Calcium Sulfonate Research Articles

Probing the Synergy of Calcium Sulfonate Complex Soap and Polyurea Complex Thickener Towards Good Lubrication and Rheological Properties

Abstract Polyurea complex thickener was introduced into calcium sulfonate complex grease (CSCG) to prepare a new type of grease. The microstructure, rheological properties, and tribological properties of new greases were studied in detail. The experimental results show that the combination of calcium sulfonate complex soap and polyurea complex thickener can form a new thickener system, which combines the layered structure of calcium sulfonate complex soap and the rod-shaped structure of polyurea complex thickener. The thermal decomposition temperature of new greases is reduced, but its fluidity is improved and the friction coefficient is lower. Their synergistic effect is related to the special structural skeleton of the new thickener system, and calcium sulfonate and urea molecules share the same calcium ion, which may be an important reason for maintaining the stability of this special structure skeleton.

Synergistic lubricating effect for calcium phosphate modified calcium sulfonate grease with highly load bearing capacity

Calcium sulfonate complex grease exhibits different lubrication mechanisms due to its different combination of calcium carbonate soap and complex agents. In an effort to explore the synergistic lubricating effect of complex agents and find breakthroughs in the performance of calcium sulfonate grease, calcium phosphate modified calcium sulfonate grease was prepared and tested compared with borates. At high loads of 600 N, the introduction of P-containing complex improved load bearing capacity of calcium sulfonate grease. The advantage it exhibited in terms of lubrication was attributed to the synergistic effect of calcium carbonate and calcium phosphate in thickener under harsh condition. The synergistic films about 30 nm depth composed of iron oxide, calcium oxide and iron phosphate played a decisive role in lubrication.

A nonlinear dynamic analysis of skidding behavior in rolling bearings using lubricant traction coefficients and cage flexibility

Skidding is a primary cause of rolling element bearing (REB) failure, which is influenced by operating conditions, lubricant properties, and bearing design. This paper presents an improved nonlinear dynamic model of REBs to analyze the impact of lubricant characteristics on REB skidding at different speed states. The model considers time-varying traction coefficient, cage flexibility, and cage pocket clearance. The selected tested lubricants include lithium grease (LGT2), compound calcium sulfonate (CCS) grease, and 4109 Chinese aviation oil. Simulation results show that CCS grease effectively reduces cage skidding, with the lowest load limits (300 N at 2000 RPM) under constant speed conditions and the highest stable limit (2932 RPM) during acceleration. LGT2 grease exhibits minimal sensitivity to acceleration and fluctuation speed parameters change.

The Effect of Lubricity of Calcium Sulfonate on ZnDTP and MoDTC

Reduction of friction and wear by lubrication is necessary to improve the efficiency and prolong the lifespan of industrial machinery. However, several aspects regarding the lubrication effects in additive-combined oil are still unresolved. This study focuses on the effects of combining zinc dialkyldithiophosphate (ZnDTP), molybdenum dithiocarbamate (MoDTC), and Ca sulfonate on the frictional behavior of poly-α-olefin 4 (PAO4) lubricant oils. Ball-on-disk friction tests demonstrated that the exclusive addition of high-base Ca sulfonate solution reduced friction and wear of the lubricating oil. When combined with ZnDTP and MoDTC, the friction coefficients of PAO with high-base and low-base Ca sulfonate are affected by competitive reactions on the sliding surface. Quartz crystal microbalance with dissipation monitoring measurements suggests that high-base Ca sulfonate forms a stronger adsorption film than low-base Ca sulfonate. Atomic force microscope observations confirmed that the addition of low-base Ca sulfonate reduced friction and wear, whereas high-base Ca sulfonate induced competitive reactions with ZnDTP and MoDTC. This study provides valuable insights into the effects of the combination of additives on the lubricity of PAO and their impact on friction and wear characteristics, which are valuable for the design of suitable lubricants for industrial machinery.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project

BackgroundThe pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care.MethodsObservational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019–2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments.ResultsA total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38–1.10) and after 60 days 0.89 (95% CI 0.45–1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups.ConclusionWe observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.Graphical abstract

Оценка эффективности работы сульфонатных присадок в смазочных маслах

The work carried out a comparative assessment of the effectiveness of domestic calcium sulfonates of various alkalinity (150, 300 and 400) in the concentration range of 1-3% by weight in base oils of different nature, but of the same viscosity. The obtained oil samples were subjected to high-temperature oxidation and the physico-chemical properties were determined before and after oxidation, with special attention being paid to the change in acid and base numbers. It was found that isoparaffin base oil is more resistant to thermal degradation compared to poly-α-olefin oil. The results of comparative studies of samples of oils with additives before and after oxidation showed that the optimal concentration of calcium sulfonate, which ensures minimal change in physico-chemical properties after oxidation, is 3% by weight. Moreover, both medium- and ultra-alkaline calcium sulfonate can be used.

