What materials are artificial. Synthetic fabrics: description, varieties, characteristics. Acrylic: polyacrylonitrile materials
"Artificial materials: plastic, plastic, polyethylene."
Software Content:
To deepen the understanding of children about artificial materials: plastic, plastic, polyethylene.
Clarify children's knowledge of natural and artificial materials.
To consolidate knowledge about the properties and qualities of plastics, plastics and polyethylene.
Oak is a light deciduous wood that is easy to process despite its good hardness. It is easy to draw and resist moisture absorption. Oak is ideal for furniture because of its natural aesthetic qualities and its structural retention. It is also used in the construction of boats, frames, chests and flooring. This gives the wine a taste when used in a ripening barrel.
Pine is a fast-growing coniferous wood native to Scandinavia. It has a uniform texture and is very easy to use. It is easy to grind and resists compression, swelling due to moisture and deformation, despite its wide grain. It is widely used in the construction of wooden frame houses, panels, industrial furniture, wooden pallets and many other products.
To expand children's understanding of the use of these materials in everyday life.
To cultivate a caring attitude to nature and a respectful attitude to the work of people.
Material for the lesson:
A set of items made from plastic (cans for bulk products, toys, corks, pens, a bucket); from plastic (bottles, vase, disposable tableware); polyethylene samples, tablecloth, plastic bag; samples of natural materials (clay, wood, leather, coal, sand).
Sequoia comes from a narrow strip of land along the west coast of America. It is light, but relatively strong, soft wood, which is easy to work with, has good natural resistance to decomposition and is therefore widely used in the manufacture of outdoor furniture, fencing and wooden products for the home. It is also called mahogany because of its dark pinkish color.
The rosewood or rosewood is very solid and with a low degree of detail. It is a dark reddish brown color. It is difficult to work and become fit, and it needs to be completely polished in order to have a finished look. It is commonly used to make musical instruments, such as the piano, as well as instrument pens, some sculptures, decorative veneers and some pieces of furniture that give it a unique and pleasant aroma that sets it apart from most other forests.
Class progress.
Children, we know that the objects that surround us are made of different materials. Man found some of them in nature (these are natural, natural materials). What is their concern? (clay, sand, wood - they are given to us by plants or people get them from the earth (coal, oil)).
(Show samples of natural materials).
Spruce is a soft but mechanically resistant wood from Scandinavia that works well but has low resistance to environmental conditions. It is light and light in color and low density. This is a good option for the manufacture of masts of ships, aircraft, crates, crates and carpentry in general due to its good structural strength due to its light weight.
Teak - hardwood, known for its high resistance to moisture, it is also resistant to deformation, cracking and has good durability. It is used in a wide variety of products, which must be very durable or must be wear parts and include furniture, paneling, carpentry, ships, construction, church doors and teak floors.
And there are also materials that are received at industrial enterprises. They are created by human hands or by technology invented by him. These materials are called - remember which? (man-made or artificial).
Children, look, there are objects on my table (show plastic toys, a bucket, corks, a telephone). What do you think they are made of?
Walnut has a fine texture, dark color and is easy to use. It is resistant to deformation and elongation and is able to withstand most finishes, such as paints or furnaces. It is mainly used for the production of solid wood and veneer furniture, cabinets, panels and decorative trinkets. Luminous walnut is native to Persia, and black walnut is native to the United States.
Attention to the used resins and adhesives, studies show that they are harmful. As a precaution, it is recommended to aerate a piece of furniture from a particle board several hours before placing it in the house and avoid several in the same room. Again, be careful when using it due to enamel glue when assembling furniture or working this kind of wood. It is quite soft, flexible enough and very easy to use. It cuts and works very easily and is widely used for indoor furniture, especially for cabinets and shelves.
These are plastic items.
Do you think this is natural or artificial material?
Artificial. (Why?)
The word plastic means "plastic mass." Plastic because with strong heating it turns into a mass resembling plasticine, and from this mass any object can be made (like plasticine). Then the plastic cools and solidifies, and an object of any desired shape is obtained.
Due to its nature, it is highly recommended to wear a mask when grinding due to tiny particles that are easily inhaled. Plywood is artificial wood that was invented during World War II and was mainly used for the construction of boats and landing ships for the military. It is made of many thin layers of laminated wood glued together. Each layer creates a right angle with the grain of the lower layer, giving it strength, allowing it to remain flexible enough.
