Organic polymers. Organic and inorganic polymers

Inorganic polymers

• Inorganic polymers- polymers that do not contain C-C bonds in the repeating unit, but are capable of containing an organic radical as side substituents.

Classification of polymers

1. Homochain polymers

Carbon and chalcogens (plastic modification of sulfur).

Mineral fiber asbestos

Characteristics of asbestos

• Asbestos(Greek ἄσβεστος, - indestructible) is the collective name for a group of fine-fiber minerals from the class of silicates. Consist of the finest flexible fibers.

• Ca2Mg5Si8O22(OH)2 - formula

• The two main types of asbestos are serpentine asbestos (chrysotile asbestos, or white asbestos) and amphibole asbestos.

Chemical composition

• In terms of their chemical composition, asbestos is aqueous silicates of magnesium, iron, and partly calcium and sodium. The following substances belong to the class of chrysotile asbestos:

• Mg6(OH)8

• 2Na2O*6(Fe,Mg)O*2Fe2O3*17SiO2*3H2O

Safety

• Asbestos is practically inert and does not dissolve in body fluids, but has a noticeable carcinogenic effect. People involved in asbestos mining and processing are several times more likely to develop tumors than the general population. Most often it causes lung cancer, tumors of the peritoneum, stomach and uterus.

• Based on the results of comprehensive scientific research into carcinogens, the International Agency for Research on Cancer has classified asbestos as one of the most dangerous carcinogens in the first category.

Application of asbestos

• Production of fire-resistant fabrics (including for sewing suits for firefighters).

• In construction (as part of asbestos-cement mixtures for the production of pipes and slate).

• In places where it is necessary to reduce the influence of acids.

The role of inorganic polymers in the formation of the lithosphere

Lithosphere

• Lithosphere- the hard shell of the Earth. It consists of the earth's crust and the upper part of the mantle, up to the asthenosphere.

The lithosphere beneath oceans and continents varies considerably. The lithosphere beneath the continents consists of sedimentary, granite and basalt layers with a total thickness of up to 80 km. The lithosphere under the oceans has undergone many stages of partial melting as a result of the formation of the oceanic crust, it is greatly depleted in fusible rare elements, mainly consists of dunites and harzburgites, its thickness is 5-10 km, and the granite layer is completely absent.

Chemical composition

The main components of the Earth's crust and surface soil of the Moon are Si and Al oxides and their derivatives. This conclusion can be made based on existing ideas about the prevalence of basalt rocks. The primary substance of the earth's crust is magma - a fluid form of rock that contains, along with molten minerals, a significant amount of gases. When magma reaches the surface, it forms lava, which solidifies into basalt rocks. The main chemical component of lava is silica, or silicon dioxide, SiO2. However, at high temperatures, silicon atoms can easily be replaced by other atoms, such as aluminum, forming various types of aluminosilicates. In general, the lithosphere is a silicate matrix with the inclusion of other substances formed as a result of physical and chemical processes that occurred in the past under conditions of high temperature and pressure. Both the silicate matrix itself and the inclusions in it contain predominantly substances in polymer form, that is, heterochain inorganic polymers.

Granite

• Granite - silicic igneous intrusive rock. It consists of quartz, plagioclase, potassium feldspar and micas - biotite and muscovite. Granites are very widespread in the continental crust.

The largest volumes of granites are formed in collision zones, where two continental plates collide and thickening of the continental crust occurs. According to some researchers, a whole layer of granite melt is formed in the thickened collision crust at the level of the middle crust (depth 10-20 km). In addition, granitic magmatism is characteristic of active continental margins, and to a lesser extent, of island arcs.

• Mineral composition of granite:

• feldspars - 60-65%;

• quartz - 25-30%;

• dark-colored minerals (biotite, rarely hornblende) - 5-10%.

Basalt

• Mineral composition. The main mass is composed of microlites of plagioclase, clinopyroxene, magnetite or titanomagnetite, as well as volcanic glass. The most common accessory mineral is apatite.

