The soap (of Latin saponem ) is a solid substance used for washing, washing or cleaning.
The soap was invented in Syria approximately 3000 years ago, with Olive oil and vegetable Soude. This soap was particularly famous for its disinfecting properties, due mainly to the use of ashes of bay-tree in its manufacture.
It is with Gallipoli, port city on the sea Ionienne, in the South of Italy, which should be allotted the origin of the soap known as of Marseilles. Thanks to its many olive groves and with its multiple underground presses ( frantoi ipogei ), Salento marketed in all Europe an oil of excellent quality, destiny mainly with the lighting of the cities and factories textile, but also with a food use. The idea to add soda to the remainders of the olives which had just been in a hurry first once made it possible to the inhabitants of Gallipoli to manufacture white soaps and to diversify their activities durably.
As from the 15th century, the area of Marseilles becomes an important production center, using the oil of local olive. The Soude (at the time the word “soda” indicated the Sodium carbonate) comes initially from the ashes obtained by the Combustion of Plante S like the Salicorne. In 1791, Nicolas Leblanc invents a proceeded making it possible to obtain soda starting from sea water.
In 1823, the Chimiste French Eugene Chevreul explains the reaction Saponification and shows that the greasy Substance are made of a combination between the Glycérol and of the fatty-acids. At the 19th century, oils of copra and palm coming from overseas are employed in the soaps.
Since the 20th century, the soap is competed with by the synthetic Tensioactif S which are used in the Détergent S, the gel showers and the “soaps without soap”.
Its multiple employment (body toilet, shampoo, foam to be shaved, detergent, crockery, maintenance of the grounds and medical… until the fight against the plant louses) will be the target of products " modernes" more specialized, debatable so much by their ecological impact (by the production, packing and the pollution of waste water) that by their harmlessness (risks of allergies had with the multitude of new components) and even of effectiveness. Thus, for the body toilet, the products " without savon" were installed on the belief in the dehydrating effect of the soap (certain soaps, for example with glycerin, however respect particularly well the skin). It is remarkable that in these products the soap is replaced by the Laureth sulfates sodium (named sodium laureth sulfate in the compositions) which is not without disadvantages (see the heading of this product).
See also: Saponification, To manufacture soap
The soap results from a Réaction chemical known as of Saponification, conversion chemical during which greasy substances (grease S or Huile S) are hydrolized in alkaline medium by a base, generally of the Potasse (Hydroxyde of potassium - KOH) or Soude (NaOH)), with a Temperature ranging between 80 and 100 °C. The Hydrolysis of the produced greasy substance of the Glycerol and a mixture of carboxylate (of sodium or potassium) which constitutes the soap. The soaps manufactured starting from Soude are hard. The soaps manufactured starting from Potasse are soft.
Reaction of saponification:
CH2 (OOC-R) - CH (OOC-R) - CH2 (OOC-R) + 3 NaOH --> CH2OH - CHOH - CH2OH + 3 R-CO 2-Na that is to say: greasy substance + NaOH (or KOH) --> glycerol + soap
where R is a chain of carbon atoms and hydrogen. One can have for example R= (CH2) 14 - CH3
The soap is a Tensioactif. The detergent properties of the Molécule S of carboxylate R-CO2-Na are due to their amphiphilie: they are appeared as a long chain whose end, negatively polarized, is absorbent while the other end is lipophilic . The latter is thus fixed easily on the grease S, the other remaining in contact with the flushing water.
At the time of the toilet, the soap dissolves grease constituting the Film hydrolipidic which recovers the skin. Grease is involved in water with dirtinesses which it contains. The disadvantage is that the film hydrolipidic is used to protect the Peau and to retain its water. Soaping - or any washing using products comprising of surface-active, for example gel for the shower or detergents - thus weakens the skin, until the film hydrolipidic reconstitutes, at the end of several hours.
The soap is Basique. Its pH is close to 10. At the time of the toilet, it disturbs the acidity Peau (to which the pH is close to 5).
In a water lasts, the molecules of the soap react with the Ion S Calcium and form calcium salt deposits. Moreover, one needs a greater quantity of soap to clean. To avoid these disadvantages, one adds today to the soaps of the antiliming agents like l' EDTA .
The raw materials to manufacture soap are the fat contents and soda (or mugs it up). But after the reaction of saponification, the finished soap does not contain any more soda nor of oil. It is made up mainly the carboxylate ones of sodium (which is the soap molecules) and contains also eau.
The glycerin (or Glycerol) is a by-product of the saponification which one can eliminate. But one leaves sometimes glycerin because it brings its properties hydrating to the soap.
Principal fat contents used
The following table lists the fat contents which are generally used during the manufacture of the soaps.
(1) if the soap is a liquid soap manufactured containing Potasse, it is necessary to replace “sodium” by “potassium” in the names INCI.
To the basic receipt, one can add different Additif S according to the required effect:
- of the antiliming agents
- of the preserving S
- of the dye S
- of the Perfume S
- of the agents surgraissants (oils) to manufacture a soap will surgras
- hydrating agents like the Miel
- of the Abrasif S to manufacture a soap exfoliant
- essential oils extracted from plants
- of the ingredients disinfectants to manufacture a soap Antibactérien
Types of soap
The soap is presented in the form of block (bread), of powder, spangles (Lessive S) and can be sold in solution (soap says liquid).
The Savon Azul E Branco is manufactured with the Portugal. It is blue and white-yellowish.
The traditional Household soap is prepared with oil of olive and Soude.
The soap Animal is often prepared with Suif of ox.
A cake of soap is a soap bread roll, of more elaborate composition - presence of dye, perfume, bactericide or another additive - intended for the toilet (body Hygiène).
A soap will surgras is enriched in agents surgraissants, for example of plant oils. The presence of oils limits drying due to the soap which removes fatty film (Film hydrolipidic) recovering the skin naturally.
The soft soap or soft soap is obtained starting from plant oil and from potash. It was recommended for the cleaning of the tilings. There exists also soft soap for the body.
A soap without soap, as its name indicates it, does not contain soap molecules. Also called dermatological bread or syndet (for synthetic detergent), it is containing Tensioactif S synthetic. Its pH is close to the pH of the skin.
Myths and realities
- Tyler Durden, in the book and the film Fight Club uses human grease to manufacture soaps of high-quality.
After the Second world war, a rumor claimed that the Nazis manufactured soap starting from human grease coming from the concentration camps. The court of Nuremberg made it possible to clear up this legend which remains tough: ashes of the victims were the object of various experiments of which attempts to manufacture soap in an industrial way (with Danzig in 1944). But nothing corroborated the thesis of a massive production of soap by such a process.
- the card Know-how: To manufacture soap
the book '' " The manufacture of the soap: technical sides, economic and sociaux" '' of Caubergs Smoothing iron published by ATOLL. - Document with the format pdf;
- human soap: rumor, reality and history.
Nds-nl: Ziepe (reiniging) Simple: Soap Zh-yue: 番梘
|Random links:||Carl Friedrich Gauss | History of Bolivia | Villefranche-on-Expensive | Foncine-le-Haut | Ignacio Peña | Silvia Salgado|