Investigating the effect of overbased sulfonates on calcium sulfonate complex grease: enhancements in physicochemical, rheological, and tribological properties.

Overbased sulfonate plays a crucial role in calcium sulfonate complex grease, significantly impacting the grease's performance characteristics. Herein, the calcium sulfonate complex grease was formulated using overbased calcium sulfonate (T106D) and overbased magnesium sulfonate (T107) in ratios of 1 : 2, 1 : 1, and 2 : 1, labeled as CMSCG (1 : 2), CMSCG (1 : 1), and CMSCG (2 : 1), respectively. This study examined the effects of overbased sulfonates on the physicochemical, anti-corrosion, rheological, and tribological properties of the grease. Results showed that CMSCG (1 : 2) exhibited superior physicochemical properties, with the highest dropping point (354 °C), the lowest penetration (161 (0.1 mm)), and the least oil separation (1.25%). Exposure to a salt spray environment significantly altered the grease's rheological properties. The combination of T106D and T107 enhanced the corrosion resistance of the grease, attributed to the formation of a corrosion inhibition layer. Incorporating T107 increased both the yield stress and hysteresis area of the calcium sulfonate complex grease. The CMSCG (1 : 2), CMSCG (1 : 1), and MSCG showed the high thixotropic ring area, indicating the poor thixotropy. The calcium sulfonate complex grease formulated with T107 showed the highest yield stress (558 Pa). The friction mechanism revealed that MSCG showed the optimal friction reduction properties, and CMSCG (1 : 1) demonstrated the optimal wear resistance, which are attributed to the synergistic effects of tribo-chemical films composed of CaO, CaCO3, FeSO4, MgCO3, and iron oxide.

Classification and spectrum optimization method of grease based on infrared spectrum

AbstractThe infrared (IR) absorption spectral data of 63 kinds of lubricating greases containing six different types of thickeners were obtained using the IR spectroscopy. The Kohonen neural network algorithm was used to identify the type of the lubricating grease. The results show that this machine learning method can effectively eliminate the interference fringes in the IR spectrum, and complete the feature selection and dimensionality reduction of the high-dimensional spectral data. The 63 kinds of greases exhibit spatial clustering under certain IR spectrum recognition spectral bands, which are linked to characteristic peaks of lubricating greases and improve the recognition accuracy of these greases. The model achieved recognition accuracy of 100.00%, 96.08%, 94.87%, 100.00%, and 87.50% for polyurea grease, calcium sulfonate composite grease, aluminum (Al)-based grease, bentonite grease, and lithium-based grease, respectively. Based on the different IR absorption spectrum bands produced by each kind of lubricating grease, the three-dimensional spatial distribution map of the lubricating grease drawn also verifies the accuracy of classification while recognizing the accuracy. This paper demonstrates fast recognition speed and high accuracy, proving that the Kohonen neural network algorithm has an efficient recognition ability for identifying the types of the lubricating grease.

SULFONATE ADDITIVES TO LUBRICATING OILS

To expand the resource base and increase the efficiency of sulfonate additives, the possibility of obtaining them based on mixed raw materials - petroleum oil M-8 and alkylbenzene synthesized using propylene fraction C18-С30 oligomers was studied. It is shown that during sulfonation of mixed raw materials, the yield of sulfonic acids is 89-93%, the content of hard-to-recycle waste - acid tar is lower than during sulfonation of petroleum oil by 30-35%. The influence of the ratio of ingredients in the initial mixture on the indicators of neutral sulfonate was studied and the conditions for obtaining additives of the required quality were found. The properties of the developed additives in M-11 oil at a concentration of 5% were studied by standard methods. The composition and structure of sulfonates were studied by elemental analysis and IR spectroscopy. The resulting additives have a micellar structure. The results of laboratory tests have shown that neutral, medium - and highly alkaline semi-synthetic calcium sulfonates have high physico-chemical and functional properties. The neutral sulfonate is superior in yield, active substance content, and dispersing properties to NСК petroleum sulfonate and OLOA 246B additive. Medium- and high-alkaline additives in terms of physicochemical and detergent properties are at the level of commercial petroleum sulfonates C-150, C-300 and Hightech 6060M additives, and surpass them in dispersing, anti-corrosion properties and stability against oxidation. Alkaline semi-synthetic calcium sulfonates have a high stability of the colloidal dispersion to the action of water and have better performance compared to analogues. With an increase in the alkalinity of the obtained additives, the physicochemical properties improve, which is associated with the features of their colloidal structure. Using the developed neutral and high-alkaline additives as detergent-dispersant components, experimental motor oils М-10DM and М-10G2, were prepared, which meet the requirements in terms of quality. The high efficiency of semi-synthetic sulfonates allows them to be used in modern motor oils

