Viscosity Index Improvers Research Articles

Revealing the Molecular Interaction between CTL Base Oil and Additives and Its Application in the Development of Gasoline Engine Oil

In order to improve fuel economy to meet the standard for passenger car oil, a new formulation with good viscosity–temperature performance for gasoline engine oil is required. In this study, coal-to-liquid (CTL) base oil, with a high viscosity index and good low-temperature performance, was selected as the base oil to develop the gasoline engine oil. A systematic study on the molecular interaction between the CTL base oil and the viscosity index improver (VII), including three kinds of hydrogenated styrene diene copolymers (HSD-type) and four kinds of ethylene propylene copolymers (OCP-type), was conducted. It was found that in general, in CTL base oil, the HSD-type VII exhibited a much higher viscosity index, a significantly lower shear stability index, a higher thickening ability, and a lower cold-cranking simulator (CCS) viscosity than that of OCP-type VII. Moreover, when comparing CTL base oil with mineral oil 150N, the combination of CTL base oil and the VII displayed a lower CCS viscosity than that of mineral oil, suggesting it had better low-temperature performance and was able to quickly form a protective oil film on the surface, which was beneficial for the cold start. The functional group distribution state of the VII in base oil was analyzed using synchrotron radiation micro-infrared microscope (SR Micro-IR) technology, which revealed that HSD-1 had a better molecular interaction with CTL6 than 150N because of the better uniformity of the C=C group distribution. Based on this, a SP 0W-20 gasoline engine oil was developed by the combination of CTL base oil and the HSD-1 viscosity index improver, together with an additive package, a polymethacrylate pour point depressant, and a non-silicone defoamer, which showed excellent low-temperature performance, thermal oxidation stability, and detergency performance compared to the reference oil.

A nanocopper oxide supported on montmorillonite: synthesis and characterization as a green viscosity index improver additive

A nanocopper oxide supported on montmorillonite: synthesis and characterization as a green viscosity index improver additive

Synthesis and Characterization of Novel Terpolymers as Viscosity Index Improvers Using Industrial Waste for Iraqi Lubricating Oil

The potential utilization of industrial waste, specifically polyethylene wax, to enhance the efficiency of alkyl acrylate polymers as viscosity index improver (VII) additives in lubricating compositions has been investigated. Four terpolymers (w1, w2, w3, and w4) were synthesized via free radical polymerization, incorporating hexyl acrylate, 1-tetradecene, and industrial waste-sourced polyethylene wax at varying molar ratios. These terpolymers were characterized through gel permeation chromatography (GPC) for molecular weight determination, Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy for chemical structure analysis, and thermal gravimetric analysis (TGA) for thermal stability assessment. The study evaluated the efficiency of these terpolymers as viscosity index improvers (VII) in combination with free additives Iraqi lubricating oil (base oil 60). Our results demonstrate the feasibility of significantly enhancing the efficiency of viscosity improvers through the utilization of industrial waste, with improvements proportional to terpolymer concentration. The terpolymer w3, characterized by a balanced molar ratio of 1:1:1, exhibiting the highest degree of efficacy, which gave VI of 206 at 5 wt.% concentration compared with free additive lubricating oil, which gives VI of 98. This study offers promising insights into the sustainable use of industrial waste to improve lubricating compositions.

Structural and viscosity studies of dendritic hyper branched polymer as viscosity index improvers

Star-like structural compounds were synthesized from different moles % of either dodecyl acrylate or triethylenetetramine using a one-pot commercial synthesis technique. The polymers that were created had various terminations. Fourier Transform Infrared (FTIR) spectroscopy and 1HNMR were used to verify the produced polymers' chemical composition with different terminations. Furthermore, by analysis of Dynamic Light Scattering (DLS), the size and distribution of the synthesised branched polymers were evaluated. Using a Gel-permeation chromatograph, the modified hyperbranched polymer's molecular weight, synthesized with various end points, were assessed. The unorganized structured prepared compounds with various molar feed ratios dodecyl acrylate: triethylenetetramine (DDA: TETA) was designed as A, B, C, D and E. Moreover, the synthesized additives function as viscosity index improvers (VII). As the concentration of polymeric additives increases, it leads to higher VI values. Similarly, with the increase in percentage of triethylenetetramine in the prepared hyperbranched polymers, the VI also increases. Notably, the most effective VI achieved is (E) = 212. It is noteworthy that all the synthesized hyperbranched polymers exhibited Newtonian behavior in the rheological study.