• Chemical composition. The silica content (SiO2) ranges from 45 to 52-53%, the sum of alkaline oxides Na2O+K2O up to 5%, in alkaline basalts up to 7%. Other oxides can be distributed as follows: TiO2 = 1.8-2.3%; Al2O3=14.5-17.9%; Fe2O3=2.8-5.1%; FeO=7.3-8.1%; MnO=0.1-0.2%; MgO=7.1-9.3%; CaO=9.1-10.1%; P2O5=0.2-0.5%;

Quartz (Silicon(IV) Oxide, Silica)

Formula: SiO2

• Formula: SiO2

• Color: colorless, white, violet, gray, yellow, brown

• Trait color: white

• Shine: glassy, ​​sometimes greasy in solid masses

• Density: 2.6-2.65 g/cm³

• Hardness: 7

Chemical properties

Corundum (Al2O3, alumina)

Formula: Al2O3

• Formula: Al2O3

• Color: blue, red, yellow, brown, gray

• Trait color: white

• Shine: glass

• Density: 3.9-4.1 g/cm³

• Hardness: 9

Tellurium

Tellurium chain structure

• Crystals are hexagonal, the atoms in them form helical chains and are connected by covalent bonds to their nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although due to its complex of chemical properties it can rather be classified as a non-metal.

Applications of tellurium

• Production of semiconductor materials

• Rubber production

• High temperature superconductivity

Selenium

Selenium chain structure

Black Gray Red

Gray selenium

Gray selenium (sometimes called metallic) has crystals in a hexagonal system. Its elementary lattice can be represented as a slightly deformed cube. All its atoms seem to be strung on spiral chains, and the distances between neighboring atoms in one chain are approximately one and a half times less than the distance between the chains. Therefore, the elementary cubes are distorted.

Applications of gray selenium

• Ordinary gray selenium has semiconducting properties; it is a p-type semiconductor, i.e. conductivity in it is created mainly not by electrons, but by “holes”.

• Another practically very important property of semiconductor selenium is its ability to sharply increase electrical conductivity under the influence of light. The action of selenium photocells and many other devices is based on this property.

Red selenium

• Red selenium is a less stable amorphous modification.

• A polymer with a chain structure but a poorly ordered structure. In the temperature range of 70-90°C, it acquires rubber-like properties, turning into a highly elastic state.

• Does not have a specific melting point.

• Red amorphous selenium with increasing temperature (-55) it begins to transform into gray hexagonal selenium

Sulfur

Structural features

• The plastic modification of sulfur is formed by helical chains of sulfur atoms with left and right axes of rotation. These chains are twisted and pulled in one direction.

• Plastic sulfur is unstable and spontaneously turns into rhombic sulfur.

Obtaining plastic sulfur

Application of sulfur

• Preparation of sulfuric acid;

• In the paper industry;

• in agriculture (to combat plant diseases, mainly grapes and cotton);

• in the production of dyes and luminous compositions;

• to obtain black (hunting) powder;

• in the production of matches;

• ointments and powders for the treatment of certain skin diseases.

Allotropic modifications of carbon

Comparative characteristics

Application of allotropic modifications of carbon

• Diamond - in industry: it is used to make knives, drills, cutters; in jewelry making. The future is the development of microelectronics on diamond substrates.

• Graphite – for the manufacture of melting crucibles, electrodes; plastic filler; neutron moderator in nuclear reactors; component of the composition for the manufacture of leads for black graphite pencils (mixed with kaolin)

Inorganic polymers are a term that have gained prominence through their widespread use in investment casting. And all thanks to the properties inherent in these materials. But the significance of inorganic polymers for humans is much broader, and the scope of application goes far beyond the scope of this technology.

What are inorganic polymers

More common are inorganic polymers of natural origin found in the earth's crust.

Most often it is a product of the synthesis of elements of groups III-VI of the periodic system of Mendeleev. They are called inorganic because they are based on inorganic main chains and do not have organic side radicals. Bonds appear as a result of one of two processes - polycondensation or polymerization.

Generally speaking, inorganic polymers are artificially synthesized materials that replaced natural ones. At the same time, the creators pursued the goal of making them cheaper. Modern polymers are superior in their characteristics to existing natural analogues. Materials have been created that nature does not possess at all. This ensures their popularity and diversity.

Classification

A clear list of types has not yet been formed, but there are several main groups of inorganic polymers that differ in their structure. Such materials are:

• linear;
• flat;
• branched;
• three-dimensional, etc.

Also distinguished by origin:

• natural;
• artificial.

By chain formation:

• heterochain;
• homochain.

Types of inorganic polymers

Asbestos is one of the most common polymers. Its structure is a fine-fiber material - silicate. It contains molecules of iron, magnesium, calcium and sodium. The production of this polymer is considered harmful to humans, but products made from it are absolutely safe.

