Saponification numbers

The iodine value (IV) indicates the degree of unsaturation of a fat or oil. It is defined as the number of grams of iodine absorbed by 100 grams of fat. The higher value for canola oil is due in part to the replacement of erucic acid with unsaturated Ci8 acids, mainly oleic acid, together with a slight increase in the contribution of linoleic and linolenic acids (Table 4.13). The iodine value can also be calculated from fatty acid composition using specific factors for each 

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Saponification (number) NFT60-110 ISO 6293 ASTM D 94 Reaction with potash and analysis of excess... 

Animal fats and vegetable oils are triacylglycerols, or triesters, formed from the reaction of glycerol (1,2, 3-propanetriol) with three long-chain fatty acids. One of the methods used to characterize a fat or an oil is a determination of its saponification number. When treated with boiling aqueous KOH, an ester is saponified into the parent alcohol and fatty acids (as carboxylate ions). The saponification number is the number of milligrams of KOH required to saponify 1.000 g of the fat or oil. In a typical analysis, a 2.085-g sample of butter is added to 25.00 ml of 0.5131 M KOH. After saponification is complete, the excess KOH is back titrated with 10.26 ml of0.5000 M HCl. What is the saponification number for this sample of butter ... 

Rosin is compatible with many materials because of its polar functionaUty, cycloaUphatic stmcture, and its low molecular weight. It has an acid number of ca 165 and a saponification number of ca 170. It is soluble in aUphatic, aromatic, and chlorinated hydrocarbons, as well as esters and ethers. Because of its solubiUty and compatibiUty characteristics, it is useful for modifying the properties of many polymers. 

Gum Elemi. This resin, tapped from trees in the Philippines, contains a higher concentration of essential oils than other natural resins. It is a soft, sticky, plastic material that can be deformed manually. Gum elemi [9000-75-3] contains 20—25% essential oils, 13—19% acids, 30—35% resenes (condensed decarboxylated resin acids), and 20—25% terpenic resinols (condensed terpene alcohols). It has an acid number of 20—35 and a saponification number of 20—40. Gum elemi is a film-forming plasticizing resin used in lacquers. 

Sandarac. This resin, which originates in Morocco, is a polar, acidic, hard resin with a softening point of 100—130°C, an acid number of 117—155, and a saponification number of 145—157. Sandarac [9000-57-1] is soluble in alcohols and insoluble in aryl and aUphatic hydrocarbons. It is used in varnishes and lacquers for coating paper, wood, and metal. 

Mastic. Most commercial mastic [61789-92-2] is collected on the Greek island of Chios, near the Turkish coast. It is a soft resin with a softening point of 55°C. It has an acid number of 50—70 and a saponification number of 62—90. It is soluble in alcohols and aryl hydrocarbons. Mastic is used in wood coatings, lacquers, adhesives, and printing inks. 

Composition. Shellac is primarily a mixture of aUphatic polyhydroxy acids in the form of lactones and esters. It has an acid number of ca 70, a saponification number of ca 230, a hydroxyl number of ca 260, and an iodine number of ca 15. Its average molecular weight is ca 1000. Shellac is a complex mixture, but some of its constituents have been identified. Aleuritic acid, an optically inactive 9,10,16-trihydroxypalmitic acid, has been isolated by saponification. Related carboxyflc acids such as 16-hydroxy- and 9,10-dihydroxypalmitic acids, also have been identified after saponification. These acids may not be primary products of hydrolysis, but may have been produced by the treatment. Studies show that shellac contains carboxyflc acids with long methylene chains, unsaturated esters, probably an aliphatic aldehyde, a saturated aliphatic ester, a primary alcohol, and isolated or unconjugated double bonds. 

The major components of camauba wax are aHphatic and aromatic esters of long-chain alcohols and acids, with smaller amounts of free fatty acids and alcohols, and resins. Camauba wax is very hard, with a penetration of 2 dmm at 25°C and only 3 dmm at 43.3°C. Camauba also has one of the higher melting points for the natural waxes at 84°C, with a viscosity of 3960 rare]/s at 98.9°C, an acid number of 8, and a saponification number of 80. 

The major components of candelilla wax are hydrocarbons, esters of long-chain alcohols and acids, long-chain alcohols, sterols, and neutral resins, and long-chain acids. Typically, candelilla wax has a melting point of 70°C, a penetration of 3 drum at 25°C, an acid number of 14, and a saponification number of 55. Principal markets for candelilla include cosmetics, foods, and pharmaceuticals. The FDA affirmed Candelilla as GRAS for certain food apphcations in 21 CFR 184.1976. 

Japan Wax. Japan wax [8001-39-6] is a fat and is derived from the berries of a small tree native to Japan and China cultivated for its wax. Japan wax is composed of triglycerides, primarily tripalmitin. Japan wax typically has a melting point of 53°C, an acid number of 18, and a saponification number of 217. Principal markets include the formulation of candles, poHshes, lubricants, and as an additive to thermoplastic resins. The product has some food-related apphcations. 