The slimmer the board, the more flexible it will be. It is widely used in the construction industry because it can be expensive for floors or walls. However, in the car that takes him to the airport, the pride that he receives from its operation disappears when he sees a construction machine that lifts a block of concrete by several tons. Human muscles are the face of machines born from the brains of the same people.
Now take these items in your hands. Touch it. What can you say about them? What are they? (heavy or light, soft or hard, rough or smooth).
And if you look through the plastic? She's not transparent.
And if you drop objects on the floor, then they will break? No, they are durable.
Plastic is a very practical and cheap material. Due to the fact that plastic has such properties and qualities as hardness, smoothness, light weight, strength - people began to widely use plastic objects in their lives. Moreover, without them it is already impossible to imagine our life.
However, as soon as we want to build miniature devices, these machines are no longer suitable, therefore physicists develop materials, the so-called adaptive or intelligent, that stimulate, form and create forces on small devices. Actuators in which levers and drums are too bulky will be used in the development of small manipulators, such as miniature valves and articulated levers, that will move objects with cell size or even real ones. cells without damaging them.
The materials most commonly studied for these properties are piezoelectric ceramics, shape memory alloys, and polymers. Between these various materials, competition is difficult to achieve or even exceed the performance of natural muscles. Records fall regularly, but they all still suffer from serious flaws: their fragility is too great.
What are the plastic objects that you meet (toys, phones, watches, buttons, syringes, a refrigerator, a computer case; plastic parts are found in cars, on ships, and on airplanes).
This is how many plastic items, because they are convenient to use and not difficult to perform.
Children, on my table there is another group of objects made of another artificial material - it is called plastic. With items made of plastic, you also often meet. Here, for example, are plastic bottles that sell carbonated water or juices. They are different in size: large and small. They are convenient to use. And there is also plastic disposable tableware; you probably also met. Here it is, how colorful (to show), so that it would be nice to use it.
In terms of speed, strain amplitude, applied force and strength, drives created with adaptive materials sometimes outperform muscles in accordance with one of the evaluation criteria. but at the cost of one degradation of productivity in accordance with another. For example, piezoelectric devices used to regulate the development of cameras or control the read head of a hard disk deform very quickly when exposed to an electric field, but the maximum amplitude of about one percent of their deformations is in shape memory alloys that apply tremendous stress and collect metal parts more reliably than any other weld, however, their properties quickly deteriorate after several cycles.
Please touch the plastic objects and tell me what they are?
Light, hard, smooth, thin, plastic bends easily.
Compared to plastic, plastic is softer, more flexible. Less durable, if you touch something sharp or bend it badly, it can break. (Cut with scissors).
Now let's move on to the third group of items.
Polymeric materials, that is, long molecular chains connected to each other by several chemical bonds, withstand large deformations, are strong and quickly deform and are suppressed. The most promising elements for building reliable miniature drives. The mechanisms of their functioning, which resemble the natural muscles for some of them, make them “artificial muscles”, although this term is usurped, since the goal is not to replace the natural muscle of one of these devices, but to obtain accurate, reproducible and miniature movements.
Look, these are bags, a tablecloth, a food film. They also meet us every day. They are made of artificial material called (ask, who knows) - polyethylene.
Take samples of polyethylene, touch. What can you say about the properties of polyethylene?
It is soft, if tightly clenched into a fist - wrinkles, rustles (makes a sound); if you pull it, it will first stretch and then break. So he is not very durable. Light in weight. It can be either transparent or non-transparent.
Materials such as muscle
For the first two types of artificial muscles that we describe, conductive gels and polymers, energy is provided in chemical or electrical form. A substance of natural or synthetic origin that can be used in biomedical applications. Biomaterial research involves the design, manufacture and characterization of these materials. This property, called biocompatibility, concerns the analysis of the characteristics of the interaction between the biomaterial and the living organism into which it must be inserted.
From polyethylene make curtains for the bathroom, because polyethylene does not allow water to pass through.
And you also probably saw how in the country house, in the garden, mothers and grandmothers make a greenhouse (a house for growing vegetables). There, in the summer, thanks to polyethylene, it is always warm, even hot. It persists for a long time, and planted vegetables grow and ripen faster, because they love heat very much.