Silicone has also found its use due to the fact that it is superior to natural rubber in many characteristics. Strength and elasticity are provided by the combination of oxygen and silicon. Polysiliconsan withstands mechanical, temperature, and deformation effects. At the same time, the shape and structure remain unchanged.

Carbine replaced diamond. It is also durable, which is necessary in many industries. This polymer is characterized by the ability to withstand temperatures up to 5,000 ºC. A special feature is an increase in electrical conductivity under the influence of light waves.

Graphite is known to everyone who has ever picked up a pencil. A special feature of hydrocarbon polymers is their planar structure. They conduct electrical discharges and heat, but completely absorb the light wave.

Polymers based on selenium, boron and other elements are also produced, which provides a variety of characteristics.

Characteristics of inorganic polymers

When creating polymer materials, the qualities of the final product are based on:

• flexibility and elasticity;
• compressive, torsional, tensile strength;
• state of aggregation; temperature resistance;
• electrical conductivity;
• ability to transmit light, etc.

during manufacturing, they take a pure substance, subject it to specific polymerization processes, and the output is synthetic (inorganic) polymers, which:

1. Withstands extreme temperatures.
2. Capable of returning to its original shape after deformation under the influence of external mechanical forces.
3. They become glassy when heated to a critical temperature.
4. They are able to change the structure during the transition from volumetric to planar, which ensures viscosity.

The ability to transform is used in mold casting. After cooling, inorganic polymers harden and also acquire various qualities from durable hard to flexible, elastic. At the same time, environmental safety is ensured, which ordinary plastic cannot boast of. Polymer materials do not react with oxygen, and strong bonds prevent the release of molecules.

Scope of application

There is a huge variety of polymers. Every year, scientists develop new technologies that make it possible to produce materials with different quality indicators. And now polymers are found both in industry and in everyday life. No construction is complete without asbestos. It is present in slate, special pipes, etc. Cement is used as a binding element.

Silicone is an excellent sealant used by builders. The automotive industry, the production of industrial equipment, and consumer goods are based on polymers, which make it possible to achieve high strength, durability, and tightness.

And returning to asbestos, it is impossible not to mention that the ability to retain heat made it possible to create suits for firefighters.

When talking about diamonds, it is customary to identify them with polished diamonds (cut diamonds). Some inorganic polymers are not inferior to this natural crystal, which is necessary in various industrial fields, including the production of diamonds. In the form of crumbs, this material is applied to the cutting edges. The result is incisors that can cut anything. This is an excellent abrasive used for sanding. Elbor, borazon, cyborite, kingsongite, cubonite are super-strong compounds.

If it is necessary to process metal or stone, inorganic polymers made by boron synthesis are used. Any grinding wheel sold in construction supermarkets contains this material. For the production of decorative elements, for example, selenium carbide is used. It produces an analogue of rock crystal. But the list of advantages and the list of applications is not limited to this.

Phosphornitride chlorides are formed by combining phosphorus, nitrogen and chlorine. Properties may vary and depend on mass. When it is large, an analogue of natural rubber is formed. Only now it can withstand temperatures up to 350 degrees. No reactions are observed under the influence of organic compounds. And in the permissible temperature range, the properties of the products do not change.

Special properties used by humans

The bottom line is that as a result of synthesis, macromolecules of a three-dimensional (three-dimensional) type are formed. Strength comes from strong bonds and structure. As a chemical element, inorganic polymers behave amorphously and do not react with other elements and compounds. This feature allows them to be used in the chemical industry, medicine, and food production.

Thermal resistance exceeds all indicators possessed by natural materials. If fibers are used to form a reinforced frame, then such a structure can withstand temperatures up to 220 degrees in air. And if we are talking about boron material, then the temperature strength limit rises to 650 degrees. That is why space flights without polymersan would be impossible.

But this is if we talk about qualities that are superior to natural ones. The same products that are made from these compounds, which are similar in quality to natural ones, have a special meaning for humans. This makes it possible to reduce the cost of clothing by replacing, for example, leather. At the same time, there are practically no external differences.

In medicine, special hopes are placed on inorganic polymers. It is planned to use these materials to produce artificial tissues and organs, prosthetics, etc. Chemical resistance allows products to be treated with active substances, which ensures sterility. The tool becomes durable, useful and safe for humans.

Organic polymers play a significant role in nature. In addition, they are widely used in industry. Next, the composition, properties, and use of organic polymers are considered.

