The Effect of Some Additives on the Rheological Properties of Engine Lubricating Oil (original) (raw)
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Experimental Investigation of Polyacrylates Copolymers as Lube Oil Viscosity Index Improvers
The International Conference on Chemical and Environmental Engineering, 2010
Six copolymers, based on polyacrylates, were prepared and evaluated as viscosity index improvers. The synthesizing process begins by estrification of acrylic acid with different alkyl chain length alcohols (octyl, decyl, odecyl, tetradecyl, and hexadecyl alcohol), ranging from C 8 to C 16. The completion of the esterification process was confirmed by FIIR spectrometry. Linear copolymerization was carried out to produce six copolymeric viscosity index improvers. All copolymers were tested for solubility in the selected base oil (SAE 30). Acceptable solubility in the base oil has been recorded. Molecular weight of the prepared copolymers was determined by the technique of Gel Permeation Chromatography (GPC). Samples with different concentrations from each copolymer (0.5%, 1%, 1.5%, 2%, 2.5%, 3% by weight) were prepared and evaluated as viscosity index improvers. Also, a rheological test for oil samples, with and without additives, was carried out with different shear rates and at different temperatures, for characterization of the improved lubricant. It has been found that all of the prepared compounds are effective as viscosity index improvers, and their effectiveness becomes more pronounced by increasing either the molecular weight of copolymer (140,000-236,000) or the alkyl chain length (C 8-C 12). Effectiveness could be increased by increasing the concentration of the additives in the base oil (6%-46%). There are no reflection points through the tested range of concentrations. Finally, the executed rheological tests oil showed that the improved oils exhibits a Newtonian behavior, except a slight non-Newtonian behavior at the starting of shear application.
Evaluation of acrylate-sunflower oil copolymer as viscosity index improvers for lube oils
2011
Copolymers of sunflower oil with methyl methacrylate and decyl acrylate were synthesized and characterized. Intrinsic viscosity and viscometric molecular weight were determined by using Huggins and MarkHouwink equation respectively. Viscosity index (VI) of the additive doped base oils were evaluated and compared with that of the mineral base oils. VI values of the additive doped base oils depend on the nature of mineral base oils used and the type and concentration of VI improvers. For a comparison, respective homopolymers e.g. polymer of sunflower oil, poly(methyl methacrylate) and poly(decyl acrylate) were also prepared, characterized and evaluated in the similar fashion.
Rheological Behavior of Lubricating Oil with Polyacrylates Copolymers
The International Conference on Chemical and Environmental Engineering, 2012
Six copolymers based on acrylates were used as viscosity index improvers [1]. The effect of these copolymers on the rheological behavior such as viscosity thinning or thickening has been studied. A rheological study was carried out to SAE 30 base oil before and after adding the viscosity index improvers with different concentrations (1, 2, 3% wt). Brookfield rheometer model (DV-III+) was used with different shear rates and at different temperatures (40, 60, 100 ˚C), for characterization of the enhanced lubricant. It was noticed that Freeadditives Base oil exhibits a Newtonian behavior at all temperatures, on the other hand; all enhanced samples exhibit a weak non-Newtonian behavior that disappears with increasing either temperature or shear rate or both of them. The effect of temperature on specific viscosities of the blends under different shear rates was studied to determine the efficiency of viscosity index improvers and record its mechanism of action at different shear rates and temperatures.
2013
The influence of the composition and structure of amorphous ethylene-propylene copolymer, EPC on viscometric behavior of mineral lubricating oils was examined and described. It is shown that even small differences in composition and structure of the same polymeric product, which are unavoidable consequence of the statistical nature of polymerization reactions, can display significant changes related to viscosity and thickening efficiency. Molecular weight of the additive has the most significant effect on viscosity since their very small increase causes a substantial increase in viscosity of olefin copolymer (OCP) solutions. Composition and distribution of comonomer sequences are important parameters, but do not show explicit nor linear effect on the solution viscosity. The interdependence of ethylene content, molecular weight and viscosity of additive solutions is expressed by an empirical function which is calculated using the Marquardt-Levenberg iterative algorithm. Understanding...
