Lubricant Formulations Research Articles

Green synthesis of biolubricant base stock from canola oil

A green process for the preparation of biolubricant base stock from canola oil was developed. Three branched chain products were synthesized from commercially available canola oil. This process involves two steps, first, the preparation of epoxidized canola oil by using amberlite IR 120 catalyst followed by ring opening reaction with different alcohols such as n-butanol, amyl alcohol, and 2-ethylhexanol catalyzed with Amberlyst-15 (dry). These products were confirmed by using FTIR, 1H and 13C NMR. The prepared oleo chemical derivatives show improved low temperature properties determined by measuring pour point and cloud point. These derivatives were used as additives in low lubricating diesel fuel and the lubricating properties were studied by using HFRR wear scar. These derivatives have good anti-wear and friction reducing properties at relatively low concentrations. Thermal stability of these derivatives was studied by using TGA. The material with higher chain alcohol had shown more lubricity and good thermal stability. The finding of this study shows that derivatives of epoxy canola oil can be used as a starting material for the lubricant formulations.

Choice of Artificial Tear Formulation for Patients With Dry Eye

Dry eye is prevalent in many parts of the world. As a result, ophthalmologists and other health care professionals, such as optometrists and general practitioners, often help these patients manage their symptoms. The most common form of treatment for management of dry eye is over-the-counter tear lubricants. A number of tear lubricant formulations are available that vary by their mechanism of action. This article suggests simple guidelines on how lubricants can be selected for patients with mild to moderate dry eye. Side effects of lubricants, such as burning on instillation because of mismatches of eye drop with tear acidity, are also discussed.

Lubricating and Waxy Esters II: Synthesis, Crystallization, and Melt Behavior of Branched Monoesters

A comprehensive study of branched derivatives of four pure jojoba wax-like esters (JLEs), having 36, 40 (two isomers), and 44 carbons was conducted to elucidate their crystallization and melting behavior. Crystallization and melting characteristics depended strongly on the number of branches, molar mass, and symmetry. The derivatives demonstrated a very strong tendency to form glassy liquids rather than crystal phases and remain liquid-like at very low temperatures. As the number of branches increased, their crystallinity decreased drastically while their glassy phase increased concomitantly with the depression of the onset of crystallization and/or glass transition temperature. A variety of possible transformation paths, ranging from very little polymorphic activity to extremely polymorphic behavior, depending on number of branches, mass, and symmetry were revealed. It is shown that asymmetry plays a large role in the low temperature behavior, rendering the branched derivatives of the asymmetrical JLEs much better candidates for lubricant formulations.

Frequency, patterns, and preferences of lubricant use during anal intercourse within male sexual partnerships in Lima, Peru: Implications for a rectal microbicide HIV prevention intervention

Understanding current practices of lubricant use during anal intercourse can help to assess the contexts for the introduction of topical rectal microbicides as an HIV prevention tool for men who have sex with men (MSM). We used quantitative and qualitative methods to assess: current patterns of lubricant use; preferred characteristics of commercial lubricant formulations; and social and behavioral contexts of lubricant use within male sexual partnerships in Lima, Peru. Between 2007 and 2008, we conducted a quantitative behavioral survey with 547 MSM followed by qualitative individual and group interviews with 36 MSM from Lima, Peru. Approximately half of all participants in the quantitative survey (50.3%) reported using commercial lubricant during intercourse occasionally or consistently during the preceding two months, with lack of availability at the time of intercourse the most commonly reported reason for non-use. No clear preferences regarding the color, smell, taste, or viscosity of commercial lubricants were identified, and all participants who reported using a commercial lubricant used the same product (“Love-Lub”). In the qualitative analysis, participants characterized lubricant use as a sexual practice consistently controlled by the receptive partner, who typically obtained and applied lubricant independently, with or without the consent of the insertive partner. Quantitative findings supported this differential pattern of lubricant use, with men who reported sexual identities or roles consistent with receptive anal intercourse, including unprotected receptive intercourse, more likely to report lubricant use than MSM who claimed an exclusively insertive sexual role. Given the social, behavioral, and biological factors contributing to increased vulnerability for HIV and STI acquisition by the receptive partner in anal intercourse, delivery of a topical rectal microbicide as a lubricant formulation could provide an important HIV prevention resource for at-risk MSM in Lima, Peru.

