Cleansing Agents
The word detergent means cleansing agent. Actually detergent word is derived from Latin word „ detergere ‟ means“ to wipe off”, Cleansing agents are the substance which remove dirt and have cleansing action in water. These are also called surfactants.
Detergents can be classified into two types. 1. Soapy detergents or soaps, and 2. Non-soapy detergents or soapless soap.
1. Soaps Soaps are sodium or potassium salts of higher fatty acids( containing 15-18 carbon atoms) e. g., stearic acid, oleic acid and palmitic acid. Sodium salts of fatty acids are known as hard soaps while the potassium salts of fatty acids are known as soft soaps.
Hard soaps are prepared by cheaper oil and NaOH while soft soaps are Jlrepared by oil of good quality and KOH. The soft soaps do not contain freealkali, produce more lather and are used as toilet soaps, shaving SOapsand shampoos.
Preparation of soaps
Soaps containing „ Sodium salts are formed by heating fat( glyceryl ester ~ fatty acid) with aqueous sodium hydroxide solution. This reaction is known as saponification.