Bar soap - how to choose? Everything about soap from a chemist's point of view.

It would seem - what could be more familiar and ordinary than an ordinary piece? But in recent times the counters were filled with bars of all colors, shapes, and most importantly, properties. How does it differ from each other? Of course, the composition! Is it possible to wash with soap and which soap is better? - you decide!

WHAT SOAP TO CHOOSE?

Despite the myriad of options, any contains fat. Most often it is palm or coconut oil. The higher the percentage of fat, the higher the quality and more expensive the product. Another required component is alkali. You need to know that even at very low concentrations, it violates the hydrolipid mantle of the skin. As a result, dry and sensitive integuments become even drier, and with increased sebum secretion, oddly enough, even fatter. That is why they try to make it as comfortable and safe as possible with the help of various additives. They, in fact, determine the basic properties of the foaming bar. Which soap to choose? To choose the right one and find out which one is better, you need to decide which type is right for you.

TOILET

The traditional and well-known lumpy toilet soap is extremely convenient for cleansing hands and body. Today, there are a lot of its types on the market - with the addition of cream, glycerin, petroleum jelly, extracts of herbs, algae and plants, honey, oats, even beer! Thanks to the additions, in addition to cleansing, this takes great care of the skin: softens, moisturizes, relieves inflammation, soothes, nourishes.

DURU Gourmet Toilet Soap Mango ice cream with a moisturizing action of glycerin (Nominal weight 75 g / g, Turkey). COMPOSITION OF DURU TOILET SOAP: (INCI) Sodium Tallowate, Sodium Cocoate, Aqua, Sodium Palm Kemelate, Glycerin, Parfum, Sodium Chloride, Tetrasodium EDTA, Propylene Glycol, Citric Acid, Mangifera Indica, Trideceth-9, Bisabolol, CI 77891, Etidronic, Acid, CI 15510 Hexyl Cinnamal, Linalool, Limonene.

Toilet solid cream soap with cosmetic cream, brand K, TM "GREEN WAY" A touch of silk (Nominal weight 100 g / g, DSTU 4537: 2006). COMPOSITION OF HARD SOAP GREEN WAY: (INCI) Sodium Palmitate (sodium palmitate), Sodium Cocoate (sodium cocoate), Aqua (water), Parfum (perfume composition), Hydrolized Silk (silk protein hydrolyzate), Glycerin (glycerin), Octyldodecanol (euthanol G), Paraffinum Liquidum (cosmetic cream), Disodium EDTA (EDTA disodium), Citric Acid, Etidronic Acid (bleach), Disodium Distyrylbiphenyl Disulfonate, Stearic Acid, BHT, Anthemis Nobilis Extract, Bidens Tripartita Extract, Calendula Officinalis Extract, Cetearyl Alcohol, Triethanolamine, Methylparaben, Propylparaen89, L.

Laundry solid soap FRIEND For washing with a bleaching effect (Weight 135 g / g). COMPOSITION OF HOUSEHOLD SOAP: (INCI) Sodium Palmitate (sodium palmitate), Sodium Cocoate (sodium cocoate), Aqua (water), Parfum (perfume), Sodium Perborate (sodium perborate), Pentasodium Triphosphate (sodium triphosphate), Disodium EDTA (EDTA disodium), Citric Acid (citric acid), Etidronic Acid, Hexyl Cinnamal, Limonene, Linalool, CI 77891.

CHILDREN

For children - the simplest composition, a minimum of fragrances - in order to gently and safely cleanse the delicate baby skin.
Mink fat is added to the best baby soap, which not only softens, but also helps moisturize the epidermis. Vitamins normalize water balance. Extracts of chamomile, calendula, sage, oak bark have an antiseptic effect. Bars "for the little ones" are ideal for adults with sensitive skin and allergy sufferers. It is indispensable for wearers of contact lenses - it does not leave perfumed particles or creams on the skin, which can irritate the eye if they come into contact with the lens.

Cream toilet soap "Sonechko / Sonechko" with a series, brand "CHILDREN" (75 g / g). SOAP: (INCI) Sodium Palmate (sodium salts of fatty acids of natural fats), Sodium Palm Kernelate (sodium salts of fatty acids of natural oils), Aqua (water), Glycerin (glycerin), Parfum (perfume), Sodium Chloride (sodium chloride), Isocetyl Stearate (isocetyl stearate), Titanium Dioxide (titanium dioxide), Octyldodecanol (octyldodecanol), Citric Acid (citric acid), Alcohol (alcohol), Tetrasodium EDTA (sodium EDTA), BHT, Bidens Tripartita (string extract).

Laundry solid soap FRIEND For washing children's clothes (Weight 135 g / g). COMPOSITION OF HOUSEHOLD SOAP FRIEND: (INCI) Sodium Palmitate (sodium palmitate), Sodium Cocoate (sodium cocoate), Aqua (water), Parfum (perfume), Pentasodium Triphosphate (sodium tripolyphosphate), Triclosan (triclosan), Disodium EDTA (EDTA disodium), Citric Acid ( citric acid), Etidronic Acid, Hexyl Cinnamal, Limonene, CI 77891.

NATURAL

Natural soap is made according to "grandmother's" recipes, that is, according to all the rules of old soap making - with the addition of vegetable oils, beeswax, herbs and flowers, honey, oats and tea extracts - the composition of natural soap. Only natural ingredients and fragrances are used, therefore, most often the blocks have an unpresentable appearance, an indistinct brownish color and a rather pungent smell. Also, they don't foam very well. But this does not dry the epidermis and has good softening properties. But natural ingredients and essential oils are strong allergens, so people with sensitive skin should be more careful about such soap products.

Natural cream-soap "Noise of the surf" TOV "CITA LIETA", Latvia. COMPOSITION OF NATURAL SOAP: cream base, olive oil, milk powder, honey (honeycomb with honey), herbal additives: almonds, sesame seeds, calendula, chamomile, green tea, cocoa, coffee, oatmeal, poppy seeds, coconut, mint and linden leaves, glycerin , perfumed composition, natural essential oils and more.