Peculiarities

The materials under consideration consist of monomers represented by repeating fragments of a structure of several atoms. They are connected into three-dimensional structures or chains of branched or linear shape due to polycondensation or polymerization. They are often clearly visible in the structure.

It should be said that the term "polymers" refers mainly to organic options, although inorganic compounds also exist.

The principle of naming the materials under consideration is to attach the prefix poly to the name of the monomer.

The properties of polymers are determined by the structure and size of macromolecules.

In addition to macromolecules, most polymers include other substances that serve to improve functional characteristics by modifying properties. They are presented:

• stabilizers (prevent aging reactions);
• fillers (inclusions of different phase states that serve to impart specific properties);
• plasticizers (increase frost resistance, reduce processing temperature and improve elasticity);
• lubricants (allows you to avoid sticking of metal elements of equipment used in processing);
• dyes (serve for decorative purposes and to create markings);
• flame retardants (reduce the flammability of some polymers);
• fungicides, antiseptics, insecticides (give antiseptic properties and resistance to insects and fungal mold).

In the natural environment, the materials in question are formed in organisms.

In addition, there are compounds close to polymers in structure, called oligomers. Their differences consist in a smaller number of units and a change in the initial properties when one or more of them is removed or added, while the parameters of the polymers are preserved. In addition, there is no clear opinion regarding the relationship between these compounds. Some consider oligomers to be low-molecular-weight variants of polymers, while others consider them to be a separate type of compound that is not high-molecular-weight.

Classification

Polymers are differentiated by the composition of units into:

• organic;
• organoelement;
• inorganic.

The former serve as the basis for most plastics.

Substances of the second type include hydrocarbon (organic) and inorganic fragments in their units.

According to their structure they are differentiated into:

• options in which atoms of different elements are framed by organic groups;
• substances where carbon atoms alternate with others;
• materials with carbon chains framed by organoelement groups.

All types presented have main circuits.

The most common inorganic polymers are aluminosilicates and silicates. These are the main minerals of the planet's crust.

Based on their origin, polymers are classified into:

• natural;
• synthetic (synthesized);
• modified (modified variants of the first group).

The latter are divided according to the method of production into:

• polycondensation;
• polymerization

Polycondensation is the process of formation of macromolecules from monomer molecules containing more than one functional group with the release of NH 3, water and other substances.

Polymerization refers to the process of forming macromolecules with multiple bonds from a monomer.

Classification by macromolecular structure includes:

• branched;
• linear;
• three-dimensional stitched;
• staircases

Based on their response to thermal effects, polymers are differentiated into:

• thermosetting;
• thermoplastic.

Substances of the first type are represented by spatial variants with a rigid frame. When heated, they undergo destruction and some catch fire. This is due to the equal strength of internal connections and chain connections. As a result, the thermal effect leads to the rupture of both chains and structure, therefore, irreversible destruction occurs.

Thermoplastic options are represented by linear polymers that soften reversibly when heated and harden when cooled. Their properties are then preserved. The plasticity of these substances is due to the rupture of intermolecular and hydrogen bonds of chains upon moderate heating.

Finally, according to their structural features, organic polymers are divided into several classes.

1. Weak and non-polar thermoplastics. They are presented in variants with a symmetrical molecular structure or with weakly polar bonds.
2. Polar thermoplastics. This type includes substances with an asymmetric molecular structure and their own dipole moments. They are sometimes called low-frequency dielectrics. Due to their polarity, they attract moisture well. Also, most of them are wettable. These substances also differ from the previous class in having lower electrical resistance. Moreover, many of the polar thermoplastics are characterized by high elasticity, chemical resistance, and mechanical strength. Additional processing allows these compounds to be converted into flexible rubber-like materials.
3. Thermosetting polymers. As mentioned above, these are substances with a spatial system of covalent bonds. They differ from thermoplastic options in hardness, heat resistance and fragility, a higher elastic modulus and a lower coefficient of linear expansion. In addition, such polymers are not susceptible to conventional solvents. They serve as the basis for many substances.
4. Laminated plastics. They are represented by layered materials from resin-impregnated sheets of paper, fiberglass, wood veneer, fabric, etc. Such polymers are characterized by the greatest anisotropy of characteristics and strength. But they are of little use for creating objects of complex configuration. They are used in radio, electrical engineering, and instrument making.
5. Metal-plastics. These are polymers that include metal fillers in the form of fibers, powders, and fabrics. These additives serve to impart specific properties: magnetic, improve damping, electrical and thermal conductivity, absorption and reflection of radio waves.

