API Group Research Articles

The Effects of Resveratrol and Apigenin on Jejunal Oxidative Injury in Ducks and on Immortalized Duck Intestinal Epithelial Cells Exposed to H2O2.

Oxidative stress increases the apoptosis of intestinal epithelial cells and impairs intestinal epithelial cell renewal, which further promotes intestinal barrier dysfunction and even death. Extensive evidence supports that resveratrol and apigenin have antioxidant, anti-inflammatory, and antiproliferative properties. Here, we investigated the ability of these two compounds to alleviate diquat-induced jejunal oxidative stress and morphological injury, using the duck as a model, as well as the effects of apigenin on oxidative stress induced by H2O2 in immortalized duck intestinal epithelial cells (IDECs). Ducks were randomly assigned to the following four groups, with five replicates: a control (CON) group, a diquat-challenged (DIQ) group, a resveratrol (500 mg/kg) + diquat (RES) group, and an apigenin (500 mg/kg) + diquat (API) group. We found that serum catalase (CAT) activity and total antioxidant capacity (T-AOC) markedly reduced in the RES and API groups as compared to the DIQ group (p < 0.05); moreover, serum S superoxide dismutase (SOD) levels increased significantly in the API group as compared to the DIQ group (p < 0.05). In jejunal mucosa, the malondialdehyde (MDA) content in the RES and API groups decreased more than that in the DIQ group (p < 0.05). In addition, the jejunal expression levels of the NRF2 and GCLM genes in the RES and API groups increased notably compared with those in the DIQ group (p < 0.05); meanwhile, CAT activity in the RES and API groups was markedly elevated compared with that in the CON group (p < 0.05). In IDECs, apigenin significantly restrained the H2O2-mediated increase in MDA content and decrease in CAT levels (p < 0.05). Furthermore, apigenin increased the protein expression of p-NRF2, NRF2, p-AKT, and p-P38; downregulated that of cleaved caspase-3 and cleaved caspase-9; and reduced the ratio of Bax/Bcl-2 in H2O2-treated IDECs (p < 0.05). In conclusion, resveratrol and apigenin can be used as natural feed additives to protect against jejunal oxidative stress in ducks.

Exploring the Therapeutic Potential of Apigenin in Obesity-Associated Fibrinolytic Dysfunction: Insights From an Animal Study.

Obesity (Obe) is a chronic metabolic disorder usually complicated by impaired fibrinolytic activity. Apigenin (Api) is one of the flavonoids that have anti-adiposity effects. This study aimed to explore the therapeutic potential of Api in high-fat diet (HFD)-induced obese rats. Twenty-four Wistar adult male rats were randomly allocated into control group, supplemented with a normal pellet diet (NPD); Api group, supplemented with Api (10 mg/kg) for eight weeks; Obe group, obesity was induced byfeeding HFD for eight weeks; and Obe/Api group, obese rats supplemented with Api for eight weeks. Body mass index (BMI), homeostatic model assessment of insulin resistance (HOMA-IR), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), total superoxide dismutase(t-SOD) activity, and plasminogen activator inhibitor-1 (PAI-1) were measured. Compared to the control group, Obe group exhibited a significant increase in BMI, HOMA-IR, TNF-α, MDA, and PAI-1. These results were also associated with a significant decrease in serum t-SOD activity. Supplementation of Api alleviated the measured deteriorated parameters and ameliorated visceral adiposity in obese rats. This study provides compelling evidence regarding a promising role for Api in ameliorating the impairment of fibrinolytic activity in an Obe animal model. The observed effects are likely mediated through Api's anti-obesity properties, as well as its indirect modulation of PAI-1, oxidative stress, and inflammation. Future clinical studies are recommended that may make benefit of the preclinical therapeutic use of apigenin in obesity-associated fibrinolytic dysfunctions.

Cooling Performance of Fresh and Aged Automatic Transmission Fluids for Hybrid Electric Vehicles

The cooling performance of automatic transmission fluids (ATFs) plays an important role in hybrid electrical vehicles, in which the electric motor (EM) is placed inside the transmission housing due to their mission of cooling the EM. The cooling performance of the ATFs depends on their thermophysical properties, but these properties change with the oxidation of the ATFs. This work studies the influence of the oxidation of three ATFs (A, B, C) on their thermophysical properties, as well as on some figures-of-merit (FOMs) which are relevant for evaluating the cooling performance. The results indicated that the influence of the molecular structure on thermal conductivity and heat capacity is stronger than on density and viscosity, whereas the molecular structure hardly affects the FOMs of the fresh ATFs; ATFs B and C, formulated with base oils from API Group III, indicated better cooling performance than ATF A which was formulated with base oils from API Group I; the sensitivity to temperature of the variation with oxidation of the studied properties, including the FOMs, was almost null, except for ATF A; therefore, FOMs should be used to compare the cooling performance of ATFs for electric drivetrains instead of a single property, such as thermal conductivity.