ANTIBACTERIAL

Antibacterial soap contains triclosan. Recently, scientists have been talking a lot about the fact that long-term use of funds with this component reduces natural immunity. In addition, it is antibacterial - it dries out the skin very much. Therefore, it is reasonable to use it only in cases where there is a real threat of infection - for example, during a flu epidemic.

Toilet soap "SAFEGUARD ACTIVE" classic with an antibacterial effect is suitable for sensitive skin. (100g) SAFEGUARD SOAP COMPOSITION: Sodium Tallowate, Sodium Palmate, Aqua, Sodium Palm Kemelate, Glycerin, Parfum, Triclocarban, Citric Acid, Sodium Citrate, Sodium Chloride, Palm Kernel Acid, Pentasodium Pentetate, Tetrasodium Etidronate, Disodium Distyrylbiphenyl Disulfonate, Alpha-Hexomeinn Butylphenyl Methylpropional, Benzyl Benzoate, Citronellol, Linalool, Eugenol, Geraniol, CI 77891, CI 42090.

Exfoliating

The exfoliating bar soap is enhanced with the addition of scrubbing particles - natural crushed bones or polymer granules. With such an assistant, a washcloth is not needed: the scrub soap perfectly cleans the skin not only from sweat and dirt, but also from keratinized scales. It also perfectly prepares the epidermis for the effects of other cosmetics and enhances their effect by 20%. True, you should not use it every day - two or three times a week is enough. Suitable for normal to oily skin with stone scrubs, for dry and sensitive skin - with artificial granules. The latter have a smooth spherical shape, so they do not injure and easily exfoliate dry particles.

Perfumed

A large number of fragrances are added to the perfumed, so after use, a subtle, barely perceptible aroma remains on the body. As a rule, it is included in bath series along with shower gels, body milk, deodorant and eau de toilette. A great option for the hot season when you want to minimize the actual use perfume and even toilet water. Most often, this has a high-quality composition and a very soft formula, therefore it does not dry the skin.

NIVEA lemongrass & oil / LEMONGRASS AND OIL, CREAM SOAP with nourishing oils. Hydra-IQ moisturizing formula for perfectly delicate skin. Gently cleanses and cares for your skin every day. Application: Foam with water. Rinse thoroughly. In case of contact with eyes, rinse with water. SOAP COMPOSITION: Sodium Tallowate, Sodium Cocoate, Aqua, Glycerin, Glyceryl Glucoside, Helianthus Annuus Seed Oil, Prunus Amygdalus Dulcis Oil, Prunus Amygdalus Dulcis Oil, Octyldodecanol, Sodium Thiosulfate, Tetodium Chloro- laside, Limiton Esoterium , Geraniol, Butylphenyl Methylpropional, Parfum, CI 77891, CI 11680, CI 74160. Made in Germany

DOVE Cream Soap Figs and Orange Petals (135 g) Exotic combination of juicy fig and flower aromas orange tree will charge you with energy and give you strength. 1/4 moisturizer.

/ DOVE: Sodium Lauroyl Isethionate, Stearic Acid, Sodium Palmitate, Sodium Stearate, Aqua, Sodium Isethionate, Lauric Acid, Sodium C14-16 Olefin Sulfonate, Sodium Palm Kernelate, Parfum, Glycerin, Sodium Chloride, Dipropylene Glycol, Propylene Acid , Sodium Benzoate, Zinc Oxyde, Tetrasodium EDTA, Tetrasodium Etidronate, Alumina, Benzyl Alcohol, Butylphenyl Methylpropional, Coumarin, Geraniol, Hexyl Cinnamal, Limonene, Linalool, CI 19140, CI 42090, CI 77891. Made in Germany

LIQUID

For liquid - surface-based active substances... To soften their action, natural plant extracts and essential oils are added to liquid soap. It is more convenient and more hygienic in operation, since it is enclosed in a bottle with a dispenser. In addition, it has a lower level of acidity, therefore it acts softer on the epidermis.

Liquid hand soap "Celandine" Natural Cosmetics, Moisturizes and soothes the skin (465 ml / ml). LIQUID SOAP COMPOSITION: (INCI) Aqua, Sodium Laureth Sulfate, Sodium Chloride, Cocamide DEA, Cocamidopropyl Betaine, Polyquaternium-7, Glycerin (Glycerin), PEG-7 Glyceryl Cocoate, Chelidonium Majus (Propandine) Extract, Citric Acid, Disodium, EDyleneTA, Glycol, Diazolidinyl Urea, Methylparaben, Propylparaben, Methylisothiazolinone, Hexyl Cinnamal, Linalool, CI 19140, CI 42090.

MEDICAL

Bars, which contain components that revitalize the skin, such as tar and sulfur. Suitable for problem skin owners - excessively dry, prone to dermatitis. Use tar soap carefully and only when indicated.

Solid toilet soap OJSC NEVSKAYA COSMETICS "Tar" (140 g), a unique Russian grade of soap. Contains natural birch tar, which has an antiseptic effect, improves blood circulation to the skin, and has a beneficial effect on its condition. The soap does not contain artificial colors or perfume additives. COMPOSITION OF DARK SOAP NEVSKAYA COSMETICS: sodium salts of fatty acids of natural fats and vegetable oils, water, birch tar, triethanolamine diethylene glycol, PEG-9, disodium EDTA, citric acid, sodium carboxymethyl cellulose, benzoic acid, sodium chloride. (INCI) Sodium Tallowate, Sodium Cocoate, Sodium Palmitate, Aqua, Betula Tar, Triethanolamine, Diethylene Glycol, PEG-9, Disodium EDTA, Citric Acid, Cellulose Gum, Benzoic Acid, Sodium Chloride.

SOAP WITHOUT SOAP

The ideal solution for those who like to wash - the soap-free soap, which is called, looks and lathers like ordinary bars, perfectly removes makeup, dust and sebum from the face. But at the same time it has a completely different composition, due to which it does not violate the integrity of the protective hydrolipid film and does not take away moisture from the skin. Most often it is presented in pharmacy and cosmeceutical series.

