Additives antiwear improver

Lubricants, Fuels, and Petroleum. The adipate and azelate diesters of through alcohols, as weU as those of tridecyl alcohol, are used as synthetic lubricants, hydrauHc fluids, and brake fluids. Phosphate esters are utilized as industrial and aviation functional fluids and to a smaH extent as additives in other lubricants. A number of alcohols, particularly the Cg materials, are employed to produce zinc dialkyldithiophosphates as lubricant antiwear additives. A smaH amount is used to make viscosity index improvers for lubricating oils. 2-Ethylhexyl nitrate [24247-96-7] serves as a cetane improver for diesel fuels and hexanol is used as an additive to fuel oil or other fuels (57). Various enhanced oil recovery processes utilize formulations containing hexanol or heptanol to displace oil from underground reservoirs (58) the alcohols and derivatives are also used as defoamers in oil production. 

Practically all lubricating oils contain at least one additive some oils contain several. The amount of additive that is used varies from < 0.01 to 30% or more. Additives can have detrimental side effects, especially if the dosage is excessive or if interactions with other additives occur. Some additives are multifimctional, eg, certain VI improvers also function as pour-point depressants or dispersants. The additives most commonly used in hydrautic fluids include pour-point depressants, viscosity index improvers, defoamers, oxidation inhibitors, mst and corrosion inhibitors, and antiwear compounds. 

Lubrication Additive. Cerium fluoride, CeF, can be used as an additive to lubricant formulations to improve extreme pressure and antiwear behavior (43). The white soHd has a crystal stmcture that can be pictured as [CeF] layers separated by [F] atom sheets, a layer stmcture analogous to that of M0S2, a material that CeF resembles in properties. 

Ethers, esters, amides and imidazolidines containing an epithio group are said to be effective in enhancing the antiwear and extreme pressure peiformance of lubricants. Other uses of thiiranes are as follows fuel gas odorant (2-methylthiirane), improvement of antistatic and wetting properties of fibers and films [poly(ethyleneglycol) ethers of 2-hydroxymethyl thiirane], inhibition of alkene metathesis (2-methylthiirane), stabilizers for poly(thiirane) (halogen adducts of thiiranes), enhancement of respiration of tobacco leaves (thiirane), tobacco additives to reduce nicotine and to reduce phenol levels in smoke [2-(methoxymethyl)thiirane], stabilizers for trichloroethylene and 1,1,1-trichloroethane (2-methylthiirane, 2-hydroxymethylthiirane) and stabilizers for organic compounds (0,0-dialkyldithiophosphate esters of 2-mercaptomethylthiirane). The product of the reaction of aniline with thiirane is reported to be useful in the flotation of zinc sulfide. 

A) Surface protective additives (i) antiwear (AW)/extreme-pressure (or temperature) improver (EP), (ii) anticorrosion and rust inhibitor, (iii) detergent and dispersant, and (iv) friction modifier. Examples of protective additives are listed in Table 2.4. 

The antiwear mechanism of ZDDP in the presence of dispersants has been studied and it has been concluded that ZDDP forms an association complex with an amino group of a succinic type dispersant, and this complexation has been proved to be antagonistic to antiwear action (Gallopolous and Murphy, 1991 Rounds, 1986 Shiomi et al., 1986 Willermet et al. 1995b). The solubilization of ZDDP helps the adsorption of ZDDP on the surface, thus improving the antiwear performance of the additives (Forbes et al., 1970b). RMs would decrease the... 

Environmental demands and are as follows (a) improved fuel economy (reduced viscosities, reduced friction, special viscosity improvers), (b) reduced oil consumption (unconventional base oils, improved seal compatibility), (c) extended oil life (improved thermo-oxidative stability), (d) extended engine life (improved detergents and antiwear additives), (e) beneficial effects on emission/after treatment hardware (new additives), (f) technological and environmental sensitivity (no halogens, limited metal types/concentrations, new organic compounds), (g) recyclability (limitations the polycyclic aromatic hydrocarbons content and high chlorine levels (Havet et al., 2001 Waara et al., 2001). 

Total removal of phosphorus and sulfur would require the use of synthetic base-oils and new additive systems to provide antiwear antioxidation protection. Synthetic base-oil PAOs or esters have high values of viscosity improver VI and low temperature operating properties. The lubricants in diesel engines require a reduction in Ca carbonate-sulfonate concentrations. This may be less of a problem when ultra low sulfur diesel fuel is widely deployed, since a significant part of the requirement for these additives arises from the need to neutralize sulfur oxides from combustion processes. 

Certain performance limitations of vegetable oil basestocks are poor oxidative stability due to bis-allylic protons in the fatty acyl chain, deposit forming tendency, low-temperature solidification, and low hydrolytic stability. Oxidation results in increased acidity, corrosion, viscosity, and volatility of the lubricant. On the other hand, parameters like lubricity, antiwear protection, load carrying capacity, mst prevention, foaming, demulsibility, etc., are mostly additive dependent. Antioxidant additives (4) provide limited improvement of oxidative stability therefore, other approaches are required to improve the above characteristics. 