Effect of Additives on the Viscosity Index of Lubricant Oil (Engin Oil)
The effects of four different additive formulations namely 5748, 801, 264 and 261 on the viscosity index of two lubricating oils (base oils) namely 150N and 500N at two temperatures 400C and 1000C were investigated. The base oils were blended with the additives in three different proportions of 100/4. 100/8 and 100/12. The results gave a viscosity index of 96 and 98 respectively for 150N and 500N without additives. On the other hand, the addition of 12g of 261 additive formulations to 100cm3 of both base oils gave about 180% increase in kinematic viscosity at 400C, about 161% increase and 146% increase at 1000C for 150N and 500N respectively. About 60% in viscosity index was achieved by 100/12 blend of 261 additives in 150N. The results revealed that 261 additive formulations gave the highest increase in viscosity in all proportions increasing as the weight of the additive increases. Generally, all the four additive formulations used improved the viscosities of all the blends in all the proportions and at both temperatures. The blends can be classified as very high viscosity index being above 110. This means that they will undergo very little change in viscosity with temperature extremes and so can be considered to have stable viscosity.
Performance of polymeric viscosity improver as bio-lubricant additives
International Journal of Structural Integrity, 2019
Purpose The purpose of this paper is to study the influence of polymeric viscosity improver on the tribological performance of palm kernel methyl ester (PKME). Design/methodology/approach Tribological performances of the PKME added with the various concentration of ethylene-vinyl acetate copolymer (EVA) were evaluated using four-ball tribotester under extreme pressure condition. The morphologies of the worn surfaces were observed by using the optical microscope. Findings The addition of polymeric viscosity improver (EVA copolymer) has produced positive results towards the tribological properties of PKME. In total, 4 per cent of EVA copolymer is found as the optimum concentration by improving the friction reducing properties and anti-wear behaviour due to the formation of film thickness between two rubbing surfaces. Originality/value This work might contribute to the development of vegetable oils as a new source of environmental-friendly lubricant.
Alkyl methacrylate: a-Olefin copolymers as viscosity modifier additives in lubricants
Indian Journal of Chemical Technology, 1998
The potential for use of copolymers of iso-decyl methacrylate and 1-decene as viscosity modifying additives in lubricant compositions has been investigated. Three copolymers were prepared by free-radical initiated polymerization in toluene solvent, using AIBN as initiator and employing different levels of 1-decene (10-40 wt %) in the monomer mixture. The copolymers were characterized employing GPC, DSC/TGA, FTIR and NMR techniques for determining the thermal characteristics, average molecular weights (M w and M n ), and copolymer composition. The composition of the copolymers with respect to relative proportion of two monomers was determined by two independent methods described in literature based on FTIR and Proton NMR spectroscopy. The level of incorporation of 1-decene monomer in the copolymers as determined by these methods was only of the order of 7-13%, while literature reports suggest scope for incorporating upto 12-15% α-olefin under free-radical polymerization conditions. T...
Lubrication Science, 2000
Capillary viscometry has been employed to measure the viscosities of dilute polymer solutions over the temperature range-10 to 150°C. A Group 11 base oil containing 95% saturates was used as solvent for a n olefin copolymer (OCP), a hydrogenated diene copolymer (HDP), and a polymethacrylate (PMA). These three polymers represent the three major families of viscosity index WI) improvers used nowadays in lubricant formulations. Intrinsic viscosities and Huggins' constants were also determined. The thickening effects of the olefin copolymer and the hydrogenated diene copolymer were found to be higher at low temperatures (e.g., 40°C) than at higher ones (e.g., lOO"C), which phenomenon was attributed to stronger intermolecular hydrodynamic interactions at low temperatures, as indicated by the Huggins constants. For the hydrogenated diene copolymer and the polymethacrylate polymer, the viscosity increased abruptly when the temperature went below 10°C. This unusual observation was attributed to the crystallisation of a small fraction of the base oil. Based on the intrinsic viscosity data, it was concluded that at temperatures between 10 and 15OoC, the polymer coil dimension remains a constant for the olefin copolymer and the hydrogenated diene copolymer V I improvers, but increases with increasing temperature for the polymethacrylate V I improver.
IASET, 2020
Homopolymer of the prepared dodecylmethacrylate (DDMA) monomer was synthesized and a series of copolymers of it were prepared by varying the ratio between the ester and vinyl acetate (VA) by free radical polymerization using BZP as initiator. The synthesized polymers were characterized by spectral studies (FT-IR and NMR) and by gel permeation chromatography (GPC). Thermogravimetric analysis (TGA) was used to investigate the thermal behaviour of the polymers at high temperature. Performances of the polymers as additives, and their responses as PPD and viscosity modifiers in the base oil were evaluated by standard ASTM methods in terms of pour point and viscosity index. Wax crystallization behaviour of the additives was examined byphoto micrographic image. The copolymers showed better thermal stability, better flow improving efficiency and induced better viscosity modification than the homopolymer. It is also observed that the viscosity modification and the pour point performance of the additives depend on the concentration of the additives in the base fluid.