Polyols are widely used in modern industry. These are substances of organic origin with a number of useful properties. Polyols are used for the production of polymers, antifreezes, explosives, in cosmetics and food products.
Definition and general properties of polyalcohols
Polyalcohols, or polyols, are called organic compounds whose molecules contain more than one hydroxyl group. Other names for polyalcohols are polyol and polyhydric alcohol. The most significant polyol agents are diatomic ethylene glycol and triatomic glycerin.
The main method of producing alcohols is the synthesis of natural raw materials. In nature, polyols can be found in wax, sperm whale oil and other substances of similar composition. These are esters of organic acids, from which polyhydric alcohols are easily isolated.
Physical and chemical properties of higher alcohols
Alcohols containing two or more hydroxyl groups have all the properties of chemical compounds with one hydroxyl group. An exceptional property is the creation of blue complexes when combining copper hydroxide and polyol - this is a qualitative reaction to polyhydric alcohols.
Higher alcohols are oxidized faster than low molecular weight compounds. Light and contact with air accelerate the oxidation process.
Alcohols with a quantitative content of carbon atoms up to 11 are liquids containing a greater number of carbon atoms - solids that dissolve in ether and ethanol.
Industrial application
Polyalcohols are used in almost all industrial fields. It is surprising to use the same substances in industries very distant from each other. So, glycerin is used in cosmetology and in the manufacture of explosives. Without polyols, it is impossible to manufacture plastics, paints and varnishes, polyurethanes, thermosetting polymer resins, antifreezes.
In the production of plastics, polyalcohols can increase elasticity, resistance to deformation, increase the durability of products.
Consumers are particularly interested in information on the use of polyhydric alcohols in the food industry. These substances have unique properties that allow you to add them to food to achieve a sweet taste. Polyols are excellent sweeteners, which at the same time have many positive qualities:
- non toxic
- completely absorbed by the human body;
- low calorie;
- do not cause caries;
- can be consumed by patients with diabetes.
The use of alcohols in food does not require insulin secretion for assimilation, therefore the possibility of their use in the manufacture of diabetic products is especially important. So, with the use of polyalcohols, chewing gum, chocolate, carbonated drinks, and diabetic sweets are produced.
Some sugar substitutes have useful properties that are not related to the ability to add sweetness to products. So, glucite (the second name of sorbitol) is used in pharmacology as a flavoring and thickening agent for liquid dosage forms. Xylitol is included in the solution for intravenous nutrition.
Sorbitol is also used as a hygroscopic substance in the manufacture of semi-finished meat products to increase the shelf life of the product. The same ability to retain moisture allows the use of sorbitol in cosmetology in the manufacture of creams, lotions and toothpaste.
Sweeteners. Polyols in the food industry
The most famous sweeteners are sorbitol and xylitol. These are substances obtained from plant materials, which makes them especially valuable in the eyes of the consumer. Sorbitol and xylitol on the packaging are designated as food additives E420 and E967. In pure form, they are substances of crystalline form with a sweet taste.
Sorbitol and xylitol are synthesized from corn starch, processed cotton waste, and some deciduous wood.
By sweetness, sweeteners are inferior to regular sugar by more than 50%. But the other advantages of polyols outweigh the importance of the intensity of taste sensations:
- do not harm the shell of the teeth - anti-caries effect;
- used in diet - low calorie content;
- absorbed by the body without insulin - diabetic products;
- have a mild laxative effect - therapeutic use.
In addition to sweetness, a cooling effect is added to the taste sensations, which makes the use of sorbitol and xylitol unsuitable for addition to some products. However, these same effects are valuable qualities for the production of chewing gum.
Chocolate with polyols
The chill and residual taste inherent to sorbitol and xylitol can distort the taste of cocoa products. That is why most often diabetic chocolate has such a specific taste and a residual cooling sensation on the tongue.
This fact does not mean that polyols in chocolate should be avoided. Using beets as raw materials for the production of polyols, a product such as isomalt is synthesized. This substance is indistinguishable from regular sugar, but less caloric and suitable for diabetics. Seeing E953 chocolate among the ingredients, the buyer can be sure that he will get a product with a clean and rich cocoa flavor.
The effect of polyalcohols on humans. Benefit and harm
With increasing interest in good nutrition, consumer interest in polyol information is emerging. What is it, harmful or not, many want to know. Speaking about the benefits and dangers of polyhydric alcohols, first of all, it is necessary to consider the substances used as food additives.
As mentioned above, sorbitol, xylitol and isomalt are sugar substitutes in foods. At the same time, their usefulness as antibacterial, diabetic, dietary and preventive supplements is obvious. Sorbitol and xylitol have a positive effect on intestinal motility and are used as a gentle laxative.
The negative effect on the human body depends on the amount and frequency of use. The constant use of polyol-based sugar substitutes in large doses can provoke an imbalance in the digestive tract, exacerbate cholecystitis, cause nausea, and headaches. The use of sweeteners for people suffering from liver or kidney failure, gastrointestinal diseases and chronic hepatitis is not recommended.
Xylitol poses a mortal danger to dogs. The animal’s body takes even a minimal dose of the substance for sugar and triggers a powerful release of insulin. The result is glycemia with a sad prognosis.
World and Russian market of polyols
Polyalcohol for the needs of industry is synthesized in all developed countries of the world. The existing volume of production capacity of higher alcohols in our country is not enough to saturate the entire market. Therefore, most of the raw materials are imported from other countries. The ratio of domestic production to imports of polyols looks like 1: 3. This primarily relates to petrochemical products.
Domestic production of polyols in Russia is carried out in volumes corresponding to real demand. Most of the polyols for the production of polymeric materials in our country go for the manufacture of foam rubber, in second place - the needs of the automotive industry and construction.
The market for sugar alcohols in Russia is 90% composed of imported products. Own production of food polyols from plant materials has been launched at only one plant - Marbiopharm LLC.
An assessment of the demand for polyhydric alcohols unambiguously predicts an increase in the needs of all industries in all countries. This means that the production of polyols will develop and increase volumes worldwide.