What soap is not there today! Multi-colored, bright, beautiful. There is a transparent one in which temptations can be seen patterns or fruits, different images. Very popular types for children, which are made in the form of favorite cartoon characters, cute animals and other characters. In general, soap makers are trying their best. But what is this product inside out? What is its chemical composition when it appeared and how is it obtained? Let's try to figure it out.
The chemical basis of soap
From the point of view of science, this product is the result of alkaline hydrolysis of oils or fats. For the first time, soaps and fats have something in common, Michel Chevrel, a French chemical scientist, guessed. He devoted almost his entire life to the study of higher carboxylic acids. Therefore, he belongs to the merits of a theoretical explanation of the composition of fats, and therefore soap.
Chevrel said that if the higher trihydric alcohol glycerol containing three hydroxo groups reacts with an acid, the general formula of which is R-COOH, then triglycerides - acid esters - will form. They will be fats. If the reaction is carried out in an alkaline medium, then the resulting product will interact with NaOH (KOH) with the formation of soap.
Later, these theoretical findings were supported by Berthelot's experiments in the laboratory. Typically, the composition of different soaps includes the following components:
- water;
- oleic acid ;
- naphthenic acids;
- stearic;
- palmitic;
- rosin;
- sodium or potassium hydroxide.
Therefore, the chemical formula of soap is conventionally written as follows: R-COOMe, where R is a radical containing from 8 to 20 and above carbon atoms. Me is a metal, alkaline or alkaline earth.
If we talk about the usual household product used for washing clothes, the soap formula will look something like this: C 17 H 35 -COONa. It includes:
- stearic acid;
- sodium hydroxide;
- rosin;
- water;
- Coconut oil is sometimes used.
In different countries, the production of this type of product occurs in different ways, so most often the result is different in composition, color, and washing quality. Thus, the very formula of the soap becomes clear. Chemistry gives the following definition of this product: these are salts of higher carboxylic acids, which include alkali or alkaline earth metals.
It should be noted that the products are very different in terms of aggregate state, transparency, smell and other organoleptic parameters. It all depends on the chemical composition and production method.
Liquid Soap Formula
Very popular in recent years, the option of detergent are liquid products. It is convenient, it seems that it is more gentle for the skin of the hands and aesthetically pleasing for the bathroom shelf. Therefore, liquid soap is one of the most common types of these salts. How do they differ from solid ones and why is there such a difference in state of aggregation?
It turns out that the whole thing is in the metal cation that forms the compound, as well as in production technology. The soap formula, which is liquid, conditionally looks like this: R-COOK. That is, the composition necessarily includes potassium ions. Accordingly, potassium hydroxide is involved in the production.
The main characteristics of such products:
- viscosity;
- hygroscopicity;
- ductility;
- transparency;
- better solubility.
Solid soap
To obtain the product in a more traditional state of aggregation, it is necessary to use soda lime or caustic soda in the manufacture. It should be noted that if the composition includes Na ions, then the product is solid and nothing else. Lithium ions most often also form similar soaps.
Thus, the soap formula takes on a slightly different look: R-COONa, R-COOLi. From the chemical point of view, the quantitative composition and structure of substances does not change at the same time - soap corresponds to its nature, being salts of carboxylic acids. Physical characteristics, organoleptic properties, external design - all this is subject to change by the person himself, what people are actively doing.
Classification
Two bases can be designated for dividing the described substances into categories. The first sign of classification is the chemical basis in the manufacture. According to this criterion, there are:
- sound soap - fatty acids of at least 60% in the composition;
- semi-core - about 30%;
- glue - not higher than 47%.
You can give the soap completely different options for the appearance of the chosen base. You can make it marble, transparent, with decorations and components embedded inside, color and matte, and so on. The soap formula will also be expressed by the general composition of R-COOMe, however, the product itself often also includes rosin and naphthenic acids, as well as sorbitol, sodium chloride, flavorings, colorants, preservatives, foaming agents and other compounds.
The second sign of classification is household use. So, there are three varieties of the product.
- Dressing - used for cosmetic purposes for washing, washing the body. It should have good foaming ability, be soft and not cause irritation and dryness. For this, fatty acids should not drop beyond 72% of the composition.
- Special - used in the leather, textile industry, medicine and so on. Contains special technical additives.
- Household - designed for washing household items, washing clothes, cleaning and other household needs.
The soap formula of this kind does not differ from the previous one, it can also be transparent, matte, color, and so on. The ratio of components varies depending on the destination.
Industrial Production
The production of soap on a large scale is carried out at special soap factories. There, according to pre-planned and outlined technologies and designs, the release of a huge number of product copies of both solid and liquid plan is arranged. The main process chains are as follows:
- neutralization reaction between soda ash and fat hydrolysis products (carboxylic acids);
- interaction with caustic soda or caustic soda;
- alkaline hydrolysis of triglycerides.
In any case, you can get a different soap for its physico-chemical properties.
History of soap making
It is known that people knew about cooking soap more than 6 thousand years ago, that is, even before our era. In ancient Egypt, ash was boiled with the addition of fat and the desired product was obtained. Future generations continued to do so for several centuries in a row.
In Europe, the production of soap was weakly intensive, since no one cared about the purity of their bodies, this was considered shameful. And only from the XVIII century soap making reaches its peak. New simplified production technologies were invented, aromatic oils and emollients are included in the soap, it becomes more diverse and pleasant to use.
DIY making
How to make soap with your own hands? Is it possible? The answer is clear: yes, maybe. Today, many people have done this as their home business and earn very good money on it.
If you have creative imagination, creativity and innovative thinking, dexterous hands, a desire and a room for work, then it will not be difficult to make soap at all.
Soap technology at home
There are three main ways to prepare a product without leaving your home.
- Purchase a special ready-made basis for production. This is a convenient, inexpensive and fast-performing option on how to make soap yourself. This base will require only your imagination and the addition of the necessary flavors and colors. It is plastic and easy to handle, you can give it any shape. Also, if desired, you can get a transparent product.
- To buy a finished soap without fragrances, dyes and aromatic additives. For example, baby. Then grind, melt in a water bath, and then proceed as in the first case.
- Cooking from scratch. The most dangerous in terms of security and laborious process. Can be carried out by any of the described industrial methods. However, it should be remembered that working with alkalis should be extremely careful. And not at home, but in a special room.