Acid Palmitic

During the distillation it is advisable to hold the Bunsen and to heat the rctoit with the bare flame. Under a pressure of 36 min. the acid distils at 245. The pale yellow oil which collects in the receiver is poured out into a basin whilst hot and allowed to cool. The cake of acid is spread on a poious ]jlate and left to drain, when it becomes nearly colourless, and, after one or two crystallisations from small quantities of spirit, is pure. 

The aqueous portion from which the cake of acid is removed contains free hydrochloric acid, potassium chloride, and glyceiol. The latter may be obtained by evapoiating to dryness on the water-bath, and extracting the residue with small quantities of alcohol, which dissolves out the glycerol. On evaporating the alcohol impure glycerol is left. 

Properties.—Crystallises in tufts of colourless needles m. p. 62 soluble in alcohol and ether insoluble in -wmter. 

Reactions.—Dissolve a small quantity of the acid in caustic soda solution and add salt. Sodium palmitate separates as a curdy white piecipitate. 

Boil another portion of the acid with caustic soda and let it cool. Pour off the liquid from the crust of sodium palmitate, which forms on the surface, wash once or twice with 

This is a white crystalline solid with a melting point of 63 °C. It occurs in palm oil, beeswax and other animal and vegetable fats and oils. It is insoluble in water but soluble in alcohol and ether. 

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Dapalm The aluminium soap of naphthenic and palmitic acids used to gel gasoline. The thickened gasoline has been used for military flame throwers and incendiary bombs. See metallic soaps. 

This observation that the length of the hydrocarbon chain could be varied from 16 to 26 carbon atoms without affecting the limiting area could only mean that at this point the molecules were oriented vertically. From the molecular weight and density of palmitic acid, one computes a molecular volume of 495 A a molecule occupying only 21 A on the surface could then be about 4.5 A on the side but must be about 23 A long. In this way one begins to obtain information about the shape and orientation as well as the size of molecules. 

Laurie acid Myristic acid Palmitic acid Stearic acid Arachidic acid... 

Palmitic acid [57-10-31] Palmitine P almi to di stearin Palmitoleamide... 

The most volatile product (myristic acid) is a small fraction of the feed, whereas the least volatile product (oleic—stearic acids) is most of the feed, and the palmitic—oleic acid split has a good relative volatility. The palmitic—oleic acid split therefore is selected by heuristic (4) for the third column. This would also be the separation suggested by heuristic (5). After splitting myristic and palmitic acid, the final distillation sequence is pictured in Figure 1. Detailed simulations of the separation flow sheet confirm that the capital cost of this design is about 7% less than the straightforward direct sequence. 

The first step in CTO distillation is depitching. A relatively small distillation column is used as a pitch stripper. The vapor from the pitch stripper is fed directiy into the rosin column, where rosin and fatty acids are separated. Rosin is taken from the bottoms of the column and fatty acids as a sidestream near the top. Palmitic acid and light neutrals are removed in the rosin column as heads. The operation is designed to minimize holdup and product decomposition. Care is taken to prevent carryover of some of the heavier neutrals, such as the sterols, from the depitcher to the rosin column (24). 

Distillation By-Products. Of the CTO distiHation by-products, ie, pitch, heads, and DistiHed TaH Oil (DTO), only the last, a unique mixture of rosin and fatty acids, has significant commercial value. Pitch and heads are used as fuel the former has a fuel value of 41,800 kj/kg. TaH oil heads have outstanding solvent properties, but also have a bad odor, which is hard to remove. They contain a relatively high fraction of palmitic acid which can be recovered by crystallization. 

Bayberry Wax. Bayberry wax [8038-77-5] is removed from the surface of the berry of the bayberry (myrtle) shmb by boiling the berries in water and skimming the wax from the surface of the water. The wax is green and made up primarily of lauric, myristic, and palmitic acid esters. The wax has a melting point of 45°C, an acid number of 15, a saponification number of 220, and an iodine number of 6. The wax has an aromatic odor and is used primarily in the manufacture of candles and other products where the distinctive odor is desirable. 