ALISSA LEAUTE Essential Mousse detergente - Viso / Cleansing Mousse - Face (150 ml). COMPOSITION FOR WASHING SENSITIVE SKIN: Aqua, Dipropylene Glycol, Disodium Laureth Sulfosuccinate, Glycerin, Mea-Lauryl Sulfate, PEG-200 Hydrogenated Glyceryl Palmate, PEG-30 Glyceryl Cocoate, PEG-7 Glyceryl Cocoate, Phenoxyrea Uethanol, Sorbutolium Potylinylate, Mel, Sodiumopylate , Disodium EDTA, Citric Acid, CI 18050, CI 42720, CI 42735, Methylchloroisothiazolinone, Methylisothiazolinone.
Made in Italy

CHOICE:
1) with the scent of Flowerparty eau de toilette leaves a light floral scent on the body and softens the skin (100 g, 240 rubles)
2) Creamy Cherry Pudding from Lush is filled with pieces of fruit, cleansing citrus oil and crushed almonds for a gentle scrubbing (100 g, 210 rubles)
3) "Before going to bed" with the scent of lavender helps to gently cleanse the baby's delicate skin and tune it to a healthy and restful sleep (100 g, 25 rubles)
4) Perfumed Volare Magnolia from Oriflame exudes a delicate floral scent (4 pcs., 170 rubles)

Xvi Regional scientific and practical conference

"Step into the future" Usolye-Sibirskoye

Vaseline "href \u003d" / text / category / vazelin / "rel \u003d" bookmark "\u003e vaseline-lanolin soap is prepared by taking 3.5 kg of vaseline and 1.5 kg of lanolin add them to 95 kg of melted soap mass. vaseline-lanolin soap as a skin softener.Also medical soaps include liquid potassium soap, which is prepared from liquid vegetable oils by saponifying them with caustic potassium; the content of fatty acids is not less than 40%. Medical soap, applied externally in the form of plasters, ointments, pastes , has a therapeutic value in accordance with the effect of the active principle added to the soap.This is the use of turpentine soap in the form of an ointment for rheumatism.

Special types of soaps also include soaps, which are mainly used in the textile, leather, metallurgical industries, in the production of insectofungicides, etc. Special soaps are known mainly in the form of liquid soaps prepared by saponifying a fatty mixture with sodium or potassium alkalis or their mixture.

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Effect of the composition of the soap on the skin.

There are a great many varieties and brands of soaps, and before choosing the most suitable one, you need to determine the type of your skin.

Oily skin is often shiny due to intense sweat - and fat secretion, and usually has large pores. Within 2 hours after washing, oily skin leaves spots on the napkin applied to the face. This skin requires soap

with a slight drying effect.

Dry skin is thin and very sensitive to wind and weather, and the pores on it are small and thin; it cracks easily, as it is not elastic enough. Such skin needs to create maximum comfort and gentle treatment, it is better

use expensive soaps.

Normal skin is soft, smooth and has medium pores. This kind of skin "glows", but does not shine. However, normal skin, like any other, needs gentle care.

Soap made from short carbon fatty acids (lauric and myristic) and from long carbon unsaturated fatty acids (oleic). Irritating to skin. Non-irritating soap made from saturated fatty acids with long carbon chain (palmitic and stearic). Alkaline and acidic soaps can irritate the skin by exposing it to microbial attack. Better to use neutral soap

Raw materials for soap production

Animal and vegetable fats, fat substitutes (synthetic fatty acids, rosin, naphthenic acids, tall oil) can be used as raw materials for obtaining the main component of soap. Animal fats - an ancient and very valuable raw material of the soap-making surface. They contain up to 40% saturated fatty acids. Artificial, that is, synthetic, fatty acids are obtained from oil paraffin by catalytic oxidation with atmospheric oxygen. The paraffin molecule breaks down during oxidation into different places, and a mixture of acids is obtained, which are then separated into fractions. In the production of soap, mainly two fractions are used: C10-C16 and C17-C20. In laundry soap, synthetic acids are added in an amount of 35-40%. For the production of soap, naphthenic acids are also used, released during the refining of petroleum products (gasoline, kerosene, etc.). For this purpose, oil products are treated with sodium hydroxide solution and an aqueous solution of sodium salts of naphthenic acids (monocarboxylic acids of the cyclopentane and cyclohexane series) is obtained. This solution is evaporated and treated with table salt, as a result of which a greasy mass of dark color - mylonft - floats to the surface of the solution. For purification, soap is treated with sulfuric acid, that is, naphthenic acids themselves are displaced from the salts. This water-insoluble product is called asidol, or asidolmylonft. Directly from asidol, only liquid or, in extreme cases, mild soap can be made. It has an oil smell, but it has bactericidal properties.

In the production of soap, rosin has long been used, which is obtained by processing the resin of coniferous trees. Rosin consists of a mixture of resin acids containing about 20 carbon atoms in the carbon chain. 12-15% of rosin from the mass of fatty acids is usually introduced into the composition of laundry soap, and no more than 10% into the composition of toilet soaps. Introduction of rosin into large quantities makes soap soft and sticky.

Soap making technology.

Obtaining soap is based on the saponification reaction - hydrolysis of esters of fatty acids (that is, fats) with alkalis, as a result of which alkali metal salts and alcohols are formed.

In special containers (boilers), heated fats are saponified with caustic alkali (usually caustic soda). As a result of the reaction, a homogeneous viscous liquid is formed in digesters, which thickens upon cooling - soap glueconsisting of soap and glycerin. The fatty acid content of soap made directly from soap glue is usually 40-60%. Such a product is called “ adhesive soap". The method of producing adhesive soap is commonly called the "direct method".

The "indirect method" of obtaining soap consists in the further processing of soap glue, which is subjected to salting - processing with electrolytes (solutions of caustic alkali or sodium chloride), as a result of which liquid stratification occurs: the upper layer, or soap core... Contains at least 60% fatty acids; bottom layer - soap lye, an electrolyte solution with a high content of glycerin (also contains contaminants contained in the feedstock). The soap obtained as a result of the indirect method is called “ sound».

The highest grade of soap - sawed, obtained by grinding dried sound soap on rollers pillary cars. At the same time, the content of fatty acids in the final product increases to 72-74%, the structure of the soap is improved, its resistance to drying out, rancidity and the action of high temperatures during storage. When caustic soda is used as an alkali, solid sodium soap is obtained. Mild or even liquid potassium soap is formed when caustic potash is applied.

