Currently, the media often conduct campaigns aimed at forming consumer opinions about the dangers of cookware with non-stick coating based on polytetrafluoroethylene (PTFE). It should be noted here that at the moment, non-stick coatings for cookware on any other basis do not yet exist.

Two statements have been chosen as the “scientific” basis for such statements:

1. The non-stick coating contains the substance PFOA (C7F15COOH) - perfluorooctanoic acid, which increases the risk of developing diabetes and cancer.

2. When heated, the non-stick coating releases harmful substances.

This is confirmed by studies by the American State Environmental Protection Agency - EPA, and statements in the media by some experts about the inclusion of PFOA in the list of such substances by the Stockholm Convention on Persistent Organic Pollutants.

The current situation can be commented on as follows:

1. Coatings created by well-known manufacturers undergo all stages of hygienic and chemical-technical research, both here and in Europe, on the basis of which they are issued appropriate certificates confirming their harmlessness to humans.

2. PFOA is actually used to make some—not all—nonstick coatings. In this case, the fraud is as follows: it is said that a semi-finished product of some kind of coating contains acid, but what is in the sintered (polymerized) coating There is no PFOA on all finished dishes!!!- remains silent. All finished dishes do not contain PFOA!!!

There are currently no studies confirming that non-stick cookware is harmful to humans.

The US Environmental Protection Agency - EPA - does not find exposure to PFOA harmful: http://www.epa.gov/oppt/pfoa/pubs/faq.html (EPA explanations with translation will be provided at the end of the article.

Statements regarding the Stockholm Convention are yet another lie. The text of the convention is easy to find on the Internet, in particular, on one of the websites of UN organizations. The distortion is as follows: the list of persistent organic pollutants contains perfluorooctane sulfonic acid PFOS and not PFOA, these are completely different substances!!!

Such cookware is positioned as having a ceramic non-stick coating that does not contain PTFE, has the best characteristics and is absolutely harmless to health.

What can you say about this?

The entire ideology of promoting cookware with non-stick coatings without PTFE is based on two pillars:

· Most consumers are not specialists in the field of chemistry and tableware technology.

· Modern fashion for the word ecology and its derivatives.

The so-called “ceramic” coatings do not correspond to the characteristics of non-stick coatings, and according to the Western classification they are “easy to clean”. Claims about them being non-stick are, to put it mildly, untrue.

This type of coating is not new. These are technical coatings that have been used for a relatively long time, slightly modified for cookware, and are available in the range of chemical concerns that produce non-stick coatings, such as Dupont, Akzo Nobel, Whitford, etc. However, reputable companies do not offer them as food products.

All traces of the origin of coatings without PTFE lead to China..... The attitude towards ecology in China is no secret to anyone.

Currently, there are no known studies confirming the harmfulness or harmlessness of such coatings to humans in the long term (as, for example, is the case with GMOs). There is no experience of using these coatings in contact with food.

Most European market participants, where this company began earlier than here, consider this a kind of fashionable trend that will allow the smartest to make money and will go down in the annals of the history of marketing projects such as Tseptor, etc.

FrequentQuestions(see last question)

Aretherestepsthatcan consumers take to reduce their exposure to PFOA?
Consumer products made with perfluorochemicals include some non-stick cookware and products such as breathable, all-weather clothing. They are also employed in hundreds of other uses in almost all industry segments, including the aerospace, automotive, building/construction, chemical processing, electrical and electronics, semiconductor, and textile industries. Telomers are used as surfactants and as surface treatment chemicals in many products, including fire fighting foams; personal care and cleaning products; and oil, stain, grease, and water repellent coatings on carpet, textiles, leather, and paper. Consumer products made with fluoropolymers and fluorinated telomers, such as Teflon and other trademark products, are not PFOA. PFOA is used as a processing aid in the manufacture of fluoropolymers and can also be produced by the breakdown of some fluorinated telomers. The information that EPA has available does not indicate that the routine use of consumer products poses a concern. At present, there are no steps that the EPA recommends that consumers take to reduce exposures to PFOA.

Thanks to the strong fluorine-carbon compound and the reliable protection of carbon atoms by fluorine atoms, Teflon has almost universal chemical resistance.

The properties of Teflon are not affected by solvents such as alcohols, esters, ketones, or aggressive acids (concentrated sulfuric acid, nitric acid, hydrofluoric acid, etc.)

Only when the material is placed in refrigerants (freon) is there a reversible increase in weight in the range of 4-10%.

A minor chemical reaction (brown coloring) occurs when Teflon comes into contact with alkali metals.

At high temperatures and pressure, Teflon reacts with elemental fluorine and chlorine fluorites.

From the above it is clear that when using Teflon there is no need for numerous material compatibility tables.