In particular, from a technological point of view, an ideal biomaterial should have: good chemical stability, it should not cause toxic and carcinogenic phenomena or provoke rejection phenomena. Particular attention should also be paid to its electrical properties, mainly in the case when the biomaterial must come into contact with blood in order to avoid the occurrence of possible coagulation phenomena.
Materials of biological origin
Finally, it must also have good mechanical and corrosion resistance characteristics, a density that allows you to save the weight of the devices in which it is used within acceptable limits, and a characteristic of the ability to repeatedly sterilize without destruction. In addition to transplantation, when replacing organs, the use of materials of both animal and human origin in already organized structures or at the molecular stage is successfully developing, and also presents good characteristics of their own nature of biocompatibility, in general, they do not require particularly complex and expensive technologies production and delivery, so that their production is also within the reach of a small industry or a small research group.
Now think and tell me, where did you meet polyethylene?
Children, imagine that you played a plastic toy and it broke; drank from a plastic bottle, ate from disposable plastic utensils; used plastic bags, they were torn, squeezed - what do you do with them then?
Throw it away. Often people throw it not in special places, but directly on the ground. Or the wind took a lightweight plastic bag out of the trash, and not one! So what is the problem? - We litter nature, litter our land. The artificial materials plastic, plastic, polyethylene have one negative (bad) property - they are difficult to destroy. They are not afraid of either the sun's rays or water; they can lie in the earth for hundreds of years! And if you throw it away every day, then how much garbage can accumulate!
Materials of this type can be divided into materials from soft tissues. from hard fabrics and suture materials. At first, the first application was in the cardiovascular sector, in which materials of pork, beef and, naturally, of human origin were used to implement prostheses and signs of blood vessels of blood vessels. In addition, pig and sheep skin were effectively used to repair damaged tissue due to injuries or burns. Naturally, before use, these materials must undergo a complex series of treatments aimed at destroying the perishable component of the material in order to make it immune to the attack of bacteria.
One scientist said about these artificial materials: “You can break, chop, bury them, but they still refuse to die!”
And if you burn them, then they emit harmful toxic smoke, and we pollute the air.
Therefore, if you used something plastic, plastic, polyethylene, then throw it away only in special places for garbage. And then the car will take it away and it will be recycled at special plants.
Materials made from hard tissues were mainly used in orthopedics mainly to fill gaps resulting from bone defects or after removal of tumors. The necessary basic requirements relate to both the mechanical characteristics of the biomaterial, which should be similar to the mechanical characteristics of the bone, as well as compatibility with the bone itself, which should be high. The first material used was the same human bone taken from corpses, which obviously has optimal characteristics in terms of biocompatibility. from properly treated animals and, more recently, various materials, such as coral fragments and madrepores.
Summing up:
Today we examined items made of plastic, plastic and polyethylene. These are artificial materials created by man.
Determined what properties and qualities they possess. They remembered where and how a person uses objects made from these materials in his life.
And now you also know that used objects, getting into nature, clog it. Therefore, we must take care of nature, protect it and do the right thing.
Another area in which materials of biological origin seem to be confirmed relates to bioadhesives, taking into account the not very good biocompatibility of artificial adhesives. this is a fibrin glue obtained by mixing human fibrinogen with various reagents. Through a reaction similar to the reaction in the human body, the production of fibrin can be used as a conventional synthetic glue. However, it should be remembered that the use of materials of biological origin remains limited in a relatively small range of applications, both for those inherent in these materials, as well as because of difficulties with the supply.
General information
Materials are the substances from which various products are made: products and devices, cars and airplanes, bridges and buildings, spacecraft and microelectronic circuits, charged particle accelerators and nuclear reactors, clothes, shoes and much more. Each type of product needs its own materials with well-defined characteristics.
High demands have always been made on the properties of materials. Although modern technologies make it possible to produce a wide variety of high-quality materials, the problem of creating new materials with better properties remains relevant to this day.
When searching for a new material with desired properties, it is important to establish its composition and structure, as well as provide conditions for managing them.
The search result largely depends on the sensitivity and resolution of the devices with which the composition and structure of the synthesized material are determined. Such devices are created on the basis of only the latest achievements of natural science and, above all, physics.
When processing the material and manufacturing the final products necessary for consumption, engineering achievements are no less important, allowing to produce high-quality products.
In recent decades, materials with amazing properties have been synthesized, for example, materials of thermal screens for spacecraft, high-temperature superconductors, etc.