Castor Wax. Castor wax [8001-78-3] is catalyticahy hydrogenated castor bean oil. The wax has a melting point of 86°C, acid number of 2, saponification number of 179, and an iodine number of 4. Castor wax is used primarily in the formulation of cosmetics. Derivatives of castor wax are used as surfactants and plastics additives. 

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. 

The composition of montan wax depends on the material from which it is extracted, but all contain varying amounts of wax, resin, and asphalt. Black montan wax may be further processed to remove the resins and asphalt, and is known as refined montan wax. White montan wax has been reacted with alcohols to form esters. The wax component of montan is a mixture of long-chain (C24—C q) esters (62—68 wt %), long-chain acids (22—26 wt %), and long-chain alcohols, ketones, and hydrocarbons (7—15 wt %). Cmde montan wax from Germany typically has a melting point of 80°C, an acid number of 32, and a saponification number of 92. 

Chemically Modified Waxes. Hydrocarbon waxes of the microcrystaHine, polyethylene, and polymethylene classes are chemically modified to meet specific market needs. In the vast majority of cases, the first step is air oxidation of the wax with or without catalysts (11). The product has an acid number usuaHy no higher than 30 and a saponification number usuaHy no lower than 25. An alternative step is the reaction of the wax with a polycarboxyHc acid, eg, maleic, at high temperature (12). Through its carboxyl groups, the oxidised wax can be further modified in such reactions as saponification or esterification. Oxidised wax is easily emulsified in water through the use of surfactants or simple soaps, and is widely used in many coating and poHsh appHcations. 

The hydrophile—hpophile balance (HLB) is an empirical system based on the fact that oil—water (o/w) emulsions are best stabilized by water-soluble-emulsifiers and water—oil (w/o) emulsions are best stabilized by oil-soluble ones (3). The HLB scale mns from 0—20 and is based on the ratio of the saponification number of ester, A, to the acid number of recovered acid, where HLB = 20 1-Sj A). The dispersibiUty of an emulsifier in water is related to HLB value. 

If nutmeg butter, a commercial fat obtained by the hot pressing of ground nutmegs, is available, the above extraction may be omitted. The only operation necessary is a double crystallization of the crude material from boiling 95 per cent alcohol. Since nutmeg butter is frequently adulterated with foreign fats, the purity of the product should be checked by the saponification number (232 for pure trimyristin). 

Commercial data sheets generally provide the following properties for the resins softening point colour degree of unsaturation acid number saponification number density ash content odour. 

Saponification number (DIN 51 559). The saponification number is indicative of the presence of ester groups in a resin. The saponification number is defined as the consumption of potassium hydroxide in milligrams by one gram of resin under standardized conditions. 

The specific gravity ol the crude oil at C. = 0 S705 rotation a = -(- 15-1 relractiTe index at23 C. = lAtHl. The saponification number is 2 4, equal to (l 84 per cent, of ester as bornyl or gemoyl acetate. 

Allyl cyanide, OHj. CH CEI. ON. The analytical values of a frac-tiori amounting tc a Few grama, which passed over botw ui 190° and 123°, and which also coolained sulphur (d, O fi- iTO saponification number 47 7) pointed to the prolialile presi.-nce oF allyl cyanide. 

Verseifunga-fass, n. saponifying tun. -mittel, n. saponifying agent, -vorgang, m. saponification process, -zahl, /. saponification number or value. 

Discussion. For oils and fats, which are esters of long-chain fatty acids, the saponification value (or number) is defined as the number of milligrams of potassium hydroxide which will neutralise the free fatty acids obtained from the hydrolysis of 1 g of the oil or fat. This means that the saponification number is inversely proportional to the relative molecular masses of the fatty acids obtained from the esters. A typical reaction from the hydrolysis of a glyceride is ... 

Saponification, 22 732, 70 502-503, 20 465 See also Soap entries continuous, 22 737-738, 741 in kettle soap making, 22 736-737 of oils and fats, 22 736-741 in vinyl alcohol polymerization, 25 609-610 Saponification number of waxes, 26 223... 

The saponification number expresses the amount of base that will react with 1 g of a sample when heated in a specific manner. Since certain elements are sometimes added to asphalt and also consume alkali and acids, the results obtained indicate the effect of these extraneous materials in addition to the saponifiable material present. In the test method (ASTM D94 IP 136), a known weight of the sample is dissolved in methyl ethyl ketone or a mixture of suitable solvents, and the mixture is heated with a known amount of standard alcoholic potassium hydroxide for between 30 and 90 minutes at 80°C (176°F). The excess alkali is titrated with standard hydrochloric acid and the saponification number is calculated. 

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