Product Upgrading Analysis of Instant Coffee Industry: A Case Study of Kapal Api Group

Kapal Api Group as the lead firm of the coffee industry in Indonesia has become one of the main players in the global value chain. This achievement cannot be separated from the upgrading strategy implemented by Kapal Api from upstream to downstream. This research examines the global value chain of PT Kapal Api Global by analyzing the upgrading strategy that focuses on functional upgrading and intersectoral upgrading. Besides that, this research also further reviews how the company synergizes with government and non-governmental actors, as well as explores the implementation of domestic and international norms at PT Kapal Api Global. Through all the information and data obtained, the authors also provide four upgrading solutions or recommendations that can be implemented by PT Kapal Api Global in the future, such as product innovation and expansion, involvement of cultural elements, marketing strategies abroad, and cooperation with non-governmental organizations.

Apiaceous vegetables protect against acrolein-induced pulmonary injuries through modulating hepatic detoxification and inflammation in C57BL/6 male mice

Acrolein (Acr) is a reactive aldehyde in the environment. Acr causes oxidative stress and a cascade of catalytic events and has, thereby, been associated with increased risk of pulmonary diseases. Whether apiaceous vegetables (API) consumption can prevent Acr-induced pulmonary toxicity has not yet been explored hence, we investigated the effects of API on Acr-induced pulmonary damages in C57BL/6J mice. The mice were assigned into either negative control [NEG group; American Institute of Nutrition (AIN)-93G diet only], positive control (POS group; AIN-93G+Acr) or API intervention group (API group; AIN-93G+21% API+Acr). After 1 week of dietary intervention, the POS and API mice were exposed to Acr (10 µmol/kg body weight/day) for 5 days. During the exposure period, assigned diets remained the same. Prominent indicators lung of toxicity of POS mice were found, including mucus accumulation, macrophage infiltration, and hemorrhage, all of which were ameliorated by the API. Serum and lung inflammation markers, such as a tumor necrosis factor alpha were also increased by Acr while reduced by API. In the liver, API upregulated expression of glutathione S-transferases, which enhanced the metabolism of Acr into water-soluble 3-hydroxypropyl mercapturic acid for excretion. This is consistent with observed reductions in serum Acr-protein adducts. Taken together, our results suggest that API may provide protection against Acr-induced pulmonary damages and inflammation via enhancement of the hepatic detoxification of Acr.

Carbon Nanoparticles of Varying Shapes as Additives in Mineral Oil Assessment of Comparative Performance Potential.

In this work, carbonaceous nanoparticles (NPs) of varying morphology, viz., multilayer graphene (lamellar, thickness ∼ 3-7 nm), graphite (spherical ∼70 nm), and multi-walled carbon nanotubes (tubular), were selected to explore their tribo-potential in oil under identical operating conditions. A series of nano-oils were prepared using API group III mineral base oil with a dispersant (1%) and selected NPs in incremental concentration (0.5-4%). The tribo-performance of oils was evaluated on a four-ball tester and SRV-IV for extreme-pressure, antiwear (AW), and antifriction performance. Formulations were characterized for density, viscosity, and viscosity index. The stability of oils was monitored through visual observation weekly. Results revealed that the graphene particles showed excellent wear-preventive ability as an AW additive with (41-50) % increase followed by nanographite. Worn surfaces were studied to understand the plausible wear mechanism using a different spectroscopic technique. Tribo-behavior performance was supported with lateral force microscopy on the surfaces of tribo-films.

Comparative stability and outcomes of two surgical approaches for correction of class III asymmetry with lip or occlusal cant.

