Calcium Sulfonate Research Articles

Compatibility of Vegetable Oil Based Lubricating Greases With Different Mineral Oil Based Greases

Abstract Applications of lubricants and greases based on vegetable or animal sources route back to horary past. Until the beginning of the 19th Century, lubricants were reported to be primarily based on beef tallow and vegetable oils. However, advances in petroleum derived mineral oils led to the replacement of these greases with mineral oil based lubricants. The reasons for their dominance may basically be attributed to high performance compared to vegetable oil based lubricants and greases and also their cheaper cost. Environmental consciousness and the speeding race for green lubricants has once again revived vegetable oil based lubricants. Compatibility of greases is an important property of greases that plays a crucial role in some applications like centralized lube system. As the base oil composition of mineral/synthetic oils is significantly different than vegetable oils, it might considerably influence the compatibility of the greases. In view of this, compatibility studies of vegetable oil based greases with mineral oil based greases have been carried out. The vegetable oil based greases formulated with lithium complex, lithium–calcium, and aluminum complex thickeners have been studied to determine the compatibility with non-vegetable oil based greases having lithium, lithium complex, aluminum complex, polyurea, calcium sulfonate thickeners, etc. However, the various greases covered in this paper are just base greases and do not contain any performance additives considering the fact that additives may significantly influence the compatibility of finished grease with other greases under investigation. It is interesting to note that the vegetable oil based greases evaluated so far have either been found incompatible or just borderline compatible.

Calcium carbonate phase transformations during the carbonation reaction of calcium heavy alkylbenzene sulfonate overbased nanodetergents preparation

The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO3 serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)2 prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications.

Structure determination of seven phases and solvates of Pigment Yellow 183 and Pigment Yellow 191 from X-ray powder and single-crystal data

The crystal structures of two industrially produced laked yellow pigments, Pigment Yellow 183 [P.Y. 183, Ca(C16H10Cl2N4O7S2), alpha phase] and Pigment Yellow 191 [P.Y. 191, Ca(C17H13ClN4O7S2), alpha and beta phases], were determined from laboratory X-ray powder diffraction data. The coordinates of the molecular fragments of the crystal structures were found by means of real-space methods (simulated annealing) with the program DASH. The coordinates of the calcium ions and the water molecules were determined by combining real-space methods (DASH and MRIA) and repeated Rietveld refinements (TOPAS) of the partially finished crystal structures. TOPAS was also used for the final Rietveld refinements. The crystal structure of beta-P.Y. 183 was determined from single-crystal data. The alpha phases of the two pigments are isostructural, whereas the beta phases are not. All four phases exhibit a double-layer structure, built from nonpolar layers containing the C/N backbone and polar layers containing the calcium ions, sulfonate groups and water molecules. Furthermore, the crystal structures of an N,N-dimethylformamide solvate of P.Y. 183, and of P.Y. 191 solvates with N,N-dimethylformamide and N,N-dimethylacetamide were determined by single-crystal X-ray analysis.

Boundary film formation from overbased calcium sulfonate additives during running-in process of steel–DLC contact

The initial stage of boundary film formation from overbased calcium sulfonate at steel–DLC (diamond like carbon) contact was studied. A running-in process was clearly observed by the combination of fresh DLC with fresh steel or fresh DLC with rubbed steel. On the other hand, rubbed DLC does not possess the running-in process. Surface analysis by TOF-SIMS was applied to investigate the formation process and structure of films. It was found that the transfer of iron from the steel ball on to the DLC surface plays a significant role in the formation of boundary film. The depth profile of the film was also obtained by means of an etching technique. The boundary film on steel ball and DLC are mainly composed of iron and calcium oxide. However the depth profiles indicate that distribution of calcium oxide on steel ball is different from that on DLC coated disk.

Antiwear properties of high-temperature greases

The antiwear properties of high-temperature greases were investigated on a four-ball friction machine in a wide temperature range with different loads. The dependence of the tribological characteristics of the greases on the nature of the thickener was established. Ordinary complex and complex ultrabasic calcium salicylate, sulfonate, and phenolate greases have the maximum level of antiwear properties.