A series of sorbitol-based nonionic surfactants are used ia foods as water-ia-oil emulsifiers and defoamers. They are produced by reaction of fatty acids with sorbitol. During reaction, cycHc dehydration as well as esterification (primary hydroxyl group) occurs so that the hydrophilic portion is not only sorbitol but also its mono- and dianhydride. The product known as sorbitan monostearate [1338-41 -6] for example, is a mixture of partial stearic and palmitic acid esters (sorbitan monopalmitate [26266-57-9]) of sorbitol, 1,5-anhydro-D-glucitol [154-58-8] 1,4-sorbitan [27299-12-3] and isosorbide [652-67-5]. Sorbitan esters, such as the foregoing and also sorbitan monolaurate [1338-39-2] and sorbitan monooleate [1338-43-8], can be further modified by reaction with ethylene oxide to produce ethoxylated sorbitan esters, also nonionic detergents FDA approved for food use. 

Equations foi the heat capacities in J/g for sohd and hquid states of palmitic acid are, respectively (2)... 

Alkali fusion of oleic acid at about 350°C ia the Varrentrapp reaction causes double-bond isomerization to a conjugated system with the carboxylate group followed by oxidative cleavage to form palmitic acid (75). In contrast, alkaU fusion of riciaoleic acid is the commercial route to sebacic acid [111 -20-6] ... 

Panning and pressing is no longer used because of high labor costs, but it gave us the terms single-pressed, double-pressed, and triple-pressed stearic acid. These terms are widely used to denote the quaUty of stearic acid. These commercial "stearic" acids are actually mixtures of palmitic acid and stearic acid. 

Pressure, kPa Caproic acid Caprylic acid Cap tic acid Laurie acid Myristic acid Palmitic acid Stearic acid Oleic acid Linoleic acid... 

Z,Z,Z,)-9,12,15-octadecatrienoic acid). Fish oils contain esters of eicosanoic and docosanoic acids with four to six double bonds separated by single methylene groups, eg, (i7//-Z)-4,7,10,13,16,19-docosahexaenoic acid [6217-54-5] in menhaden oil (4). The fatty acid with conjugated double bonds in tung oil is a-eleostearic acid [506-23-0] ((F,Z,F)-9,ll,13-octadecatrienoic acid) the predominant fatty acid in oiticica oil is licanic acid [17699-20-6] (4-oxo-(F,Z,F)-9,ll,13-octadecatrienoic acid). In all oils, other fatty acids including palmitic acid [57-10-3] (hexadecanoic acid), stearic acid [57-11-4] (octadecanoic acid), and oleic acid [112-80-1] ((Z)-9-octadecenoic acid) also are present. 

Hexadecanoic acid (palmitic acid) [57-10-3] M 256.4, m 62-63°, b 215°/15mm, pK 6.46 (50% aq EtOH), 5.0 (H2O). Purified by slow (overnight) recrystn from hexane. Some samples were also crystd from acetone, EtOH or EtOAc. Crystals were stood in air to lose solvent, or were pumped dry of solvent on a vaeuum line. [Iwahashi et al. J Chem Soc, Faraday Trans 1 81 973 1985, pK White J Am Chem Soc 72 1858 1950]. 

Palmitic acid anhydride (hexadecanoic anhydride) [623-65-4] M 494.9, m 63-64 , 64 , d 0.838, n 1.436. It is moisture sensitive and hydrolyses in water. Purified by refluxing with acetic anhydride for Ihr, evaporating and freeing the residue of acetic acid and anhydride by drying the residue at high vac and crystallising from pet ether at low temperature. 

A purified fatty acid is recommended for the preparation of a pure a-sulfo acid. Purified palmitic acid (m.p. 60.8-61.4°, neutralization equivalent 256.2) is prepared by twice recrystallizing a good commercial grade of palmitic acid from acetone at 0°, using a solvent ratio of 10 ml. to 1 g. However, the reaction may be applied to commercial saturated higher fatty acids, if the iodine number is sufficiently low. The checkers obtained similar results with recrystaUized Neo-Fat 1-56 (Armour and Company, Chicago, 111.) or Eastman white label palmitic acid. 

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