It is hardly possible to list all types of modern materials. Over time, their number is constantly increasing. In ancient times, the most widely used was one type of material - the stone from which axes and arrowheads were made. Caves for housing were hollowed out in stone. The next important step was taken several millennia ago when it was possible to obtain metallic iron from iron oxide. There were metal products in the form of weapons, household items, simple devices for cultivating the land.
And then the second millennium from the birth of Christ ends. Iron as a material in terms of production volume begins to yield to other materials to polymers. Since 1980, for example, in the United States they have been producing more than iron. A variety of clothes made of polyester, plastic dishes, carpets made of polypropylene, furniture made of polystyrene, tires made of polyisoprene, etc.
- These are all examples of an extremely large variety of polymer applications.
Many structural elements of modern aircraft are made of composite polymer materials. One of these materials - Kevlar - surpasses many materials, including the highest quality steel, in an important indicator - the strength / mass ratio.
In recent decades, the issue of manufacturing a car entirely from polymeric materials has been actively discussed, which will help reduce its weight and thereby save fuel.
Modern materials include wood, glass, and silicates, each of which is usually considered a traditional material. Wood is not only a building material, but also a raw material for the production of valuable diverse products.
Glass - the material is not new, but promising: in the last decade, glasses with amazing properties have been made.
Silicate materials still form the basis of the construction industry.
Modern plastics
Plastics are materials based on natural or synthetic polymers that can take on a given shape when heated under pressure and stably maintain it after cooling. In addition to the polymer, plastics may contain fillers, stabilizers, pigments and other components. Sometimes other names of plastics are used - plastics, plastics.
Plastics differ in operational properties (for example, antifriction, weather-, heat- or fire-resistant), type of filler (fiberglass, graphitoplastics, etc.), as well as the type of polymer (aminoplastics, protein plastics, etc.).
) Depending on the nature of the transformations that occur in the polymer during the molding of products, plastics are divided into thermoplastics (the most important of them are created on the basis of polyethylene, polyvinyl chloride, polystyrene) and thermosets (the largest tonnage of them are phenoplasts). The main methods for processing thermoplastics are injection molding, vacuum molding, pneumoforming, etc. Reactoplastics are molded by compression and injection molding.
To date, mass industrial production of various types of plastics has been established.
And plastics can be attributed to traditional materials, although the search for plastics with new properties continues.
More than a hundred years have passed since the birth of the first organic material - celluloid. Today, the variety of synthetic substances is so great that it is hardly possible to list them. When it comes to artificial materials, many have in mind primarily plastics - substances created under artificial conditions. In 1980, American scientists first discovered natural polyester plastic in the nests of bees living in the ground.
Mass production of plastics began in the second half of our century. In 1900 world plastic production amounted to about 20 thousand tons, and in 1970 - already 38 million tons. It is assumed that by the end of the millennium the volume of plastic production will reach the level of steel production and will amount to hundreds of million tons per year.
Often, mutually exclusive requirements are imposed on the same material. For example, the material for winter clothing should have a good heat-insulating property and elasticity, but at the same time be durable. Builders are interested in materials with good heat and sound insulation, strength and other properties.
Among the aforementioned requirements, among a variety of materials, artificial organic compounds — polymers — most satisfy.
The polymers are built from macromolecules, consisting of numerous small basic molecules - monomers. The process of their formation depends on many factors, variations and combinations of which allow you to get a huge variety of polymer products with different properties.
The main processes of macromolecule formation are polymerization and polycondensation.
About 2/3 of the total world production of polymers is composed of materials of mass industrial consumption: polyethylene, polytetrafluoroethylene, polyvinyl chloride, polypropylene, etc. The fields of application of these polymers are very diverse - from the textile industry to microelectronics.
Their cost is relatively low. The remaining 1/3 of polymeric materials include polyester resins, polyurethane, aminos, phenoplast, polyacrylates, polyformaldehyde, polycarbonates, fluoropolymers, silicones, polyamides, epoxies and other types of polymers.
By changing the structure of molecules and their various combinations, it is possible to synthesize plastics with desired properties.
An example is an ABS polymer.
It consists of three main monomers: acrylonitrile (A), butadiene (B) and styrene (C). The first one provides chemical stability, the second one provides impact resistance, and the third one provides hardness and ease of thermoplastic processing.
