Esters as lubricants

In 1929, polymerized olefins were the first synthetic oils to be produced commercially in an effort to improve on the properties of petroleum oils. Interest in esters as lubricants appears to date back to 1937 in Germany, and their production and use expanded rapidly during and following World War II to meet the needs of the military and the newly developed jet engines (2). 

The pendant hydroxy groups of ethylene oxide-propylene oxide copolymers of dihydroxy and trihydroxy alcohols may be sulfurized to obtain a sulfurized alcohol additive. This is effective as a lubricant in combination with oils and fats [387,533]. The sulfurized alcohols may be obtained by the reaction of sulfur with an unsaturated alcohol. Furthermore, fatty alcohols and their mixtures with carboxylic acid esters as lubricant components [1286] have been proposed. 

H. Muller, C. P. Herold, and S. von Tapavicza. Use of selected fatty alcohols and their mixtures with carboxylic acid esters as lubricant... 

Dimer acids. Dimer acids are produced by heating monoene or diene fatty acids (e.g., tall oil acids, a byproduct of wood pulping) with a cationic clay catalyst (92). Typical conditions are 4% montmoriUonite at 230°C for 4—8 hours. After distillation, the product is a complex mixture of acyclic, cyclic, and bicyclic dimers along with some trimer. Dimer acids are dibasic and react with diamines and tria-mines to give polyamides. Imidazole derivatives are used as corrosion inhibitors and esters as lubricants. 

Shibata, D., Shimada, Y., Yonezawa, Y., Sunada, H., Otomo, N., Kasahara, K. Application and evaluation of sucrose fatty acid esters as lubricants in the production of pharmaceuticals. J. Pharma. Sci. Technol. 2002 62(4) 133-145. 

The application of sorbitan esters and/or ethoxylated sorbitan esters as lubricant components has been discussed in the literature. It has been shown, among others, that sorbitan monoesters, monolaurate and monooleate, efficiently improve the lubricating properties of paraffin oil. When sorbitan trioleinate was used as an additive, no improvement in the lubricating properties of paraffin oil was observed [111],... 

Esters as lubricating oil pour point depressants United States 3,536,461 1970 Sinclair Research... 

Kulkami, M.G., Dalai, A.K. and Bakhshi, N.N. 2007. Transesterification of canola oil in mixed methanol/ethanol system and use of esters as lubricity additive. Biores. Technol. 98 2027-2033. 

Lang, X., Dalai, A.K., Reaney, M.J. and Hertz, P.B. 2001b. Biodiesel esters as lubricity additives Effects of process variables and evaluation of low-temperature properties. Fuels Int. 1-3 207-227. 

Mansot, J.L., Martin, J.M. and Candau, S.J. Amphiphilic complex ester as lubricant additive. Part one stmeture of paraffinic solutions. Colloids and Surfaces, 7,1983, 301. 

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. 

Olefin oligomers are used widely as automotive lubricants. They often are combiaed with some of the organic esters as base fluids ia engine oils, gear oils, and hydrauHc fluids, eg, for equipment intended for operation ia extremely cold climates, and for premium oils, eg, for the service station market ia temperate climates. 

Halogenated hydrocarbons that are inexpensive sometimes are used alone or in blends with phosphate esters as fire-resistant hydrauHc fluids. Other halogenated fluids are used for oxygen-compressor lubricants, lubricants for vacuum pumps that are in contact with corrosive materials, solvent-resistant lubricants, and other lubricant appHcations where highly corrosive or reactive materials are being handled. 

To overcome these difficulties, drilling fluids are treated with a variety of mud lubricants available from various suppHers. They are mostly general-purpose, low toxicity, nonfluorescent types that are blends of several anionic or nonionic surfactants and products such as glycols and glycerols, fatty acid esters, synthetic hydrocarbons, and vegetable oil derivatives. Extreme pressure lubricants containing sulfurized or sulfonated derivatives of natural fatty acid products or petroleum-base hydrocarbons can be quite toxic to marine life and are rarely used for environmental reasons. Diesel and mineral oils were once used as lubricants at levels of 3 to 10 vol % but this practice has been curtailed significantly for environmental reasons. 

The phosphonate esters, HP(=0(OR)2, of alkylated phenols are used extensively as lubricating-oil additives to control bearing corrosion and oxidation, and to impart antimst properties as stabilizers, as antioxidants (qv) and flame retardants in plastics, as specialty solvents, and as intermediates (see Corrosion AND corrosion control Heat stabilizers). 