To assess and compare the stability and outcomes of the two surgical approaches for patients with roll asymmetry. A total of 50 adult patients were consecutively recruited for this prospective study. Patients with class III asymmetry and lip or occlusal cant who underwent bimaxillary surgery were grouped according to surgical approach: asymmetric posterior impaction on both sides (API, n = 31) and posterior impaction on one side and posterior extrusion on the other side (PIE, n = 19). Postsurgical stability and outcomes between groups were determined with cone-beam computed tomography for facial midline, lip, and occlusal cant at 1 week (T1), and at least 12-month postsurgery (T2, completion of orthodontic treatment). Presurgery, the upper anterior occlusal cant and lip cant were significantly greater for the PIE group (p < 0.05). Postsurgery (T2), the mandible moved upward and rotated upward in both groups. However, the upward rotation was significantly greater in the PIE group compared with the API group. Although the two approaches resulted in significant improvements in facial symmetry, the deviation in the facial midline remained under-corrected for most API patients. Patient outcomes for mandibular stability and facial symmetry differed between the two surgical approaches for correction of class III asymmetry with lip or occlusal cant. The findings of this study suggest that planned over-correction is a reasonable option for the approach of asymmetric posterior impaction on both sides.

Effects of Apigenin Treatment on Random Skin Flap Survival in Rats.

Random skin flaps are often used in plastic surgery, but the complications of marginal flap ischemia and necrosis often limit their wider clinical application. Apigenin (Api) is a flavonoid found in various fruits and vegetables. Api has been shown to promote angiogenesis, as well as reduce oxidative stress, membrane damage, and inflammation. In this study, we assessed the effects of Api treatment on random skin flap survival. Dorsal McFarlane skin flaps were transplanted into rats, which were randomly divided into three groups: control (normal saline), low-dose Api (20 mg/kg), and high-dose Api (50 mg/kg). Seven days after the surgery, the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were measured. Histological analyses were performed to determine flap survival and tissue edema. H&E staining was performed to assess the histopathological changes in skin flaps, and the levels of microvascular density (MVD) were determined. Laser doppler flowmetry was used to assess microcirculation blood flow. Flap angiography was performed by injection of lead oxide/gelatin. The expression levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interlukin-1β (IL-lβ) were evaluated by immunohistochemistry. Rats in the high-dose Api group exhibited higher average flap survival area, microcirculatory flow, increased SOD activity, and higher VEGF expression levels compared with the other two groups. Furthermore, the levels of MDA and pro-inflammatory cytokines were significantly decreased in rats treated with high-dose Api. Our findings suggest the potential usefulness of Api in preventing skin flap tissue necrosis.

Перспективы развития производства российских биоразлагаемых смазочных материалов на базовых маслах V группы

Currently, requirements for the environmental safety of lubricants are being tightened. The production of biodegradable lubricants is growing in European countries. The analysis of the production of biodegradable lubricants in the Russian Federation is carried out. Currently, the range of biodegradable lubricants in Russia is limited due to the lack of capacity for the production of polyalkylene glycol oils and esters. However, increasing environmental requirements in the oil, metallurgical, machine-building, construction industries, energy, agriculture, forestry, and water resources require more and more production of lubricants with high environmental performance. To assess the Biodegradability of Russian lubricants, it is necessary to use GOST 32433-2013 identical to the international standard OECD 301B. It is shown that in European countries, polyalkylene glycols and synthetic esters (diesters and esters) are widely used for the production of biodegradable motor, transmission, hydraulic, and turbine oils. To expand the production of modern biodegradable lubricants in the Russian Federation, it is necessary to develop industrial production of API group V oils. The use of biodegradable greases, coolant and separation lubricants based on vegetable oils is promising.

Исследование качеств светлых и масляных фракций нефти Азери

The article provides research on the qualities of Azeri oil and its light and oil fractions. A characteristic feature of Azeri oil is its high content of light fractions. This oil is light, low-sulfur, and paraffinic. Azeri oil in terms of density, sulfur content, content of light (light) fractions corresponds to marketing grades of oils and is called Azeri Light. Along with light fractions, Azeri Light oil contains up to 30-32% of oil fractions boiling above 350°C. Studies of 50°C oil fractions 350-500°C showed that the viscosity of the fractions at 100°C is in the range of 2.5-10.2 mm2/s, the viscosity index is 72-79.3, and the pour point is 12-36°С, potential content of base oils - 25.73%, their hydrocarbon composition, %: n-paraffinic oils - 50.7; isoparaffinic + naphthenic - 10.67; aromatic - 8.94%. Using traditional methods of purification using a selective solvent, followed by dewaxing and hydrotreating, from 50°C oil fractions of Azeri oil, base oils with a viscosity of 4.2-9.0 mm2/s at 100°C and a viscosity index of 91.0 can be obtained - 95.8, pour point minus 15°С / minus 20°С. By cleaning a wide oil fraction of 350-500°C, it is possible to obtain a base oil with a viscosity at 100 C of 6.5 mm2/s (SAE 20), a viscosity index of 95, a pour point of minus 15°C, an oil yield (350-500°C) is 20.3% for distillate (12.4% for oil). In terms of saturated hydrocarbons content (≥90%, sulfur content less than 0.03%), viscosity index &gt; 90, the oil has good antioxidant properties and can be assigned to API group II.

