Commercial Lubricants Research Articles

The tribochemical study of novel phosphorous-nitrogen (P-N) type phosphoramidate additives in water

Purpose – The purpose of this paper is to investigate the tribological properties of novel phosphorous-nitrogen (P-N) type additives in water. Design/methodology/approach – The tribological properties of the novel P-N additives in water are compared with a commercial lubricant additive of the P-N type using a four-ball machine. The tribological mechanism was investigated by X-ray absorption near-edge structure (XANES) spectroscopy. Findings – The experimental results indicate that the phosphoramidate derivatives possess good anti-wear and friction-reducing properties. The XANES analysis shows that the prepared compounds can form a protective film containing phosphate and/or polyphosphate that affects the tribological behavior. Originality/value – The purpose of this paper is to investigate the tribological properties of the novel P-N type additives in water.

Women's Use and Perceptions of Commercial Lubricants: Prevalence and Characteristics in a Nationally Representative Sample of American Adults

Use of commercial lubricant is common in the United States among adult women. However, little is known about the sexual behaviors for which women use lubricant, women's perceptions of lubricant, or reasons for use, particularly in a nationally representative sample. The aim of this study was to document the prevalence and characteristics of lubricant use among adult women in the United States and their perceptions of lubricants in relation to subjective sexual experiences. Data are from a subset of individuals who were sampled as part of the 2012 National Survey of Sexual Health and Behavior, which involved the administration of an online questionnaire to a nationally representative probability sample of U.S. adults ages 18 and older. Sociodemographic characteristics, recent and lifetime commercial lubricant use, lubricant use during specific sexual behaviors, frequency of lubricant use, and reasons for lubricant use of participants were studied for the article. Of the women who participated in the study, 65.5% (n = 1,021) reported ever having used lubricant and 20% had used a lubricant within the past 30 days. Across age groups, lubricant was most commonly used during intercourse (58.3% of women) or partnered sexual play (49.6%). Common reasons for lubricant use included to make sex more comfortable, fun, and pleasurable and to decrease discomfort/pain. Most American women have used lubricant. Also, lubricant is more common as part of partnered intercourse and sexual play or foreplay compared with other solo and partnered sexual behaviors. Clinicians may find it helpful to broaden conversations with patients to include questions about their sexual behaviors, comfort and/or pain during sex, and lubricant use and to share, particularly with younger women, that lubricant use is prevalent and commonly used for reasons related to pleasure as well as comfort.

Tribological characteristics of amorphous hydrogenated (a-C:H) and tetrahedral (ta-C) diamond-like carbon coating at different test temperatures in the presence of commercial lubricating oil

Currently, the application of diamond-like carbon (DLC) coatings for automotive components is becoming a favorable strategy to cope with the new challenges faced by the automotive industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, consequently improving the fuel efficiency and durability of these components. Commercially available fully formulated lubricating oils enhance the lubrication of ferrous materials. Therefore, the interaction between nonferrous coatings (e.g., DLC) and commercial lubricating oil must be investigated. A ball-on-plate tribotester was used to run the experiments using stainless steel plates coated with amorphous hydrogenated DLC (a-C:H) and tetrahedral DLC (ta-C) sliding against a 440C stainless steel ball. Wear track was investigated by scanning electron microscopy and atomic force microscopy. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used to analyze the tribofilms inside the wear track. Raman analysis was performed to investigate the structural change of the coatings. At high temperatures, the CoF decreases but the wear rate increases in the a-C:H and ta-C DLC-coated plates. CoF and wear rate (coated layer and counter surface) are mostly influenced by coating graphitization. Tribochemical films, such as polyphosphate glass, are formed in ta-C and act as protective layers. Therefore, the wear rate of ta-C DLC is lower than that of a-C:H DLC.