Influence of nature of dispersed phase on antiwear properties of high temperature greases

Antiwear properties of modern high temperature greases have been studied by simulating various temperature and load conditions on friction machines. Differences in tribological characteristics of greases depending on the nature of their thickeners were determined and explained. Maximum antiwear properties were revealed in conventional complex and overbased complex calcium salicylate, sulfonate and phenolate greases

Study of Surface Films of the ZDDP and the MoDTC with Crystalline and Amorphous Overbased Calcium Sulfonates by XPS

The role of amorphous or crystalline overbased detergent and sulfur containing AW/EP additives on the surface films created in a tribometer was investigated. In the crystalline overbased sulfonate containing samples the weld point was higher than for the equivalent blend using an amorphous overbased sulfonate. The calcium carbonate core of the overbased sulfonates was deduced to be present in the surface film when combined with either ZDDP or MoDTC. For samples containing ZDDP the crystalline overbased sulfonate, reduced the phosphate film thickness, while for the MoDTC it reduced the MoS2 film thickness. In both cases significantly more carbon, likely as calcium carbonate (which acts to improve the EP/AW properties of the lubricant), was present when using the crystalline overbased calcium sulfonate compared to the amorphous overbased calcium sulfonate.

Determination of Synthesis Conditions of Medium, High, and Overbased Alkali Calcium Sulfonate

This review covers a method for preparing an overbased detergent−dispersion additive called overbased calcium sulfonate solution (OBCSS) containing 38.9% (w/w) CaCO3, with a total base number (TBN) value of 436 mg KOH, starting from neutral calcium sulfonate solution (NCSS).1,2 After the column conditions were optimized, the reaction parameters (PCO2 and the amounts of Ca(OH)2, water, and monoethanolamine (MEA)) were examined throughout the tests. The first product medium alkali calcium sulfonate solution (MACSS) with 8.5% (w/w) CaCO3 (TBN = 95 mg KOH/g) is obtained, but higher base values could not be reached. In the second stage, monoethanolamine is added to the feed as a promoter and high alkali calcium sulfonate solution (HACSS) containing 30.4% (w/w) CaCO3 with the value of TBN = 274 mg KOH/g is obtained. In the third stage of the study, targeted product OBCSS is obtained by using HACSS as a feedstock component instead of NCSS.

Study of surface films of crystalline and amorphous overbased sulfonates and sulfurized olefins by X-ray absorption near edge structure (XANES) spectroscopy

In the past large synergistic effects have been reported for combinations of overbased sulfonate and sulfurized olefin in four-ball EP testing. In this study, we examined the effect of crystallinity on the formation of the tribofilms using X-ray absorption near edge structure (XANES) spectroscopy. Using this technique, we were able to differentiate the carbonate from organic carbon in C K-edge spectra, as well as, determining the difference between FeS, FeS2, RSO3−, and SO42− in the sulfur spectra. While the overbased calcium sulfonates do not react strongly with the substrate there is evidence to suggest that the overbased sulfonate promotes decomposition of the sulfurized olefin on the surface to form both CaSO4 and FeS, which improves the EP performance of the lubricant. A putative intermediate is H2S from the decomposition of the sulfurized olefin which can react with O2 and the Fe-rich surface to form FeSO4 and FeS, respectively. A new ‘FeS’ species has been detected in the tribofilms that is believed to be a non-stoichiometric Fe-enriched FeS. Depending on the presence or absence of the overbased calcium sulfonate either FeSO4 or FeS formation is favored and changing the concentration of the crystalline, C300C, or amorphous, C400A, overbased calcium sulfonate from 5% to 10% does not appear to have any effects on FeS formation, although the C300C produces more Fe-enriched FeS than the C400A in the bulk.

