Waxes and fats

C, b.p. 81"C. Manufactured by the reduction of benzene with hydrogen in the presence of a nickel catalyst and recovered from natural gase.s. It is inflammable. Used as an intermediate in the preparation of nylon [6] and [66] via caprolactam and as a solvent for oils, fats and waxes, and also as a paint remover. For stereochemistry of cyclohexane see conformation. U.S. production 1980 1 megatonne. 

CH2C1 CH2C1. Colourless liquid with an odour like that of chloroform b.p. 84 C. It is an excellent solvent for fats and waxes. Was first known as oil of Dutch chemists . Manufactured by the vapour- or liquid-phase reaction of ethene and chlorine in the presence of a catalyst. It reacts with anhydrous ethano-ales to give ethylene glycol diethanoate and with ammonia to give elhylenediamine, these reactions being employed for the manufacture of these chemicals. It burns only with difficulty and is not decomposed by boiling water. 

Other uses of HCI are legion and range from the purification of fine silica for the ceramics industry, and the refining of oils, fats and waxes, to the manufacture of chloroprene mbbers, PVC plastics, industrial solvents and organic intermediates, the production of viscose rayon yam and staple fibre, and the wet processing of textiles (where hydrochloric acid is used as a sour to neutralize residual alkali and remove metallic and other impurities). 

Major uses of ethyl chloride are the manufacture of tetraethyl lead and the synthesis of insecticides. It is also used as an alkylating agent and as a solvent for fats and wax. 

Lipids are classified into two broad types those like fats and waxes, which contain ester linkages and can be hydrolyzed, and those like cholesterol and other steroids, which don t have ester linkages and can t be hydrolyzed. 

The third bond, and perhaps the weakest of the three, is that due to van der Waals forces. These forces pull together particles of all material regardless of composition or electric charge. They vary with the size of the particle and would be greater for a hydrocolloid than for a smaller particle. They are the predominating bonds in crystals of fats and waxes. 

In a sensitive and specific colorimetric method 1,1,1-trichloro-2,2-bis(p-methoxyphenyl)-ethane is extracted from plant or animal tissue, using benzene or petroleum ether as the solvent. The solvent is evaporated at room temperature by a current of air and the residue dehydroha log ena ted with 2% alcoholic potassium hydroxide. By petroleum ether extraction the resulting 1,1-dichloro-2,2-bis(p-methoxyphenyl)-ethylene is removed from the reaction mixture. After the solvent is removed by air evaporation the dehydroha log ena ted methoxychlor is isolated from the nonsaponifiable portion of the fats and waxes by dissolving the residue in hot acetone, chilling, and filtering. After the acetone is removed by air evaporation, the residue is treated with 85% sulfuric acid. This produces a red solution with an absorption maximum at 555 m/z, the intensity of which can be read on a colorimeter and is a function of the methoxychlor concentration. Beer s law is obeyed over the range of 1 to 50 micrograms. 

The dehydrohalogenated product reacts with 85% sulfuric acid to produce a red complex of unknown composition with an absorption maximum at 555 mfi (Figure 1). No other organic insecticide now in use produces any color under similar conditions. Therefore, the method is specific for methoxychlor. Fats and waxes, however, yield strong brown colors which will completely mask the methoxychlor reaction. In the method described this interference has been reduced to a point where it introduces an error of less than 1% when the methoxychlor concentration is between 5 and 50 micrograms. Quantities of methoxychlor of less than 1 microgram may be determined by this method. 

Further isolation of this material from the nonsaponifiable portion of fats and waxes with acetone. 

It is necessary to isolate the dehydrohalogenated methoxychlor from the nonsaponi-fiable portion of the fats and waxes. To do this, advantage is taken of the fact that both methoxychlor and its dehydrohalogenated product are readily soluble in acetone, whereas fats are relatively insoluble. The residue is first dissolved in hot acetone, and then the acetone is chilled to —15° C., which causes precipitation of the fats. After the fats are filtered off, the acetone is removed by evaporation. 

Even with the best technique, however, some interference will still be encountered from fats and waxes. With the acetone separation method described this interference is reduced to a point where it seldom lowers the transmittance by as much as 1% and never by more than 3%. It has been found that the off-colors introduced by any one type of biological material are remarkably constant and it is therefore thoroughly practical to apply a correction for this interference. 

Lewkowitsch, J. (1922), Chemical Technology and Analysis of Oils, Fats, and Waxes, Macmillan, London. 

Serpico, M. and R. White (2000b), Oil, fat and wax, in Nicholson, P. T. and I. Shaw, Ancient Egyptian Materials and Technology, Cambridge Univ. Press, Cambridge, UK, pp. 390-429. 

Explosions occurred dining the extraction of fats and waxes from the soils with ether, as well as when heating the extract at 100°C. Although the latter is scarcely surprising (the ether contained 230 ppm of peroxides), the former observation is unusual. 

Charters, S., Evershed, R.P., Blinkhorn, P. and Denham, V. (1995). Evidence for the mixing of fats and waxes in archaeological ceramics. Archaeometry 37 113-127. 

Schemes for recrystallisation from melts are similar to those for solutions, although a solvent is not normally added. Usually, simple sequences of heating (melting) and cooling (partial crystallisation) are followed by separation of the purified crystals from the residual melt. Selected melt fractions may be mixed at intervals according to the type of scheme employed, and fresh feed-stock may be added at different stages if necessary. As Bailey1114 reports, several such schemes have been proposed for purification of fats and waxes.

---