Resistance to light and weather conditions

It is distinguished by its extraordinary resistance to light and weather conditions. Therefore, it is without any restrictions suitable for outdoor use under the most unfavorable weather conditions, while all mechanical and electrical properties remain unchanged.

Hygroscopicity

The hygroscopicity of Teflon is practically zero. Even after long-term storage in water, no water absorption was detected (according to DIN 53472/8.2).

Physiological properties of Teflon

Teflon without fillers is a physiologically neutral material. Several experiments on implanting the material into living tissues did not show any incompatibility. There are approvals from the FDA (US Food and Drug Industry Committee) and BGA (Federal Union of Wholesale and Foreign Trade of Germany), according to which the material can be used in medicine and the food industry. In this regard, an indispensable quality of the material is its resistance to hot water steam, due to which it can be sterilized when used for medical purposes, as well as in the pharmaceutical and food industries.

Antifriction properties of Teflon

Very weak intermolecular forces are the reason why it has the lowest coefficient of friction of all solid materials. Moreover, the values ​​of the static and dynamic friction coefficients are almost the same. No jerky movement is observed. The anti-friction ability is also maintained at temperatures below 0 °C. At temperatures above 20 °C, the friction coefficient increases slightly. When adding various fillers to Teflon, an insignificant change in the friction coefficient may be observed.

Physical properties of Teflon in comparison with other fluorothermoplastics

material				PTFE	FEP	PFA	PCTFE	PVDF
properties		Test method	Unit
Density	23°C	DIN 53479	g/cm 3	2,15-2,19	2,12-2,17	2,12-2,17	2,10-2,20	1,76-1,78
Strength at break	23°C	DIN 53455	N/mm 2	22-40	18-25	27-29	30-38	38-50
Elongation at break	23°C	DIN 53455	%	250-500	250-350	300	80-200	30-40
Ball indentation hardness	23°C	DIN 53456	N/mm 2	23-32	23-28	25-30	30	65
Indentation limit	23°C	DIN 53455	N/mm 2	10	12	14	40	46
Motion modulus of elasticity	23°C	DIN 53457	N/mm 2	400-800	350-700	650	1000 - 2000	800 - 1800
Flexural modulus	23°C	DIN 53457	N/mm 2	600-800	660-680	650-700	1200 - 1500	1200 - 1400
Ultimate bending stress	23°C	DIN 53452	N/mm 2	18-20		15	52-63	55
Shore D hardness	23°C	DIN 53505		55-72	55-60	60-65	70-80	73-85
Melting temperature	.	ASTM 2116	°C	327	253-282	300-310	185-210	165-178
Operating temperature without load	.	.	°C	260	205	260	150	150
Thermal expansion coefficient 10 -5	.	DIN 52328	K-1	10-16	8-14	10-16	4-8	8-12
Thermal conductivity	23°C	DIN 52612	W/K m	0,25	0,2	0,22	0,19	0,17
Specific heat	23°C		KJ/kg K	1,01	1,17	1,09	0,92	1,38
Oxygen content	.	.	%	>95	>95	>95	>95	>43
Hygroscopicity	.	DIN 53495	%	<0,01	<0,01	<0,03	<0,01	<0,03

Friction coefficients Teflon / pearlitic cast iron during dry running (p = 0.2 N/mm 2, T = 30°C, R t ß <1,5 µm)

Teflon cookware has long been used in modern kitchens. It is considered convenient, since the food in it does not burn even with the use of a small amount of oil. But such products also have disadvantages - a not entirely favorable effect on human health and nature. Is it worth using Teflon coating or is it better to abandon such an invention?

Definition

Teflon is an industrial product used in the manufacture of kitchenware. It is also used in the aerospace and textile fields, in cardiology, in the production of heart valves, and bags for microwave ovens.

Teflon has a complex chemical structure. It contains toxic components that, when the cookware heats up, penetrate into the food and air. If the pan is heated frequently, the coating will crack faster and volatile components will become airborne. Strong detergents speed up this process significantly. The substances formed from this are harmful to human health, and small doses are considered fatal to birds that live in the house.

Polytetrafluoroethylene (PTFE) is included in the Teflon coating. The substance is like plastic. It is used in the creation of various “non-sticky” kitchen products. It turns out that toxic components accumulate in nature, in living organisms. About 100 types of such substances are considered to be studied. A Teflon-coated frying pan allows you to comfortably cook food that will not burn.

Coating features

Teflon materials are created with or without adhesive. Imported glue is used. Teflon fabric comes in thicknesses of 80-230 microns. The material is produced in the form of a sheet of reliable fiberglass, which is treated with a non-stick Teflon layer. It has a light or dark brown, as well as black color.

The adhesive layer is on one side. This material is used in various fields. It is indispensable in paper production and the aviation field. The fabric is used in printed products and clothing. Not so long ago, it began to be used in medicine, the manufacture of glass products, and construction. Teflon coating at home must be properly cleaned to extend the life of such products.