Effect of Calcium Compounds in Lubrication Oil on the Frictional Properties of Fe2O3-Al2O3 Ceramics under Boundary Lubricating Conditions

Calcium sulfonate, a detergent/dispersant component in lubricating oils, greatly increase the friction coefficient of TiO2 added Fe2O3-Al2O3 ceramics under boundary lubricating conditions. ESCA studies showed that the average thickness of an organic thin film sticking to the surface of wear tracks was thicker than that away from wear tracks, and the concentrations of Ca, S and P were much higher in the wear track than those off the wear track, suggesting that most of the -SO3-Ca-OH groups in sulfonate remained unchanged. It is concluded that oil containing rich calcium compounds possibly formed a layer, blocking other oily additives with which the surface would have been wettable. This is assumed to increase the friction coefficient of the TiO2 added Fe2O3-Al2O3 ceramics.

Recent Advances in Nanoparticles Production by High Gravity Technology—from Fundamentals to Commercialization

This paper reviewed our group work on the high gravity (Higee) technology and its applications to nanoparticles production, which is fulfilled in a rotating packed bed (RPB). Fundamentals of the fluid flow, mass transfer and micromixing in the RPB are discussed. Various pharmaceutical nanoparticles were prepared via reactive precipitation or anti-solvent precipitation in the RPB reactor. CaCO3 nanoparticles dispersion in overbased petroleum calcium sulfonate was produced by in situ synthesis of amorphous nano CaCO3 in microemulsions formed by neutral petroleum calcium sulfonate and CH3OH in the RPB. Commercial production of CaCO3 nanoparticles by the Higee technology has reached a throughput capacity of 36,000 t/y and a typical production line is illustrated and analyzed. As one example of the application of such commercially produced inorganic nanoparticles, polymer-based nanocomposites were produced by adding CaCO3 nanoparticles into different polymer matrixes such as PVC, ABS, PP, etc., and it was observed that nano CaCO3 significantly improved the mechanical properties of the polymer matrixes.

臭気対策を施した高性能温間鍛造油の開発

Recently the demands of a performance and environmental treatment for forging lubricant oil have been getting stronger. Especially, in the warm forging which is spread gradually for the purpose of near net shaping or complex shaping, the environmental problem is considerable. Concerning to the lubricant performances of the oil, both of the high lubrication and cooling abilities are required in warm forging. As for the environmental treatment, the harmful gas and sharp smell must be reduced as much as possible. We have developed the new oil contained overbased calcium sulfonate for warm forging to be satisfied with the needs. The results are follows. 1. The smell was much reduced even at 800 ℃ comparison to conventional high performance forging oil which contains Zn-DTP. 2. The forging load decreased about 35 % at 800 ℃ in backward extrusion. 3. The depth of punch wear was reduced about 14 % after 5000 shots.

Study of Surface Films of Amorphous and Crystalline Overbased Calcium Sulfonate by XPS and AES

We have shown that the crystalline overbased sulfonate shows superior Reichert test results over the conventional amorphous overbased materials, and a subsequent X-ray photoelectron spectroscopy (XPS) analysis revealed that thicker Ca films were observed on a test specimen with tribofilms formed from crystalline overbased sulfonate compared to amorphous overbased sulfonate. From the XPS analysis of the wear scars produced in the Reichert test, it appears that amorphous overbased and crystalline overbased calcium sulfonate both form thin layers of CaCO 3 on top of a thicker layer of CaO (from CaCO 3 decomposition) on the surface of the test piece. Additionally, we examined the morphology of the Ca and S films using auger electron spectroscopy (AES). In the presence of sulfurized olefin, an additional AES analysis reveals that a layer of both S and Ca cover the surface. From the AES analysis of selected regions, the surface either possessed high S or high Ca concentrations, but not both together. The authors hypothesize that there is a reaction between the sulfurized olefin and the carbonate of the overbased sulfonate, which forms a more “active” film during tribotesting. Presented at the STLE Annual Meeting in Toronto, Ontario, Canada May 17-20, 2004 Review led by Elaine Yamaguchi

Study of surface films of overbased sulfonates and sulfurized olefins by X-Ray Absorption Near Edge Structure (XANES) spectroscopy

