Fats, Oils, Soaps, and Detergents

Our understanding of solubility can be used to explain why soap and detergent help clean greasy dishes and oily clothes. As always, the properties of substances are a consequence of their chemical structures, so let s take a look at those structures. 

Typical Liquid Triglyceride Liquid triglycerides are rich in carbon-carbon double bonds. 

The hydrophobic, nonpolar hydrocarbon portion of each soap anion does not mix easily with water, but the hydrophilic, negatively charged end of each anion does form attractions to water molecules, and these attractions are strong enough to keep the anion in solution. 

Cleaning Greasy Dishes Why do soaps and detergents help clean grease away  

For soap to work, its anions must stay in solution. Unfortunately, they tend to precipitate from solution when the water is hard. FFard water is water that contains dissolved calcium ions, Ca, magnesium ions, Mg +, and often iron ions, Fe or Fe. These ions bind strongly to soap anions, causing the soap to precipitate from hard water solutions. 

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Saponification of Fats and Oils Soaps and Detergents 1207 An alkylbenzenesiilfonate detergent... 

Uses Carbon tetrachloride is a clear, colorless, volatile liquid with a characteristic sweet odor. It is miscible with most aliphatic solvents and is itself a solvent. Its solubility in water is low. Carbon tetrachloride is nonflammable and is stable in the presence of air and light. In the presence of flame or hot metal, carbon tetrachloride partially converts into phosgene—a highly poisonous war gas. Carbon tetrachloride is a solvent for fats and oils, and is extensively used in a variety of products such as soaps and detergents, textiles, and rubber cements. Decomposition may produce phosgene, carbon dioxide, and hydrochloric acid. 

Like other esters, fats and oils (Section 27-14) can be hydrolyzed in strongly basic solution to produce salts of the acids and the trihydric alcohol glycerol. The resulting sodium salts of long-chain fatty acids are soaps. In Section 14-18 we described the cleansing action of soaps and detergents. 

Soaps and detergents represent an interesting and rather different sector. Interesting in that early production of soap, with its demand for alkali, can be viewed as the beginnings of the modern chemical industry. Different from the other sectors in that its products are sold directly to the public and market share probably has more to do with packaging and marketing than the technical properties of the product. Many of its products can be derived from both petrochemical intermediates and from animal and vegetable oils and fats, e.g. alkyl and aryl sulphonates. Chemicals from oils and fats are discussed in section 2.2.4. 

Acid dyes Reactive dyes Basic Direct dyes Mordant dyes Disperse dyes Vat dyes Solvent dyes Fluorescent brightners Other dye classes Nylon, sUk, wool, paper, inks and leather Cotton, wool, sUk and nylon Paper, polyacrylonitrile, modified nylon, polyester and inks Cotton, rayon, paper, leather and nylon Wool, leather and anodised altiminirun Polyester, polyamide, acetate, acrylic and plastics Cotton, rayon and wool Plastics, gasoline, varnishes, lacquers, stains, inks, fats, oils and waxes Soaps and detergents, aU fibres, oils, paints and plastics Food, drugs and cosmetics, electrography, direct and thermal transfer printing... 

Soaps and detergents Oils, fats, and greases Fruit juices... 

Yes, and quite an important part. Fats are made from long-chained hydrocarbons with a carboxylic acid group at one end. These are called fatty acids, and the sodium salts of these are often used as soaps and detergents, because one part of the molecule is soluble in water while the other part is soluble in oil and greases (see p27l). 

In the preparation of foods, fats and oils modify product texture, carry flavors, improve mouthfeel, provide a sensation of product richness, and induce satiety. They are used in many other commercial applications, including soaps and detergents, plastics and protective coatings, printing inks, and feeds for domesticated animals, and as carriers of pesticides for aerial spraying, for control of grain dust, and as feedstocks for chemical manufacturing processes. 

Uses Vise, builder for shampoos thick, copious, stable foam useful in shampoos, facial scrubs, bubble baths, hand soaps, and detergent compositions Properties Yei. Iiq. when fresh (cryst. on aging) mild, fruity odor sol. in alcohols, glycols, glycol ethers, polyols, aliphatic (lower members), aromatic, and chlorinated hydrocarbons, and natural fats disp. in water and min. oil sp.gr. 0.96 0.01 dens. 8.0 Ib/gal vise. 2500cps min. (10% disp.) flash pt. (OC) > 170C acid no. 1.0 max. pH 10.2 0.5 (10% disp.) 100% active 88% min. amide content Schercomid SLM [Lubrizoi Advanced Materials]... 

The concept of a soap-LSDA detergent represents a simple solution to the quest for less polluting highly efficient laundry detergents [47,48]. If present worldwide price trends for petrochemicals, phosphates, and other builders continue to rise, the use of tallow or other fats and oils, which are replenishable agricultural products or byproducts, should become economically more attractive. Since the USD A research team initiated research on soap-LSDA detergents, the a-sulfonated fatty acid esters (MES) have become commercially available in the United States, Europe, and Japan. 

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