Ribbon

The material is made with an adhesive layer on the film. It has a Teflon coating and silicone adhesive. Such tapes are used for devices in the food, packaging, and textile industries.

Product features include:

• Non-stick surface.
• Heat resistance.
• Chemical inertness.
• High resistance to chemical environments.
• Low coefficient of friction.
• High tensile strength.
• Dielectric properties.

Teflon tapes are used in sealing parts of packaging machines and BEG machines, devices for welding plastics, and belt conveyors. Used in lamination, duplicating procedures, and insulating electrical cables.

Tablecloths

There is also a Teflon coating on the tablecloths. Such products have an original appearance and practicality. They do not require special care. These tablecloths are used for dining tables. They serve as protection for the countertop and are easy to clean. The Teflon layer is resistant to moisture and dirt. The coating is applied to fabric - linen, cotton, polyester.

This tablecloth is easy to care for; you just need to wipe it with a damp cloth. If the product is heavily soiled, wash it with a mild detergent. Then it must be rinsed with clean water and wiped dry. The tablecloth can be washed, but only by hand and with water no more than 40 degrees. When washing, do not make creases so that the coating is not damaged. There is no harm from such a product, since it is not subjected to heat treatment.

Irons

The main component of irons is the sole. Its condition and material determine the heating rate, the quality of ironing, and the ease of sliding on fabrics. Therefore, it is important to choose a high-quality device that will perfectly cope with its functions.

There is a Teflon coated iron, and the body materials may vary. Such devices require careful treatment, especially with the soles, because this way they will work much longer. But such a surface also has disadvantages. It is easily scratched by a metal fastener or shirt button. A Teflon-coated iron must be used carefully, following safety rules.

Multicookers

This device has already been appreciated by many housewives. It is multifunctional, easy to use, and affordable. Teflon coating is also available in multicookers. Many buyers are interested in whether it is harmful. When heated to 260 degrees, the material produces negative components. This coating is easily damaged if used incorrectly. Even a minor scratch can degrade the non-stick coating.

A Teflon multicooker lasts no more than 3 years. A ceramic bowl is even less durable. This applies to inexpensive devices. A high-quality device with a reliable ceramic coating is expensive. This multicooker is not protected from alkalis, so you cannot use detergents.

Care

Experts believe that the Teflon coating does not heat up to a critical level, since the bowl is closed during cooking. In this case, harm is excluded. To avoid hazardous exposure, the integrity of the coating must be checked regularly.

Do not use metal spoons and forks when cooking. The bowl must be washed after each preparation. To do this, use soft sponges and delicate detergents that do not damage the protective layer.

Negative sides of Teflon

Scientists have discovered that Teflon components are toxic. Because of them, insulin problems, obesity, and thyroid cancer may appear. Chemical scientists believe that the coating is dangerous for 9 types of cells necessary for the immune system. In animals, it causes changes in the volume of the liver, brain and spleen. And in people, the endocrine system is destroyed, and the risk of cancer increases. Dishes are dangerous for children if the integrity of the product is compromised. Nowadays there is a Teflon ceramic coating, the dishes from which have similar properties.

Advantages

Although the coating has its disadvantages, it also has advantages. This cookware protects the product from burning, even with the use of small amounts of oil and fat. It is easy to clean with a soft sponge and detergent.

Teflon cookware has high heat resistance and retains its properties up to +260 degrees. Soups can be cooked at 100 degrees, and meat can be fried at 190. In the oven, the temperature increases to 300 degrees, so there is no need to use dishes for baking.

Cleaning the pan

Many Teflon surfaces develop a residue. It usually appears on dishes, although it can also be found on the soles of irons. Products must be cleaned promptly to ensure they last a long time. To wash the frying pan, you need to take into account that when it is hot, do not place it under cold water. The product must be cleaned as soon as possible. To do this, pour warm water inside, add soda or mustard. After a while you can wash the dishes.

How to clean the Teflon coating on a frying pan? A solution based on borax (10 g) and ammonia performs this function perfectly. Mix the ingredients with warm water (1 glass), then wash the pan with them. You can soak it overnight, for example in a basin. This method allows you to eliminate even complex plaque.

You can clean a Teflon frying pan with water (0.5 cups) to which baking powder (2 tbsp) is added. The composition must be placed on the stove and boiled. After cooling, you can wash the dishes using a foam sponge. A product with baking powder and soda copes well with the problem. Helps remove plaque and citric acid. The powder is poured into water, the solution must be boiled, and you can use it.