Exploring the Impact of Additives on Tribological Characteristics in Lubricating Oils: A Critical Review

In mechanical systems, lubricants play a crucial role in minimizing friction, dissipating heat, and preventing wear. Additives, comprising both organic and inorganic compounds and typically constituting 0.1% to 30% of lubricant volume, are introduced to enhance lubricant performance. This study investigates the influence of various additives on lubricant behaviour and performance, encompassing antifoam agents, corrosion inhibitors, antioxidants, detergents, extreme pressure additives, pour-point depressants, and viscosity index improvers. Friction coefficients were meticulously measured using a pin-on-disk tribometer to assess the Tribological and physical properties of these additives. Surface analysis via SEM provided insights into wear characteristics influenced by the additives. The comprehensive tribological assessment reveals that the incorporation of additives consistently reduces friction and wear across different base oil types. This underscores the critical role of additives in improving lubricant properties, maintaining thermal stability, and forming protective films on surfaces. Our findings advocate for the strategic use of additives to enhance lubricant performance and longevity.

Comparison between methacrylate copolymers and their magnetite nanocomposite as pour point depressant for lubricating base oil

A novel pour point depressant was synthesized by developing a polymeric nanocomposite using polymethacrylate and magnetite nanoparticles. The primary objective was to assess and compare the efficacy of PMA and PMA/Fe3O4 nanocomposite in reducing the gelation point, yield stress, apparent viscosity, and pour point of waxy crude oil. Extensive assessments were conducted to evaluate the performance of these additives. Rheometry tests were employed to measure the pour point of the lubricating oil pour point following the addition of PMA and PMA/Fe3O4 nanocomposite. The findings demonstrated a significant reduction in pour point, reaching values of − 18 °C, − 27 °C, − 24 °C, and − 36 °C for CP1, CP2, NP1, and NP2, respectively, at an optimal concentration of 10,000 ppm. Various characterization techniques such as Fourier Transform Infrared Spectrometer, Proton Nuclear Magnetic Resonance, X-ray Diffraction, Scanning Electron Microscope, Differential Scanning Calorimetry, Dynamic Light Scattering, Polarized Optical Microscope, and Gel Permeation Chromatography were utilized to analyze the polymers. Furthermore, the effectiveness of each polymer as a viscosity index improver (VII) and pour point depressant for mineral-based oil was evaluated. The mechanism of action of the polymers as pour point depressants was investigated through photomicrographic analysis. Additionally, the rheological properties of the formulated lubricant were assessed and reported. Thermogravimetric analysis was used to determine the thermal stability of the polymers, revealing that the copolymer nanocomposites exhibited higher thermal stability, viscosity index (VI), and molecular weights compared to the copolymers alone. These enhancements in thermal stability and molecular properties contributed to the improved pour point depressant (PPD) properties. Overall, the study successfully synthesized a novel pour point depressant and evaluated its performance using various tests and characterization techniques. The results demonstrated the effectiveness of the additives in reducing the pour point and improving the thermal stability of the lubricating oil.

A novel polyionic liquid with lubricity and viscosity-increasing dual functionalities as the additive in aqueous lubrication system

The polyionic liquid poly-PEGMA-r-METAC (PPM) with quaternary ammonium has been synthesized and evaluated as additive in aqueous lubricating fluids. The rheological behavior of aqueous lubricating fluids with PPM has been characterized to confirm PPM’s function as a viscosity modifier. The tribological behavior of aqueous lubricating fluids with PPM has been investigated on SRV-V and MTM testing machines. It was found that PPM has excellent viscosity-increasing, lubricating, and anti-wear properties as an additive for aqueous, which can be attributed to the ability of PPM to form the protective film and boundary tribofilm generated from complex tribochemical reaction on rubbing surface. The obtained PPM with dual functions of anti-corrosion additives and viscosity index improver can play an important role in diverse lubrication regimes.