The effects of vaginal lubricants on sperm function: an in vitro analysis

Despite being marketed as "sperm friendly", some vaginal lubricants are known to be detrimental to sperm function and therefore could negatively affect fertility. Many others have not yet been assessed in regards to their effect on sperm function. This issue may concern couples trying to conceive both naturally and via artificial reproductive technologies (ART). The aim of this research was to analyse the effects that lubricants, commonly used in the setting of natural conception and ART, have on sperm function in an in vitro setting. This was done by assessing sperm motility, vitality and DNA fragmentation following treatment with commercial lubricants or control preparations. We have attempted to mimic the conditions of the vaginal environment in our clinical trial, and so have compiled a list of lubricants that are likely to have minimal negative effect on sperm function in vivo or are "sperm friendly". Ten samples were obtained for the study from patients attending a fertility clinic. Once collected, the sperm samples were prepared by density gradient centrifugation and incubated with 11 different lubricants including positive and negative controls for 30 min at 37 °C to mimic the temperature inside the female reproductive tract. Sperm motility, vitality and DNA fragmentation were assessed to determine the effects of the lubricants on sperm function and DNA integrity. Nine lubricants were investigated including Sylk™, Conceive Plus®, glycerol, Johnson's® Baby Oil, SAGE® Culture Oil, Yes®, Forelife™, MaybeBaby® and Pre-seed®. The lubricant which had the best results in terms of vitality, at 92%, was Pre-seed® and the worst was Forelife™ with 28% vitality. In terms of motility, Pre-seed® resulted in the highest percentage of spermatozoa with progressive motility at 86% and Sylk™ resulted in the lowest percentage of progressively motile cells in the sample with 31% of sperm progressively motile. There were no significant effects on DNA integrity. Pre-seed® was the lubricant which had the least negative effect on sperm function, with Conceive Plus® a close second, due to the significantly higher sperm motility and vitality parameters measured following lubricant exposure.

S1140102 脂肪酸吸着膜のナノ機械特性と潤滑性との関係に関する研究([S114-01]トライボロジーの基礎と応用(1),機素潤滑設計部門)

Components of a lubricant are divided into base oil and additives. Base oil dominates basic fluid properties of a lubricant. Additives support to improve the lubrication performance of oils. Oiliness additives have the friction decreasing effect due to the formation of the adsorption layer preventing contact of the sliding surfaces. Previous studies about oiliness additives were performed using a single additive in base oil. However, commercial lubricant contains several additives, which interacts each other. The interaction between the additives is not elucidated. In this research, tribological characteristics of adsorption layers of stearic acid, oleic acid and the mixture of both of them were studied for elucidating the interaction of the additives by using a pendulum type friction tester, AFM (Atomic Force Microscopy) and QCM (Quartz Crystal Micro balance). The friction reduction effect of mixed additives was higher than that of single additives. In case of the mixed additives, the ratio of oleic acid and stearic acid was calculated to be 2:3 by each occupied area in the adsorption layer. The relationship between the adsorption property and friction behavior was discussed based on the experimental results.

Surface and Wear Analysis of Zinc Phosphate Coated Engine Oil Ring and Cylinder Liner Tested with Commercial Lubricant

The objective of this study was to evaluate the tribological performance through investigating protective additive layer and friction coefficient and implementing the quantitative wear measurements on the rubbed surface of the sliding pairs. The specimens of oil ring were rubbed against cast iron engine cylinder liner under boundary lubrication conditions. The ring and liner surfaces were examined by optical, scanning electron microscope and atomic force microscopy. The elemental analysis of surfaces was performed by using energy dispersive X-ray spectroscopy. Surface observations showed that coating was removed from the ring surface. Higher levels of Ca, Zn, P, and S elemental ratios (0.93%, 0.45%, 1.55%, and 1.60% as atomic percent) were detected on the cylinder liner surface. Wear width, length, and depth measurements were performed by optical and atomic force microscopies on the ring and cylinder liner surface. The results showed that wear widths for oil ring were 1.59 μm and 1.65 μm; wear widths for cylinder liner were 3.20 μm and 3.18 μm; wear depths for oil ring were 100 nm; and wear depths for cylinder liner were 482 nm. Wear data were taken mostly from the additive layer points detected by SEM and X-ray measurements.

Effect of DLC Coating on Tribological Behavior of Cylinder Liner-piston Ring Material Combination When Lubricated with Jatropha Oil

The expansion of modern engines would have been unfeasible without advanced lubricant chemistry and proper lubricant formulation. Introduction of diamond like carbon (DLC) coatings opens further possibilities in improving performance of engine and transmission components, which cannot longer be achieved only by lubricant design.DLC coatings show extremely good promise for a number of applications in automotive components as they exhibit excellent tribological properties. In this paper, the tribological performance of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil was evaluated using a four ball Tribometer also with commercial synthetic lubrication oil (SAE 40) used as base lubricant. Experimental results demonstrated that the hydrogenated amorphous carbon (a-C: H)DLC coating exhibited better performance with Jatropha oil in terms of wear and friction under similar operating conditions compared to the uncoated stainless. Thus, usage of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil in the long run may have a positive impact on engine life.