Cleaning the iron

How to clean a Teflon coated iron? An effective way is to use ammonia, vinegar, salt and paraffin. If rust has accumulated in the nozzles of the equipment, it is necessary to treat the device with a cloth soaked in vinegar and ammonia. Then you need to wipe it only with vinegar. Fine table salt moistened with water can replace this product.

Then you need to set the iron to maximum mode and iron the fabric for about 2 minutes. Clogged holes are cleaned with table vinegar. The liquid must be poured into a water container and the iron must be turned on at full power. After the vinegar has evaporated, add water to the container.

If fabric is stuck to the surface, it must be treated with a cotton swab dipped in nail polish remover. If this method does not help, then another method will help. Grate the candle and add 1 tbsp. l. salt. The mixture should be placed on a cloth and covered with a rag. The device should be turned on and ironed. When 10 minutes have passed, the sole must be carefully cleaned with a cotton swab and vinegar.

The Teflon surface is special, so proper methods must be used to clean it. This will allow you not to spoil it, but, on the contrary, to preserve it. Teflon dishes and utensils are of high quality and reliable, which is why many housewives choose them. To avoid the negative effects of the substance on the human body, it is necessary to follow all the rules for using such utensils.

Modern people have long been accustomed to having Teflon-coated utensils in their kitchen. It is very convenient - food does not burn on it even with minimal use of oil. It would seem that all that remains is to rejoice at this invention. However, researchers from the UK (University of Exeter) took up this coating and spent 7 years studying it. They were interested in the effect of Teflon on the environment and human and animal health. The results were, to put it mildly, unexpected. Scientists have found that Teflon coating is not so safe. The harm to human health seems obvious. Is it really? Let's try to figure it out.

What is Teflon

Today it is one of the most advertised industrial products, which is widely used in the production of various kitchen utensils, the aerospace and textile industries, in cardiology, for the production of heart valves, and in the manufacture of bags for microwave ovens.

Teflon has a very complex chemical structure. It is known that it contains many toxic substances that, when the dishes are heated, enter the food and air. The more often, for example, a Teflon-coated frying pan is heated to a high temperature, the sooner the coating bursts, and volatile substances and its smallest particles enter the air.

Strong detergents speed up this process. Substances released from Teflon are harmful to human health, and very small doses are even fatal to birds living in your home.

Polytetrafluoroethylene (PTFE) - Teflon - is a substance similar in composition to plastic. It has found wide application in the manufacture of all non-stick kitchen items. Previously, researchers believed that the substances released from Teflon do not end up in nature, but even if they do, they do not decompose, in other words, they remain biologically inert.

Unfortunately, this turned out to be a fallacy. Today it has been proven that toxic substances gradually accumulate in nature, in the bodies of people and animals. So far, only two of the nearly 100 types of these substances have been well studied.

Textile

PTFE (Teflon) fabrics are produced in two versions - with or without adhesive backing. Imported glue is used. Teflon fabric comes in thicknesses from 80 to 230 microns.

This material is produced in the form of a sheet of especially strong fiberglass, which is impregnated with a non-stick Teflon layer. It is light brown, brown or black in color. The adhesive layer is applied on one side. It is a multifunctional material with a very wide range of uses.

Used in paper production and the aviation industry. In addition, the fabric has found application in the production of printed products and clothing. Relatively recently, it began to be used in medicine, in the production of glass products, and in construction.

Manufacturers of this material claim that the Teflon coating applied to it does not cause harm to humans. They believe that their products are not exposed to such high temperatures that the surface layer may begin to deteriorate.

Teflon tape

This material is produced with a film-based adhesive layer. It also has a layer of silicone glue. Used for equipment in the food, packaging, textile, chemical, woodworking and rubber industries.

Teflon tape has unique properties:

• non-stick surface;
• heat resistance (from -60 to +200 o C);
• chemical inertness allowing contact with products;
• high resistance to chemical environments;
• low friction coefficient;
• high tensile strength;
• dielectric properties.

Teflon tape is used in:

• heating and sealing elements of packaging machines and BEG machines;
• in special equipment for welding plastics, used in lamination, in duplicating processes, insulating electrical cables.

Teflon coated tablecloths

Today, many housewives prefer to use just such tablecloths. They have an attractive appearance, do not require complex care, and are very practical.

Teflon tablecloth is usually used as a covering for the dining table. It reliably protects the tabletop and is easy to clean. This product has a Teflon layer that is resistant to moisture and various contaminants.

This coating is applied to a fabric base. It can be linen, polyester, cotton, etc. A Teflon tablecloth attracts buyers primarily because of its ease of care - it is enough to simply wipe it with a damp cloth. If serious contamination appears, then, without removing it from the table, wash it with a mild detergent. After this, rinse it with clean water and wipe dry.

You can wash it if necessary, preferably by hand, at a maximum temperature of -40 degrees. When washing, it is important not to make creases on it, so as not to damage the Teflon coating. No harm to such a product has been identified, since the tablecloth is not subjected to heat treatment.

