Surfactants - what are they, why, and should we be afraid of them? Surface-active substances (surfactants). Definition, composition, classification and scope

Needs National economy in surfactants are enormous. Their production around the world is increasing every year. From what raw materials are huge quantities of various surfactants obtained?

We have already said that until the mid-60s, mainly natural surfactants were used. The main volume of surfactants was obtained by relatively simple processing of restricted raw materials of animal and, less often, plant origin. Some of these substances, which have proven themselves in industry and in everyday life, have not lost their importance. This is explained not only by the fairly high efficiency of their action, but also to a large extent by their low cost.

Food-derived surfactants are mentioned in various sections of the book.

Non-sulfonated compounds - no more than 3; sodium sulfates and sulfites - no more than 15. Sulfanol is available in two types - liquid (active substance content of at least 45%) and powder (100% active substance).

Azolates (A, B, A-2) - a mixture of sodium salts of alkyl benzene sulfonic acids. It is obtained from kerosene-gas oil fractions of oil in the form of pastes that are highly soluble in water. Average molecular weight 300-350, active substances 50-70%, water 20-35%; belong to the “biologically soft” Kim" Surfactant Biodegradability in wastewater at an initial surfactant concentration of 20 and 10 mg/l is 85 and 95%, respectively. The surface activity of azolates is quite high: the surface tension for azolate A and azolate B is 31.2 and 35.6 N/m, respectively, at a concentration of 0.1%, and 27.9 and 30.0 at a concentration of 0.5%. N/m.

Calcium salts of alkylaryl sulfonic acids - high molecular weight alkylaryl sulfonate. It is obtained from the condensation products of catalytic cracking reflux and cracking kerosene, followed by sulfonation and neutralization. The average molecular weight is from 40 to 500. The content of active substances is 14-15%, water up to 80%. Significantly reduces the surface tension of water (up to 37 N/m) already at a solution concentration of 0.25%. Gives high expansion and stable foam. Effective in cementitious materials, clay suspensions.

Disodium salts of sulfocarboxylic acids - mixture High molecular weight acids with more than 18 carbon atoms. General formula

R - CH - COONa I

Biodegradability in wastewater reaches 90-95%. Cheap and abundant raw materials are obtained using simple technology, which makes disodium salts of sulfocarboxylic acids promising surfactants for producing medium expansion foams.

Nekal mixture sodium salts of mono-, di- and triiso-butylnaphthalene sulfonic acids. Mainly composed of dialkyl derivatives

(iso-C4H 9)2C 10H 5SO 3Na

The polar group is SO 3Na. Non-polar part - cyclic and aliphatic hydrocarbon radicals.
In appearance it is a non-separating paste containing 20-40% moisture.

Sodium lauryl sulfate - general formula R0S03Na, and de R = C9-C15. This is the cheapest foaming agent. Note that that potassium lauryl sulfates give a higher multiplicity (almost three times) compared to sodium salts. Parctic use is found Also neutralization products of trieth lauryl sulfate - nolamine.

Hydroxyethylene sodium lauryl sulfate- Condensation product of ethylene oxide and C,2-Sm fatty alcohols, followed by treatment with chlorosulfonic acid and neutralization with NaOH. It has been established that with an increase in the number of carbon atoms in an alcohol molecule, solubility in an alkaline medium decreases; Of greatest practical interest are the more accessible alcohols with an odd number of carbon atoms in the molecule (C,-C15).

Foam concentrates PO-1 and PO-1A - liquids from yellow to Brown, without sediment and foreign inclusions.

PO-1 is obtained by neutralizing kerosene contact. Contains at least 45% sulacids. To ensure high expansion and durability of the foam, 3.5-5.5% bone glue and 10% ethyl alcohol or ethylene glycol are added to the composition.

PO-1 A is a mixture of sodium alkyl sulfates based on sulfuric acid esters of secondary alcohols with the number of carbon atoms in the alkyl radical from 8 to 18. The active substance content is not less than 20%.

These foam concentrates are designed to produce fire extinguishing foam. When using high-expansion foam generators (fire trucks are equipped with such installations) from 2-5% aqueous solutions

4-111
These foaming agents produce stable foam with a multiplicity of 70-150. This foam extinguishes burning petroleum products well.

Substance to Progress" - a mixture of sodium salts of sulfuric acid esters of secondary alcohols with the carbon number in alkyl radicals from 6 to 16. Serves as a detergent in a number of synthetic detergents, produced by domestic industry.