Properties

Many organic polymers have good electrical insulating parameters over a wide range of voltages, frequencies and temperatures, and at high humidity. In addition, they have good sound and heat insulation characteristics. Organic polymers are also usually characterized by high resistance to chemical attack and are not subject to rotting or corrosion. Finally, these materials have great strength at low density.

The examples above demonstrate characteristics common to organic polymers. In addition, some of them are distinguished by specific features: transparency and low fragility (organic glass, plastics), macromolecular orientation with directed mechanical influence (fibers, films), high elasticity (rubber), rapid change in physical and mechanical parameters under the influence of a reagent in small quantities. quantity (rubber, leather, etc.), as well as high viscosity at low concentrations, radio transparency, anti-friction characteristics, diamagnetism, etc.

Application

Due to the above parameters, organic polymers have a wide range of applications. Thus, the combination of high strength with low density makes it possible to obtain materials with high specific strength (fabrics: leather, wool, fur, cotton, etc.; plastics).

In addition to those mentioned, other materials are produced from organic polymers: rubbers, paints and varnishes, adhesives, electrical insulating varnishes, fibrous and film substances, compounds, binding materials (lime, cement, clay). They are used for industrial and domestic needs.

However, organic polymers have a significant practical disadvantage - aging. This term refers to a change in their characteristics and sizes as a result of physical and chemical transformations occurring under the influence of various factors: abrasion, heating, irradiation, etc. Aging occurs through certain reactions depending on the type of material and influencing factors. The most common among them is destruction, which implies the formation of lower molecular weight substances due to the rupture of the chemical bond of the main chain. Based on the reasons, destruction is divided into thermal, chemical, mechanical, photochemical.

Story

Polymer research began to develop by the 40s. XX century and emerged as an independent scientific field in the middle of the century. This was due to the development of knowledge about the role of these substances in the organic world and the identification of the possibilities of their use in industry.

At the same time, chain polymers were produced at the beginning of the 20th century.

By the middle of the century, they mastered the production of electrically insulating polymers (polyvinyl chloride and polystyrene) and plexiglass.

At the beginning of the second half of the century, the production of polymer fabrics expanded due to the return of previously produced materials and the emergence of new options. Among them are cotton, wool, silk, lavsan. During the same period, thanks to the use of catalysts, the production of low-pressure polyethylene and polypropylene and crystallizing stereoregular variants began. A little later, they mastered the mass production of the most famous sealants, porous and adhesive materials, represented by polyurethanes, as well as organoelement polymers, which differ from organic analogues in greater elasticity and heat resistance (polysiloxanes).

In the 60s - 70s. Unique organic polymers with aromatic components, characterized by high heat resistance and strength, were created.

The production of organic polymers is still intensively developing. This is due to the possibility of using cheap materials such as coal, associated gases from oil refining and production and natural gases, together with water and air as feedstock for most of them.

In 1833, J. Berzelius coined the term “polymerism,” which he used to name one of the types of isomerism. Such substances (polymers) had to have the same composition, but different molecular weights, such as ethylene and butylene. The conclusion of J. Berzelius does not correspond to the modern understanding of the term “polymer”, because true (synthetic) polymers were not yet known at that time. The first mentions of synthetic polymers date back to 1838 (polyvinylidene chloride) and 1839 (polystyrene).

Polymer chemistry arose only after A. M. Butlerov created the theory of the chemical structure of organic compounds and was further developed thanks to an intensive search for methods of synthesizing rubber (G. Bushard, W. Tilden, K. Harries, I. L. Kondakov, S. V. Lebedev) . Since the beginning of the 20s of the 20th century, theoretical ideas about the structure of polymers began to develop.

DEFINITION

Polymers- chemical compounds with high molecular weight (from several thousand to many millions), the molecules of which (macromolecules) consist of a large number of repeating groups (monomer units).

Classification of polymers

The classification of polymers is based on three characteristics: their origin, chemical nature and differences in the main chain.

From the point of view of origin, all polymers are divided into natural (natural), which include nucleic acids, proteins, cellulose, natural rubber, amber; synthetic (obtained in the laboratory by synthesis and having no natural analogues), which include polyurethane, polyvinylidene fluoride, phenol-formaldehyde resins, etc.; artificial (obtained in the laboratory by synthesis, but based on natural polymers) - nitrocellulose, etc.