Iron

As you know, the most important part of an iron is its sole. Not only the heating speed, but also the quality of ironing and the ease of sliding of the device on various types of fabrics depend on its condition and the material from which it is made.

“Teflon iron” is actually a misnomer. It can be made of different materials, but the sole must have a Teflon coating. The main difference between such devices is that they require a more careful treatment of the sole. Then they will last a long time.

We should not forget that the Teflon coating of the sole also has disadvantages. It is scratched quite easily by a metal fastener or shirt button. We already know the dangers of damaged Teflon coating. The harm of its fumes is obvious.

Multicooker

The multicooker is a modern miracle, the amazing capabilities of which are appreciated by many housewives. Multifunctionality, ease of use, affordability - these are only a small part of the undeniable advantages that are characteristic of this device. At the same time, many buyers are deterred from purchasing it by disputes about how harmful Teflon is. The multicooker does not always have such a coating.

When the multicooker bowl is heated to a temperature of more than 260 degrees, it releases harmful substances. This coating is easy to damage, of course, if you use it incorrectly. Even a small scratch on it can damage the non-stick layer.

And the most important disadvantage of the Teflon multicooker bowl is that the Teflon model will last a maximum of 3 years.

A ceramic bowl is even less durable and will last you no more than two years. But this, according to manufacturers, applies to budget models. A high-quality multicooker with a very durable ceramic coating is expensive. Of course, this will not suit everyone. And a multicooker with a ceramic layer is not protected from alkalis, so the use of detergents is prohibited!

Multicooker care

Experts say that the Teflon coating in this device cannot heat up to a critical temperature, since the bowl always remains closed while preparing your favorite dish, so the harm of Teflon in this type of household appliance is exaggerated.

In order not to harm the health of your family members, it is necessary to constantly check the integrity of the coating. Do not use metal spoons or forks when cooking. The multicooker bowl should be washed after each preparation. To remove food debris, use soft sponges and detergents so as not to damage the protective layer.

Harm of Teflon to health

Research by scientists has proven that the substances released by Teflon are extremely toxic. They can provoke insulin problems, the development of obesity, and thyroid cancer.

According to chemists, (doctors confirm this) Teflon poses a huge threat to nine types of cells that regulate the immune system.

Recently, this coating has been associated with the appearance of increased levels of triglycerol and cholesterol in the human body. Animals react to this substance with noticeable changes in the volumes of the liver, brain and spleen.

In humans, when destroyed, the risk of developing cancer increases many times over.

Particularly dangerous for children (if its integrity is damaged).

Ceramic or Teflon

Ten years ago, when buying a frying pan with a non-stick coating, no one doubted that it should only be Teflon. At that time, such dishes were called “Tefal”, since almost the entire Russian market for dishes of this type was in the “hands” of the Tefal company.

Today, a housewife looking for a replacement for her old frying pan may face a serious choice problem. In addition, several years ago they started talking about the dangers of such coverage. At this time, Teflon models from different manufacturers began to appear in our stores, offering their own cookware. These were very expensive European designs and cheap Chinese products.

Each manufacturer began to claim that its coating was the safest, that it was a patented innovation that had no analogues.

At this time, the main competitor of Teflon appeared - sol-gel, or ceramic coating. So, maybe this ceramic coating, which is fashionable these days, is ideal, but Teflon is bound to make everyone sick? We'll talk about this further.

Advantages of Teflon

Despite the rather serious disadvantages of Teflon coating, it also has undoubted advantages. Such dishes will reliably protect your food from burning, and with minimal use of fat. It is easy to clean with a soft sponge and detergent.

Teflon-coated cookware has high heat resistance and retains its properties up to +260 C. It should be noted that liquid dishes - soups, sauces are prepared at a temperature of 100 degrees, meat is fried at a higher temperature (190 degrees). But in the oven the temperature rises to 300 degrees, so you should not use such dishes for baking.

Disadvantages of Teflon

This polymer is not resistant to mechanical damage. It can easily be damaged with ordinary kitchen metal spatulas or a knife.

Ceramic coating

Sol-gel - this is the name of this coating, which is more often called ceramic, is not such a new invention. It was first announced in the first half of the twentieth century. It began to be used in the production of tableware quite recently.

As usual, manufacturers assure their customers that it is harmless and durable. One might assume that a worthy replacement for Teflon with its toxic fumes and brittle coating had been found. As it turns out, this is a rather controversial issue.

In order to figure out whether ceramic or Teflon coating is better, you should know all the advantages and disadvantages of sol-gel.

Positive traits

The non-stick properties of this coating are not inferior to Teflon. At the same time, its main advantage is considered to be its environmental friendliness. If the coating is damaged or overheated, no harmful substances are released.