Several ester-based oils are suitable as lubricants [532,690], as are branched chain carboxylic esters [1588]. Tall oils can be transesterified with glycols [1536] or condensed with monoethanolamine [51]. 

Saturated hydrocarbons (waxes), fatty acids, metal soaps, fatty acid amides and esters (primarily Cig-Cis) act as internal lubricants, fluoro elastomers as external lubricants. Many other polymer additives, e.g. antistatic agents, antifogs, antioxidants, UV stabilisers, etc., act as lubricants in the barrel of the extruder once they are in the liquid form. 

Raffinate-II typically consists of40 % 1-butene, 40 % 2-butene and 20 % butane isomers. [RhH(CO)(TPPTS)3] does not catalyze the hydroformylation of internal olefins, neither their isomerization to terminal alkenes. It follows, that in addition to the 20 % butane in the feed, the 2-butene content will not react either. Following separation of the aqueous catalyts phase and the organic phase of aldehydes, the latter is freed from dissolved 2-butene and butane with a counter flow of synthesis gas. The crude aldehyde mixture is fractionated to yield n-valeraldehyde (95 %) and isovaleraldehyde (5 %) which are then oxidized to valeric add. Esters of n-valeric acid are used as lubricants. Unreacted butenes (mostly 2-butene) are hydroformylated and hydrogenated in a high pressure cobalt-catalyzed process to a mixture of isomeric amyl alcohols, while the remaining unreactive components (mostly butane) are used for power generation. Production of valeraldehydes was 12.000 t in 1995 [8] and was expected to increase later. 

By this approach, esters such as di(2-ethylhexyl) adipate and an oligomeric ester of neopentyl glycol have been synthesized recently by alcoholysis of dimethyl adipate ester and the corresponding alcohols, with alkaline earth metal compounds as the catalysts (171) (Scheme 30). These types of esters find application as lubricants, and it is suggested that they can be used as environment-friendly substitutes for petroleum-derived lubricants. The reactions were carried out with isooctane as a... 

The advantages of this new process are the high n/i ratio and the low formation of heavy ends (1.5%) and alcohols (1%) without any formation of formates. In the original cobalt-based high-pressure process the n/i ratio was 67/33, with substantial formation of heavy ends (6.7%), alcohols (6.6%) and pentylformates (4.2%).350 The n-valeraldehyde product is oxidized with molecular oxygen to n-valeric acid, the trimethylolpropane, pentaerythritol, or dipentaerythritol esters of which are used as lubricants.350... 

Esters - [AMYL ALCOHOLS] (Vol 2) - [FATS AND FATTY OILS] (Vol 10) -from castor oil [CASTOR OIL] (Vol 5) -m chamomile oil [OILS, ESSENTIAL] (Vol 17) -as congener m spirits [BEVERAGE SPIRITS DISTILLED] (Vol 4) -as lubricants [LUBRICATION AND LUBRICANTS] (Vol 15) -sodium borohydnde reduction [HYDPJDES] (Vol 13)... 

Organic esters are used as solvents, plasticizers, in resins, plastics, and coatings, as lubricants, in perfumes, flavors, cosmetics, and soap, as surface-active agents, as mcdicinals. and as herbicides and pesticides. 

Murray [91] has described a gas chromatographic method for the determination in water of triarylphosphate esters (lmol S-140, tricresyl phosphate, cresol phosphate). These substances are used commercially as lubricant oil and plastic additives, hydraulic fluids and plasticisers. The method involves extraction from the samples, hydrolysis and measurement of the individual phenols by gas chromatography as the trimethylsilyl derivatives. The lower detection limit was about 3ppm. 

As emulsifiers Na and K salts of glycine, lysine and taurine (total < 0.8 %) as well as N-(2-amino-ethyl)-3-amino propane sulfonate and/or N-(2-amino-ethyl)-2-amino ethane sulfonate (total < 5.0%) are recommended. These emulsifiers are incorporated into the macromolecules and therefore can be found only in very small amounts in the finished product. Esters of montanic acid with ethanediol and/or 1,3-butanediol and mixtures of these esters with unesterified montanic acid as well as Ca salts (total <1.5 %) can be used as lubricants and mold release agents. 

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