Influence of Some Additives on the Efficiency of Viscosity Index Improver for Base Lubricating Oils

The effects of three different additives formulations namely Lubrizol 21001, HiTEC 8722B and HiTEC 340 on the efficiency of VII namely OCP of three base lubricating oils namely 40 stock and 60 stock and 150 stock at four temperatures 40, 60, 80 and 100oC were investigated. The efficiency of OCP is decreased when blended with 4 and 8 wt% of Lubrizol 21001 for all the three base oil types. But it is increased when adding 4 wt% and 8 wt% of H-8722B in 40 stock. While for 60 stock and 150 stock the OCP efficiency decreased by adding 4 and 8 wt% of H-8722B. In the other hand, it is decreased with a high percentage by adding 4 and 8 wt% of H-340 for 60 stock and 150 stock and for 40 stock it is increased by adding 4 wt% of H-340 and decreased with insignificant percentage when adding 8 wt%. Finally, a number of VI correlations have been obtained depending on the results predicted in this study. These correlations represent the functional relationships between the VI and the concentration of OCP for three types of base lubricating oil and for each type of additives.Keywords: Lubricating oil, Kinematic Viscosity, Viscosity

Performance of hydraulic oils and its additives in fluid power system: A review

The main objective of this paper is to analyze various hydraulic oils and the effect of additives like nanomaterials in order to increase lubricity, counter friction, reduce wear, etc. A detailed list of additives is focused in this review which will enhance the performance and working of the hydraulic fluid by enhancing lubrication, modifying viscosity and cleaning engine deposits. Mineral oils or Synthetic hydrocarbon blends are used to derive lubricants. Although they lack properties of their own to fulfill the requirements set by the Original Equipment Manufacturers (OEMs). By using nanomaterials in mineral oils various advantages can be obtained. Various nanomaterials such as metal chalcogenides, soft metals, carbon-based materials, etc. are available which via mechanisms such as the rolling effect, protective film effect, etc., can change the various properties of hydraulic oils as required. Similarly, additives are added to hydraulic oils like viscosity index improvers, anti-wear agents which will improve the properties of the hydraulic oil by eliminating negative properties and improving the life of the fluid. These additives play a crucial role in sustainability of hydraulic oils and their size can be optimized to get better tribological characteristics. The increasing usage of these high performance additives in the country is projected to register a compound annual growth rate (CARG) of more than 1.5% during the forecast period (2021-2026). The review focusses on the improved performance of these nanomaterials and additives when added to the Hydraulic Fluid and will serve as a reference for future developments in the application of additives and nanotechnology in hydraulic oils.

Quantification of oil film thickness on the top ring sliding surface by visualization

The oil film thickness of the piston ring at the sliding surface affects oil consumption, friction loss and wear of the ring and liner in internal combustion engines. It is important to know the oil film thickness on the piston ring sliding surface in order to improve the engine efficiency. Accurate measurement of oil film thickness on the piston rings is difficult because the oil film thickness is extremely thin. A modified method is proposed for measuring thin oil film. The authors have measured the oil film thickness on the piston skirt and land to contribute. The optical measurement system and analytic method are improved. The presented method present the oil film thickness on the sliding surface of the top ring from the oil film visualization images. The verification of the measured oil film thickness carried out by comparing with the data obtained from the numerical calculation. For evaluating the effect of the oil characteristics, 0W-20 oil and #8 oil were tested with different engine speeds and different crank angle where different ring loads. It was confirmed that the top ring oil film thickness became thick due to the high engine speed. A large load on the top ring reduces the oil film thickness. The oil film became thick when the oil viscosity was high. The effect of oil viscosity on the oil film thickness of the top ring was clarified. The effect of the viscosity index improver was also discussed. It is shown from the experimental results that the present measurement system for the top ring oil film thickness has enough accuracy.

Core-Crosslinked Star Copolymers as Viscosity Index Improvers for Lubricants

Core cross-linked star (CCS) copolymers were prepared by reversible addition–fragmentation chain-transfer polymerization according to the arm-first technique and studied as viscosity index improvers for the application in hydraulic lubricants. A one-pot two-step synthetic procedure was optimized: starting from PMA arms with a precisely controlled structure and three different molecular weights and using different amounts of either divinylbenzene or ethylene glycol dimethacrylate as cross-linking agents, CCS copolymers with a high star yield (63 to 88%) were obtained. CCS copolymers present weight average molecular weight values ranging from 130,000 to 420,000 g mol–1 and a number of arms comprised between 4 and 13. All samples were employed, without any purification step, in the preparation of model lubricant formulations for hydraulic fluid applications. A good compromise between viscosity index improvement and capability to resist chain breaking reactions was obtained for CCS copolymers with target molecular weight for the PMA arms of 20,000 g mol–1. Improved performances with respect to a commercial additive were obtained.