Sol-gel cookware is heat-resistant - it retains non-stick properties at temperatures of 400 degrees or more.

Cons of ceramics

This coating loses its qualities much faster than Teflon, even with proper use (after approximately 132 uses).

Right choice

When choosing Teflon cookware, do not be like that stingy person who pays twice. Cheap fakes from unknown manufacturers use anything as a coating, even epoxy resin. Products from a reliable and trusted manufacturer in a large specialized store are sold with a warranty receipt and instructions.

15..27 N/mm² Thermal properties T. dec. 415 °C Ud. heat capacity 1040 J/(kg K) Thermal conductivity 0.25 W/(m K) Coeff. warm extensions (8..25)∙10 -5 Classification Reg. CAS number 9002-84-0 Reg. EINECS number 618-337-2 ChEBI Data are given for standard conditions (25 °C, 100 kPa), unless otherwise stated.

Polytetrafluoroethylene, teflon or fluoroplast -4(-C 2 F 4 -) n is a polymer of tetrafluoroethylene (PTFE), a plastic that has rare physical and chemical properties and is widely used in technology and in everyday life.

The word "Teflon" is a registered trademark of the DuPont Corporation. The nonproprietary name for the substance is “polytetrafluoroethylene” or “fluoropolymer.” In the USSR and Russia, the traditional technical name for this material is fluoroplastic.

Polytetrafluoroethylene was discovered in April 1938 by 27-year-old chemist Roy Plunkett of Kinetic Chemicals, who accidentally discovered that tetrafluoroethylene gas he pumped into pressurized cylinders spontaneously polymerized into a white paraffin-like powder. In 1941, Kinetic Chemicals was granted a patent for Teflon, and in 1949 it became a division of the American company DuPont.

Properties

Physical

Teflon is a white, transparent substance in a thin layer, resembling paraffin or polyethylene in appearance. Density according to GOST 10007-80 from 2.18 to 2.21 g/cm3. It has high heat and frost resistance, remains flexible and elastic at temperatures from -70 to +270 °C, an excellent insulating material. Teflon has very low surface tension and adhesion and is not wetted by water, fats, or most organic solvents.

Fluoroplastic is a soft and flowing material, and therefore has limited use in loaded structures. Has very low adhesion (stickiness).

DuPont specifies the melting temperature according to ASTM D3418 for different types of Teflon from 260 °C to 327 °C.

Chemical

In terms of its chemical resistance, it surpasses all known synthetic materials and noble metals. It is not destroyed under the influence of alkalis, acids and even a mixture of nitric and hydrochloric acids. Destroyed by molten alkali metals, fluorine and chlorine trifluoride.

Production

The production of polytetrafluoroethylene includes three stages: in the first stage, chlorodifluoromethane is obtained by replacing chlorine atoms with fluorine in the presence of antimony compounds (Swarts reaction) between trichloromethane (chloroform) and anhydrous hydrogen fluoride; in the second stage, tetrafluoroethylene is obtained by pyrolysis of chlorodifluoromethane; at the third stage, the polymerization of tetrafluoroethylene is carried out.

Products from f-4 are produced by cold pressing followed by baking at a temperature of 365±5 °C. The pressing process proceeds from an aqueous PTFE emulsion in the presence of a surfactant (for example, perfluorooctane or perfluorooctanesulfonic acids), which stabilizes the emulsion and makes it possible to produce water-dispersed polytetrafluoroethylene.

The main producer of fluoroplastic in Russia is the Kirovo-Chepetsk Chemical Plant named after Konstantinov, Kirovo-Chepetsk, Kirov Region.

Application

Industry and technology

Due to its chemical inertness, hydrophobicity and fluidity, the material is widely used for sealing threaded and flange connections (FUM tape).

Lubrication

Fluoroplastic (Teflon) is an excellent anti-friction material with a sliding friction coefficient that is the lowest of any known structural material available (even less than that of melting ice). Due to their softness and fluidity, solid fluoroplastic plain bearings are rarely used. In highly loaded units, metal fluoroplastic liner bearings and metal fluoroplastic support belts are used. Such a sliding element can withstand tens of kilograms per square millimeter and consists of a metal base on which a fluoroplastic coating is applied.

Electronics

Teflon is widely used in high-frequency technology because, unlike polyethylene or polypropylene with similar properties, it has a dielectric constant that varies very little with temperature, a high breakdown voltage, and extremely low dielectric losses. These properties, along with heat resistance, determine its widespread use as insulation of wires, especially high-voltage ones, all kinds of electrical parts, in the manufacture of high-quality capacitors, and printed circuit boards.

