Iodine, number

Hanus solution (for determination of iodine number) dissolve 13.2 g of iodine in a liter of glacial acetic acid that will not reduce chromic acid add sufficient bromine to double the halogen content determined by titration (3 mL is about the right amount). The iodine may be dissolved with the aid of heat, but the solution must be cold when the bromine is added. 

Wijs solution (for iodine number) dissolve 13 g resublimed iodine in 1 liter of glacial acetic acid (99.5%), and pass in washed and dried (over or through H2SO4) chlorine gas until the original thio titration of the solution is not quite doubled. There should be only a slight excess of iodine and no excess of chlorine. Preserve the solution in amber colored bottles sealed with paraffin. Do not use the solution after it has been prepared for more than 30 days. 

Kalbus, G. E. Lieu, V. T. Dietary fat and Health An Experiment on the Determination of Iodine Number of fats and Oils by Goulometric Titration, /. Chem. Educ 1991, 68, 64—65. 

The iodine number of fats and oils provides a quantitative measurement of the degree of unsaturation. A solution containing a 100% excess of IGl is added to the sample, reacting across the double-bonded sites of unsaturation. The excess IGl is converted to I2 by adding KI. The resulting I2 is reacted with a known excess of Na2S203. To complete the analysis the excess 8203 is back titrated with coulometrically generated I2. 

Naphthenic acids occur ia a wide boiling range of cmde oil fractions, with acid content increa sing with boiling point to a maximum ia the gas oil fraction (ca 325°C). Jet fuel, kerosene, and diesel fractions are the source of most commercial naphthenic acid. The acid number of the naphthenic acids decreases as heavier petroleum fractions are isolated, ranging from 255 mg KOH/g for acids recovered from kerosene and 170 from diesel, to 108 from heavy fuel oil (19). The amount of unsaturation as indicated by iodine number also increases in the high molecular weight acids recovered from heavier distillation cuts. 

Primary amide CAS Registry Number Iodine number Fatty acid, max % Mp, °C Gardner color... 

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. 

ASTM number Iodine number DBP CTAB N2 absorption... 

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. 

Liquid-phase adsorption methods are widely used for quaUty control and specification purposes. The adsorption of iodine from potassium iodide solution is the standard ASTM method D1510-83 (2). The surface area is expressed as the iodine number whose units are milligrams of iodine adsorbed per gram of carbon. It is quite fortuitous that the values of iodine numbers turn out to be about the same as the values for surface areas in square meters per gram by nitrogen adsorption for nonporous carbon blacks. 

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. 

Barrett Gardner Iodine number US Colophonium standard... 

Degree of unsaturation. Unsaturation accounts for the existence of carbon-carbon double bonds in resins. It is generally indicated by the bromine or iodine number. Both methods are based on the halogen addition to the double carbon-carbon bonds. Because the different reactivity of bromine and iodine, both numbers cannot be compared. The bromine or iodine number does not necessarily correlate with the reactivity of the resin, for instance in the ageing process. However, within a given resin series of the same structure, relative comparisons can be made. 

Iodine number ASTM 1959-69. The iodine number is defined as the amount of iodine in grams accepted by 100 g of resin. 

Some unsaturated compounds are capable of quantitative hydrogenation in a solution of colloidal palladium. It has been found that a hydrogen number corresponding to the iodine number of fatty oils may be ascribed to some ethereal oils. 

The absorption potential of carbon is given by its iodine number (IN). The IN is a measure of how many milligrams of iodine, present in a 0.02 N iodine solution, can be adsorbed by 1 gram of carbon. Usually the IN is between 850 and 1,200. 

Fatty acid methyl esters (low) Iodine number 0.2-0.5 (g J2/100 g)... 

Uintaite is described in Kirk-Othmer [1329]. Typical uintaite used in drilling fluids is mined from an area around Bonanza, Utah and has a specific gravity of 1.05 with a softening point ranging from 190° C to 205° C, although a lower softening point (165° C) material is sometimes used. It has a low acid value, a zero iodine number, and is soluble or partially soluble in aromatic and aliphatic hydrocarbons, respectively. 

The major fatty acids present in plant-derived fatty substances are oleic acid (9-octadecenoic, C18 l), linoleic acid (9,12-octadecadienoic, C18 2) and the conjugated isomers thereof and linolenic acid (9,12,15-octadecatrienoic, C18 3) (Scheme 31.1). Their rates of oxygen absorption are 100 40 1, respectively, hence partial hydrogenation with consequent lowering of the iodine number would lead to a significant increase in oxidative stabihty, particularly when C18 3 is reduced. 

We focused our attention on Tall oil, a by-product of the paper industry, whenever this is prepared according to the KRAFT process. Said material consists of a mixture of highly unsaturated fatty acids (many of which with conjugated diene systems) and terpene derived rosin acids. The rosin acids have the molecular formula C20H30O2 and thus belong to the diterpenes (pimaric and abietic acids). Tall Oil has an iodine number equal to approximately 170 gl2/100 g. 

Addition as a preceding reaction. In comparison with the use of I2, the more reliable results of the two-step electrophilic addition of IC1 in glacial acetic acid with some CC14 (Wijs iodine number for edible oils and fats) according to... 

The acid obtained contains a small percentage of arachidic acid and other higher saturated fatty acids, and has an iodine number of 66.9 (instead of about 75). If not entirely colorless, the product may be distilled under reduced pressure, when it boils at 24t-243°/5 mm. or 252-2540/12 mm. there is practically... 

The iodine number is an indication of the degree of unsaturation of triglycerides, and is the amount of iodine (in mg) required to react with 1 g of lipid material. 

The oils from which factices are manufactured are unsaturated vegetable and animal oils, which react with sulphur. Fatty oils with iodine number greater than 80 (iodine number is defined as the number of grammes of iodine absorbed by 100 g of fat/oil) are generally used, i.e., oils with three or more double bonds per triglyceride molecule. Rapeseed oil is the most common oil used for general purpose grades and castor oil is used for oil resistant factice. Other oils are used in preference by other countries due to local availability and cost. 

This stearolic acid has been thoroughly characterized 3 6 by the freezing-point curve, ultraviolet and infrared spectra, ozonization, and hydrogenation. It has been shown to be free both of positional isomers and of olefinic acids such as oleic and elaidic acids. Its properties include m.p. 46-46.5°, iodine number (Wijs titration, 30 minutes) 89.5, d 5 1.4510, d 5 1.4484, neutral equivalent 279.2-279.6 (theory 280.4), hydrogen uptake 95-100% of theory for a triple bond. The last trace of color is difficult to remove by recrystallization from petroleum ether. It can be removed, however, by crystallization from a 20-30% solution in acetone at —5 to —8°, or from an 8-10% solution at —20°, or by distillation (b.p. 189-190°/2mm.). 

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