Salts of alkylamines and salts of tetrasubstituted Ammo-i Nyl-these cationic substances are obtained on the basis of | amines to varying degrees substitution, quaternary ammonium-1 and other nitrogen-containing bases (hydrazines, guanidine, heterocyclic compounds).

RNHT - HCI- hydrochloride salt of an alkylamine, where I R is a hydrocarbon radical from Сі0Н2і to С20Н41;

RR"R"R""NCI-coflb tetra-ammonium,! where R is a long hydrocarbon radical with 12-18 carbon atoms, and R"R"R"" are short hydrocarbon radicals (CH3 or C2H5).

OP-7, OP-Yu, syntanol DS-10- Substances of nonionic type. All of them are products of the interaction of phenol, alkylphenols OR HIGH FATTY ALCOHOLS with yu Cjg with HЄ-1 how many moles of ethylene oxide by reaction

ROH + nH2q-CH2 R(OCH2CH2)/JOH

Where R is the hydrocarbon radical from C10H21 to C20H41.

Organosilicon compounds - characterized by high surface activity, some of them can be used as foaming agents in the production of waterproof materials. The most common
Valuable compounds of this class in domestic practice are ethylchlorosilanes (GKZh-94), methyl and ethyl silconates (GKZh-10 and GKZh-11).

The development of new synthetic surfactants is carried out in more than ten academic and industrial research institutes of the country. Surfactants are created with a set of specially specified properties, which, in addition to high foaming ability, must have low toxicity and weak physiological activity, high biodegradability and many other properties important for practice.

Surfactants (surfactants) are, as a rule, chemical substances, which are found in any cleaning product, even regular soap. It is thanks to surfactants that the cleaning product cleans.

Why are surfactants needed?

The problem is that dirt, especially grease, is very difficult to wash off with water. Try washing your oily hands with water. The water will drain without washing away the fat. Water molecules do not stick to fat molecules and do not take them with them. Therefore, the task is to attach fat molecules to water molecules. This is exactly what surfactants do. A surfactant molecule is a sphere, one pole of which is lipophilic (connects with fats), and the other is hydrophilic (connects with water molecules). That is, one end of a surfactant particle is attached to a fat particle, and the other end is attached to water particles.

How do surfactants affect our health?

Most of The moisture in the human body also has a fatty base. Those. For example protective layer skin (lipids - fats that protect the skin from various bacteria entering the body) is a fatty film and is naturally destroyed by surfactants. And the infection attacks the place that is least protected, which is of course harmful to human health. Experts say that after using a detergent, the protective layer of the skin should have time to recover within 4 hours to at least 60%. This established by GOST hygiene standards. However, not all detergents provide such skin restoration. And fat-free and dehydrated skin ages faster.

In addition, non-biodegradable surfactants can accumulate in the brain, liver, heart, fat deposits (especially a lot) and continue to destroy the body long time. And since almost no one can do without detergents, surfactants are constantly replenished in our body, causing continuous harm to the body. Surfactants also affect reproductive function in men, similarly radioactive radiation.

The problem is made worse by the fact that our wastewater treatment plants do a poor job of removing surfactants. Therefore, harmful surfactants return to us through the water supply in almost the same concentration in which we pour them into the drain. The only exceptions are products with biodegradable surfactants.

What types of surfactants are there?

Anionic surfactants. The main advantage is the relatively low cost, efficiency and good solubility. But they are the most aggressive towards the human body.
- Cationic surfactants. They have bactericidal properties.
- Nonionic surfactants. The main advantage is its beneficial effect on fabric and, most importantly, 100% biodegradability.
- Ampholytic surfactants. Depending on the environment (acidity/alkalinity), they act as either cationic or anionic surfactants.

How do surfactants affect the environment?

One of the main negative effects of surfactants in environment- decrease in surface tension. For example, in the ocean, a change in surface tension leads to a decrease in the retention rate of CO2 and oxygen in the water mass. And this negatively affects aquatic flora and fauna.

In addition, almost all surfactants used in industry and households, when they come into contact with particles of earth, sand, or clay, under normal conditions can release ions heavy metals, retained by these particles, and thereby increase the risk of these substances entering the human body.

What is a biodegradable surfactant?

One of the main criteria for the environmental safety of goods household chemicals is the biodegradability of surfactants that are included in their composition. Surfactants are divided into those that are quickly destroyed in the environment and those that are not destroyed and can accumulate in organisms in unacceptable concentrations.

Moreover, a distinction is made between primary biodegradability, which implies structural changes in surfactants by microorganisms, leading to the loss of surface-active properties, and complete biodegradability - the final biodegradation of surfactants to carbon dioxide and water. Only completely biodegradable surfactants are safe.