And now we will talk about soap production technology. For the preparation of a simple solid soap, take 2 kg of caustic soda and dissolve in 8 kg. water, bring the solution to 25 ° C and pour it into melted and cooled to 50 ° C lard (lard must be unsalted and take 12 kg 800 g for the specified amount of water and salt). The resulting liquid mixture is thoroughly stirred until the whole mass becomes completely homogeneous, after which it is poured into wooden boxeswell wrapped in felt and placed in a warm, dry place. After 4-5 days, the mass hardens and the soap is ready.

To get good toilet soap for every 100 g of pork fat take 5-20 g of coconut oil. Make sure that the resulting soap is neutral. For this purpose, it is salted several times and then boiled. After the last salting, boiling continues until the sample taken with a glass rod on the plate is completely satisfactory, that is, when the mass is squeezed between the fingers, hard plates are obtained that should not break.

The dyes used to tint toilet soap can be very diverse. The main conditions that they must satisfy: be strong enough, mix well with soap and

do not have a harmful effect on the skin.

The red color for a transparent soap is obtained using fuchsin and eosin; for opaque soaps, cinnabar and red lead are used.

The yellow color of the soap is due to turmeric extract and picric acid.

To obtain green soap, aniline green or chrome green paint is used.

The brown color of soap is formed from light or dark brown aniline dye or burnt sugar. In the manufacture of toilet soap, perfumery plays an especially important role. The fact is that a perfume should not only be pleasant, but it should also retain its smell for a long time and even, if possible, improve upon lying and drying the soap. Therefore, when perfuming, the first question is at what temperature the soap should be perfumed. Then, what is the effect of alkalis on the used odorous substances. And, finally, are these odorous substances well preserved in alkalis?

Good soap has a pleasant, unobtrusive smell due to the perfume additives introduced into it - fragrances. Special varieties of soaps also include antiseptics (triclosan, chlorhexidine, salicylic acid) and biologically active substances, including those obtained from natural raw materials of medicinal plants.

Soap making technology at home

In order to make soap at home, you must follow the following sequence of operations:

1. Fill a glass ½ with water, place it on a tripod with a metal mesh and boil the water.

2. Pour castor oil and sodium hydroxide solution into a cup for evaporation.

3. Place the cup for evaporation on a glass of boiling water and heat for 10-15 minutes, stirring its contents with a glass rod.

4. Add saturated sodium chloride solution and mix.

5. Cool the cup with the contents.

6. Using a spatula, collect the soap, mold from it two pieces the size of a grain of rice.

You can aromatize the resulting soap with the help of plant extracts, using for this purpose such plants: currant leaves, needles, calendula flowers, chamomile.

Soap applications.

In addition to using soap as a detergent, it is widely used in bleaching fabrics, in the production of cosmetics, for the manufacture of polishing compositions for water-based paints.

In everyday life, not to mention industry, various objects and objects are subjected to the washing process. There are a wide variety of pollutants, but most often they are slightly soluble or insoluble in water. Such substances, as a rule, are hydrophobic, since they are not wetted with water and do not interact with water. Therefore, various detergents are also needed.

If we try to define this process, then washing can be called cleaning a contaminated surface with a liquid containing a detergent or a system of detergents. Mainly water is used as a liquid in everyday life. A good cleaning system has a dual function: to remove dirt from the surface to be cleaned and to transfer it to an aqueous solution. This means that the detergent must also have a double function: the ability to interact with the pollutant and the property to convert it into water or an aqueous solution. Therefore, the detergent molecule must have a hydrophobic and hydrophilic portion. Phobos in Greek means fear. Fear. Hence, hydrophobic means "fearful, avoiding water." "Phileo" in Greek means "love", hydrophilic - loving, holding water. The hydrophobic moiety of the detergent molecule has the ability to interact with the surface of the hydrophobic contaminant. The hydrophilic part of the detergent interacts with the water, penetrates into the water and carries with it a particle of contaminant attached to the hydrophobic end.

In this way, detergents must have the ability to adsorb on the boundary surface, that is, have surfactants (surfactants).

Heavy carboxylic acid salts such as CH3 (CH2) 14COONa are typical surfactants. They contain a hydrophilic part (in this case, a carboxyl group) and a hydrophobic part (a hydrocarbon radical).

Practical work

"Secrets of Soap Making".

Objective: to study the process of saponification of higher fatty acids.

Having studied the theory, we will try to get soap in practice by cooking it in an artisanal way.

To make our soap safe for health, we will use natural raw materials.

We use as equipment and raw materials:

Round flat-bottomed flask with a capacity of 1000 cm3,

Glass rod,

Tripod with fixtures,

Alcohol lamp,

Porcelain glasses with a capacity of 500 cm3 and 200 cm3,

Porcelain spoon,

Tweezers,

Technical scales,

Glass beaker with a capacity of 100 cm3,

Beef fat 70g,

Pork lard 30g,

Ethyl alcohol 20 ml,

Na2CO3 solution,

NaCl solution 20% 200 ml,

Eucalyptus oil 2 drops, a fragrance dissolved in alcohol, 5X5 cm scraps of cloth,

· Mold for pressing soap.

Working process: And so let's start by getting a high quality sound soap.

· Weigh 70 g of beef and 30 g of pork fat on a technical scale and place it in a 1000 cm3 flask fixed in a stand.

· Prepare a solution of soda ash Na2CO3 (25 g Na2CO3 + 30 ml H2O).

· Add 20 ml of ethyl alcohol to the flask. It will help dissolve, contact non-polar fat in polar alkali.

· Carefully, while heating and stirring, add the prepared alkali solution Na2CO3.

· The reaction of saponification of fat takes place only when heated. A reaction is indicated by the appearance of soap.

· Pour 20% NaCl solution into the resulting mixture and again heat the mixture until the soap is completely separated.

· Unlike hot water, soap hardly dissolves in sodium chloride solution. Therefore, when salting out, it separates from the solution and floats.