The X-Ray Absorption Near Edge Structure (XANES) spectroscopy technique has been successfully applied to complex matrices such as tribological films, coal, DLC films and, where other instrumental analytical techniques are less sensitive for molecular analysis. Four-ball tests were performed for lubricating oils containing the synergistic combination of overbased sulfonate (calcium and magnesium) and sulfurized olefin. The surface films were analyzed by XANES using C K-edge, Ca L-edge and S L- and K-edge. Using this technique we were able to differentiate the carbonate from organic carbon in C K-edge spectra, as well as, determining the difference between FeS, FeS2, RSO3− and SO42− in the sulfur spectra. It was found while the sulfurized olefin reacts very strongly with the substrate to form FeS, the overbased calcium sulfonate and overbased magnesium sulfonate do not react strongly with the substrate without sulfurized olefin present. There is evidence to suggest that the overbased sulfonate promotes decomposition of the sulfurized olefin on the surface to form both CaSO4 and FeS, which improves the EP performance of the lubricant.

TOF-SIMS analysis of boundary films derived from calcium sulfonates

Tribological properties of over-based and neutral calcium sulfonate were examined under boundary lubrication conditions by using a ball-on-flat type tribo-tester. It was found that over-based calcium sulfonate reduced friction and wear of steel–steel contacts, whereas the neutral calcium sulfonate did not. It was found that boundary film composed of calcium oxide plays significant role on improving the tribological properties. Surface analyses by XPS and Time-of-flight secondary mass spectroscopy (TOF-SIMS) revealed that the major component of the film on upper surfaces is calcium carbonate and that at subsurfaces are composed of calcium oxide. A depth profile of the film obtained by TOF-SIMS using an etching technique revealed that thickness of the film is up to 240 nm. A static pyrolysis of the over-based calcium sulfonate on steel surface affords a thin film composed of calcium oxide, indicating that rubbing process is essential for the formation of the boundary film.

Crystal structures of the trifluoromethyl sulfonates M(SO3CF3)2 (M = Mg, Ca, Ba, Zn, Cu) from synchrotron X-ray powder diffraction data

The crystal structures of divalent metal salts of trifluoromethyl sulfonic acid ("trifluoromethyl sulfonates") M(SO(3)CF(3))(2) (M = Mg, Ca, Ba, Zn, Cu) were determined from high-resolution X-ray powder diffraction data. Magnesium, calcium and zinc trifluoromethyl sulfonate crystallize in the rhombohedral space group R(bar)3. Barium trifluoromethyl sulfonate crystallizes in the monoclinic space group I2/a(C2/c) and copper trifluoromethyl sulfonate crystallizes in the triclinic group P(bar)1. Within the crystal structures the trifluoromethyl sulfonate anions are arranged in double layers with the apolar CF(3) groups pointing towards each other. The cations are located next to the SO(3) groups. The symmetry relations between the different crystal structures have been analysed.

Sulfonation of base oils as corrosion inhibitor for temporary protection of steel in atmospheric environment

Base oil corrosion temporary protective coatings were synthesized. These coatings contain of inhibitor agent, antioxidant agent, and base oil as main bed. Inhibitor agents were prepared by sulfonation of Iran traditional mineral base oils. Iran traditional base oils were SAE10, SAE30 and SAE40. They are sulfonated at different temperatures with oleume as reactive agent. Sulfonation efficiency and production quality of this process are evaluated in different conditions. Neutralization of sulfonate groups were complied with calcium hydroxide to achieved hydrophilic salt groups of calcium sulfonate. Final products are used as inhibitor agents in base oils to prepare temporary protective coatings. They are applied to 1020 steel panels by dipping method. Panels were coated by different percentage of final products in base oil, and examined for corrosion resistance efficiency in 100% relative humidity cabinet via ASTM D1784. Protection efficiency of formulated coatings was investigated, by determining MPY, time for observation of first stain of rust, and protection percentage after 240 h in humidity cabinet. The results obtained reveal that synthesized temporary corrosion protective coatings are very efficient. First stain of rust have been observed after 720 h in 100% relative humidity cabinet for the best temporary protective coating formulation.

