Viscosity oxide

Solvent Extraction - Solvent extraction uses solvents to dissolve and remove aromatics from lube oil feed stocks, improving viscosity, oxidation resistance, color, and gum formation. A number of different solvents are used, with the two most common being furfural and phenol. Typically, feed lube stocks are contacted with the solvent in a packed tower or rotating disc contactor. Each solvent has a different solvent-to-oil ratio and recycle ratio within the tower. 

Procedure 3 Addition of MPP to Polymerizing DMP. Procedure 1 was followed with only the DMP initially present. After two hours, the MPP was added, causing a prolonged decrease in solution viscosity oxidation was continued for three hours after MPP addition. The copolymer was obtained in 92% yield, with an intrinsic viscosity of 0.58 dl/g. 

The catalyst was prepared as in the previous examples, 9.9 grams of DPP was added, and oxidation continued at 60° C the volume was maintained about constant by periodic addition of benzene. After four hours, 7.3 grams of DMP was added, causing a sharp decrease in solution viscosity. Oxidation was continued for four hours after addition of the DMP. The copolymer, obtained in 8135 yield, had an intrinsic viscosity of 0.37 dl/g. 

The manner in which well completion is carried out has a marked effect on the success of sand coking in the bottomhole zone of production wells and, therefore, on the recovery of additional petroleum during the subsequent in situ combustion drive. As a side effect of the cementing treatment, high viscosity oxidation products form in the bottomhole zone of producing wells. Because well output may suffer as a result, these products must be removed during well completion. This task can be accomplished in one of the following ways ... 

KuanC.K. Inoki, T. S. (2000), Compliant substrates A comparative study of the relaxation mechanisms of strained films bonded to high and low viscosity oxides. Journal of Electronic Materials 29, 897-900. 

PAO blended with mineral oil are also used in many partial synthetic lubricant formulations. In this case, PAO is used as a blending stock to improve the volatility, high or low-temperature viscosity, oxidative stability, etc. of the mineral oil blend. 

The chemical composition of a fuel is very complex and generally a lot of additives are added in order to improve some properties such as viscosity, oxidative stability, cold flow behavior, cetane number, color or smell etc. The impact on fuel properties of a complex mixture of miscellaneous additives is not always very well known. It has been already shown that it can bring a positive or negative synergy. Therefore, DSC and P-DSC can be very useful in evaluating with high accuracy and in a reasonable time the impact of a package of additives on the oxidative stability or the cold flow behavior of an alternative or conventional diesel fuel. 

For gear trains Protection from seizing and rapid wear Extreme-pressure and anti-wear properties Resistance to oxidation Thermal stability High viscosity Low pour point Anti-foaming properties Anti-corrosion properties... 

Greases Mechanical and rheological behavior and its persistence Consistency and viscosity Mechanical stability Oxidation resistance... 

Oxidation first produces soluble oxygenated compounds of molecular weights between 500 and 3000 that increase the viscosity of oil then they polymerize, precipitate, and form deposits. Oxidation also causes formation of low molecular weight organic acids which are very corrosive to metals. 

When sulphur is melted viscosity changes occur as the temperature is raised. These changes are due to the formation of long-chain polymers (in very pure sulphur, chains containing about 100 (X)0 atoms may be formed). The polymeric nature of molten sulphur can be recognised if molten sulphur is poured in a thin stream into cold water, when a plastic rubbery mass known as plastic sulphur is obtained. This is only slightly soluble in carbon disulphide, but on standing it loses its plasticity and reverts to the soluble rhombic form. If certain substances, for example iodine or oxides of arsenic, are incorporated into the plastic sulphur, the rubbery character can be preserved. 

The next significant strength improvement followed the 1950 Du Pont (19) discovery of monoamine and quaternary ammonium modifiers, which, when added to the viscose, prolonged the life of the ziac cellulose xanthate gel, and enabled even higher stretch levels to be used. Modifiers have proliferated siace they were first patented and the Hst now iacludes many poly(alkylene oxide) derivatives (20), polyhydroxypolyamines (21—23), and dithiocarbamates (24). 

The process operated by ACl is outlined in Figure 7. Bales of cotton linter are opened, cooked in dilute caustic soda, and bleached with sodium hypochlorite. The resulting highly purified ceUulose is mixed with pre-precipitated basic copper sulfate in the dissolver, and 24—28% ammonium hydroxide cooled to below 20°C is added. The mixture is agitated until dissolution is complete. If necessary, air is introduced to aUow oxidative depolymerization and hence a lowering of the dope viscosity. 

The apparent viscosity, defined as du/dj) drops with increased rate of strain. Dilatant fluids foUow a constitutive relation similar to that for pseudoplastics except that the viscosities increase with increased rate of strain, ie, n > 1 in equation 22. Dilatancy is observed in highly concentrated suspensions of very small particles such as titanium oxide in a sucrose solution. Bingham fluids display a linear stress—strain curve similar to Newtonian fluids, but have a nonzero intercept termed the yield stress (eq. 23) ... 

Dowtherm LE is a mixture of diphenyl oxide and methylated biphenyl for use in Hquid-phase systems. The low crystal point and low viscosity obviate protection from freezing at temperatures down to —30°C. 

Ucon HTF-500. Union Carbide Corp. manufactures Ucon HTE-500, a polyalkylene glycol suitable for Hquid-phase heat transfer. The fluid exhibits good thermal stabHity in the recommended temperature range and is inhibited against oxidation. The products of decomposition are soluble and viscosity increases as decomposition proceeds. The vapor pressure of the fluid is negligible and it is not feasible to recover the used fluid by distiHation. Also, because the degradation products are soluble in the fluid, it is not possible to remove them by filtration any spent fluid usuaHy must be burned as fuel or discarded. The fluid is soluble in water. 

The polymerization is carried out at temperatures of 0—80°C in 1—5 h at a soHds concentration of 6—12%. The polymerization is terminated by neutralizing agents such as calcium hydroxide, calcium oxide, calcium carbonate, or lithium hydroxide. Inherent viscosities of 2-4 dL/g are obtained at 3,4 -dianiinodiphenyl ether contents of 35—50 mol %. Because of the introduction of nonlinearity into the PPT chain by the inclusion of 3,4 -dianiinodiphenyl ether kinks, the copolymer shows improved tractabiUty and may be wet or dry jet-wet spun from the polymerization solvent. The fibers are best coagulated in an aqueous equiUbrium bath containing less than 50 vol % of polymerization solvent and from 35 to 50% of calcium chloride or magnesium chloride. 

The fluid is formulated from a premium mineral od-base stock that is blended with the required additive to provide antiwear, mst and corrosion resistance, oxidation stabdity, and resistance to bacteria or fungus. The formulated base stock is then emulsified with ca 40% water by volume to the desired viscosity. Unlike od-in-water emulsions the viscosity of this type of fluid is dependent on both the water content, the viscosity of the od, and the type of emulsifier utilized. If the water content of the invert emulsion decreases as a result of evaporation, the viscosity decreases likewise, an increase in water content causes an increase in the apparent viscosity of the invert emulsion at water contents near 50% by volume the fluid may become a viscous gel. A hydrauHc system using a water-in-od emulsion should be kept above the freezing point of water if the water phase does not contain an antifreeze. Even if freezing does not occur at low temperatures, the emulsion may thicken, or break apart with subsequent dysfunction of the hydrauHc system. 

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