Let the mass cool down a little, collect the separated layer of soap with a spoon on a piece of fabric, wrap it (you need to work in rubber gloves!) and rinse in cold water.

· Slightly squeezing, transfer it to another piece of fabric.

· Let's check the pH of the soap (normal pH is 6-7). It was higher for us, so we salted off the soap again and washed it with water.

Our second experience will be getting toilet soap.

To obtain toilet soap, grind and knead the sound soap. Then add 2 drops of eucalyptus oil to the soap (essential oil, liquid, yellow, antiseptic and anti-inflammatory).

Studying the properties of soap

To study the properties of soap, it is necessary to carry out a series of experiments confirming its detergent properties. To do this, you should:

1. Pour 5 ml of distilled water into one test tube, the same amount of tap water into the other, place a bar of soap in each.

2. Cap and shake both tubes simultaneously for a few seconds.

3. Place the tubes in a rack and use a stopwatch to determine how long the foam remains in each tube. In a test tube with distilled water, foam lasts - 30 seconds, and with tap water - 10 seconds.

4. Mark the type of contents of each tube. The solution became cloudy from soap in two test tubes.

5. Using universal indicator paper, determine the acidity of the soap solution. The soap solution has weak alkaline environment.

6. The presence of glycerin in the reaction mixture can be detected by a qualitative reaction for polyhydric alcohols, ie, by adding freshly prepared copper hydroxide. When copper hydroxide was added to the test tubes, the solution turned bright blue.

Conclusions:

Homemade soap smells good, foams and lathers well, has antibacterial properties and is environmentally friendly;

· Soap has a slightly alkaline reaction of the environment;

· Gives a characteristic reaction to the content of glycerin.

Literature:

1. Aleksinsky experiments in chemistry - M., 1995

2. Bogdanov. Laboratory works. 8 - 11 cl .: Textbook. manual for educational institutions. - M .: Astrel ": AST", 2001. - 112s .: ill.

3. Great Soviet Encyclopedia (in 30 volumes). Ch. ed. ... Ed. 3rd M., "Soviet Encyclopedia". 1972.T.17 Morshansk - Blueberry. 1974.616s.

4. Grosse, Weismantel H. Chemistry for the curious - M., 1993

5. Zinoviev fat - M., 1990

6. Selemenev at home - http: // festival. 1 *****

7. Tobbin for soap production - M 1991

8. - Chemistry at leisure - M., 1996

9. Shabanova students' activities - http: // festival. 1 *****

10. Shcherbakov's projects: organization of activities in chemistry - http: // festival. 1 *****

11. I get to know the world: Children's encyclopedia: Chemistry / Auth. - comp. ; Artist. ,. - M .: "Publishing house AST"; 1999 .-- 448s.

Review of the special course « Methodology for solving computational problems in chemistry for students in grades 10-11» chemistry teacher Kulikova N, S.

MOU "Umyganskaya secondary school",from. Umygan, Tulunsky district

This work is part of the program for the study of organic chemistry topic "Fats", an elective course "Chemistry in everyday life."

Valentina decided to study this topic on her own, since she was interested in whether it was possible to get soap at home and whether it would turn out the same as sold in stores.

In this project, the teacher is already acting as a consultant. Knowing this, it can be noted that this work is a continuation of the continuous process of the formation of cognitive interests, skills of research activities, the development of the ability to observe and analyze what is happening during the experiments, the development of skills practical activities and recording the results of observation, and then draw the necessary conclusions based on the results.

The paper presents basic information about the origin of soap, the history of soap making, composition, properties, classification of soap, raw materials for its production and applications.

The study of the theoretical part makes it possible to learn how to cook soap at home so that it is an environmentally friendly product. All these aspects are reflected in this research project.

And the choice of this topic contributes to the development of practical skills, the development of creativity.

The main principle of the work is the student's personal interest in obtaining chemical knowledge. This interest arose in Valentina due to the originality of the project idea and the fascination of the results obtained.

All sections of the project are interconnected and have continuity at every stage.

The work implements the principle of developmental education aimed at obtaining new knowledge through research activities, develops the practical skills of research activities.

But the most important outcome of this project is that it fosters curiosity, exploratory thought, and a sustained interest in chemistry.

Project Manager.

Soap structure, its properties

Soaps are sodium or potassium salts of higher fatty acids (Scheme 1) that hydrolyze in an aqueous solution to form an acid and an alkali.

General formula of solid soap:

Salts formed by strong alkali metal bases and weak carboxylic acids undergo hydrolysis:

The resulting alkali emulsifies, partially decomposes fats and thus releases dirt adhering to the fabric. Carboxylic acids form foam with water, which traps dirt particles. Potassium salts are better soluble in water than sodium salts and therefore have a stronger detergent property.

The hydrophobic part of the soap penetrates into the hydrophobic contaminant, as a result, the surface of each contaminant particle is surrounded by a shell of hydrophilic groups. They interact with polar water molecules. Due to this, the ions of the detergent, together with the contamination, are torn off the surface of the fabric and pass into aquatic environment... This is how the contaminated surface is cleaned with a detergent.

Soap production consists of two stages: chemical and mechanical. At the first stage (soap boiling), an aqueous solution of sodium (less often potassium) salts, fatty acids or their substitutes is obtained.

Obtaining higher carboxylic acids by cracking and oxidation of petroleum products:

Obtaining sodium salts:

FROM n H m COOH + NaOH \u003d C n H m COONa + H 2 O.

The soap boiling is finished by treating the soap solution (soap glue) with an excess of alkali or sodium chloride solution. As a result, a concentrated layer of soap, called the core, floats to the surface of the solution. The resulting soap is called sound, and the process of its separation from the solution is called salting out or salting out.

Mechanical processing consists of cooling and drying, grinding, finishing and packaging of finished products.

As a result of the soap-making process, we get a wide variety of products that you can get acquainted with.

The production of laundry soap is finished at the salting-out stage, while the soap is purified from protein, coloring and mechanical impurities. The production of toilet soap goes through all stages of mechanical processing. The most important of these is grinding, i.e. transferring the sound soap into a solution by boiling with hot water and repeated salting out. In this case, the soap is extremely clean and light.

