fuel, using waste lubricants made of various types, namely mineral, semi-synthetic, full synthetic, and mixtures from different sampling sites, with the scope of lubricant waste coming from motorcycles. Recycling waste lubricants is chosen in 2 stages, to get purer fuel and better fuel performance, it is called a distillation pyrolysis process. The advantage of using this distillation pyrolysis process is that it does not use high temperatures, and is cheap and fast. Waste lubricant recycling using a two-stage distillation pyrolysis process produces a fuel with a sulfur content that decreases by 61.98 %wt -68.61%wt in stage I and 66.32 %wt - 70.66 %wt in stage II for waste lubricants with four different base oil. Thus, proving that the two-stage distillation pyrolysis process can reduce sulfur content and can also improve fuel performance at the characteristic values of several other chemical properties.

A Comprehensive Review on Applicability and Bioactivity of Rogan-I-Kunjad (Sesamum indicum L-Oil): Unani Prospective

Sesame oil has a long history of usage as a food and medicine. It is the most used oil as a medicine or as a base oil for preparations of many compound drugs in the Unani system of medicine. It has a wide range of biological activities as mentioned in Unani classical text; this review highlights its pharmacological activities and their possible mode of action. Searched many Unani classical literature online and offline and simultaneously did parallel search on databases like PubMed, and Science Direct, and extraction of data related to sesame oil, sesame seeds with its pharmacological activities, mode of action, then interpretation and summarization of all related data. Sesame oil possesses many biological activities like anti-inflammatory, antihyperlipidemic, antiatherosclerotic, hepatoprotective, antiasthmatic, analgesic, emollient, antipruritic, and wound healing effects, which were scientifically demonstrated as mentioned in Unani literature. Sesame oil has a hopeful effect on modulating diseases with no significant toxic effect; so, there is a need to identify its safety and efficacy on human subjects to develop a new potential drug.

Potential valorization of used cooking oil into novel biolubricating grease through chemical modification and its performance evaluation

Non-edible vegetable oil derived lubricants feedstock have come up strongly in recent time but diverting the used cooking oil (UCO) for bio-lubricant production is a viable and attractive approach in countries like India where availability of non-edible oils are limited. In this regard, this work explores for the very first time, the consideration of environmental-friendly ethylhexyl esters (EHEs) as base oil produced from used cooking oil through transesterification of fatty acid methyl esters (FAMEs) and 2-ethylhexanol in the presence of p-Toluenesulfonic acid to develop eco-friendly grease. The produced biolubricant (UCO-BL) was identified using FTIR and NMR techniques. The fatty acid composition of UCO-BL was determined using the quantitative GC-FID technique and it was found that linoleic and oleic were the major unsaturated fatty acids present in UCO-BL. The experimental results show that the different fatty acid profiles in UCO-BL have a significant impact on the tribological and rheological performance of the prepared grease. The friction coefficient of UCO-BL based grease was 30.6% lower compared to mineral oil (MAK150) based grease. The surface lubricated by MAK150 based grease exhibits lower wear but deep scratches, whereas UCO-BL based grease showed fine scratches. Also, the high solvency of UCO-BL promotes a strong gel network, resulting in higher viscosity and lower values of loss tangent of the prepared grease. This study demonstrates that biolubricant derived from used cooking oil could be utilize to develop eco-friendly grease. Additionally, it can contribute to the effective utilization of waste cooking oils and aid in waste management.

Recovery of Base Oil from Used Oil through Solvent Extraction Followed by Adsorption: A Review

Base oil is the major component of lubricating oil, which is present in its original form and used lubricating oil in a sufficient amount. This review article focuses on the recovery of base oil from used oil through solvent extraction followed by adsorption. Different solvents and various solvent-to-oil ratios are studied. Solvent selection is based on its ability to selectively dissolve the base oil from used oil and to reject the impurities in the solution. The percentage yield and quality of extracted oil usually depend upon the nature of the solvent, solvent-to-oil ratio, and nature of impurities. Various solvents and solvent-to-oil ratios are studied. However, results show that methyl ethyl ketone (MEK) is the best solvent because it gives the maximum sludge removal, is more easily recovered, and also has a low cost. A two-phase system occurs after adequate mixing of solvent and oil. Before solvent addition, oil is dehydrated to remove water present as impurities, and then light hydrocarbons are removed using vacuum distillation. After solvent addition, the extracted phase is separated, leaving behind the sludge phase, which consists of aggregates of impurities. The solvent is evaporated from the extracted phase. The extracted oil is put in contact with a suitable adsorbent to absorb the aromatic contents and heavy metals in it. In the end, additives are added to the recovered oil for the formulation of a new lubricant.

Surface tension, wettability and tribological properties of a low viscosity oil using CaCO3 and CeF3 nanoparticles as additives

The rise of the electric vehicles as a more sustainable transport alternative makes it necessary to study new transmission fluids that adapt to their needs and improve their efficiency. The thermophysical properties (contact angle, surface tension and rheology) and tribological properties (friction and wear) of potential PAO8 transmission nanofluids using CaCO3 and CeF3 nanoparticles as additives are evaluated at mass concentrations of 0.05, 0.10, 0.15 and 0.20 wt%. Low contact angle and surface tension values are obtained, indicating good wettability. When the nanoparticles are used as PAO8 additives, small reductions in surface tension are achieved, but no differences in contact angle are observed. All nanolubricants and base oil exhibit Newtonian behavior. Concerning the tribological behavior, reductions in the friction coefficient are achieved for both types of nanoparticles, with the largest reductions comparing to PAO8 base oil being 13 % and 10 % for nanolubricants containing 0.05 wt% CaCO3 and 0.10 wt% CeF3 nanoparticles (NPs), respectively. In terms of antiwear performance, maximum reductions are obtained for the CaCO3 nanolubricant of 28 % (0.15 wt%), 41 % (0.10 wt%) and 59 % (0.15 wt%) and for the CeF3 nanolubricant of 19 % (0.20 wt%), 53 % (0.10 wt%) and 58 % (0.20 wt%) for the parameters of diameter, depth, and area of the worn track, respectively. Through Raman microscopy, the tribological mechanisms of tribofilm formation, repairing, and rolling can be proposed. A discontinuous tribofilm formed by the CaCO3 and CeF3 nanoparticles reduces the contact area between the two surfaces protecting them.