In addition to these methods, the selective deposition of tungsten metal has been explored as an antiwear coating on polysilicon microstructures. This coating is accomplished by heating polysilicon microstructures in a tungsten hexafluoride (WFs) gas at about 450°C [see Eqs. (7) and (8)]. In this manner, only exposed silicon is coated with W, and the reaction is self-limiting because the deposition of W obscures the underlying Si. W coated micromachines have been shown to exhibit lower wear and improved lifetime vs. uncoated microstructures. ... 

It was observed that these ILs could effectively reduce the friction and wear of sliding pairs compared to PEG films without the additives. Specifically, 1 -(3,5-Ditert-butyl-4-hydroxybenzyl)-3-methyl-imidazolium hexafluorophosphate (BHT-1) MIMPFg exhibited better antiwear properties at an optimum concentration of 1 wt.%. At this level, its antiwear property was significantly improved 100-fold with respect to the PEG base oil (Figs. 9.17d, 9.18). 

In the majority of cases, chemical additives are used to enhance the properties of base oils to improve such characteristics as oxidation resistance (ASTM D-2893, ASTM D-4742,ASTM D-5846) change in viscosity (ASTM D-445, IP 71) with temperature, low-temperature flow properties as derived from the pour point (ASTM D-97, ASTM D-5853, ASTM D-5949, ASTM D-5950, ASTM D-5985, IP 15) and fluidity measurements (ASTM D-6351), emulsifying ability (ASTM D-2711), extreme pressure (ASTM D-2782, ASTM D-2783, ASTM D-3233, IP 240), antiwear and frictional properties (ASTM D-5183, ASTM D-6425), and corrosion resistance (ASTM D-4636). The selection of components for lubricating oil formulation requires knowledge of the most suitable crude sources for the base oils, the type of refining required, the types of additive necessary, and the possible effects of the interactions of these components on the properties of the finished lubricating oil. 

The primary function of a lubricant is to create a film barrier between moving mechanical parts to reduce friction and wear. It also acts as a coolant, suppresses harmful deposit formation and controls corrosion/oxidation. Since the base oil alone would struggle to meet these challenging demands, performance-enhancing additives in tailor-made formulations are added to the lubricant formulation. These packages can include antioxidant, antiwear, corrosion inhibitor, viscosity modifier, detergent and dispersant components. Not only do these additives improve overall efficiency in the engine, but they also extend the lifetime of the lubricant. 

Antiwear. It has been shown that the addition of nitroxyl radicals of the 2,2,6,6-tetramethylpiperidine series to lubricating compositions consisting of mineral oil and alkyl adipates (20%) considerably improves their lubricating properties (75). When utilizing the suggested compositions, the maximum load can be increased by 1.2-1.6 times for the same and sometimes even smaller friction factor. At the same time, the weight wearout rate is reduced by 1.2-2.0 times for bronze samples and by 2-8 times for steel samples. 

As mentioned earlier, oil additives play a very important role (such as that of VI improvers for multigrade oils). Antiwear agents such as zinc dialkyldithiophosphate (ZDDP) are shown in Figure 7.4. These compounds feature zinc bound to the anion of dithiophosphoric acid. ZDDPs are soluble in mineral and synthetic oils. This antiwear additive is present in most commercial oils. Its quantity is limited in order to minimize interactions with catalytic converters. ZDDP also contains calcium and protects engine oil from oxidative breakdown and sludge formation. Concentrations in fluids are around 1-2% [4], These compounds are manufactured by treating phosphorus penta-sulflde with an alcohol. Zinc oxide is then reacted with the resulting dithiophosphate ... 

Antioxidants. These eliminate or slow down lubricant oxidation, increasing the time between oil changes through improved resistance to high temperatures. Dithiophosphates that are used as antiwear additives are also excellent antioxidants. Other chemical families such as substituted phenols and aromatic amines are also used. 

EINECS 246-614-4 Isooctyl phosphite ((C8H170)3P) Phosphorous acid, triisooctyl ester Triisooctyl phosphite Weston TIOP. Intermediate insecticides lubricant additive specialty solvents stabilizer for acrylics, nylon, unsaturated polyester, PVC improves antiwear and antifriction properties. Stabilizer tor hot-melt adhesives. PU, polyesters used in molding, extrusion, and film applications in PP, HOPE, LDPE, PVC, and polyesters also useful for PP fiber applications and calendering of PVC. Oil d = 0.891. Albright i Wilson Americas Inc. GE Specialities Stave. 

Bis(dithio)thiadiazoles (e.g., 524)113,515 and bis(thiosulfenamides)516 are employed as corrosion inhibitors in lubricants. The antiwear and extreme-pressure properties of lubricating greases are improved by the addition of (polymeric) 3,5-dimercapto-l,2,4-thiadiazole,517 2,4-dialky 1-1,2,4-thiadiazo-... 

Soybean fatty acids are conjugated thermally or catalytically to yield dimer and tri-mer polybasic acids (Erhan et al., 2005). Hydrolyzed dimer acids improve color and oxidative stability. These are used in polyamide resins, paints, plastics, and coatings, bodying/curing/flexibilizing agents, corrosion inhibitors, antiwear agents, lubricants, fuel, and lubricant additives (Antonucci et al., 1984 Bhowmick Basu, 1988 Kale et al., 1991 Savastano, 2001 Watanabe et al., 1996). The annual dimer acid production is about 18,000 MT (20,000 t). 

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