Protective and Tribological Properties of Sulfonate Greases

The protective properties and temperature resistance of sulfonate greases based on petroleum oil KS-19 have been assessed. Highly alkaline calcium sulfonates of Russian and foreign production are used as thickeners for such greases. Sulfonate greases have been shown to have good protective properties. It has been established that the ability of sulfonate greases to prevent corrosion depends on the protective properties of calcium sulfonate used as a thickener. Based on the totality of the indicators obtained, the grease based on the Russian-made K-314 thickener has the best properties; in temperature resistance, it is superior to the sample on the foreign thickener Lubrizol 86 GR, and in terms of protective properties, it is on the same level with it.

Effect of ash on temperature and particulate emission characteristics of diesel particulate filter during active regeneration

As one of the most effective devices to reduce particulate emission from diesel engines, the diesel particulate filter (DPF) has been widely used. However, long-term use of the DPF can cause a large amount of ash to deposit in it, which can significantly affect its performance. In this study, a burner was utilized to deposit ash, derived from four different lubricating oil additives (zinc dialkyl dithiophosphate (Zn-based), calcium sulfonate (Ca-based), magnesium sulfonate (Mg-based), and composite), into four DPFs with the same specification. The four ash-loaded DPFs and a fresh ashless DPF were subsequently tested for active regeneration on an engine bench at the same soot load. The temperature and particulate emission characteristics of the DPFs were measured using thermocouples and a particulate analyzer. The peak regeneration temperature of ash-loaded DPFs moved forward when compared to the fresh DPF, and the peak regeneration temperature of Mg-based DPF reached 694 °C and moved forward to the axial position of 71.5 mm. A low temperature zone appeared at the rear end of edge channels, forming a large temperature gradient up to 75.5 °C/cm. The emission of nucleation-mode particulates at each DPF outlet increased to different degrees during active regeneration, especially for the Zn-based DPF, whose particulate concentration even approached 108 #/cm3. The X-ray computed tomography (X-CT) images of ash-loaded DPFs showed that the distribution of ash in each DPF was quite different, and ash plugs or bridges appeared in the middle and front of some channels, forming a strong blocking effect. It is due to the presence of ash that the soot deposition position moved forward and the wall-flow velocity rose, which increased the local soot density, causing the peak regeneration temperature to rise and move forward. The increase in wall-flow velocity reduced the diffusion filtration efficiency of ash-loaded DPFs, so escaped particulates that were broken up from soot agglomerate burning increased.

The size effect of typical micro‐ and nano‐calcium carbonate additives on the friction properties of calcium sulfonate grease

AbstractThis paper firstly reports the size effect of typical micro‐ and nano‐ calcium carbonate additives on the friction properties of calcium sulfonate grease. The rheological and tribological performance of calcium sulfonate grease with typical micro‐ and nano‐ calcium carbonate additives were investigated at 30 or 80°C by Rheometer and Optimol SRV‐V tester. To its surprise, calcium sulfonate grease with 5% calcium carbonate microparticles behave remarkable lubrication performance than calcium sulfonate grease with 5% calcium carbonate nanoparticles under boundary lubrication condition according to the rheological analysis and tribological evaluation. The enhancement in excellence tribological performance can be attributed to the synergistic effect between calcium carbonate microparticles and calcium carbonate in thickener of calcium sulfonate grease. The thin film composed of CaCO3 and CaO on the worn surface generated by solid particles is conducive to reducing friction and wear.

