Preparation of detergents Maria Arshad BC-12-05 BZU –MULTAN PAKISTAN
Introduction Detergents are the sodium salts of sulphonic acid. Detergent are primarily Surfactants, which could be produced easily from petrochemicals. Surfactants lower the surface tension of water, essentially making it “wetter” so that it is less likely to stick to itself and more likely to interact with oil and grease. 2
Chemical Composition 3
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EXAMPLES OF DETERGENTS Two basic examples of well-known detergents of the sulphonate group or the sulphate group are: 5
Chemical Classification Of Detergents Anionic Detergents Cationic Detergents Zwitterionic Detergents 6
Anionic Detergents Typical anionic detergents are alkylbenzenesulfonates . alkylbenzene portion of these anions is lipophilic and the sulfonate is hydrophilic . 7
Cationic detergents Cationic detergents are similar to the anionic ones, with a hydrophobic component, but, instead of the anionic sulfonate group, the cationic surfactants have quaternary ammonium as the polar end. The ammonium center is positively charged. The most common is Acetyl trimethyl ammonium bromide. 8
zwitterionic detergents Zwitterionic detergents possess a net zero charge arising from the presence of equal numbers of +1 and −1 charged chemical groups. Examples include CHAPS .(3-[(3-cholamidopropyl) dimethylammonio ]-1-propanesulfonate ) 9
Industrial Preparation Powder detergents are produced by spray drying process agglomeration process Dry mixing process 12
Spray Drying Process 1.In the spray drying process, dry and liquid ingredients are first combined into a slurry, or thick suspension , in a tank called a crutcher. 2.The slurry is heated and then pumped to the top of a tower where it is sprayed through nozzles under high pressure to produce small droplets . The droplets fall through a current of hot air, forming hollow granules as they dry. 13
Continue.. 3.The dried granules are collected from the bottom of the spray tower where they are screened to achieve a relatively uniform size. 4.After the granules have been cooled , heat sensitive ingredients that are not compatible with the spray drying temperatures (such as bleach, enzymes and fragrance) are added. 5.The final step is the packing of Detergents. 14
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Hard Water & its effect on Detergents.. Hard water contains dissolved calcium and magnesium compounds such as: magnesium hydrogen carbonate [Mg(HCO 3 ) 2 ] calcium hydrogen carbonate [Ca(HCO 3 ) 2 ] magnesium sulfate [MgSO 4 ] calcium sulfate [CaSO 4 ] detergent molecules have a long chain of carbon and hydrogen atoms, but at the end of the molecule there is this group -SO 3 - called sulphonate ,so hard water does not effect its cleaning action because they are soluble in hard water and do not form scum. 16
Advantages of Detergents. Since detergents are the salts of strong acids they do not decompose in acidic medium. Thus detergents can effectively clean fabric even if the water is acidic. Synthetic detergents are more soluble in water than soaps. They have a stronger cleansing action than soaps. As detergents are derived from petroleum they save on natural vegetable oils, which are important as essential cooking medium 17