Fats and Oils

Fats – naturally occurring polyesters with the same link between ester monomers as Terylene. The chains typically contain 12 to 20 carbon atoms. Fats and oils are rich in energy and this is their normal function to us. They are also important in soap and detergent products. A fat molecule is made of two components, a glycerol (the “backbone” of the molecule) and fatty acids (which are attached to the backbone.

Soaps – long chains derivatives of fatty acids. The fatty acid is reacted with a base such as caustic soda. This causes the formation of the sodium salt of the fatty acid which is used as soap. Soap (sodium stearate) is an ionic compound and can remove dirt with the covalent end (non-polar) attracting to the dirt and the ionic end attracting to water molecules. Soap molecules can make oils and water form a stable emulsion. However, it forms a scum with hard water by reacting with Ca2+ or Mg2+ present.