The efficiency of a hypoid axle—a thermally coupled lubrication model

The final drive unit in road vehicles, such as medium and heavy trucks, and four-wheel-drive and rear-wheel-drive passenger cars, usually consists of a hypoid or spiral bevel geared transmission and differential, housed in a self-contained, dip-lubricated axle. Such units are subjected to very variable duty—including extreme combinations of speed, gradient, applied torque and external temperature—and are typically cooled by natural and forced convection on the exterior surface. On the other hand, there are appreciable internal power losses due to gear friction and churning and to bearing and seal losses. These losses are highly dependent upon the lubrication regime of the internal components and hence to the thermal behaviour of the entire axle.In the present paper, we describe a thermally coupled model of axle lubrication. The torque and speed demand is first found from a specified duty (“drive cycle”) which includes terrain as well as speed-versus-time and external temperature data. The evolution of sump oil and component temperatures is followed, and increments of energy loss evaluated in each time-step. Elastohydrodynamic film thickness is determined for the hypoid gear set, using a development of Buckingham's method, and friction losses calculated using a simple oil rheological model based on tribometer (MTM) testing. Churning, seal and bearing (speed-dependent) losses are found using empirical algorithms. Energy losses over complete drive cycles for different lubricants are derived, enabling the relative fuel economy for different oils to be evaluated.Results show that (i) the bulk temperature rise of the axle is highly dependent on the specified vehicle duty and (ii) the efficiency can be strongly influenced by choices available to the lubricant formulator. Taken together, these findings suggest that specialist axle lubricant formulations for particular vehicle types and applications will be attractive as a route to optimum fuel economy.

Direct analysis in real time mass spectrometry for analysis of sexual assault evidence

Sexual assault crimes are vastly underreported and suffer from alarmingly low prosecution and conviction rates. The key scientific method to aid in prosecution of such cases is forensic DNA analysis, where biological evidence such as semen collected using a rape test kit is used to determine a suspect's DNA profile. However, the growing awareness by criminals of the importance of DNA in the prosecution of sexual assaults has resulted in increased condom use by assailants as a means to avoid leaving behind their DNA. Thus, other types of trace evidence are important to help corroborate victims' accounts, exonerate the innocent, link suspects to the crime, or confirm penetration. Direct Analysis in Real Time Mass Spectrometry (DART-MS) was employed for the comprehensive characterization of non-DNA trace evidence associated with sexual assault. The ambient ionization method associated with DART-MS is extremely rapid and samples are processed instantaneously, without the need for extraction, sample preparation, or other means that might compromise forensic evidence for future analyses. In a single assay, we demonstrated the ability to identify lubricant formulations associated with sexual assault, such as the spermicide nonoxynol-9, compounds used in condom manufacture, and numerous other trace components as probative evidence. In addition, the method can also serve to identify compounds within trace biological residues, such as fatty acids commonly identified in latent fingerprints. Characterization of lubricant residues as probative evidence serves to establish a connection between the victim and the perpetrator, and the availability of these details may lead to higher rates of prosecution and conviction, as well as more severe penalties. The methodology described here opens the way for the adoption of a comprehensive, rapid, and sensitive analysis for use in crime labs, while providing knowledge that can inform and guide criminal justice policy and practice.

Comparison of tooth profiles and oil formulation focusing lower power losses

Environmental awareness, lower consumption of raw materials and longer life of equipment are main concerns nowadays and are leading to the research and development of lubricants and equipment to access those requirements. In this study, the power loss performance of three different tooth profile geometries, developed with the purpose of decreasing power losses while keeping the predicted life, were tested and evaluated in a FZG test rig. The path to reduce power losses was based on the decrease of the module, the increase of the helix angle and increase of the addendum modification coefficients in order to reduce the path of contact, i.e. the sliding velocity. The power loss behaviour of two different lubricants was also evaluated for each tooth profile geometry considered. The influence of the oil level in the gearbox was also evaluated. One of the lubricants has an ester base while the other has a polyalphaolefin base and both are fully formulated. An energetic model was developed for the FZG test gearbox and applied to these tests to improve the knowledge about the influence of tooth geometries as well as lubricant formulation in the power losses and coefficient of friction between gear teeth. The developed geometries showed that the path followed for the reduction of power losses produced the expected results and can be implemented with success on gear design.

