Answer to Question #31019 in Organic Chemistry for dora

Question

What chemical in detergent bar that make the bar soild?

Answer 1

The FDA has a definition for what true soap is:
“Ordinary soap is solely made up of fats and an alkali. In the past, people made their own soap from animal fats and wood ashes.
Today there are very few true soaps in the traditional sense on the market.
Most body cleansers on the market today are actually synthetic detergent products and come under the jurisdiction of FDA. These detergent cleansers are popular because they make suds easily in water and don’t form gummy deposits. Some of these detergent products are actually marketed as “soap” but are not true soap in the common and legal definition of the word.”
True soap is only made using Sodium Hydroxide (Lye) and fats for solid bars or Potassium Hydroxide and fats for liquid soap with the addition in both cases of enough water to dissolve the lye. There is just no other way to make true soap and this is the method we use at By Valenti Organics.
Saponification is the reaction generated between an alkali (Sodium Hydroxide or Potassium Hydroxide) and a fat.
Detergent bars, classified by the FDA as synthetic bars, are the ones that don’t use lye to be made, so there isn’t per se a saponification process taking place when these soaps are manufactured. Melt and Pour formulas, also known as Clear Glycerine Soap — those fabulous transparent soaps with decorative elements embedded in them — are classified as detergent bars or synthetic soaps not true soaps. These detergent bars are formulated with a combination of synthetic ingredients designed to rapidly foam when in presence of water.
The following is the list of ingredients of a regular melt&pour base for ultra clear detergent soap commonly used by many soap detergent bar makers:
• Propylene Glycol,
• Sorbitol,
• Sodium Stearate,
• Sodium Laureth Sulfate,
• Sodium Laurate,
• Glycerin,
• Triethanolamine.