Theoretical insight into chlorine adsorption on the Fe(100) surface

This study represents a detailed DFT periodic-slab study on the interaction between atomic chlorine and the Fe(100) surface. Energetic and structural parameters are calculated for a wide range of coverages corresponding to top, bridge and hollow pure on-surface adsorptions. Calculated chemisorbed energies are found to increase gradually with the degree of coverage. Formation of iron chlorides via substitutional adsorption is predicted to be not feasible in view of the calculated chemisorption energies. This finding is in line with earlier experimental measurements with regard to the absence of chlorine diffusion into bulk Fe. Sublimation energies for FeCl2 and FeCl3 are estimated and discussed to elucidate the fate of the chlorine-iron thin layer. A stability temperature-pressure diagram is constructed for a wide range of chlorine chemical potentials to mimic real operational conditions.

Sexual lubricants in South Africa may potentially disrupt mucosal surfaces and increase HIV transmission risk among men who have sex with men

Men who have sex with men (MSM) are at high risk for HIV acquisition and transmission. There is a high HIV-transmission potential associated with unprotected anal intercourse (UAI), which requires sexual lubrication for comfortable, non-traumatic anal sex. Lubricant distribution remains poor in many developing nations and MSM have been known to substitute a number of common household or food products to ensure comfortable anal sex. Concern has been raised about the potential toxicity of lubricants used during anal sex. Epithelial injury is related to the osmolality of the lubricant product. To analyse commercially available water-based sexual lubricant products to ascertain their osmolality and potential to cause rectal epithelial damage. The osmolality and glycerol concentration was determined for eight of the most frequently purchased water-based sexual lubricants and some commonly used household/food products. Osmolality ranged from 270 - 9 440 mosmol/l (Lubrimaxxx Premium, containing phytosqualane, and JO H(2)O Water Based Lubricant, respectively). Seven (88%) of the commercial lubricants had high osmolalities, with two products approaching 10 000 mosmol/l, far in excess of serum which has an osmolality of ~280 mosmol/l. The results of this study show that many of the top-selling brands of water-based sexual lubricants available in SA are hyperosmolar. Given that hyperosmolar products have been shown in vitro and in vivo to cause epithelial injury, they may have the potential to increase HIV acquisition and transmission, if they are used during UAI. Awareness needs to be raised about the mucosal safety of lubricants designed for use during anal sex.

The quantitative surface analysis of an antioxidant additive in a lubricant oil matrix by desorption electrospray ionization mass spectrometry

RATIONALEChemical additives are incorporated into commercial lubricant oils to modify the physical and chemical properties of the lubricant. The quantitative analysis of additives in oil-based lubricants deposited on a surface without extraction of the sample from the surface presents a challenge. The potential of desorption electrospray ionization mass spectrometry (DESI-MS) for the quantitative surface analysis of an oil additive in a complex oil lubricant matrix without sample extraction has been evaluated.METHODSThe quantitative surface analysis of the antioxidant additive octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix was carried out by DESI-MS in the presence of 2-(pentyloxy)ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate as an internal standard. A quadrupole/time-of-flight mass spectrometer fitted with an in-house modified ion source enabling non-proximal DESI-MS was used for the analyses.RESULTSAn eight-point calibration curve ranging from 1 to 80 µg/spot of octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix and in the presence of the internal standard was used to determine the quantitative response of the DESI-MS method. The sensitivity and repeatability of the technique were assessed by conducting replicate analyses at each concentration. The limit of detection was determined to be 11 ng/mm2 additive on spot with relative standard deviations in the range 3–14%.CONCLUSIONSThe application of DESI-MS to the direct, quantitative surface analysis of a commercial lubricant additive in a native oil lubricant matrix is demonstrated. © 2013 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons, Ltd.