Single cam tribometer for evaluating tribological parameters and tribochemistry of DLC coated valve train follower

In engine valve train systems, due to the sliding–rolling motion at the cam/follower interface, mixed and boundary lubrications dominate. It is in this regime that the effects of the lubricant chemistry at the molecular scale prevail over lubricant rheology effects in determining the friction and wear performance. The precise evaluation of friction and wear on the contact surfaces is essential to understand the tribochemistry of modern lubricant formulations and modern coating technologies. In the literature, a range of experimental tribometers have been used to simulate the tribology and tribochemistry of the cam/follower interface, leading to valuable information on the lubrication of this system. However, conventional tribometers such as pin on plate (PoP), pin on disc and disc on disc are not precise simulators due to their steady load operating conditions. This study looks into the opportunity of using the single cam tribometer (SCT) for better simulation of tribology and tribochemistry of engine valve train systems. The friction, wear and surface chemistry characteristics of a-C:15H (diamond like carbon) coated shims in contact with a chilled Cr cast iron cam lubricated using model oils have been evaluated using the SCT. Single cam test results are discussed in relation to the results obtained from a reciprocating PoP tribometer.

Synthesis and characterization of isocyanate‐functionalized PVA‐based polymers with applications as new additives in lubricant formulations

AbstractThis work deals with the incorporation of reactive isocyanate groups into polymer additives, which could be potentially used to modify the rheological properties of lubricating greases by reinforcing the role of traditional thickening agents. Thus, a batch of partially protected poly(vinylalcohol) (PVA) copolymers was successfully synthesized. Some of their OH groups were blocked as tetrahydropyranyl (THP) ethers (PVA–THP), while the spare hydroxyl groups were further functionalized with NCO pendant groups by reaction with 1,6‐hexamethylene diisocyanate, leading to several isocyanate‐functionalized PVA‐based polymers (PVA–THP–NCO), which were tested as rheology modifiers of lithium lubricating greases. The highest protection degree of hydroxyl groups achieved as THP‐ether was 58.5% and the recovered polymers were isolated with excellent yields (close to 90% in most cases). NCO‐functionalized PVA‐based polymers (PVA–THP–NCO) exerted a significant rheological modification in lithium 12‐hydroxystearate lubricating greases, increasing the values of the linear viscoelastic functions. The influence of the degree of protection and later functionalization of PVA on the rheological properties of PVA–THP–NCO‐additivated lubricating greases is discussed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Friction coefficients for mechanically damaged bovine articular cartilage

We used a pin-on-disc tribometer to measure the friction coefficient of both pristine and mechanically damaged cartilage samples in the presence of different lubricant solutions. The experimental set up maximizes the lubrication mechanism due to interstitial fluid pressurization. In phosphate buffer solution (PBS), the measured friction coefficient increases with the level of damage. The main result is that when poly(ethylene oxide) (PEO) or hyaluronic acid (HA) are dissolved in PBS, or when synovial fluid (SF) is used as lubricant, the friction coefficients measured for damaged cartilage samples are only slightly larger than those obtained for pristine cartilage samples, indicating that the surface damage is in part alleviated by the presence of the various lubricants. Among the lubricants considered, 100 mg/mL of 100,000 Da MW PEO in PBS appears to be as effective as SF. We attempted to discriminate the lubrication mechanism enhanced by the various compounds. The lubricants viscosity was measured at shear rates comparable to those employed in the friction experiments, and a quartz crystal microbalance with dissipation monitoring was used to study the adsorption of PEO, HA, and SF components on collagen type II adlayers pre-formed on hydroxyapatite. Under the shear rates considered the viscosity of SF is slightly larger than that of PBS, but lower than that of lubricant formulations containing HA or PEO. Neither PEO nor HA showed strong adsorption on collagen adlayers, while evidence of adsorption was found for SF. Combined, these results suggest that synovial fluid is likely to enhance boundary lubrication. It is possible that all three formulations enhance lubrication via the interstitial fluid pressurization mechanism, maximized by the experimental set up adopted in our friction tests.

An analytical method for lubricant quality control by NIR spectroscopy

The excellent compatibility of polyol esters (POEs) with general fluids coolants such as CO2 and non-chlorinated coolants (e.g. hydrofluorocarbons, HFCs) in terms of solubility, miscibility and chemical stability has fostered their use as lubricants by the refrigeration industry. The most widely used POEs bases consist of esters of polyalcohols – such as pentaerythritol, dipentaerythritol and neopentylglycol – with mixtures of carboxylic acids of 4–10 carbon atoms. Their thermophysical properties (viscosity mainly) are crucial with a view to producing efficient lubricants for specific applications. Usually, POE formulations, which usually contain several bases, are characterized in terms of global indices.In this work, we developed a methodology based on NIR spectroscopy for the characterization and analysis of lubricant formulations. The products, including lubricant bases and lubricant formulations, are characterized by reference to two spectral libraries that are used to identify as the starting lubricant bases as well as the lubricant formulations. It has been proposed to build libraries in cascade for the differentiation of lubricant formulations without and with low content in additives. Once the identification of the formulation is applied PLS multivariate models are used to determine the components of a lubricant formulation and its viscosity.