Only some nonionic surfactants, primarily those obtained from biological raw materials rather than petroleum products, are 100% biodegradable.

Bio-surfactant - what is it?

In 1995, ECOVER, together with the French company Agro-Industrie Recherches et Développements (ARD), took part in the European research project, whose goal was to learn how to synthesize surfactants from agricultural waste, such as straw and wheat bran. The project was successfully completed back in 1999, and production on an industrial scale began in 2008.

Nowadays, bio-surfactants form the basis of the entire line of ECOVER brand dishwashing detergents. Test results confirm that such surfactants have a strong cleaning effect, are completely biodegradable and are characterized by low toxicity. It's like a fairy tale where straw turned to gold, but this is a real story.

Before the invention of soap, fat and dirt were removed from the skin using ash and fine river sand. The Egyptians washed their faces with a paste based on beeswax mixed with water. IN Ancient Rome When washing, they used finely ground chalk, pumice, and ash. Apparently, the Romans were not bothered by the fact that during such ablutions, along with the dirt, it was possible to “scrape off” part of the skin itself. The credit for the invention of soap probably belongs to the Gallic tribes. According to Pliny the Elder, the Gauls made an ointment from the tallow and ash of the beech tree, which was used to dye hair and treat skin diseases. And in II century, it began to be used as a detergent.

The Christian religion considered washing the body a “sinful” act. Many "saints" were known only for not washing their entire lives. But people have long noticed the harm and health hazards of skin pollution. Already in the 18th century, soap making was established in Rus', and in a number of European countries even earlier.

The technology for making soap from animal fats has evolved over many centuries. First, a fat mixture is prepared, which is melted and saponified - boiled with alkali. To hydrolyze fat in an alkaline environment, take a little rendered lard, about 10 ml of ethyl alcohol and 10 ml of alkali solution. Table salt is also added here and the resulting mixture is heated. This produces soap and glycerin. Salt is added to precipitate glycerin and impurities. Two layers are formed in the soap mass - the core (pure soap) and the soapy lye .

Soap is also produced industrially.

Saponification of fats can also occur in the presence of sulfuric acid (acid saponification). This produces glycerol and higher carboxylic acids. The latter are converted into soaps by the action of alkali or soda. The starting materials for soap production are vegetable oils (sunflower, cottonseed, etc.), animal fats, as well as sodium hydroxide or soda ash. Vegetable oils They are preliminarily hydrogenated, i.e. they are converted into solid fats. Fat substitutes are also used - synthetic carboxylic fatty acids with a large molecular weight. Soap production requires large quantities raw materials, so the task is to obtain soap from non- food products. The carboxylic acids necessary for soap production are obtained by oxidation of paraffin. By neutralizing acids containing from 9 to 15 carbon atoms per molecule, toilet soap is obtained, and from acids containing from 16 to 20 carbon atoms, laundry soap and soap for technical purposes are obtained.

Soap composition

Conventional soaps consist primarily of a mixture of salts of palmitic, stearic and oleic acids. Sodium salts form solid soaps, potassium salts form liquid soaps.

Soap - sodium or potassium salts of higher carboxylic acids,
obtained as a result of hydrolysis of fats in an alkaline environment

The structure of soap can be described by the general formula:

R – COOM

where R is a hydrocarbon radical, M is a metal.

Benefits of soap:

a) simplicity and ease of use;

B) removes sebum well

B) has antiseptic properties

Disadvantages of soap and their elimination:

Soap structure- sodium stearate.

The sodium stearate molecule has a long non-polar hydrocarbon radical (indicated by a wavy line) and a small polar part:

The surfactant molecules on the boundary surface are arranged in such a way that the hydrophilic groups of carboxyl anions are directed into the water, and the hydrophobic hydrocarbon groups are pushed out of it. As a result, the surface of the water is covered with a palisade of surfactant molecules. Such a water surface has lower surface tension, which facilitates rapid and complete wetting of contaminated surfaces. By reducing the tension surface of water, we increase its wetting ability.

Surfactants (Surfactant) - chemical compounds, which, concentrating on the phase interface, cause a decrease in surface tension.