Based on their chemical nature, polymers are divided into organic polymers (based on a monomer - an organic substance - all synthetic polymers), inorganic (based on Si, Ge, S and other inorganic elements - polysilanes, polysilicic acids) and organoelement (a mixture of organic and inorganic polymers – polysoxanes) of nature.

There are homochain and heterochain polymers. In the first case, the main chain consists of carbon or silicon atoms (polysilanes, polystyrene), in the second - a skeleton of various atoms (polyamides, proteins).

Physical properties of polymers

Polymers are characterized by two states of aggregation - crystalline and amorphous - and special properties - elasticity (reversible deformations under light load - rubber), low fragility (plastics), orientation under the action of a directed mechanical field, high viscosity, and the dissolution of the polymer occurs through its swelling.

Preparation of polymers

Polymerization reactions are chain reactions that represent the sequential addition of molecules of unsaturated compounds to each other with the formation of a high-molecular-weight product - a polymer (Fig. 1).

Rice. 1. General scheme for polymer production

For example, polyethylene is produced by polymerization of ethylene. The molecular weight of the molecule reaches 1 million.

n CH 2 =CH 2 = -(-CH 2 -CH 2 -)-

Chemical properties of polymers

First of all, polymers will be characterized by reactions characteristic of the functional group present in the polymer. For example, if the polymer contains a hydroxo group characteristic of the class of alcohols, therefore, the polymer will participate in reactions like alcohols.

Secondly, interaction with low molecular weight compounds, interaction of polymers with each other with the formation of network or branched polymers, reactions between functional groups that are part of the same polymer, as well as the decomposition of the polymer into monomers (chain destruction).

Application of polymers

The production of polymers has found wide application in various areas of human life - the chemical industry (plastic production), machine and aircraft construction, oil refining enterprises, medicine and pharmacology, agriculture (production of herbicides, insecticides, pesticides), construction industry (sound and thermal insulation), production of toys, windows, pipes, household items.

Examples of problem solving

EXAMPLE 1

EXAMPLE 1

There is practically no person in the modern world who does not have at least some idea about polymers. Polymers go through life with a person, making his life more and more convenient and comfortable. When mentioning polymers, the first associations will be with synthetic organic substances, since they are more visible. Natural polymers - natural organic substances - although there are more of them in the world around us, in the associative perception of a person they fade into the background. They always surround us, but no one thinks about the nature of the origin of flora and fauna. Cellulose, starch, lignin, rubber, proteins and nucleic acids are the main materials used by nature to create the animal and plant world around us. And absolutely no one will perceive precious stones, graphite, mica, sand and clay, glass and cement as polymers. Nevertheless, science has established the fact of the polymeric structure of many inorganic compounds, including those listed above. Polymer substances consist of macromolecules. When polymers are formed, a large number of atoms or groups of atoms are bonded to each other by chemical bonds - covalent or coordination. Polymer macromolecules contain tens, hundreds, thousands or tens of thousands of atoms or repeating elementary units. Information about the polymer structure was obtained by studying the properties of solutions, the structure of crystals, and the mechanical and physicochemical properties of inorganic substances. In support of the above, it should be noted that there is a sufficient amount of scientific literature confirming the fact of the polymeric structure of some inorganic substances.