Synthesis, Chemical Modification and Tribological Evaluation of Plant oil as Bio-Degradable Low Temperature Lubricant

An increasing demand for environmentally acceptable lubricant has led researchers to look to plant oils as an alternative to petroleum based lubricants. These plant oil based products are sustainable, renewable and biodegradable that can replace petroleum derived products in numerous industrial applications such as stabilizers, plasticizers, cutting fluids, automotive lubricants and in coating formulations. For formulation of bio-degradable lubricants, crude rapeseed oil, methyl ester of sunflower oil, palm oil and rapeseed oil were selected and to this bio-additive package were added to improve some of the properties. Various tribological studies of the formulated lubricants were evaluated then it is compared with conventional synthetic lubricant SAE20W40. However plant oils are limited by their poor low temperature fluidity and poor oxidative stability. In order to produce rapeseed oil based bio-lubricant with good oxidative stability and low pour point, in the present work the raw rapeseed oil was chemically modified via, epoxidation and hydroxylation process. The formation of the epoxidized group was confirmed by Fourier Transform Infrared spectral (FTIR) analysis. Epoxidized rapeseed oil showed superior oxidative stability, lower pour point and friction reducing ability compared to base oil.

Tribological Properties of Metal V-Belt Type CVT Lubricant

The priority for lubricant performance for metal V-belt-type CVT (B-CVTFs) should be the improvement of transmittable torque capacity between the belt and pulley plus excellent antishudder properties for lockup clutch used in B-CVTs. This study intends to investigate the effect of lubricant additives for improving these performances of B-CVTs. In addition, surface analysis techniques were utilized to gain a novel insight into the chemical composites and morphology of the tribofilms. As a result, it is vital for greater torque capacity to give higher boundary friction coefficient between the metal contacting interfaces, and the process of boundary lubricant film formation derived from antiwear additives used in B-CVTFs strongly impacts on the torque capacity. Moreover, it is found that a sort of lubricant formulation gave an excellent antishudder performance for wet clutch with keeping higher friction coefficient between the metals, which would result in improving the performance of B-CVTs.

Luminescent Bacteria as an Indicator Species for Lubricant Formulation Ecotoxicity

Abstract For a number of years, luminescent bacteria have been used as an indicator species for acute toxicity of substances in aquatic marine environments. Various other higher organisms have been used for this exact same purpose. Many of the higher organism test evaluations have been used successfully, but they have a few limitations, such as a low number of organisms exposed to toxicant during a test, less than desirable precision and the need for highly trained individuals to run the tests. One luminescent bacterial bioassay includes many organisms, can be run rapidly and requires training in sample dilution techniques. ASTM Subcommittee D02.12 has been working to develop an ecotoxicity method to evaluate the effects of lubricant formulations on luminescent bacteria. The theory describing this method, as well as the D02.12 method development activities, will be discussed.

A Search for Ecofriendly Detergent/Dispersant Additives for Vegetable‐Oil Based Lubricants

AbstractCarbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used for several decades to solve this problem particularly in petroleum oils. But future lubricants and new engine hardware require development of new nontoxic detergent/dispersant additive technologies. Environmental concerns limit the formulation of the future lubricants. It requires not only the base oil to be ecofriendly but the additives also. In the present work, some of the potential ecofriendly chemical's molecules were identified. Specific detergents applications along with effects of chemical modifications were evaluated by Blotters Spot and Panel Coker Tests. Among the studied compounds, the PIB (polyisobutylene) succinimides are showing promising results at lower temperature, while at higher temperature piperazine derivatives citrate and oleate have the best potential to be develop as ecofriendly detergent/dispersant additives.