Optimization of the Tribological Performance and Service Life of Calcium Sulfonate Complex—Polyurea Grease Based on Unreplicated Saturated Factorial Design

In order to further extend the service life of calcium sulfonate complex–polyurea grease (CSCPG) while ensuring its tribological performance, this article starts with the production of raw materials and the preparation process of the grease and explores the factors that significantly affect the tribological performance and service life of CSCPG based on unreplicated saturated factorial design (USFD). The Kriging prediction model is used along with the optimization objectives of friction coefficient and service life, and nondominated sorting genetic algorithm II (NSGA-II) was used for a multi-objective optimization solution. The tribological and service life tests were conducted before and after optimization. The results show that the viscosity of the base oil and the content of the nano-solid friction reducers have a significant impact on the tribological properties of CSCPG. The content of polyurea thickeners and antioxidants, as well as the thickening reaction temperature, have a significant impact on the service life of CSCPG. When the friction coefficient and service life are optimized as objectives and are compared to the initial group, the friction coefficient of CSCPG could be reduced by 5.3%, and the service life could be extended by 3.8%. The Kriging prediction model based on USFD has high accuracy and can be used to guide the preparation and performance optimization of CSCPG.

Tribological Investigation of the Effect of Nanosized Transition Metal Oxides on a Base Oil Containing Overbased Calcium Sulfonate

In this study, copper(II) oxide, titanium dioxide and yttrium(III) oxide nanoparticles were added to Group III-type base oil formulated with overbased calcium sulfonate. The nanosized oxides were treated with ethyl oleate surface modification. The tribological properties of the homogenized oil samples were tested on a linear oscillating tribometer. Friction was continuously monitored during the tribological tests. A surface analysis was performed on the worn samples: the amount of wear was determined using a digital optical and confocal microscope. The type of wear was examined with a scanning electron microscope, while the additives adhered to the surface were examined with energy-dispersive X-ray spectroscopy. From the results of the measurements, it can be concluded that the surface-modified nanoparticles worked well with the overbased calcium sulfonate and significantly reduced both wear and friction. In the present tribology system, the optimal concentration of all three oxide ceramic nanoadditives is 0.4 wt%. By using oxide nanoparticles, friction can be reduced by up to 15% and the wear volume by up to 77%. Overbased calcium sulfonate and oxide ceramic nanoparticles together form a lower friction anti-wear boundary layer on the worn surfaces. The results of the tests represent another step toward the applicability of these nanoparticles in commercial engine lubricants. It is advisable to further investigate the possibility of formulating nanoparticles into the oil.

Enhancing Lubrication Performance of Calcium Sulfonate Complex Grease Dispersed with Two-Dimensional MoS2 Nanosheets

Calcium sulfonate complex greases (CSCG) have proven to be a sustainable alternative to lithium complex greases, which still require appropriate additives to deliver lubrication performance benefits under extreme working conditions such as heavy load, high speed, and high temperature. The anti-wear and friction reducing properties of CSCG enhanced by two-dimensional MoS2 nanosheets (2D MoS2) with a narrow lateral size and thickness distributions were evaluated by a four-ball tribometer. The results showed that the CSCG with 0.6 wt.% 2D MoS2 performs best, with a 56.4% decrease in average friction coefficient (AFC), 16.5% reduction in wear scar diameter (WSD), 14.3% decrease in surface roughness, and a 59.4% reduction in average wear depth. Combining SEM-EDS images, Raman, and X-ray photoelectron spectra, it is illustrated that the physical transferred film and tribo-chemical film consisting of MoS2, Fe2O3, FeSO4, CaCO3, CaO, and MoO3 were generated on the worn surface, which improves the lubrication performance of CSCG considerably.

Tribological Behavior of WS2 Nanoparticles as Additives in Calcium Sulfonate Complex–Polyurea Grease

In order to improve the tribological properties of calcium sulfonate complex–polyurea grease, WS2 nanoparticles were used as additives to prepare WS2 calcium sulfonate complex–polyurea grease. The tribological behavior of WS2 grease on the GCr15 surface was systematically studied. The results indicate that WS2 nanoparticles can significantly improve the extreme pressure performance of calcium sulfonate complex–polyurea grease. When the concentration of WS2 nanoparticles is 2 wt.%, the friction coefficient decreases by 14.94%, and the maximum nonseizure load PB increases by 31.41%. As the temperature increases, the friction coefficient and wear rate of WS2 grease first decrease and then increase. This is mainly attributed to the adsorption and frictional chemical reaction between WS2 nanoparticles and the matrix.