Исследование свойств некоторых перспективных нефтей Апшеронского нефтегазоносного района для получения качественных нефтепродуктов

The article presents the characteristics of characteristic oils of the Apsheron oil and gas region, as well as the hydrocarbon composition of light and oil fractions. Oils of the Apsheron oil and gas region in terms of light fractions, sulfur content, and density are comparable to marketing grades of oils. The standards for prices are: graded crude oil WTI, Light Sweet, Brent, and Russian oils Sokol, Urals, Siberian Light are approaching them. We have studied in detail the yields and hydrocarbon composition of light and oil fractions of oils from the Apsheron oil and gas region. To obtain oils with a high viscosity index, studies were carried out to change the structure of oil fractions using hydrogen using the example of oil fractions of Azeri oil. Due to the significant content of aromatic hydrocarbons, schemes for the processing of oil fractions have been developed, including selective purification of distillates, dewaxing (except for Guneshli oil), as well as hydrocatalytic treatment in a severe mode in the presence of industrial Russian catalysts. As a result, it was possible to obtain API group I oils, according to the viscosity classification corresponding to SAE 20 and SAE 30. Thus, a study of the qualities and hydrocarbon composition of oils from the Absheron oil and gas region showed that these oils are characterized by a high content of light fractions, low density, and low sulfur content. According to these indicators, these oils correspond to the marker oils. In order to obtain base oils with a viscosity index of ≥90 and an aromatic hydrocarbon content of ≥10, a traditional refining method was used: selective refining, dewaxing, and severe hydrotreating.

Anion Exchange Membranes Prepared from Quaternized Polyepichlorohydrin Cross-Linked with 1-(3-aminopropyl)imidazole Grafted Poly(arylene ether ketone) for Enhancement of Toughness and Conductivity.

A novel anion exchange membrane was synthesized via crosslinking of the quaternized polyepichlorohydrin (QPECH) by 1-(3-aminopropyl) imidazole grafted poly(arylene ether ketone) (PAEK-API). While the QPECH provided an excellent ion conductive property, the rigid rod-structured PAEK-API played a reinforcing role, along with providing the high conductivity associated with the pendant API group. The chemical structure of QPECH/PAEK-API membranes was identified by 1H nuclear magnetic resonace spectroscopy. A variety of membrane properties, such as anion conductivity, water uptake, length swelling percentage, and thermal, mechanical and chemical stability, were investigated. The QPECH/PAEK-API1 membrane showed quite high hydroxide ion conductivity, from 0.022 S cm−1 (30 °C) to 0.033 S cm−1 (80 °C), and excellent mechanical strength, associated with the low water uptake of less than 40%, even at 80 °C. Such high conductivity at relatively low water uptake is attributed to the concentrated cationic groups, in a cross-linked structure, facilitating feasible ion transport. Further, the QPECH/PAEK-API membranes showed thermal stability up to 250 °C, and chemical stability for 30 days in a 4 NaOH solution, without significant loss of ion exchange capacity.

Measurement of EHD Friction at Very High Contact Pressures

EHD friction curves have been measured up to very high pressure (pmean = 5 GPa, pmax = 7.5 GPa) using a newly developed, rolling-sliding, ball on disc machine, the ETM. Six base fluids have been studied, spanning the API base oil categories Group I to Group V. At high pressures, thermal effects become substantial even at quite modest slide-roll ratios, and these must be considered when analysing friction measurements in terms of the underlying rheological properties of the oils. By comparing measurements from steel/steel and WC/WC ball and disc combinations with very different thermal conductivities, the use of thermal correction to derive isothermal friction curves has been validated. At relatively low pressures (mean pressure = 1 GPa), there are substantial differences between the EHD friction properties of the various API Group base oils, but as pressure is raised these diminish and the EHD friction coefficients of all the Groups approach a similar maximum value at a given temperature. EHD friction continues to be quite strongly temperature dependent even at very high pressure. As pressure is increased, EHD friction curves become progressively steeper, so that friction coefficients at very low slide-roll ratios (1 to 2% SRR) become several times greater at high than at low pressure. This has important practical implications for the efficiency of rolling element bearings at high pressures since these components normally operate in this SRR range. There is no evidence of any of the base oils reaching a limiting shear stress over the whole pressure and temperature range studied. Instead, shear stress continues to increase with log(strain rate) in accord with the Eyring-activated flow model up to very high pressures.