Washing powders can:

Irritating to the respiratory tract;

Stimulate the penetration of toxic substances into the skin;

Cause allergies and skin dermatitis.

In all these cases, it is necessary to switch to the use of soap, the only drawback of which is that it dries out the skin.

If the soap was cooked from animal or vegetable fats, then from the solution after separation of the kernel, the glycerin formed during saponification is released, which is widely used: in the production of explosives and polymer resins, as a softener for fabric and skin, in the manufacture of perfumery, cosmetic and medical preparations, in production of confectionery.

In the production of soap, naphthenic acids are used, which are released during the refining of petroleum products (gasoline, kerosene). For this purpose, petroleum products are treated with sodium hydroxide solution and an aqueous solution of sodium salts of naphthenic acids is obtained. This solution is evaporated and treated with table salt, as a result of which an oily mass of dark color - mylonoft - floats to the surface of the solution. To clean mylonft, it is treated with sulfuric acid. This water-insoluble product is called asidol or asidol-mylonft. Soap is made directly from asidol.

Kornei Chukovsky, in the lines "Long live fragrant soap ...", urged children to cleanliness and hygiene, which at the beginning of the 20th century, as well as in postwar Russia, was especially relevant.

Do I need to use soap today, is it safe to wash it every day, and what are the main functions of soap?

An analysis of more than a dozen studies carried out in scientific laboratories around the world has shown that daily hand washing with soap and water reduces the incidence of viruses during epidemics by 21%, and infection with gastrointestinal infections by 31%.

This proves to us once again that you need to wash your hands with soap. A piece of solid toilet soap today is a necessary hygiene product that every family has, it is used by adults and children.

It is interesting that the first soap in our country was only a luxury item. In the XIV-XV centuries, soap was given for special occasions: on birthdays and weddings. But what can I say, if even 80 years ago (in the childhood of our grandmothers) soap was in short supply. Hair was cleaned with water with bread and ash, linen was washed with coastal clay soil or soda.

The very solid soap that is sold in stores today was invented in the 8th century by the famous Arab alchemist Gabir ibn Haen. Almost 9 centuries have passed until Russian Empire for the first time they began to produce soap in an industrial way. But despite this, until the middle of the 19th century, only noblemen used soap.

At this time, the first washstand appeared, and in aristocratic circles, ladies gathered for a fashionable action - washing with soap. The 20th century greatly changed the field of use of soap, since it was at this time that synthetic detergents and various chemical additives appeared. It is interesting that it was in Russia in 1912 that the first synthetic surfactants without fats were invented, but they did not find widespread distribution. Subsequently, already in 1930, the production of these substances was launched by the Americans, thanks to which today we have washing powders, shampoos, liquid soaps.

To understand how safe it is to use soap, let's analyze its composition.

Soap composition

Solid soap:

a mixture of salts of higher fatty acids (lauric, oleic, stearic, palmitic),
glycerol,
flavors,
dyes.

Get solid soap by the reaction of saponification of oils and fats with sodium hydroxide (alkali). Solid soap is always alkaline as it contains sodium hydroxide residues.

Liquid soap:almost always obtained on the basis of synthetic surfactants (surfactants).

Difference from solid soap: gives good foam due to surfactants, less alkaline pH, the presence of various softening and moisturizing additives.

The main functions of soap

Cleansing dirt and hand hygiene

The soap molecule consists of two parts: hydrophobic (afraid of water) - it contains long organic radicals and, due to this, copes with pollution, and the hydrophilic part contains a carboxyl group, which is responsible for the interaction of the molecule with water.

Antibacterial function of soap

Specialists are developing all new components to fight pathogenic bacteria on the skin's surface. Today, there are two of the most common antibacterial ingredients, triclosan and triclocarban, which are registered with the US EPA as hazardous pesticide ingredients. The worst thing is that these components are very persistent, and when we flush them down the drain, they end up in rivers and lakes.

A study of the water composition of the Great Lakes, located in Canada and feeding the Atlantic Ocean (the most famous Lake Michigan), showed that triclosan was found in 90 percent of water samples and in many fish. What we use every day and pour into the sewer will certainly return to us as a result of the cycle. Triclosan is even found today in samples breast milk... In our country, triclosan and triclocarban are permitted ingredients in soap.

According to dermatologists, excessive use of antibacterial soap can lead to unpleasant consequences: allergies and disorders of the skin microflora.

The well-known dermatologist Irina Skorogudaeva in many of her interviews has repeatedly emphasized that ordinary solid soap, and even more so antibacterial, together with harmful ones, destroys beneficial microorganisms on the skin surface. In addition, triclosan soap, when used continuously, can be addictive, as it leads to microbial resistance and even their mutation. Studies have shown that hospital bacteria such as Pseudomonas aeruginosa are generally resistant to its action.

There are several works devoted to the acquisition of microbial resistance to antibiotics under the influence of triclosan. Doctors advise using this soap only in unsanitary conditions. The FDA (TheFoodandDrugAdministration) banned the use of triclosan in soap for general production in 2016. Buy triclosan soap in America is now only possible with a prescription in pharmacies.

Cosmetic function of soap

In modern conditions, soap products are used as a cosmetic or care cleanser for the face. Experts add ingredients that are gentle to the skin, nourish, wound healing, moisturizing and radiant. However, dermatologists advise using only soaps for the face, obtained from natural oils (olive, coconut) or special foams and mousses containing mild surfactants.

Is it safe to use soap?

To answer this question, we turned to specialists, as well as to scientific literature. It is known that a person needs skin in order to restrict the body from an aggressive external environment. The aggressor can be sudden changes in temperature, humidity, various sources of pollution, UV radiation, pathogenic microorganisms, as well as cleaning agents such as soap. The protective function of the skin is performed by the upper lipid layer located in the stratum corneum. The lipid layer consists of free fatty acids, ceramides and cholesterol, and has an acidic pH of about 4.5-5. Maintaining pH at this level is extremely important for healthy skin and microflora (LambersH.Int.Cosmet.Science 2006, 28, p. 359).