Molecular features of sulfonic acids used for synthesis of overbased detergent additives

Overbased calcium sulfonates are used in many modern oil formulations to provide cleaning action and to neutralize the organic acids formed during combustion, preventing corrosion. The performance of detergents is related to their molecular structure, which is generally known only as a chemical category. In the present work, nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization mass spectrometry are used to analyze the molecular structure of three alkyl-benzene sulfonic acids in detail. Some important molecular features were obtained by elaborating the NMR signal intensities, such as the number and positions of alkyl substituents on the benzene ring, the distribution of alkyl chain lengths and the mole fraction of 1-phenyl isomers (synthesized by alkylation of benzene with α-olefin). Ion-trap mass spectrometry is used to obtain the mass spectrometry/mass spectrometry (MS2) spectra of the principal molecular ions. By choosing suitable molecular ions, MS2 spectra can ascertain the presence of different substituted benzene isomers within a mixture because the MS2 spectra show specific fragments due to the number of alkyl substituents on the aromatic ring. Copyright © 2006 John Wiley & Sons, Ltd.

Study of Hydroforming Lubricants with Overbased Sulfonates and Friction Modifiers

Due to the high cost of hydroforming equipment, attempts have been made to model this process using bench testing. While tensile and twist compression tests have yielded promising results, they do not simulate any single metal forming process. In this study we investigated the use of expansion zone, guiding zone, and twist-compression tests to simulate hydroforming processes and evaluated various overbased sulfonates and organic friction modifiers performance. The amorphous overbased magnesium sulfonate improved the performance of the hydroforming oil in the expansion zone and provided no harm in the guiding zone, while the crystalline overbased calcium sulfonate provided no harm in the expansion zone and improved performance in the guiding zone. It was found that the friction modifiers tested display an antagonism, where, as the expansion zone performance increased, the guiding zone performance decreased. Additionally, we found in twist-compression testing that the initial coefficient of friction displayed a small correlation with the guiding zone test (from r = 0.26–0.47), while the failure time displayed a small correlation with the expansion zone test (r = 0.36–0.40).

Combination of ashless antiwear additives with metallic detergents: interactions with neutral and overbased calcium sulfonates

The interactions of neutral and overbased calcium sulfonate detergents with ashless thiophosphate oil additives under boundary lubrication were studied. The ashless additives used were neutral and acidic dialkyldithiophosphate (DTPs) and neutral triaryl monothiophosphate (MTP). This study uses three surface analytical tools to provide elemental and chemical information at the surface and in the bulk of the derived tribochemical films. The elemental composition of the tribofilms was studied using X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray analysis (EDX) (combined with scanning electron microscopy (SEM)). Corresponding P and S X-ray absorption near edge structure (XANES) spectroscopy was also used to provide further insight into the chemical composition of the films. SEM images of the derived tribofilms revealed that each film had distinct topographical features associated with it. XPS and EDX revealed that when oil is blended with calcium sulfonate, considerable amount of calcium is incorporated into all the tribochemical films. The phosphorus content of the tribofilm was reduced substantially when the overbased detergent was combined with MTP additive. XANES spectroscopy of the P L-edge provided direct evidence for the formation of calcium phosphate in tribofilms from the ashless additives in combination with the detergent. S K-edge revealed that sulfate is the main sulfur species formed in the bulk for all three tribofilms in the presence of the neutral detergent while a mixture of sulfite and sulfide species are formed when the overbased was used. S L-edge XANES showed that calcium sulfonate has undergone some oxidation at the surface. A more antagonistic effect was observed for MTP, with the formation of a very thin phosphate film. Tribological performance was also evaluated. Surprisingly, combination of the neutral detergent with any of the AW additives did not result in any significant change in wear to the substrate. For MTP plus neutral detergent, the thinner phosphate film produced, combined with very little change in wear protection confirms that, not only is the tribochemistry dominated by calcium sulfonate, but also confirms the anti-scuffing and AW properties that are associated with it as well. Even more surprising, was the significant decrease in wear when the overbased detergent is used. This illustrates not only that the tribochemistry was dominated by the detergent, but also the exceptional AW properties of calcium carbonate.