A logical remark would be: why is there so much information about synthetic organic polymers and so little about inorganic ones? If there are inorganic polymeric substances, what exactly are they and where are they used? Several examples of inorganic polymers were given above. These are well-known substances that everyone knows, but few people know that these substances can be classified as polymers. By and large, the average person doesn’t care whether graphite can be classified as a polymer or not; as for precious stones, for some it may even be offensive to equate expensive jewelry with cheap plastic jewelry. Nevertheless, if there is reason to call some inorganic substances polymers, then why not talk about it. Let's look at some representatives of such materials and look in more detail at the most interesting ones.
The synthesis of inorganic polymers most often requires very pure starting materials, as well as high temperatures and pressures. The main methods for their production, like organic polymers, are polymerization, polycondensation and polycoordination. The simplest inorganic polymers include homochain compounds consisting of chains or frameworks built from identical atoms. In addition to the well-known carbon, which is the main element involved in the construction of almost all organic polymers, other elements can also participate in the construction of macromolecules. These elements include boron from the third group, silicon, germanium and tin from the fourth group, which also includes carbon, phosphorus, arsenic, antimony and bismuth from the fifth group, sulfur, selenium, tellurium from the sixth. Mainly homochain polymers obtained from these elements are used in electronics and optics. The electronics industry is developing at a very high pace and the demand for synthetic crystals has long exceeded supply. Of particular note, however, is carbon and the inorganic polymers that are produced on its basis: diamond and graphite. Graphite is a well-known material that has found application in various industries. Pencils, electrodes, crucibles, paints, and lubricants are made from graphite. Thousands of tons of graphite go to the needs of the nuclear industry due to its properties to slow down neutrons. In the article we will dwell in more detail on the most interesting representatives of inorganic polymers - precious stones.
The most interesting, pretentious, and beloved by women representative of inorganic polymers are diamonds. Diamonds are very expensive minerals, which can also be classified as inorganic polymers; they are mined in nature by five large companies: DeBeers, Alrosa, Leviev, BHPBilliton, RioTinto. It was the DeBeers company that created the reputation of these stones. Smart marketing boils down to the slogan, “forever.” DeBeers has turned this stone into a symbol of love, prosperity, power, and success. An interesting fact is that diamonds are found quite often in nature, for example sapphires and rubies, which are rarer minerals, but they are valued lower than diamonds. The most interesting thing is the situation that has developed in the natural diamond market. The fact is that there are technologies that make it possible to obtain synthetic diamonds. In 1954, General Electric researcher Tracy Hall invented a device that made it possible to obtain diamond crystals from iron sulfide at a pressure of 100,000 atmospheres and a temperature of over 2500ºC. The quality of these stones was not high from a jewelry point of view, but the hardness was the same as that of natural stone. Hall's invention was improved and in 1960 General Electric created a plant in which it was possible to produce gem-quality diamonds. The negative point was that the price of synthetic stones was higher than natural ones.
At the moment, there are two technologies for synthesizing diamonds. HPHT (high pressure/high temperature) technology is the synthesis of diamonds in a combination of high pressure and high temperature. CVD (chemical vapor deposition) technology is a chemical vapor deposition technology that is considered more progressive and allows you to grow diamond, as if simulating the natural conditions of its growth. Both technologies have advantages and disadvantages. Campaigns using them solve the shortcomings of technology by using their own inventions and developments. For example, back in 1989, a group of Soviet scientists from Novosibirsk managed to reduce the fusion pressure to 60,000 atmospheres. After the collapse of the Soviet Union, developments in the field of diamond synthesis continued, thanks to many foreign investors interested in obtaining the technology for cheap synthesis of high-quality gemstones. For example, DeBeers, in order not to lose the opportunity to control the market, financed the work of some scientists. Some private entrepreneurs bought diamond synthesis equipment in Russia, for example, the now thriving American company Gemesis began by purchasing a diamond growing installation in Russia in 1996 for $60,000. Now Gemesis produces and sells diamonds of rare colors: yellow and blue, and the difference in price between these and exactly the same natural stones reaches 75%.

Another large company synthesizing diamonds, Apollo Diamond, is improving HPHT technology by synthesizing stones in a gas atmosphere of a certain composition (symbiosis technology of HPHT and CVD). This method brings Apollo Diamond to the market of jewelry stones; at the same time, the quality of synthetic diamonds grown using this technology is very high. It is increasingly difficult for gemotologists to distinguish synthetic stones from natural ones. This requires a complex of analyzes using quite complex and expensive equipment. Apollo Diamond synthetic gem diamonds are almost impossible to distinguish from natural minerals using standard analysis methods.

World diamond production is now 115 million carats or 23 tons per year. Theoretically, this gigantic market could collapse and the reputation of diamonds as precious stones would be lost forever. Monopoly firms invest in stabilizing the situation and controlling the market. For example, expensive marketing campaigns are carried out, patents for artificial diamond manufacturing technologies are purchased so that these technologies are never introduced, certificates and quality passports are issued for branded diamonds confirming their natural origin. But will this hold back the progress of fusion technology?

Having talked about diamonds, we were distracted by the brilliance of the precious stones of the jewelry industry, but we should also point out industrial stones. In this case, most diamond-growing enterprises operate primarily for the needs of the electronics and optical industries. The industrial stone market may not be as intriguing as the jewelry market, but it is nonetheless huge. For example, Apollo Diamond's main income is the synthesis of thin diamond disks for semiconductors. By the way, now a diamond synthesis installation with a productivity of about 200 kg of diamonds per month can be purchased for 30 thousand dollars.