In special-purpose electronic equipment, wiring with fluoroplastic insulation, resistant to aggressive environments and high temperatures, is widely used - wires of the MGTF, MS and a number of others brands. It is impossible to melt a wire in Teflon insulation with a soldering iron. The disadvantage of fluoroplastic is its high cold fluidity: if you hold a wire in fluoroplastic insulation under mechanical load (for example, put a furniture leg on it), the wire may become exposed after some time.

Medicine

Due to its biological compatibility with the human body, polytetrafluoroethylene is successfully used for the manufacture of implants for cardiovascular and general surgery, dentistry, and ophthalmology. Teflon is considered the most suitable material for the production of artificial blood vessels and cardiac stimulators. In 2011, it was first used for plastic surgery of damaged nasal septum and walls of the paranasal sinuses instead of titanium meshes. After 12–15 months, the implant completely dissolves and is replaced by the patient’s own tissue.

Teflon is also used in the production of other household appliances. Teflon coating in the form of a thin film is applied to razor blades, which significantly extends their service life and makes shaving easier.

Caring for Teflon-coated cookware

Teflon coating is not very durable, so when cooking in such dishes, you should use only soft - wooden, plastic or plastic-coated accessories (spatulas, ladles, etc.). Teflon-coated dishes should be washed in warm water with a soft sponge, with the addition of liquid detergent, without using abrasive sponges or cleaning pastes. Avoid overheating and frying over high heat.

Cloth

In the production of modern high-tech clothing, membrane materials based on expanded polytetrafluoroethylene are used.

By physically deforming Teflon, a thin porous film is obtained, which is applied to fabrics and used in sewing clothes. Membrane materials, depending on the manufacturing features, can have both windproof and waterproofing properties, while the normalized pore size of the polytetrafluoroethylene membrane allows the material to effectively transmit evaporation from the human body.

There is a fabric-based polytetrafluoroethylene membrane material that allows air to pass through but does not allow wind to pass through.

• Gore-Tex is a waterproof, breathable membrane fabric.

Other products

Products in the production of which Teflon is used:

heating lamps; portable heating devices (electric heating pads); iron plates; ironing board coverings; stove burners; baking sheets; electric grills; devices for making popcorn; coffee pots; rolling pins (with anti-stick coating); bread baking machines; trays for skewer or grill; ice cream molds; toilets with Teflon coating;

boilers; corkscrews; surfaces of kitchen stoves; kitchenware; pots and pans for frying; woks (Chinese pans for frying vegetables and meat); baking dishes; hot sandwich press; waffle irons; optical cryostats; razor blades; internal coatings of tank barrels; [ ] electric rocket engines [ ] . paints and varnishes [ ] seals of articulated mechanisms (hinges)

The dangers of polytetrafluoroethylene

The possible negative impact of polytetrafluoroethylene on human health has been the subject of controversial opinions for many years. The polymer itself is very stable and inert under normal conditions. Polytetrafluoroethylene does not react with food, water and household chemicals.

Polytetrafluoroethylene is harmless when ingested. The World Health Organization has asked the International Cancer Control Organization to conduct an experiment on rats. Experience has shown that when consumed in food up to 25% of polytetrafluoroethylene it has no effect. This study was conducted in the 1960s and again in the 1980s on a general population of rats that consumed 25% of their total food intake of PTFE each day.

Research by French experts, who published the results of a laboratory study of 13 samples of frying pans in the journal 60 Millions de Consomateurs, confirms the safety of the non-stick coating. The French magazine reports that tests have proven that the frying pans are completely safe. All samples successfully passed the test after rubbing the surfaces with an abrasive material a thousand times over two cycles.

Fluoroplastic is potentially biologically hazardous in two cases: during production and when the finished polymer overheats. Polymer production uses toxic and carcinogenic substances that can enter the environment both through leaks and in the form of industrial contamination of the finished product. When fluoroplastic is overheated, thermal decomposition occurs with the release of toxic substances.

Industrial pollution

The main source of biological risks in the production of fluoropolymers is considered to be perfluorooctane acid (PFOA). This compound has been used in the USA since the 50s of the 20th century. The first information about the impact on health was obtained at the 3M and DuPont factories in the 60s. In the 80s, scientific groups joined the study of biological effects. In the late 1990s, US regulatory authorities drew attention to the problem, which resulted in the recognition of the danger of the substance and the regulation of maximum concentrations. Processes throughout the United States have been modified to eliminate PFOA completely. Large-scale campaigns have been launched to monitor PFOA concentrations and clarify its impact on human health.

DuPont has received hundreds of millions of dollars in lawsuits from company workers and surrounding communities over health claims and cover-ups of manufacturing hazards. In 2006, DuPont, by then the only manufacturer of PFOA in the United States, agreed to remove the remaining reagent from its facilities by 2015. According to official company information, since January 2012, DuPont has not used PFOA in the production of cookware and bakeware.