Alpha olefin sulfonate (AOS) adsorption on calcite and dolomite: Role of active complex formation and electrical double layer capacitance

The surfactant injection process is used in the oil industry for various purposes, such as changing the wettability of the rock surfaces, decreasing the interfacial tension, and consequently increasing the oil production, using it as a de-emulsification agent and base material for foam formation. Usually in surfactant injection processes, one of the important issues is surfactant loss which can affect the economic and operational feasibility of the method. One of the phenomena involved in surfactant loss is its adsorption on the rock. In this study, the effective factors of the surfactant adsorption phenomenon in an electrolyte-mineral solid system were investigated. For this purpose, the mechanisms of surface potential formation, the electrical double layer capacitance and its relationship with the zeta potential, repulsive and attractive forces between suspended particles, and changes in the Gibbs energy of the multi-component system as a result of adsorption were explained. Laboratory measurements of adsorption of an anionic surfactant, alpha olefin sulfonate (AOS), on calcite and dolomite surfaces were performed. For this purpose, ultraviolet and infrared spectroscopy measurements were conducted for each test. Results showed that increasing the salinity, from 0.001 M to 0.1 M, reduced the adsorption of AOS on calcite by about 50%. The presence of the divalent cation of magnesium, and the divalent anion of sulfate, causes the release of the sulfonate anion from the unstable complex of calcium sulfonate and consequently adsorption reduction. The magnesium sulfonate complex is stable and more active than the calcium sulfonate complex. Therefore, the adsorption of sulfonate on dolomite was negligible. Considering that sulfonates are one of the most common surfactants used in enhanced oil recovery processes, the results of this study can be effective in controlling its adsorption phenomenon. Also, the results of this study can be used in the design of wettability alteration processes.

Lubrizol aims to replace lithium in grease

Lubrizol is opening a lab in India to investigate using calcium sulfonate as an alternative to lithium soaps, which serve as thickeners in industrial greases. Lithium prices have risen substantially over the last several years as production of lithium-ion batteries has expanded. According to the US Geological Survey, greases accounted for about 16% of global lithium use in 2008, slightly lower than batteries at the time. Batteries are now the dominant end market, and greases account for about 4% of lithium use .

ЭКОЛОГИЧЕСКИ БЕЗОПАСНЫЙ ЖИДКИЙ СМАЗОЧНЫЙ МАТЕРИАЛ ДЛЯ ПИЛЬНЫХ ЦЕПЕЙ НА ОСНОВЕ КОМБИНИРОВАННОЙ ДИСПЕРСИОННОЙ СРЕДЫ

The realization of the synergistic effect is shown on the example of creating of the composite liquid lubricant with improved properties using the combined dispersion medium obtained by mixing of the vegetable and mineral oils. The lubricant for the saw chains and the method of its production are developed. The highly purified mineral oil of group III of the NS-4 brand is added to the rapeseed oil in the amount of 20.0…25.0 wt.%, and the complex of the calcium sulfonate with calcium carbonate in the amount of 1.5…2.0 wt.% is used as a multifunctional additive in the manufacture of this lubricant. The developed lubricant has the following characteristics: kinematic viscosity at 40 °C — 61…63 mm2/s; solidification temperature is –29 °C; flash point — 242…246 °C; welding load — 2,764 N; wear index — 0.39…0.41 mm; mass fraction of free organic acids — 1.3...4.7 mg KOH/g; degree of biodegradability — 88–89 %; warranty period of storage in an open container — 12 months.

Effect of the grease thickener on tribological properties of Si3N4/GCr15 contact interface and the performance in hybrid ceramic ball bearing

Si3N4 hybrid bearings are considered the most promising motor bearings due to their characteristics of electrical insulation, high speed, low friction coefficient, and wear resistance, which can better meet the requirements of driving motors of electric vehicles. However, the tribological mechanism between the ceramic-grease-steel complex interface is unclear. Three kinds of greases, namely lithium, polyurea, and calcium sulfonate complex grease, were synthesized from poly alpha olefin 40 as base oil. The effects of grease thickener morphology on the tribological properties of Si3N4/GCr15 contact surfaces at different slip speeds were investigated, and the vibration and friction torque performances in 6204 hybrid ceramic balls were evaluated. The results showed that the thickener could form physical deposition film and friction film to protect the worn surface at low speed. The friction and wear conditions were significantly improved at high speed under lithium grease and polyurea grease lubrication, being a mixed lubrication state. In presence of lithium grease, the tribological performance of the Si3N4/GCr15 interface and the vibration performance, impacted condition, starting torque, and friction torque of the hybrid ceramic ball bearings were all the best. Because lithium grease is subjected to continuous shear of the ceramic ball, which releases the base oil stably, and forms a thick oil film with the broken thickener in the center of the raceway, the bearing is in a mild lubrication state. Therefore, for Si3N4 hybrid ceramic ball bearings, lithium grease is a lubricant with good application prospects.