ABSTRACT
I. INTRODUCTION Surfactants (short for surface-active agents) consist of a hydrophilic (watercompatible) head group and a hydrophobic (water-repellent) hydrocarbon tail. They affect all aspects of our daily life, either directly via household detergents and personal care products or indirectly via the production and processing of the materials that surround us. Generally, they are important industrial chemi cals widely used in the manufacture of household cleaning, personal care, agricultural, and food products. Most commercial surfactants in the market are synthesized by chemical process. Manufacturers of surfactants use a com bination of petrochemicals and natural feedstock. Cost, performance, and availability considerations make the petrochemicals the raw materials of choice among manufacturers. The petrochemicals used include paraffin, ben zene, olefin, fatty alcohol, fatty acid, fatty amine, ethanolamine, ethylene ox ide, propyl oxide, betaine, and imidazoline and their polymerized products. However, some chemical intermediates from the preceding chemical groups are used directly, for example, alkylbenzene from the condensation of paraffin derivatives and benzene for manufacturing sulfonates through sulfonation with S 03 in a falling-film reactor. These are mainly anionic surfactants, such as tetrapropylene benzene sulfonates.