The main purpose of these polymers is the replacement of metals in various designs.
Thermoplastics reversibly harden and soften, so products of various configurations are easily formed from them.
Artificial organic substances that do not soften when heated are called thermosetting plastics or thermosets.
These are phenolic, carbide and polyester resins. Most often, in the initial state, they are liquids that, when the catalyst is added or heated, irreversibly harden.
The most promising materials with high heat resistance were aromatic and heteroaromatic structures with a strong benzene ring: polyphenylene sulfide, aromatic polyamides, fluoropolymers, etc. These materials can be operated at a temperature of 200-400 ° C. Previously, only inorganic substances had such heat-resistant properties. Designed specifically for supersonic aircraft, polyimide plastics can withstand temperatures up to 465 ° C for 30 minutes. The main consumers of heat-resistant plastics are aviation and rocket technology. Such plastics also find application in automobile and machine tool building, in electrical engineering (for example, for insulation of wire in electric motors), etc.
Every day the share of polymer materials in the construction industry is growing.
Plastic frames, cladding materials, roofing, heat-insulating and other artificial materials are increasingly being used in modern construction.
An increasing share of materials is made up of various types of plastics for the manufacture of automobile parts, the first-born of which - a self-propelled wagon - appeared in 1886 on the streets of Mannheimer.
Over the course of more than a hundred-year history of the automotive industry, a lot of materials have been used produced by the chemical industry, among which plastics are gradually displaced and continue to displace metal. So, in 1965, there was an average of 15 kg of plastics per passenger car, in 1970 - 25-45 kg. It is assumed that in the next decade, the production of one passenger car will require hundreds of kilograms of plastic materials, among which polyethylene, polyvinyl chloride, ABS polymers, polypropylene, etc. will prevail.
Already produced cars with a completely plastic body. It is not yet possible to make the entire car and especially its engine from plastics. However, in 1980. The American company demonstrated a car engine made of heat-resistant plastic, in which only the crankshaft and piston rings are made of metal. The mass of this engine turned out to be 2 times less than the metal one, and it consumed fuel by about 15% less than usual. In addition, automobiles with a drive shaft and springs made of polymer materials are manufactured. Recently, work is underway on the mass introduction of ceramic engines.
Elastomers
Rubber also applies to polymeric materials. Numerous products from this material, including widespread rubber, have a distinctive property - elasticity. This property combines many elastic materials into one group of elastomers. For a long time, only one elastic material was known - natural rubber. It is still still mined from a rubber tree - Brazilian hevea - in the same way as resin in coniferous forests, that is, by cutting.
Chemistry took possession of rubber in the first half of the 19th century. - in 1841, when the American inventor Goodyear proposed a method of vulcanization.
It is brittle at low temperature and sticky when heated, crude rubber during vulcanization becomes elastic. Moreover, its macromolecular chains form a network structure, connecting with bridges of sulfur atoms.
Statistics on world rubber production began in 1850, when about 1,500 tons were produced. In 1900, Brazilian forests produced 53,900 tons of rubber. In the same year, rubber appeared from trees grown on plantations. In recent years, most of the natural rubber is mined on large plantations of Indochina. In 1970, rubber consumption in the world amounted to 7.8 million tons, the share of natural rubber in which was about 38%.
Natural rubber has a relatively low heat resistance, does not differ in high oil resistance and is subject to aging. Modern synthesis methods make it possible to obtain synthetic rubber with desired properties.
To date, more than 10 types of synthetic rubbers and at least 500 of their various modifications have been developed. Excellent quality is distinguished by silicone rubber. It is less elastic than natural rubber, but its properties in the temperature range from -55 to 180 ° C depend very little on temperature, and besides, it is physiologically harmless. Homogeneous and cellular polyurethane elastomers exhibit excellent wear resistance, high chemical resistance and are not subject to rapid aging.
The field of application of elastomers is very diverse - from mechanical engineering to the shoe industry, but nevertheless a significant portion of them goes to the manufacture of tires, the need for which is constantly growing with the growth of the flow of cars.
By producing synthetic rubbers, the chemical industry makes up for the shortage of natural raw materials - rubber. Similarly, synthetic leather production preserves raw materials of animal origin. In terms of their properties and quality, many varieties of modern synthetic leather are not much different from genuine leather of the highest quality.