R1234yf as a substitute of R134a in automotive air conditioning. Solubility measurements in two commercial PAG oils

Starting from January 1st 2011, as stated by the Directive 2006/40/EC, fluorinated greenhouse gases with a global warming potential (GWP) higher than 150 can not be used in automotive applications any more. For this reason, 1,1,1,2-tetrafluoroethane (R134a), commonly used for these applications, will be abandoned and substituted by refrigerants with lower GWP. In recent times, a new fluid, 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) has been proposed as an interesting alternative, since it has a very low GWP and thermodynamic properties very similar to R134a. At the moment, only few data can be found on the thermodynamic properties of this new refrigerant and, in particular, its behaviour in solution with commonly used compressor lubricants is still to be evaluated. Here, solubility experimental data of R1234yf in a Polyalkylene Glycol (PAG) and in a specifically modified Double-Capped PAG (DC-PAG) commercial lubricants are measured with a static synthetic method at isothermal conditions, in the temperature range between 258 K and 338 K.

Experimental study of lubricant depletion in heat assisted magnetic recording: different lubricants on HAMR media

Heat assisted magnetic recording (HAMR) is a promising choice to surpass the super-paramagnetic limit in magnetic recording and to allow continued increase in the areal recording density of hard disk drive. However, lubricant depletion on disk surface might be a problem in HAMR due to high temperature during writing process. In this work, depletion of four types of commercial lubricants on our HAMR media has been evaluated under equivalent HAMR conditions. Linear relationships between the lubricant depletion depth and the logarithm of the equivalent laser heating time have been established for these lubricants. The depletion depths of the lubricants at different laser heating durations are predicated. It is found that the performance of the four evaluated lubricants is acceptable in respect of lubricant depletion depth by hypothesizing the total heating duration for a given point on the media over the lifetime of the drive is 106 ns.

P2.092 In Vitro and In Vivo Evaluation of Carrageenan-Based Formulations to Prevent HPV Acquisition

BackgroundHuman papillomavirus (HPV) constitutes one of the major sexually transmitted viral infections. Vaccines against HPV are commercially available but vaccination rates are currently low around the world due to parental...

Performance analysis of drilling fluid liquid lubricants

Abstract Excessive torque is one of the most important problems in oil/gas drilling industry. Friction between wellbore/casing and drill string causes excessive torque. This study discusses performance analysis of drilling fluid lubricants, which are used as friction reducers in well-bores. Three different types of chemical commercial lubricants, which are fatty acid and glyceride based, triglyceride and vegetable oil based and polypropylene glycol based, diesel oil, and crude oil, which consists of different API gravities, paraffin and asphaltene value samples, are selected for the analysis. In the analysis section, different lubricant compositions with the mixture of crude oil, diesel oil and lubricants which are added to water based lignosulfonate mud are tested on metal–metal contact surface by the OFITE Lubricity Tester to determine the best lubricity/cost ratio of lubricant compositions. Moreover, effects of the lubricants on mud rheology and API fluid loss of mud, foam forming potential and cheesing/greasing of the lubricants and the influence of mud properties on lubricants (calcium, salt, pH and mud density) are examined.

Synthesis of biolubricants using sulfated zirconia catalysts

Synthesis of biomass-derived lubricants via esterification, transesterification, and simultaneous reactions of both was studied by using sulfated zirconia catalysts. Soybean oil or free fatty acids derived from soybean oil were used as a biomass-derived resource for the synthesis of biolubricants. Long chain alcohols (carbon number≥8) or neo-polyols (e.g., 2,2-diethyl-1,3-propanediol, trimethylol propane, pentaerythritol) were used as co-reactants. The structure of the alcohol significantly affected the conversion and yield for the esterification with oleic acid. The esters produced showed kinematic viscosity and viscosity index comparable to commercial lubricants. Various sulfated zirconia catalysts were prepared and were characterized by X-ray diffraction, NH3 temperature-programmed desorption, Brunauer–Emmett–Teller isotherm, and tested for esterification. The type of zirconium precursor demonstrated a significant effect on the physical property of the catalyst and its catalytic activity. Interestingly, esters with fully saturated hydrocarbon chains were synthesized from unsaturated free fatty acids regardless of the absence of hydrogen gas. The sulfated zirconia could be recycled for up to five repeated reactions without any degradation. The effects of reaction time and temperature were also investigated.

Effect of amorphous/recycled polypropylene ratio on thermo-mechanical properties of blends for lubricant applications

This work focuses on the development of gel-like formulations for use as lubricating greases. These dispersions were formulated using mineral oil and recycled/amorphous polypropylene blends. In particular, the influence of the polypropylene concentration ratio (Wi) on the rheology, thermal and some lubricant performance properties of polymer/oil blends were studied. The rheological responses of these systems were quite different, influenced mainly by the concentration of amorphous polypropylene. At intermediate temperatures (25 °C, 50 °C) and high recycled polypropylene concentrations (Wi > 0.5), the evolution of small-amplitude oscillatory shear (SAOS) functions was very similar to those found with other commercial lubricating greases. Samples with lower concentrations of amorphous polypropylene (12.5%) present maximum GN° values in the temperature range studied. An Arrhenius-type equation can be used to quantify the thermal dependence of the linear viscoelastic functions of these gel-like dispersions. In general, sample formulations studied exhibited values of the friction coefficient comparable to those found for traditional lithium lubricating greases.