Product marketing strategy of Kapal Api Group uses SWOT Analysis

Fastrata buana corporation was founded in 1992 in Jakarta. The fastrata buana handles the sale and product distribution of the kapal api group to ensure delivery to customer. Fastrata buana is the largest distribution company in Indonesia With branch and distribution point in Sumatra, Java, Bali, kalimantan, sulawesi and even Papua.The research aims to see what is a marketing strategy of the company's products. By doing SWOT analysis, counting the IFAS and EFAS get recapitulation S-W = a score of 1.5 and O-T = a score of 1,25.It shows that the company's strategy lies within the quadrant 1. Based on analysis of the internal strategy factors that can be seen in the diagram of the SWOT analysis, where the kopi kapal api position is in quadrant 1 that indicates the SO strategy in the SWOT matrix, which is aggressive strategy.An aggressive strategy is one that uses all the power to seize the opportunity.the strategy is one which gives benefit because having opportunity and power to be used improving Fastrata buana corporation.

Quality of Base Oils Produced From Hydrocracking Residue

Hydrocracking residue meeting physicochemical and chemical composition requirements for hydrocracking oil feedstock was studied. The optimal scheme for producing API group HI base oils was determined.

Linguistic-Based and user-Based Recommending Posts using Two-Level Clustering Methods

Online social networks have produced bunches of online social groups where individuals can collaborate and shuffle their thoughts. In spite of, the real problems that conflicts with the user security and convenience are confidentiality break, groups without inception, confusion created from various groups of which user is a member of and difficulty in moderating groups. This can be moderated to an extent by an automated filtering method required to categorizing group members based on their response patterns. This paper proposes clustering of group posts on stylistic, thematic, emotional, sentimental and psycholinguistic methods and members of the group are categorized based on their responses to the posts belonging to different clustering methods. The categorization affords security just like the conflict associated with irrelevant notifications received from more than one groups, via recommending the users, posts which might be probable to be of interest to them. It also helps to identify the group members meant closer to spreading posts that violate group policies. The categorization post shows increased performance where there are large numbers of members in a social group by performing linguistic clustering. The contribution work is to implement location-aware personalized posts recommendation using users’ behavioral patterns and their geographic location. Another, important work is to implement text-to-speech system converting English text into speech using speech synthesis technique. The system gives rating to the users who shares posts depending on clustering. Also system provides read later functionality to the user side. The system has been tested on Twitter API group data where a significant solution to an unaddressed problem associated with social networking groups is offered.

Feasibility and safety of uninterrupted apixaban in patients undergoing radiofrequency ablation for atrial fibrillation.

An optimal periprocedural anticoagulation strategy is essential for minimizing bleeding and thromboembolic complications during atrial fibrillation (AF) ablation. Limited data are available on the uninterrupted use of apixaban in patients with AF undergoing catheter ablation. This study aimed to evaluate the safety and efficacy of uninterrupted apixaban in patients undergoing radiofrequency ablation for AF. In particular, we evaluated silent cerebral infarction (CI) during radiofrequency catheter ablation of AF. This was a prospective and nonrandomized cohort study. A total of 259 consecutive patients who underwent AF ablation were evaluated; 157 patients received apixaban (Api group), and 102 patients received dose-adjusted (PT-INR 2.0-3.0) warfarin (Wf group). All oral anticoagulants were continued throughout the periprocedural period, including the morning of the procedure. Intravenous heparin was administered during the procedure and neutralized by protamine at the end of the procedure. Sixty-one patients underwent magnetic resonance imaging (MRI) after the procedure to evaluate for silent CI. Mean age was 66 ± 11years; there were 91 men (73.7%) and 148 cases of paroxysmal AF (57.1%). No symptomatic CI was observed. Silent CI occurred in 6/61 patients (9.8%). No significant difference was observed between the Api group (4/30 patients, 13.3%) and the Wf group (2/31 patients, 6.5%). There was no significant difference regarding major bleeding events between the Api group (1/157 patients, 0.6%) and the Wf group (2/102 patients, 2.0%). The safety and efficacy of uninterrupted apixaban for patients undergoing AF ablation were equivalent to warfarin for preventing bleeding and thromboembolic complications.

