Surfactants - Surface Active Agents

The definition for a detergent is a cleaning agent. The main cleaning agent used in earlier days was soap. This term means a compound formed from the reaction of a fatty acid with a base such as caustic soda, forming the sodium soap of the acid. The more commonly used cleaning agent in this day and age is the synthetic detergent (SYNDET) which is a formulation such as TIDE or FAB. The essential difference between the soaps and the newer synthetic detergents lies in the fact that the soap molecule occurs readymade in nature. As we have seen above, it consists of a long-chain fatty acid modified only to the extent that the acidic hydrogen is replaced by a sodium atom from caustic soda. The synthetic detergents are not derived directly from natural products but are tailor-made, or built up artificially, synthesized in the laboratory. These synthetic detergents are made from a wide variety of raw materials such as certain petroleum constituents, coal tar derivatives, compounds derived from cracking gases, chemically modified fatty acids, and a host of others. We now have described a detergent and the difference between a soap and a synthetic detergent, so let's continue by discussing some of the components of a synthetic detergent a little more in detail.