Pd nanoparticles lubricant additive catalyze the construction of carbon-based tribofilm to reduce graphitization-induced wear of DLC films under boundary lubrication

To explore approaches of reducing graphitization-induced wear on the friction surface of DLC films under boundary lubrication to increase their service life, Pd nanoparticles (PdNPs) prepared by chemical reduction method were used as lubricant additive of DLC films and GCr15 ball under boundary lubrication. Tribotests, reactive force field molecular dynamics (ReaxFF MD) and surface characterization methods, such as SEM, XPS, Raman and FIB-TEM, were used to study the effects of PdNPs as lubricant additive on the graphitization-induced wear of DLC films and the effect mechanisms. The results show that, PdNPs lubricant additive can reduce the friction coefficient (COF) of the tribosystems, and more importantly, they can obviously increase the lifespan of DLC films. Characterization results indicate that PdNPs can promote the tribochemical reaction on the friction surface and catalyze the formation of carbon-based tribofilm on the friction surface, which significantly reduces the graphitization-induced wear of DLC films. ReaxFF MD studies show that PdNPs effectively catalyze the massive dehydrogenation and chain-breaking of base oil hydrocarbon molecules, providing the basis for the formation of carbon-based tribofilm. These results indicate that PdNPs are promising as effective additive to prolong the service life of DLC films under boundary lubrication.

Oil-separation properties of aviation grease under thermal aging

During work or long-term storage, grease is susceptible to thermal oxygen or mechanical aging, which affects the performance of grease or even leads to the destruction of the structural surface of grease lubricated products. As the main mechanism of grease lubrication, grease partitioning can explore the aging law of grease and effectively identify whether the grease fails. In this paper, 7014 aerospace grease was selected as the research object and accelerated test was conducted by high temperature thermal oxygen. The combination of grease separation degree and mass change rate was selected for comprehensive characterization of grease separation performance. The results show that the grease partitioning degree has a significant decreasing trend; the quality change has also decreased and the degradation trajectory is similar to the partitioning degree; it is inferred that the main reason for the decrease of grease partitioning performance may be the loss of base oil and the change of thickener fiber structure.

Colloidally Stable Graphite Oleogels by Pyrene-Functionalized Telechelic Polymers for Friction and Wear Reduction.

Although graphite derivatives, such as graphene, graphene oxide, and reduced graphene oxide, have been widely used as lubricating oil additives to reduce friction and wear, their synthesis either proceeds with complicated procedures in low yield, suffering from high cost, or involves the utilization of highly corrosive chemicals, raising safety and environmental concerns. Therefore, the direct use of pristine graphite as a lubricating oil additive is indispensable for practical tribological applications. However, the realization of this idea has been seriously hampered by the incompatibility of graphite with lubricating base oils. In this work, we report a rational strategy to directly disperse graphite in base oils in the form of oleogels assisted by pyrene functionalized telechelic polymers under mild condition. The resulting oleogels exhibit long-time colloidal stability for more than one year, wherein the graphite has been exfoliated to in situ form graphene through π-π interactions with the pyrene-containing telechelics. Moreover, compared with the base oil, the graphite-based oleogels are found to exhibit remarkable reductions in friction and wear by up to 52% and 97%, respectively. Significantly, such tribological performances are comparable to those of exfoliated graphite derivatives. Taken collectively, directly using pristine graphite as a lubricating oil additive with superior tribological properties represents a revolutionary approach to create low-cost, green, and high-performance lubricants just based on pristine layered materials without involving any pre-exfoliations.

Development and characterization of novel Lycium barbarum seed oil-based oleogels and their application in functional chocolate

The shortage of cocoa butter (CB) resources has limited the growth of the chocolate industry, and the use of oleogels as a substitute for CB is an emerging strategy. Glycerol monostearate beeswax complex oleogels (GBO), glycerol monostearate rice bran wax complex oleogels (GRO) and glycerol monostearate lacquer wax complex oleogels (GLO) were prepared by using Lycium barbarum seed oil as the base oil with wax. The feasibility of these three oleogels for partial replacement of CB in chocolate was also investigated. The resulting oleogels were characterized using texture profile analysis (TPA), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and rheology. The results showed that all three oleogels were hydrogen bonded and had similar polycrystalline properties. Among the three oleogels, GRO showed the highest hardness and oil binding capacity (OBC) of 1457 g and 99.82%, respectively. And it showed the best gelation properties in 1–100 Hz and 0.001–10% strain sweep. The oleogel chocolates were characterized by rheology, crystal polymorphism and sensory properties. Compared to the control group without oleogels, GRO showed the best substitution, with GRO-chocolate having more stable rheological properties, better taste and overall acceptability. This study provides new ideas for the preparation of chocolates that are lower in saturated fatty acids and richer in nutrients.