Fatty-acid based comb copolyesters as viscosity Index improvers in lubricants

Methyl ricinoleate was functionalized using thiol-ene click chemistry in order to synthesize bio-based comb (co)poly(9-alkyl 12-hydroxystearate)s. The latter were then evaluated as Viscosity Index Improvers in a mineral based lubricant. While most of the poly(9-alkyl 12-hydroxystearate)s investigated behave as thickeners, copolyesters containing 15 to 25 wt% of methyl 9-phenyl ethyl 12-hydroxystearate exhibit a Viscosity Index improver effect, interpreted to a limited solubility of these copolyesters. The effect of these polyesters on the oil viscosity-temperature (V-T) behavior was investigated in the dilute regime of n-dodecane used as a model solvent. An aggregation-disaggregation behavior was assumed to explain the V-T behavior observed with these (co)polyesters.

Kapok Seed Oil As Viscosity Index Improved

Production, supply and development of hubricating oils for domestic use are carried out in Indonesia using domestie bate ofls and imported additives. Research on the use of kapok seed oill as a viscosity index improver for lubricating oll is as an effort for supply and development of lubricating oll additive which is produced in the country. Resuls of physical and chemical properties analysis indicate that kapok seed oil can be used Ea viscosity index improver.

Probing the interactions between pour point depressants (PPDs), viscosity index improvers (VIIs), and wax in octane using fluorescently labeled PPDs

A poly(octadecyl methacrylate) sample fluorescently labeled with 6.7 mol% of pyrene (Py(6.7)-PC18MA) was used as a mimic of a pour point depressant (PPD) to investigate how Py(6.7)-PC18MA interacts with wax found in engine oils and ethylene-propylene (EP) copolymers used as mimics of viscosity index improvers (VIIs). The fluorescence spectra of Py(6.7)-PC18MA solutions in octane were acquired in octane at low and high concentrations of Py(6.7)-PC18MA and analysed to obtain the molar fraction ( finter) of pyrene labels, which formed excimer intermolecularly, a measure of the level of intermolecular interactions between Py(6.7)-PC18MA molecules in the solution. The finter-versus- T profile obtained for Py(6.7)-PC18MA alone in octane confirmed that Py(6.7)-PC18MA formed microcrystals at solution temperatures below 0 °C. The effect induced by the addition of wax and an amorphous (EP(AM)) and semicrystalline (EP(SM)) EP copolymer on the interactions experienced by Py(6.7)-PC18MA were characterized by monitoring finter as a function of temperature and comparing the different finter-versus- T plots obtained after the addition of the different components with the finter-versus- T plot obtained for Py(6.7)-PC18MA alone. These studies demonstrated that wax and EP(AM) increased the level of intermolecular interactions between the Py(6.7)-PC18MA molecules at all temperatures in octane. EP(SM) increased the interactions between Py(6.7)-PC18MA molecules at high temperature, where it was soluble in octane, but finter reverted to its value in the absence of EP(SM) at low temperatures, where EP(SM) had crystallized. These experiments illustrate how pyrene excimer fluorescence can be applied to probe the complex interactions taking place between the different components found in engine oils.

Prediction of thickening efficiency of olefin copolymers and kinematic viscosities of the blended base oils by determining intrinsic viscosities of the copolymers in cyclohexane

The engine oil contains various performance additives along with polymer-based viscosity index improver, which are made from special types of flexible long chain polymers whose functionality is derived from their thickening efficiency, viscosity-temperature relationship, and shear stability. Olefin copolymers of the type ethylene/propylene copolymer are extensively used as viscosity index improver for engine oil formulations whose performance is a function of their composition, co-monomer sequence distribution and molar mass. Polymer coils interact with base oil and make it increasingly resistant to flow which accounts for substantial changes in viscosity parameters i.e. kinematic viscosities and viscosity index of blended base oils. Intrinsic viscosity of a polymeric solution is an important “dilute solution viscosity” parameter, which is easily measurable using Ubbelohde viscometer.In the present work, intrinsic viscosity of twenty samples of laboratory synthesized olefin copolymer in cyclohexane at 30 °C were correlated with their thickening efficiencies, kinematic viscosities of the olefin copolymer blended base oils at 40 °C and 100 °C. These correlation studies enable prediction of performance of olefin copolymer in blended base oil based on an easily and quickly measurable intrinsic viscosity parameter, leading to faster screening of large number of olefin copolymers for their utility as viscosity index improver in lubricants, in a short span of time with limited resources.