Benzimidazolyl phosphates as anti‐wear additives in poly(ethylene glycol) for steel/steel contacts

ABSTRACTFour novel benzimidazolyl phosphates (BPs) were synthesized and evaluated as anti‐wear additives in poly(ethylene glycol) for steel/steel contacts. The friction experiments were carried out on an Optimol SRV‐I oscillating reciprocating friction and wear tester (SRV) both at room temperature and high temperature. The worn surfaces of the steel discs were analysed by JSM‐5600LV scanning electron microscope and PHI‐5702 multifunctional X‐ray photoelectron spectrometer. It was indicated that poly(ethylene glycol) with 2 wt% BP additives had better friction‐reducing and anti‐wear properties than the commercial lubricant additive, tricresyl phosphate. Excellent tribological performance of BPs could be ascribed to the formation of high quality boundary films that consisted of the ordered adsorption films and tribo‐chemical reaction films. Copyright © 2013 John Wiley & Sons, Ltd.

Regeneration of used engine lubricating oil by solvent extraction

AbstractHuge amounts of used lubricating oils from automotive sources are disposed of as a harmful waste into the environment. For this reason, means to recover and reuse these wastes need to be found. Problems arising from acid treatment include environmental problems associated with the disposal of acid sludge and spent earth, low product yield (45-65%) and incomplete removal of metals. The processes of re-refining of used lubricating oils depend greatly on the nature of the oil base stock and on the nature and amount of contaminants in the lubricant resulting from operations. The study was carried out on a sample of 15W40 type used oil collected from one automobile. The re-refining process of used oil consists of dehydration, solvent extraction, solvent stripping and vacuum distillation. This study aims to investigate a process of solvent extraction of an alcohol-ketone mixture as a pre-treatment step followed by vacuum distillation at 5 mmHg. The primary step was conducted before the solvent extraction that involves dehydration to remove the water and fuel contaminants from the used oil by vacuum distillation. The solvent extraction and vacuum distillation steps were used to remove higher molecular weight contaminants. The investigated solvent to oil ratios were 2, 3, 4, 5 and 6. The solvent composition is 25% 2-propanol, 50% 1- butanol and 25% butanone or methyl ethyl ketone (MEK). The percentage of oil recovery for the solvent to oil ratio of 6:1 is further improved, but for the ratio values higher than 6:1, operation was considered economically not feasible. Finally, the re-refined oil properties were compared with the commercial virgin lubricating oil properties.

The effect of the polarity of the lubricant upon capacitance measurements of EHD contacts

Electrical methods, such as capacitance or resistance, allow the study of film formation in elastohydrodynamic (EHD) metal/metal contacts. This makes them more applicable to real machine elements, such as rolling element bearings, gears or cams. Measurements of electrical resistance give an indication of the amount of direct metal/metal contact, while electrical capacitance provides the separation between the surfaces. From the theory of capacitance it is known that electrical capacitance increases with decreasing film thickness, making it very suitable for studies in the thin film region. Measurements of film thickness by electrical capacitance were successfully performed by the authors on both glass/steel and steel/steel contacts with a nonpolar lubricant for films thinner than 20nm. All commercial lubricants contain polar additives, or are polar themselves; hence it is of practical interest to examine the influence of a lubricant's polarity on capacitance measurements. For this reason, three different types of fluids were studied: a nonpolar polyalphaolefin (PAO), glycerol—a strongly polar fluid, and polyethylene glycol (PEG) with polarity between that of PAO and glycerol. The results indicate that PAO shows a very good agreement between the film thickness measured with optical interferometry and evaluated from capacitance measurements. In case of glycerol and polyethylene glycol, however, it was found that the film thickness extracted from capacitance deviates from the optically measured values in the thinner film region. This suggests that EHD conditions may have an effect on the dielectric behaviour of polar lubricants, and that this effect becomes stronger as the polarity increases.

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.