Polysulfide and Biobased Extreme Pressure Additive Performance in Vegetable vs Paraffinic Base Oils

Twist compression tribotester (TCT) and 4-ball extreme pressure (EP) methods were used to investigate commercial polysulfide (PS) and biobased polyester (PE) EP additives in paraffinic (150N) and refined soybean (SOY) base oils of similar viscosity. Binary blends of EP additive and base oil were investigated as a function of additive concentration. In addition to weld point (WP), 4-ball EP produced a set of preweld data, notably peak torque and wear scar diameter, which were found to correlate with WP results. TCT gave a 5-fold larger time-to-failure (TTF) for neat SOY than for neat 150N, whereas 4-ball EP gave similar WP (120 kgf) values for both neat oils. This difference was explained by invoking boundary contribution to TCT but not to 4-ball EP method. Both additives improved the WP and TTF of the base oils, which further increased with increasing additive concentration. However, the extent of the improvements was highly dependent on the chemistries of the additive and base oil of the blends. Thus, at similar concentrations, the WP of PE was higher in the 150N than in the SOY base oil, while the WP of PS was higher in the SOY than in the 150N base oil. Similarly, TTF of 150N was higher with blended PE than PS; whereas for SOY, it was higher with blended PS than PE. This chemistry effect was attributed to relative compatibility between EP additives and base fluids. The results suggest that a substantial reduction (up to 4-fold) in EP additive usage in commercial lubricant formulations can be achieved through proper selection of compatible base fluids and additives.

Study on the Optimal Formula of Lubricant with Uniform Design

The experiment is performed using three additives, Neopentyl Polyol Ester (NPE) as the base oil. This uniform design involves three independent variables and three dependent variables. It is belong to many factors and multi-objective investigation problem. With experimental results adopt U7 table seven levels of uniform design, the results showed that the design is optimizes the lubricant formulation, reached improve experiment efficiency, reduce the number of purpose and have a satisfactory results in retest experiment.

Synthesis and Evaluation of Acrylate Polymers in Lubricating Oil

Additives based on polymers of alkyl acrylate used in lubricant composition improve the viscometric and rheological properties of the lubricant and provide fuel economy. However, the recent demand for eco-friendly technology prompted us to develop biodegradable additives for the lubricant formulation. Thus, in anticipation of getting an ideal blend of performance as well as eco-friendly chemistry, the present investigation comprising the incorporation of an α-pinene (α-p) moiety into the acrylate (dodecyl acrylate, DDA, and isodecyl acrylate, IDA) skeleton through copolymerization was undertaken. The analysis of different properties of the polymers indicates that copolymers of α-pinene with DDA have more thermal stability and better pour point and viscosity index (VI) values than the copolymers of α-pinene with IDA. However, the study of the biodegradability test indicates that the copolymers of α-pinene with IDA are better than the other and they show significant biodegradability against the fungal patho...

Based on the PB Neural Network of Optimization Design in Lubricant Additives

This article use the Sulphide Isobutene, Five Sulfides Dialkyl, and Star of Phosphorus as the additives, Neopentyl Polyol Ester (NPE) as base oil for screening lubricant formulation. The purpose of this article is screening the lubricant additives formula. Apply the BP neural network method in optimization design. Through the optimization of lubricant additive formula select the best formula for experiment. The selected best formula is Sulphide Isobutene 0.8%(mass percent), Five Sulfides Dialkyl 1.2%(mass percent) , Star of Phosphorus 1.6%(mass percent), relative error is 0.089.After validation experiment，it is conclusion that S-type blends with P-type additive use will acquire good result, and the method of optimal convergence faster, the forecast precision test is satisfied.

Developing environmentally friendly rolling lubricants

Swerea MEFOS pilot mill has been used as a rolling lubricant development tool. The objectives were to improve the lubrication during rolling and thereby improve the operation of the rolling mills. This was done taking into account both the technological aspect, rolling mill output, and the ecological aspect, investigating ways to use rolling lubricants that are more ecologic sustainable, i.e. alternatives to oil-based lubricants as well as the recycling/recovering of oil-based lubricants. Oil-in-water emulsions and an aqueous solution, by the producer termed a conditional emulsion, were tested where the lubricant formulation was altered to optimize the performance for hot rolling of aluminium. Cold-rolling tests were also run on steel coils, where the presence of rust protective oil was studied as well as the influence of aged emulsion behaviour compared with fresh emulsion. Finally, Sapa developed a vacuum evaporator system for recovering oil from dumped emulsion generated during aluminium hot rolling, followed by separation, centrifugation, and flocculation. The cleaned concentrates were reconditioned for reuse. The recycled and recovered emulsion was tested and compared with the original fresh emulsion in Swerea MEFOS pilot mill with results as good as the fresh emulsion.