In dermatology, there is even such a thing as the acidic mantle of the stratum corneum. The physiological role of such an acidic mantle is to protect against the effects of various microorganisms. It is very easy to break this mechanism. For example, washing your face frequently with hot water and regular solid soap or liquid cleansers containing sodium laureth sulfate or another aggressive surfactant.

The lipid layer is extremely easily soluble with solid soap, as well as with various harsh surfactants.

If the lipid barrier leaves the skin, then water leaves the skin, and at the same time the acidic environment on the surface is disturbed and the pH rises. Scientists have calculated that normal skin with a slightly acidic environment (pH5-5.5) can be in contact with soap for no more than 10-15 seconds without consequences. It will take about an hour to restore protective layer epidermis after washing with such soap.

There are many reports in scientific articles from Australia, Germany, Japan that the continuous use of soap or an alkaline cleanser significantly raises the pH of the skin (Duncan C.N. The effect of anacid icclean server sus soap on the skin pH and micro-flora of adult patients : anon-randomized two group crossover study in anintensive care unit.Intensive Crit Care Nurs 2013; 29, 291). Korting et al reported that the pH of the skin surface increased to as high as 8.5 with continuous use of soap on the face and forearm (Korting H.C. Int.J. Cosmet.Science 1991; p.91).

Research in America has shown that pH also affects the protective function of the skin. The skin of bald mice was exposed to acetone and then the pH was measured. It was found that the protective barrier function of the skin was restored faster in the presence of an acidic solution compared with a neutral one. In an article in the Journal of Investigative Dermatology, Hatano and others showed that maintaining an acidic environment in the lipid layer using alpha hydroxy acids (AHA) and beta hydroxy acids (BHA) prevents dermatitis in mice. Scientists have found that acidic topical agents are capable of treating various dermatoses (Hatano Y.J. Invest.Dermatol., 2009, 129: 1824-1835).

These acids are now included in many pharmaceutical cosmetics, as well as in products used in the treatment of skin diseases.

About soap handmade

When choosing a beautiful handmade soap, you should pay attention to its composition, as well as information about the manufacturer. Some manufacturers use a chemical alkaline base as the basis for hand-made soap. At the same time, the composition of such a soap will practically not differ from the usual bar soap. Often many colors and fragrances are added to hand-made soaps, and the word “natural” is also written in order to attract the buyer. The best natural soaps are made by hand using only natural vegetable oils. For example, coconut, olive, palm. It is worth saying that the cost of such a soap in Russia cannot be less than 150-250 rubles.

pH of the skin for various diseases

Lipid layer at correct work able to resist various microorganisms, as well as external factors. Normal flora growth is optimal at acidic pH values, while pathogenic bacteria such as S. staphylococcus thrive at neutral pH (KörtingH.C. ActaDerm.Venereol. 1990). An increased pH value has been observed in studies of the skin in various diseases. The study involved 100 children with atopic dermatitis. It has been reported that the pH of their skin is significantly higher than that of healthy children. Dermatologists also found that skin pH was higher in patients with ichthyosis vulgaris (5.3 ± 0.7) than in healthy subjects (4.5). The enzymes responsible for peeling in ichthyosis are pH dependent, changing which interferes with the normal peeling process. Therefore, for the treatment of this disease, lactic acid preparations are used worldwide (ActaDermVenereol 2013, 93, Skin pH: From Basic Science to Basic Skin Care, SabaM. ALIandGil Yosipovitch)

In people suffering from contact dermatitis, as well as mycosis of the feet, higher pH values \u200b\u200bwere recorded compared to healthy people.

Finally, a study on teenagers with acne. Invitro bacteria that cause acne, at pH 6.5, actively multiplied, and at a pH of less than 6, the growth noticeably decreased. In a study carried out over four weeks , acne lesions increased in the solid soap group. The skin pH of adolescents using acid-containing liquid cleansers decreased (KörtingH.C. Clin.Dermatol, 1996, 14, P.23.KörtingH.C. Infection 1995, 23: P. 89).

All these works prove once again that patients suffering from skin diseases should not use bar soap or other alkaline detergents. This will only make their illness worse.

Problematic skin is often alkaline, so it needs to be acidified regularly rather than alkalized further with soap. For this, it is desirable that the facial cleanser contains natural and synthetic acids (lactic, grape, malic, tartaric, citric acid, salicylic acid), as well as prebiotics.

Tips for using soaps and cleansers for face and body

Solid or liquid soap?

Since ordinary solid soap, as a rule, contains alkali residues in its composition and its pH is always too high, it is best to use such soap only for hands and feet. If possible, purchase a solid soap made from natural oils.
Liquid soap, as well as various shower gels, provide good lather due to surfactants. Therefore, their pH is less alkaline. However, the presence of "hard" surfactants (for example, sodium laureth sulfate) makes such a product difficult to wash off the skin. Some people report that after using shower gels, they have a persistent chemical feeling on their skin. Therefore, when choosing a liquid soap or gel, you must pay attention to the composition of the product.

First of all, you need to choose soap depending on which part of the body we want to use it and for what purpose (cleansing from dirt, bacteria or for cosmetic purposes).
It is recommended to use solid soap only for washing hands and feet where the skin is less sensitive. It is good to use such soap for disinfection and cleaning of dirt every day. Hands should be washed in warm water and soap.
It is better to choose baby soap as a solid soap. All components are subject to strict quality control. These soaps often contain natural plant extracts, which give them antiseptic properties.
Liquid soap and cream soap, in which the pH is from 5.5 to 6-7, can be used to wash the body, but not daily, but 2-3 times a week in combination with warm, but not hot water.
When choosing liquid soaps as well as facial cleansers, read the ingredients carefully. It is better to choose products that contain mild surfactants: any glucosides, Decylpolyglucose, betaine, polyglycosides, Cocamidopropyl Betaine, sodium cocoylisethinate, Sodiumcoco-sulfate, sulfosuccinate, Sodium sulfosuccinate, Glythereth Cocoate, Disodium Cocoamphodiacetate la, Magnryl sulfate. The less the product foams or lathers, the less surfactant it contains, the better.
You should not buy liquid soap that contains dyes and a large amount of perfume. In general, it is better for the liquid soap to have not even a transparent color, but slightly cloudy. This once again indicates that complexes of correctly selected “soft” surfactants have been added to it.
If your skin is problematic, then choose products with an acidic pH (less than 6).
For cleansing delicate or sensitive skin, intimate hygiene products are also suitable, which are not allergenic, but at the same time they remove dirt well.
In order to correctly choose a means for cleansing your face, it is better to contact a dermatologist who will select it according to your skin type.
Do not use soap containing triclosan or its analogues, even for washing your hands. Only in urgent unsanitary cases.
If you have time, try to cleanse your face and neck using natural ingredients prepared at home.