Synthetic fabrics
The introduction of chemical technologies in the textile industry began relatively long ago - about 200 years ago, when with the help of soda and bleach, it was possible to significantly improve the washing and bleaching processes. For example, with the use of bleach, the duration of bleaching cotton fabric was reduced from three months (with meadow bleaching) to six hours. In the second half of the XIX century. synthetic organic dyes were widely introduced. Since the beginning of the XX century. chemical technologies began to focus on the creation of new fibrous materials. To date, diverse artificial fibers are made mainly of four types of chemical materials: cellulose (viscose), polyamide, polyacrylonitrile and polyesters. More than 50% of modern fibers are made from materials synthesized over the past 50-60 years.
In practice, chemical refinement and fabric finishing are widely used. Chemical wool processing technologies have been developed to provide resistance against moths.
Methods have been found that make it possible to reduce the shrinkage of the material and give it crush-proof qualities.
Great attention is paid to the development of effective methods of processing materials to provide antistatic, antimicrobial, dirt-repellent and other important properties.
About 50% of the main textile products are able to burn under normal conditions. There are two ways to reduce the flammability of fibers; special processing of fibers and the creation of new fibrous heat-resistant polymers. The most promising heat-resistant polymers include aromatic and heteroaromatic compounds that withstand temperatures of 250-300 ° C for a long time. Graphite-containing fibrous materials do not lose their qualities even at 1000-2000 ° C. Designed polyester fibers by incorporating titanium atoms while maintaining mechanical strength and flexibility can withstand heat up to 1200 ° C.
Among all materials produced in the 70s, the share of artificial fabrics for clothing was about 50%, for household goods - about 25% and the same for technical purposes. Mass production of high-strength cord yarns from polyamides, polyesters and viscose for the tire industry has been established.
The volume of production of synthetic materials for the manufacture of clothing is determined by consumer demand, in which there has been a downward trend in recent years. This trend is fully justified, because synthetic fibers do not have the whole range of properties inherent in natural fibers. And one of the most important tasks of chemists is to bring artificial materials closer to natural ones in terms of properties and quality.
A new generation of fabrics, which experts are working on today, can restructure our understanding of clothing and its functions. Such fabrics are woven from fibers that their inventors call “intelligent.” Such a binding definition hides materials that have properties that are useful to humans.
In cold weather they warm, in heat they cool, remove sweat and meet other skin needs.
Light fabrics are already commercially available with a high degree of protection against sunlight. There are also fabrics that let in ultraviolet rays.
The American concern DuPont launched the first purely synthetic fiber, nylon, over 60 years ago. Then came acrylic, polyamide, polyester and other fibers born in laboratory retorts. However, consumers comparatively quickly appreciated both the advantages and disadvantages of synthetic fabrics of the time. The shirt, which does not need an iron, at the same time did not allow the body to breathe in the summer, but did not warm it in the winter. The euphoria raised by the first synthetic products ended up mostly in a trash can, not a wardrobe.
A lot of time passed before it was possible to understand and overcome the border between natural and synthetic fibers.
Now chemistry easily reproduces the best properties of flax, cotton, wool, and natural materials have long been the subject of repeated chemical treatment, giving, for example, elasticity to cotton or making linen fabric not so wrinkled.
The innovations of today have affected the geometry of the fibers. Textile makers seek to make yarns as thin as possible. The finest synthetic threads of the fabric are clearly visible in the photograph taken under a microscope (see Fig. 6.13).
A favorite material of today's fashion designers - elastic is convenient not only in sportswear, but also in everyday suits. There is already a fabric based on the smallest glass balls reflecting light; clothing made of such material is a good protection for those who are on the street at night, for example, for traffic controllers.
One of the varieties of synthetics is Kevlar, which is five times tighter than steel and is used to make bulletproof jackets.
A very original technology is the manufacture of fabric for the clothes of an astronaut, which is able to protect it outside the atmosphere from the freezing cold of space and the scorching heat of the sun. The secret of such clothes is in millions of microscopic capsules embedded in tissue or in foam plastic (see Fig. 6.14).
Capsules contain paraffins. When heated, they melt and take away heat from substances nearby. Ultimately, a suit made of such fabric becomes an obstacle to the path of sunlight to the human body. Solving the inverse problem - cooling, the same paraffin balls begin to solidify under the influence of the cold that came from outside; solidification is accompanied by the release of heat, which warms the tissue and body of the astronaut.