Another representative of precious stones is ruby. The first synthetic ruby ​​was born in 1902. It was synthesized by the French engineer Verneuil by melting aluminum oxide and chromium powder, which then crystallized into a six-gram ruby. This simplicity of synthesis allowed the relatively rapid development of industrial production of rubies around the world. This stone is in great demand. Every year about 5 tons of rubies are mined in the world, and market needs amount to hundreds of tons. Rubies are needed in the watch industry and in the production of lasers. The technology proposed by Verneuil subsequently provided the prerequisites for the synthesis of sapphires and garnets. The largest productions of artificial rubies are located in France, Switzerland, Germany, Great Britain, and the USA. The economics of production are as follows. The lion's share of the cost is consumed by energy costs. At the same time, the cost of synthesizing a kilogram of rubies is $60, the cost of a kilogram of sapphires is $200. The profitability of such a business is very high, since the purchase price for crystals is at least twice as high. Here a number of factors should be taken into account, such as the fact that the larger the grown single crystal, the lower its cost; also, when producing products from crystals, their price will be much higher than the price of sold crystals (for example, the production and sale of glass). As for equipment, Russian installations for growing crystals cost about 50 thousand dollars, Western ones are an order of magnitude more expensive, while the payback period for organized production is on average two years. As already mentioned, the market needs for synthetic crystals are colossal. For example, sapphire crystals are in great demand. About a thousand tons of sapphires are synthesized around the world per year. Annual production needs reach a million tons!
Emeralds are synthesized exclusively for the needs of the jewelry industry. Unlike other crystals, emerald is obtained not from a melt, but from a solution of boron ahydride at a temperature of 400 ° C and a pressure of 500 atmospheres in a hydrothermal chamber. It is curious that the extraction of natural stone is only 500 kilograms per year. Synthetic emeralds are also produced in the world in quantities that are not as large as other crystals, about a ton per year. The fact is that the technology for synthesizing emeralds is low-productivity, but the profitability of such production is high. Producing about 5 kilograms of crystals per month at a cost of $200 per kilogram, the selling price of synthetic emeralds is almost equal to the price of natural ones. The cost of the installation for the synthesis of emeralds is about 10 thousand dollars.
But the most popular synthetic crystal is silicon. Perhaps it will give odds to any precious stone. At the moment, silicon occupies 80% of the total market for synthetic crystals. The market is experiencing a shortage of silicon due to the rapid development of high technologies. At the moment, the profitability of silicon production exceeds 100%. The price of a kilogram of silicon is about $100 per kilogram, while the cost of synthesis reaches $25.

Ultrapure silicon is used as a semiconductor. Solar photocells with a high efficiency are made from its crystals. Silicon, like carbon, can create long molecular chains from its atoms. In this way, silane and rubber are obtained, which have amazing properties. Several years ago, the whole world was excited by the news of the experiments of the American engineer Walter Robbs, who managed to produce a film of silicone rubber 0.0025 centimeters thick. He covered the cage in which the hamster lived with this rubber and lowered the hamster into the aquarium. For several hours, the world's first submarine hamster breathed oxygen dissolved in water, and was alert and showed no signs of anxiety. It turns out that the film plays the role of a membrane, performing the same functions as the gills of fish. The film allows life gas molecules inside, while carbon dioxide is forced out through the film. This discovery makes it possible to organize human life under water by moving aside cylinders with a breathing mixture and oxygen generators.

Silicon comes in three types: metallurgical silicon (MG), electronics grade silicon (EG), and solar grade silicon (SG). Due to a series of energy crises, alternative energy technologies are being intensively introduced. These include the conversion of solar energy into electrical energy, that is, the use of solar installations powered by solar batteries. An important component of solar cells is silicon. In Ukraine, the Zaporozhye titanium-magnesium plant produced silicon for solar batteries. Under the Soviet Union, this enterprise produced 200 tons of silicon, with the all-Union production volume being 300 tons. The author currently knows nothing about the situation with silicon production in Zaporozhye. The cost of organizing a modern production of polycrystalline silicon for the needs of the energy industry with a capacity of 1000 tons per year is about 56 million dollars. The synthesis of silicon for various needs throughout the world ranks first in demand and will hold this position for a long time.

In the article we examined only some representatives of inorganic polymers. Perhaps many of the things told above were perceived by some with surprise and genuine interest. Someone took a fresh look at the concept of the philosopher's stone; even if it is not gold, it is still possible to obtain precious stones from nondescript metal oxides and other unremarkable substances. We hope that the article gave rise to thought and at least entertained the reader with interesting facts.