Esters diesters

Chemical Properties. Trimethylpentanediol, with a primary and a secondary hydroxyl group, enters into reactions characteristic of other glycols. It reacts readily with various carboxyUc acids and diacids to form esters, diesters, and polyesters (40). Some organometaUic catalysts have proven satisfactory for these reactions, the most versatile being dibutyltin oxide. Several weak bases such as triethanolamine, potassium acetate, lithium acetate, and borax are effective as stabilizers for the glycol during synthesis (41). 

Dibasic Acid Esters. Dibasic acid esters (diesters) are prepared by the reaction of a dibasic acid with an alcohol that contains one reactive hydroxyl group (see Esters, organic). The backbone of the stmcture is formed by the acid. The alcohol radicals are joined to the ends of the acid. The physical properties of the final product can be varied by using different alcohols or acids. Compounds that are typically used are adipic, azelaic, and sebacic acids and 2-ethyIhexyl, 3,5,5-trimethyIhexyl, isodecyl, and tridecyl alcohols. 

Esters of Q to Cn monocarboxylic acids [1288-1292], acid-methyl esters [1282], and polycarboxylic acid esters [1287], as well as oleophilic monomeric and oligomeric diesters [1293], have been proposed as basic materials for inverted emulsion muds. Natural oils are triglyceride ester oils [1844] and are similar to synthetic esters. Diesters also have been proposed [1293-1297]. 

Their hydrophobicity and their plasticity were appreciated and used for a long time in a wide range of activities. To our knowledge, the first wax to have been exploited is beeswax. Beeswax is produced by various species of bees in the world, and it has a melting point between 62°C and 64°C. It mainly contains homologous series of even-numbered fatty acids (C22 C34, C2 being the predominat compound), odd-numbered ra-alkanes (C2i C33, C27 being the major compound) and even-numbered palmitic esters from C40 to C52 (Tulloch and Hoffman, 1972 Kolattukudy, 1976). Hydroxy esters, diesters and hydroxy diesters also form part of beeswax to a lesser extent. 

Esters for lubricant applications are divided into five groups monocarboxylic acid esters (monoesters), dicarboxylic acid esters (diesters), glycerol esters, polyol esters, and complex esters. 

Organic esters Diesters Polyol esters Turbine oils, mixing components with PAO Turbine oils, gear, compressor, hydraulic oils... 

Lanolin is a very complex mixture of esters, diesters, and hydroxy esters of high molecular weight lanolin alcohols and lanolin acids. Being a complex natural product, the method of refinement for lanolin is very important, as this determines the composition, properties, and quality of the purified lanolin.1-7 8 It is necessary, therefore, to bear in mind that not all refined lanolins are the same. The incredibly complex composition of lanolin also means that it cannot be synthesized.1... 

The purity of lanolin and standard tests have been described in the European Pharmacopoeia (EP), in The United States Pharmacopoeia (USP), and according to other national standards.13,14 Lanolin is a semisolid with a melting point of approximately 40 6°C and has a molecular weight in the range of 790 to 880 Da. Lanolin is a complex and variable mixture of mainly esters, diesters, hydroxy esters (87.0-93.5%, w/w),7 8 15 lanolin alcohols (6.0-12.5%, w/w), lanolin acids (<0.5%, w/w), and lanolin hydrocarbons (<1.0%, w/w). The latter are also called paraffins and petrolatum by the EP and USP, respectively.13,14 16-18 Approximately 40% of the esters are a-hydroxy esters. Due to the extremely complex nature of lanolin, the true number of different esters present is unknown. Barnett calculated the theoretical number of monoester combinations from random combinations of 69 aliphatic lanolin alcohols, 6 sterols, and 138 saturated lanolin acids to total 10,350.8 This is most probably an underestimate of the total number of esters, as dibasic acids and dihydric alcohols also occur naturally in lanolin.19 Further combinations of cyclic mono- and di-esters may be formed by dehydration and from inter- and intra-esterification due to heating during the manufacturing process.7 8... 

Typical lubricants are fatty alcohols C]2-C22, fatty acids C14-Ci8, their esters with fatty alcohols, glycerol or pentaerythritol, amides (2) or diamides (3) and metallic soaps (see Heat stabilizers ), acids C28-C31 from montan wax and their esters, diesters of phthalic acid (4b), paraffin wax C2o-C70, PE waxes Ci25-C70o or their oxidized (polar) grades containing hydroxyl and carbonyl groups. 

Chemically wool wax is a complex mixture of esters, diesters and hydroxy esters of high molecular weight lanolin alcohol and acids. The lanolin alcohol consists of three main types - aliphatic alcohols, sterols (such as cholesterol) and trimethyl sterols (such as lanosterols). The lanolin acid consists of four main types - normal, iso, anteiso and hydroxy acids. On exposure to the environment wool readily undergoes auto-oxidation. The reaction product (oxidised wool wax) be-... 

The largest volume of grease in use is made from petroleum products produced from naphthenic, paraffinic, blended, hydrocracked, hydrogenated, and solvent-refined stocks. In addition to petroleum oils, other lubricating fluids, such as esters, diesters, silicones, polyethers, and synthetic hydrocarbons, are also used. Of the synthetic fluids used in grease manufacture, the most common type is poly(alpha)olefin (PAO). 

Polyols, polyoleates, C36 dimer esters, diesters WGK 0 Phthalates and trimellitates WGK 0-2... 

Figure 10 is a chromatogram of honeycomb extract. The honeycomb was simply dissolved in toluene, filtered, and injected. Honeycomb contains fatty acids, paraffins, esters, diesters, and other components. It is doubtful that all the peaks visible in Figure 10, and especially those eluting above 300 atmospheres, could be eluted by GC. 

Carbon hexachloride. See Hexachloroethane Carbonic acid, allyl ester, diester with diethylene glycol. See Diethylene glycol bis (allyl carbonate),... 

Species Squalene Sterols Sterol esters Wax esters Diesters Glyceryl ethers Triacyl- glycerols Free fatty acids Free fatty alcohols... 

Depending on the carbon monoxide pressure and on the nature of the reaction mixture (acidic or basic) the oxidative carbonylation of aUcenes can be directed toward unsaturated esters, diesters or ether-esters (Table XV). 

Kirby Younas M. The reactivity of phosphate esters. Diester hydrolysis. J Chem Soc B. 1970 510. 

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