It is known that perfluorooctanoic acid decomposes at a temperature of 190 ºС, while the technological process of sintering the base of a non-stick frying pan occurs at a temperature of 420 ºС. Therefore, it is assumed that the process is unlikely to contain PFOA in the finished pan. However, a study conducted in 2005 found PFOA levels in PTFE coatings on new cookware ranging from 4 to 75 µg/kg (with cling film up to 1,800 µg/kg and popcorn packaging up to 290 µg/kg).

Independent European studies have shown that non-stick coatings do not contain PFOA in quantities exceeding acceptable safety limits. The Chinese Academy of Quality, Inspection and Quarantine (GAQSIQ) and the Danish Institute of Technology confirm that no exposure to PFOA used in cookware has been detected. .

In Russia there are no regulatory documents limiting industrial contamination of fluoroplastic, which can negatively affect the quality of products containing fluoroplastic.

Thermal decomposition of polytetrafluoroethylene

The rate of Teflon pyrolysis depends on the degree of polymerization. Signs of decomposition are detected at a temperature of 200 °C. The process is relatively slow up to 420 °C. At temperatures from 500 °C to 550 °C, weight loss reaches 5-10% per hour in inert environments, sharply accelerating in the presence of atmospheric oxygen. At temperatures between 300 and 360 °C, the decomposition products are predominantly hexafluoroethane and octafluorocyclobutane. Above 380 °C, perfluoroisobutylene and other pyrolysis products appear.

Among the products of thermal decomposition of polytetrafluoroethylene, perfluoroisobutylene is considered the most dangerous - an extremely poisonous gas, which is approximately 10 times more poisonous than phosgene.

Thermal decomposition products cause a picture of poisoning reminiscent of foundry fever. Possibly, polytetrafluoroethylene aerosol is also poisonous and has a pyrogenic effect, especially when freshly obtained, on which destruction products are sorbed. When inhaling cold polytetrafluoroethylene dust, after 2-5 hours all workers experienced symptoms called “Teflon fever.” Typical Teflon fever has been observed when working with polytetrafluoroethylene heated to >350°C. When examining 130 people and the presence of polytetrafluoroethylene aerosol in the air at a concentration of 0.2-5.5 mg/m3, it was revealed that the majority of workers had repeated attacks of fever. The same individuals had fluoride in their urine (0.098-2.19 mg/l). Fluoride excretion turned out to be significantly higher with more experience and repeated attacks.

Since the massive release of toxic substances by Teflon begins at temperatures above 450 °C, cookware with non-stick coatings is considered safe, since such temperatures cannot be reached during normal operation. It should be borne in mind that manufacturers consider only heating with water or oil in a frying pan to be the norm. Water prevents the Teflon from overheating, and its complete evaporation signals significant heating of the cookware, which is now not visualized in any way and can become critical. Edible oils decompose at temperatures up to 200 °C, producing smoke, making it easier to identify overheating. Heating dry utensils on a stove is considered abnormal and in this case the pyrolysis temperatures of Teflon are easily achievable. To simplify operation, some models of Teflon cookware are equipped with built-in visual temperature indicators.

Soldering wires with fluoroplastic insulation requires exhaust ventilation.

Danger of Teflon decomposition products for birds

The special structure of the respiratory system of birds makes them hypersensitive to toxic substances contained in the environment. It has been established that even a minimal amount of perfluorooctanoic acid, entering the bird’s body with inhaled air, affects its respiratory system, leading to death after some time (from several minutes to tens of hours). Small birds are more sensitive to toxic substances; it only takes a few seconds for them to inhale Teflon fumes and die within the next 24 hours.

At first, when news about the deadly dangers of Teflon for birds first appeared, it was generally accepted that deadly fumes were released only at very high temperatures. To date, the death of 52% of birds that have been breathing fumes from Teflon surfaces of lighting lamps heated to 202 °C for 3 days has been reliably recorded. According to other sources, only about 163 °C (325 °F) or even 140-149 °C (285-300 °F) are enough to have a negative effect, but these data require further verification.

There is a lot of information about the death of poultry (for example, parrots) from the fumes of Teflon pans left unattended and overheated above a safe temperature.

See also

Notes

1. Slippery type: Teflon - Popular Mechanics magazine
2. Roy J. Plunkett - Chemical Heritage Foundation
3. Accidental Invention of Teflon
4. What lab accident created Teflon
5. Fluoropolymer Comparison - Typical Properties
6. Utkin V.V. Factory near Mesopotamia. Kirovo-Chepetsk chemical plant. - with color tabs. - Kirov: OJSC "House of Printing - Vyatka", 2006. - T. 3. - 240 p. - 1000 copies. - ISBN 5-85271-250-7.
7. Utkin V.V. 1 // Factory near Mesopotamia. Kirovo-Chepetsk Chemical Plant named after