The main quantitative characteristic of a surfactant is surface activity - the ability of a substance to reduce surface tension at the interface - this is the derivative of surface tension with respect to the surfactant concentration as C tends to zero. However, surfactants have a solubility limit (the so-called critical micelle concentration or CMC), with the achievement of which, when a surfactant is added to a solution, the concentration at the interface remains constant, but at the same time, self-organization of surfactant molecules in the bulk solution occurs (micelle formation or aggregation). As a result of such aggregation, so-called micelles are formed. A distinctive sign of micellization is the turbidity of the surfactant solution. Aqueous solutions of surfactants, during micellization, also acquire a bluish tint (gelatinous tint) due to the refraction of light by the micelles.

• Methods for determining CMC:

1. Surface tension method
2. Method for measuring contact angle with TV. or liquid surface(Contact angle)
3. Spinning drop method

Surfactant structure

Classification of surfactants

• Ionic surfactants
  • Cationic surfactants
  • Anionic surfactants
  • Amphoteric

• Nonionic surfactants
  • Alkylpolyglucosides
  • Alkylpolyethoxylates

Effect of surfactants on environmental components

Surfactants are divided into those that are quickly destroyed in the environment and those that are not destroyed and can accumulate in organisms in unacceptable concentrations. One of the main negative effects of surfactants in the environment is a decrease in surface tension. For example, in the ocean, a change in surface tension leads to a decrease in the retention rate of CO 2 and oxygen in the water mass. Only a few surfactants are considered safe (alkyl polyglucosides), since their degradation products are carbohydrates. However, when surfactants are adsorbed on the surface of soil/sand particles, the degree/rate of their degradation decreases many times over. Since almost all surfactants used in industry and households have positive adsorption on particles of earth, sand, clay, under normal conditions they can release (desorb) heavy metal ions held by these particles, and thereby increase the risk of these substances entering the human organism.

Areas of use

Bibliography

• Abramzon A. A., Gaevoy G. M. (ed.) Surfactants. - L.: Chemistry, 1979. - 376 p.
• Parshikova T.V. Surfactants as a factor regulating the development of algae. - Kyiv: Phytosociocenter, 2004. - 276 p. (in Ukrainian) ISBN 966-306-083-8.
• Ostroumov S. A. Biological effects when exposed to surfactants on organisms. - M.: MAKS-Press, 2001. - 334 p. ISBN 5-317-00323-7.
• Stavskaya S. S., Udod V. M., Taranova L. A., Krivets I. A. Microbiological purification of water from surfactants. - Kyiv: Nauk. Dumka, 1988. - 184 p. ISBN 5-12-000245-5.

see also

Wikimedia Foundation.

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You can buy surfactants (surfactants)we have. Call: (+38 044) 228-08-72.

Surfactants (surfactants)- chemical compounds that, concentrating at the interface, cause a decrease in surface tension.

Due to their washing, wetting, emulsifying, dispersing and other valuable properties, surfactants are widely used in the production of detergents and cleaning products, cosmetics and pharmaceuticals. Latex. Rubber. Polymers. Chemicals protection of plants, textiles, leather and paper, building materials, corrosion inhibitors, during oil production, transportation and refining, etc. Most surfactants (estimated at 55-60%) are used for the production of synthetic detergents (SDCs).

Currently used synthetic surfactants (surfactants) are divided into 4 classes:

• anionic surfactants - compounds that dissociate in aqueous solutions to form anions that cause surface activity. Among them highest value have linear alkyl benzene sulfonate, sulfates and sulfoesters of fatty acids;
• amphoteric (ampholytic) surfactants - compounds that ionize in aqueous solutions and behave depending on conditions (mainly on the pH environment), i.e., in an acidic solution they exhibit the properties of cationic surfactants, and in an alkaline solution - anionic surfactants. Among the main amphoteric surfactants, alkyl betaines, alkylaminocarboxylic acids, alkyl imidazoline derivatives, and alkylaminoalkanesulfonates should be noted.
• nonionic surfactants - compounds that dissolve in water without ionizing. The solubility of nonionic surfactants in water is determined by the presence of functional groups in them. As a rule, they form nitrates in aqueous solution due to the occurrence of hydrogen bonds between water molecules and oxygen atoms of the polyethylene glycol part of the surfactant molecule. These include: polyglycol ethers of fatty alcohols and acids, polyglycol esters of fatty acid amides, acylated or alkylated polyglycol ethers of alkylamides.
• cationic surfactants - compounds that dissociate in an aqueous solution to form cations that determine surface activity. Among cationic surfactants, quaternary ammonium compounds, imidazalines, and fatty amines are of greatest importance.

The main raw materials for large-scale production of surfactants are products of oil refining and petrochemical synthesis: low molecular weight and higher paraffins, olefins, synthetic fatty acids, higher fatty alcohols, alkyl derivatives of benzene and phenol, ethylene oxide, etc.