Pilot plant study on continuous propane deresining of atmospheric crude cylinder stock

With the market transition from API Group I to Group II and Group III lubricating base stocks and decline in the Group I supply, highly valuable grades of Group I solvent-refined bright stocks are gaining more attention today. Continuous improvement in the bright stock production is crucial for refineries to accelerate the gain from the volatile Group I base oil market. To develop a pathway for improving the production of bright stock in the refinery, the continuous propane deresining pilot plant study was conducted on the atmospheric crude cylinder stock for propane deresined cylinder stock production. The propane deresined oil is referred to as D-stock, which is the feedstock for MEK dewaxing downstream for bright stock production in the refinery. Different propane solvent to oil (vol./vol.) conditions were studied at Intertek PARC’s continuous solvent deasphalting unit with varying column top and bottom temperatures at a fixed column pressure. A significant improvement in the D-Stock yield was observed without compromising the D-Stock viscosity specification. The Intertek PARC deresining tower with staggered half-moon baffle internals enhanced separation of the D-stock from the resin component. The real-time operational data and analytical measurements were presented for propane dosages. The detailed characterization of Intertek PARC D-stock and resin was studied at 10.5/1 and 8/1 solvent to oil ratios.

Lube oil chemistry influences on autoignition as measured in an ignition quality tester

Derived Cetane Numbers (DCNs) of engine lubricating oil/multicomponent 95 Research Octane Number (RON) gasoline surrogate mixtures were measured in an Ignition Quality Tester (IQT). Measurements separately assess the effects of calcium- and magnesium-based detergent additive fraction, oil viscosity, oil degradation, and base oil classification on mixture ignition propensity at conditions with relevance to low speed pre-ignition (LSPI) in gasoline engines. Testing of 0–25% (by mass) oil blended into a six-component surrogate mixture representing an unleaded “average” European gasoline blend is used to determine sensitivity of DCN responses to variations in the properties. With one exception, mixture DCNs were found to increase with lubricating oil content. Despite variation in calcium and magnesium concentrations, DCN responses for all oil blends indicate no statistically significant effect of either calcium or magnesium. Similarly, neither aging of nor peroxide addition to the oil yields significant DCN changes compared to untreated oils. However, a distinct response is found for variations in the base lubricant chemical structural properties. At 25% oil blending with gasoline surrogate, the measured DCNs (RONs) of different group base oils range from 19.6 (95.7) to 42.1 (46.2). The DCN increases with increasing base oil API Group Number (I through IV); however, mixture DCN was found to decrease for a 25% blend of Group V-B with the gasoline surrogate. Using quantitative 1H NMR, the Group Number trend is interpreted to be a consequence of linear vs. branched character of the paraffinic base oil composition. Taken together, the present results indicate that at ASTM D6890 DCN test conditions, there is no significant ignition effect attributable to reasonable variations in the lubricant's calcium or magnesium content, viscosity, or degree of degradation. Instead, the isomeric character of the paraffinic base oil appears to be most significant in controlling lubricant autoignition properties relative to those of gasolines.

Effect of dispersant on nano‐PTFE: Striking the balance between stability and tribo‐performance

AbstractNanoparticles (NPs) of PTFE (polytetrafluoroethylene) in suspension form were reported as very efficient extreme pressure (EP) additive in 150 N API Group II oil in our earlier work. The less stability of a nanosuspension due to agglomeration of NPs beyond 3 wt%, however, was a major issue, which needed to be addressed for its possible industrial exploitation in lubricants. Using another additive, eg polyisobutylene succinimide (PIBSI), as a dispersant appeared to be a plausible solution. Its inclusion (1 wt%) increased the stability of the oil by a factor of 4. It was necessary to investigate, however, whether it influenced other properties synergistically or antagonistically. The present paper highlights the positive and negative aspects of inclusion of PIBSI on the tribo‐performance (EP and anti‐wear) of the nano‐PTFE‐based oils.A series of nano‐PTFE oils (1%‐6%) stabilised with PIBSI (1%) were developed and evaluated for EP and anti‐wear performance. The PIBSI‐PTFE combination clearly showed antagonistic behaviour due to competition for film formation on the surfaces. However, with an increase in concentration of NPs, the film formation mechanism was dominated by them. Scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy were used for the examination of the topography and surface chemistry of the protective films formed on the steel specimens.