Sebacate esters

Sebacate [3137-00-6] Sebacate esters Sebaceous glands Sebacic... 

Dibutyl sebacate is a clear liquid. It is most often used for making plastics, many of which are used for packaging food. It is also used to enhance flavor in foods such as ice cream, candy, baked goods, and nonalcoholic drinks. Some consumer products, such as shaving creams, also contain dibutyl sebacate. Other names for dibutyl sebacate are decanedioic acid, dibutyl ester, sebacic acid, dibutyl ester, and dibutyl decanedioate. 

Dibenzyl ketone. See 1,3-Diphenyl-2-propanone Dibenzyl monosulfide. See Benzyl sulfide Dibenzyl phthalate. See Benzyl phthalate Di benzyl sebacate Synonyms Decanedioic acid, bis (phenylmethyl) ester Sebacic acid, dibenzyl ester... 

Hydrolysis yields castor oil fatty acids, which consist of 87-91% - ricinoleic acid an interesting intermediate for oleochemistry. It can be used as such or is purified by - distillation and - fractional distillation. It is the starting material for making ricinenic acid, esters, - sebacic acid, - undecylenic acid, nylon 11 (- polyamides) and - hydroxy stearic acid. 

HOOC-[CHa]8-COOH, CioH.aO. Colourless leaflets m.p. 134°C. Manufactured by heating castor oil with alkalis or by distillation of oleic acid. Forms an anhydride, m.p. 78 C. The esters of sebacic acid are used as plasticizers, especially for vinyl resins. 

Method B. Reflux a mixture of 101 g. of sebacic acid, 196 g. (248 ml.) of absolute ethjd alcohol and 20 ml. of concentrated sulphuric acid for 12 hours. Distil oft about half of the alcohol on a water bath dilute the residue with 500-750 ml. of water, remove the upper layer of crude ester, and extract the aqueous layer with ether. Wash the combined ethereal extract and crude ester with water, then with saturated sodium bicarbonate solution until effervescence ceases, and finally with water. Dry with anhydrous magnesium or sodium sulphate, remove the ether on a water bath, and distil the residue under reduced pressure. B.p. 155-157°/6 mm. Yield llOg. 

By increasing the molar proportion of the monocarboxylic acid, the yield of (II) is improved. Thus electrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIH) and sebacic acid (IX) ... 

Reflux 14 6 g. of the ester with a solution of 10 g. of sodium hydroxide in 125 ml. of 80 per cent, methanol for 2 hours on a water bath. Add 200 ml. of water to dissolve the solid which separates, extract with two 30 ml. portions of ether, and warm the aqueous solution on a water bath to remove dissolved ether. Acidify the ice cold aqueous solution to litmus by the addition of concentrated hydrochloric acid. Collect the precipitated acid by suction filtration, wash it with a little cold water, and dry at 100°. The yield of sebacic acid, m.p. 133°, is 11 - 5 g... 

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. 

Plasticizers. Monomeric (mol wt 250—450) plasticizers (qv) are predominantiy phthalate, adipate, sebacate, phosphate, or trimeUitate esters. Organic phthalate esters like dioctyl phthalate (DOP) are by far the most common plasticizers in flexible PVC. Phthalates are good general-purpose plasticizers which impart good physical and low temperature properties but lack permanence in hot or extractive service conditions and are therefore sometimes called migratory plasticizers. Polymeric plasticizers (mol wt up to 5000 or more) offer an improvement in nonmigratory permanence at a sacrifice in cost, low temperature properties, and processibiHty examples are ethylene vinyl acetate or nitrile polymers. 

Low Temperature Performance. The abihty of plasticized PVC to remain flexible at low temperatures is of great importance in certain apphcations, eg, external tarpaulins or underground cables. Eor this property the choice of the acid constituent of the plasticizer ester is also important. The linear aUphatic adipic, sebacic, and azeleic acids give excellent low temperature flexibiUty compared to the corresponding phthalates and trimeUitates (Pig. 3). 

Among the preformed polymers cured by minor additions of aHyl ester monomers and catalysts followed by heat or irradiation are PVC cured by diallyl fumarate (82), PVC cured by diallyl sebacate (83), fluoropolymers cured by triaHyl trimeUitate (84), and ABS copolymers cured by triaUyl trimeUitate (85). 

Seb cic Acid. Sebacic acid [111-20-6] C QH gO, is an important intermediate in the manufacture of polyamide resins (see Polyamides). It has an estimated demand worldwide of approximately 20,000 t/yr. The alkaline hydrolysis of castor oil (qv), which historically has shown some wide fluctuations in price, is the conventional method of preparation. Because of these price fluctuations, there have been years of considerable interest in an electrochemical route to sebacic acid based on adipic acid [124-04-9] (qv) as the starting material. The electrochemical step involves the Kolbn-type or Brown-Walker reaction where anodic coupling of the monomethyl ester of adipic acid forms dimethyl sebacate [106-79-6]. The three steps in the reaction sequence from adipic acid to sebacic acid are as follows ... 

Decamethylene glycol has been prepared by the reduction of dimethyl sebacate and diethyl sebacate with sodium and ethyl alcohol by the reduction of sebacamide with sodium and amyl alcohol and by the reduction of dimethyl sebacate with sodium and liquid ammonia in absolute alcohol. The reduction of esters with sodium and alcohol has also been applied to the preparation of many other glycols. ... 

More recently methods have been developed for the catalytic hydrogenatio of sebacic esters to decamethylene glycol. ... 

Sebacic acid monometbyl ester [818-88-2] M 216.3, m 42-43°, b 169-171 /4mm. Recrystd from Me3CO+pel ether or pel ether at low temperature and distd in a vacuum. 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

---