It is a known fact that the first surfactant - soap - has been “living” for almost 4000 years, but in the 50s it gave way to detergents and cleaners based on alkylbenzenesulfonate. However, 9 million tons of soap are consumed annually in the world. Thus, soap remains the most common surfactant in the world, followed by ABS. Soap, according to strategic marketing estimates, has been in the so-called “saturation phase” for many years. The “phase of degeneration” will certainly never occur as long as humanity lives.

Surfactants in cosmetics

The concept of “Cosmetics” unites a wide range of different products intended for the care of human hair and body. This is hair shampoo and liquid soap; hair dyes; hair care products after washing; rinses, balms, etc.; cosmetic creams for the face, body, hands, including therapeutic and prophylactic effects.

Modern shampoos are multifunctional products that contain various ingredients that provide softness, stability, foaming, and improve appearance and the neck of the hair.
The basis of the raw components of shampoos are surfactants, as well as various useful additives, including biologically active ones.
Anionic substances are used as the main surfactants, which provide a sufficient cleaning effect and foaming while being gentle on the skin and hair.

For conventional commercial shampoos, anionic surfactants (alkyl sulfates and alkyl ether sulfates)
In order to obtain “soft” shampoos, alkyl amidoether sulfates, sulfosuccinates, and, to a lesser extent, isothionates, sarcosinates, etc. are used in mixtures with them.
Auxiliary surfactants include amphoteric, nonionic and cationic substances. They are necessary in shampoo formulations to increase the compatibility of main surfactants with skin and hair, increase foaming properties, regulate viscosity, and reduce the degreasing effect. For this purpose, imidazoline derivatives, betaines, alkylamides, and amine oxides are widely used.
Alkylolamides and glycol ethers of fatty alcohols are used as solubilizers for the introduction of fragrances and other hydrophobic components (oils, biologically active substances).

Cationic, non-ionic surfactants, beta-ins are used as conditioning agents that remove charges of static electricity and make it easier to comb dry and wet hair.

The most effective antistatic agents are cationic surfactants - quaternary ammonium compounds, although there are problems of incompatibility with anionic surfactants. However, in a mixture with nonionic and amphoteric substances, it is possible to achieve the desired effect and maintain the stability of the finished product.
Amine oxides and oxyesters of alkyl phosphates are also used to soften hair and reduce its electrification.

A separate group among shampoos, liquid soaps, and bath foams are made up of especially “soft” formulations intended for children and adults with sensitive skin, i.e., formulations that are extremely soft in terms of their effect on the skin. Here the requirements for raw materials are especially high. Most often, a mixture of alkyl ether sulfates with amphoteric surfactants - imidazoline derivatives, as well as betaines and monoalkyl sulfosuccinates is used as the active principle. The same base is used in anti-dandruff and medicinal shampoos.

Anionic surfactants

The main types of surfactants used in SMS are alkylbenzenesulfonates with a linear alkyl chain (LABS) and derivatives of C12-C15 alcohols (ethoxylates, sulfates, ethoxysulfates of alcohols). LABS and alcohol sulfates, along with soap, are classified as anionic surfactants, while alcohol ethoxylates are classified as non-ionic (non-ionic) surfactants.

Nonionic surfactants

The second important type of surfactant for SMS are nonionic surfactants obtained by oxyethylation of higher fatty alcohols or alkylphenols

The most commonly used nonionic surfactants are fatty alcohol oxyethylates, which can be based on either linear or branched alcohols. If ethoxylates based on long-chain alcohols (C12-C15), due to their better cleaning ability, are more often used in CMC formulations for laundries, then for cleaning hard surfaces it is preferable to use ethoxylates based on short-chain alcohols (C9-C11). These ethoxylates are characterized by better wetting ability and contact angle with respect to solid surfaces. In general, nonionic surfactants, due to the variability of their base and the degree of oxyethylation or propoxylation, can be ideally tailored to a specific task. They, as a rule, are superior to anionic surfactants in both cleaning and degreasing effects and, depending on the profile of use, emulsify more or less oils and fats.

Amphoteric surfactants

From the group of amphoteric surfactants, betaine derivatives (for example, cocaminopropyl betaine) are most often used. In combination with anionic surfactants, they improve foaming ability and increase the safety of formulations, and when combined with cationic polymers, they enhance positive impact silicones and polymers on hair and skin. These derivatives are obtained from natural raw materials, so they are quite expensive components.

We offer such surfactants (surfactants):