Studies on the application of poly(acrylate‐co‐maleic anhydride) amides with N‐phenyl‐p‐phenylenediamine as multifunctional lube additives

AbstractThree polymeric amides were developed by utilizing three acrylates of alkyl chain C‐8, C‐12 and C‐18 and maleic anhydride via polymerization pathway followed by successful coupling with N‐phenyl‐p‐phenylenediamine to give poly(Ac8‐co‐MA)PPA, poly(Ac12‐co‐MA)PPA and poly(Ac18‐co‐MA)PPA. After successful molecular identification, application as lubricant additives as viscosity index improver, pour point depressants, deposit control agents and anticorrosion was done in polyol based synthetic lube oil. A rheological study was also carried out. For comparative performance evaluation, the commercial additives were also taken. Because of the diphenyl moiety in the molecular structure, additives showed the DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging activity. Poly(Ac18‐co‐MA)PPA additive at a high concentration of 5000 ppm, the viscosity index increased from 179 to 217 while the pour point decreased from −18 to −30°C. As far as the detergent dispersant property is concerned, poly(Ac18‐co‐MA) reduced the coking value from 87.5 to 13.2 mg, while % dispersancy increased from 20% to 42%.

The Investigation of Viscometric Properties of the Most Reputable Types of Viscosity Index Improvers in Different Lubricant Base Oils: API Groups I, II, and III

Four commercial viscosity index improvers (VII) have been used to investigate the behavioral differences of these compounds in three types of universally applicable base oils. The used VIIs are structurally three types of co-polymer: ethylene-propylene, star isoprene, and two di-block styrene-isoprene. After dissolving of different amounts of VIIs in different base oils, the kinematic viscosities at two standard temperatures were determined and the intrinsic viscosities were calculated according to Huggins method, then the effects of changes in base oil and polymer type were investigated. Intrinsic viscosities as criteria for polymer molecules sizes were found to be higher at lower temperature than at higher temperature. Dependence of intrinsic viscosity on the polymer molecular weight was observed. In the previous works, one or two types of VIIs were studied in only one type of base oil and/or solvent, not different base oils. Furthermore, different ranges of temperatures and concentrations not necessarily applied ranges were selected, but in this work, common base oils and most commercial VIIs were used and the viscometric properties were compared at two temperatures. Viscosities at these temperatures are used for determining VI and definition of lubricant’s viscosity grades. VI improvement is the main cause of VII usage.

粘度指数向上剤と流動点降下剤の機能とメカニズム

粘度指数向上剤と流動点降下剤の機能とメカニズム

Potential Eco‐Friendly Multifunctional Lube Oil Additives: Synthesis, Characterization and Performance Evaluation

AbstractHomo polymer of dodecyl acrylate (DDA) and its copolymers with citral at different percentage composition (w/w) were synthesized by free radical polymerization method. The characterization of all the polymers was carried out through FTIR, NMR and GPC (gel permeation chromatography) analysis. The performance of all the prepared polymers as viscosity index improver (VII), pour point depressant (PPD) and antiwear (AW) additive in two different base oils (BO1 and BO2) were evaluated by standard ASTM methods. The results showed that all the polymers are good as VII, AW and PPD additives. AW and PPD properties of copolymers are better compared to homopolymer. Out of the three additive properties, PPD properties of copolymer (P‐2) was remarkably improved upto −26 °C for at 1 % (w/w) in base oil compared to homopolymer of dodecyl acrylate (−18 °C at 1 % w/w) as confirmed by photo micrographic analysis. The thermal stability of the polymers was determined by thermo gravimetric analysis (TGA). The stability against thermal degradation increases with increasing citral content in the acrylate backbone. Moreover the copolymers were eco‐friendly which was confirmed by biodegradability test (Disc Diffusion and Soil Burial Test method).

Synthesis of viscosity index improver for motor lubricating oil

The viscosity of lubrication oil is the important property to evaluate the behavior of lubrication activity of oil. Viscosity index VI is the standard indicator of effecting temperature on viscosity of lubricating oil. Viscosity index improvers are the chemicals that added to base lubricating oil produced from refineries to make oil stable against temperature elevation during internal combustion engine operation. In this work, special viscosity index improver was prepared by blending of DQC (that synthesized depending on Ethylene Diamine Tetra Acetic acid original compound) with polyoxyethylene (p 20) in presence of mystelene as solvent. The prepared viscosity index improver was added to base lubricating oil grade SN-500 produced from Al – Dorah refinery with different weight ratios, adding 7.8% of viscosity index improver to SN-500 base oil improved VI by 14 degrees without effect on other properties of oil.