Natural Facial Cleansers Recipes

Recipe number 1. Means for all skin types, simple preparation

For all skin types, cleanse with natural yoghurt without additives. If your skin is oily, mix 1 tablespoon of yogurt and 1 teaspoon of lemon juice. Apply the mixture to your face, avoiding the skin around the eyes. Rinse off with warm water.

Recipe number 2. For oily skin, based on honey

¼ cups of water
¼ cups of lemon juice
½ cup oatmeal
½ tablespoon honey
Place all ingredients in a bowl and mix. Apply the mixture to a wet face and leave for 15 seconds, rinse with warm water.

Recipe number 3. Summer based on cucumber

½ cup yogurt
½ cucumber
5 mint leaves

Place all ingredients in a blender, grind and apply to a pre-moistened face, rinse with warm water.

It's hard to put into words how I like natural solid soap - in my family it is in higher esteem than shower gel or liquid hand soap.

Today I will tell you about the most impressive organic products to me. And I'll start, by tradition, with those ordered on the Iherb website.

South of France soap with aicherb I really like the ergonomic oval shape (it is convenient to hold it in your hands), economical consumption and, of course, natural composition. My favorites of the tried ones - lavender Fields lavender soap (link) and with provencal herbs Herbes De Provence (link). Lavender smells very naturally of lavender, and soap with Provencal herbs has an unobtrusive herbal scent.
This soap does not dry out the skin, which is also a big plus.
Volume: 170 g
Price: 130 RUB
The composition of the soap with Provencal herbs: Mass balance sustainable palm oil, saponified coconut oil, vegetable glycerin, organic shea butter, natural colorants, blends of natural and essential oils and fragrance.

Another “soap” brand with Iherb that I love dearly is One with nature (in the title photo - their soap in the center). They have large bars of soap (200 g), which are nevertheless nice and comfortable to hold. They are consumed for a very long time, the skin does not dry out, although it is washed off until it “creaks”. I like lavender soapalthough I warn you that it has a very strong, ethereal scent that can be felt as soon as you open the package (link to this soap).
Even more than lavender One with Nature, I like dead Sea mud soap, Dead Sea Mud Soap Bar (link to this soap). It is valuable not for its aroma (soap practically does not have it), but for small exfoliating particles - I really like this effect of the scrub when washing hands and washing the body.
But there are also less, in my opinion, good example — soap One with Nature with mint Triple Milled Soap, Peppermint (link). I took it for the summer, hoping for a cooling menthol effect. At first, the soap smelled pleasantly of mint, then the usual soapy smell began to appear in it (almost like a "household" one). In addition, it seemed to me that this soap dries the skin a little.

Weight: 200 gr.
Price: 142 RUB
In the photo - soap with mint:

The composition is good:

Scented soap HONEYMANIA ™ by The Body Shop No wonder it is called fragrant: it smells fragrant for the entire bathroom. Moreover, in my opinion, the smell is more like honey acaciathan honey, which is a big plus for me.
I liked the design (the soap is translucent) and small size, when soaked, the soap is pleasantly slippery, foams well. Does not wet, does not dry the skin.

Weight: 100 g
Price: RUB 150

Composition: sodium palmate soap base is palm oil, which is very good.

Pleasantly pleased soap and from Weleda... I tried soap with calendulathat can be used for both adults and children, and rosemary soap... They differ, it seemed to me, only in aromas - they are rather weak, they do not remain on the skin. But the soap does not dry at all, I even tried to wash my face with it.
Composition of rosemary soap: soap base of palm, coconut and olive oils, rosemary oil, glycerin, a mixture of natural essential oils, malt extract, table salt.
Composition of calendula soap: soap base of palm, coconut and olive oils, water, glycerin, a mixture of natural essential oils, extracts of calendula flowers, chamomile, orris root and tricolor violet, rice and malt, table salt.

Weight: 100 g
Price: 337 r

It seemed wonderful to me clear soap from L'Occitane: Zhenipalu soap has a very pleasant fruity-floral aroma, and "Victoria Regia" - floral-aquatic. Scent the whole bathroom, buzz! Unfortunately, the fragrance on the skin does not last long, but soap is needed and not for this. It copes with all the main functions perfectly, does not dry out (despite the fact that the soap base is palm oil mixed with less natural sodium stearate), does not soak in water, foams well. It's even a pity that he has such a small size (75 g).

Weight: 75 gr.
Price: RUB 250

The composition of the soap "Zhenipalu":

On the right in the photo - leaf soap from L'Occitane Verbena. I love him for his beauty 🙂

Contains exfoliating particles, the aroma is pleasant, but weakly expressed. In this sense, it loses to transparent "Zhenipal" and "Victoria Regia", but wins in design and composition (there is no sodium stearate).

Weight: 75 gr.
Price: 320 RUB
Composition:

Another interesting soap sold in the Caucasus and on the Internet, - "Tamba"... My mother brought it to me from a Caucasian resort.

Soap contains tambukan healing mud, exfoliating particles of volcanic pumice, coffee and many other benefits.
Well, his promises are very loud.

Damn it made me believe them 😀 The instructions for the soap say that it can be used as a mask. I left this soap for just a couple of minutes: as much as then, my face has never burned in my life. I thought I wouldn't live to see the morning :)))) There was nothing to "extinguish" the skin.
But for hands and especially for the body (for priests and thighs, for example, there is pumice and coffee in the same place!) this soap is a great thing!
And the design is cool:

Weight: 80 gr.
Price: RUB 150

Here is such a hefty review I got.
Maybe you will share your soap favorites? I want to try something new 🙂