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Polymer products. Production of products from polymer materials

Most often, everyday products are made from polymer material. Their application is quite diverse - containers for storing food, liquids, various packaging, forms for concrete, etc. The direction is selected depending on the availability and capacity of the corresponding equipment on which polymer products will be produced.

Where to start

The main task of any businessman is to select the range of products offered and find customers. According to experts, the most popular products made from polymer materials are dishes and other containers that come into contact with food, packaging film for small and large items.

Concluding agreements with sellers or manufacturers of building materials, household appliances, hardware and regular stores will allow you to quickly develop a base of wholesale buyers. In the future, it will be possible to begin producing custom-made products. Low profitability (about 15%) is compensated by large sales volumes.

The initial stage of creating a business is registration. Depending on the expected production volumes, you can choose an individual entrepreneur or LLC. To start a small polymer products plant it is enough. However, when planning large-scale activities with a wide range of products, it is better to register a legal entity. The level of trust in organizations is higher both from partners and clients.


When registering, you must indicate the type of activity. The production of plastic products has the OKVED code 22 (subclass 2). The choice of subsection depends on the product.

Search for premises


The next task of a novice businessman is to find and rent suitable premises. At least 400 sq. m. will be required. m. You can rent hangars, garage buildings or any one-story buildings. Workshops, warehouses and utility rooms must meet the following requirements - the availability of communications (ventilation, water supply, the ability to use high-voltage lines under 380V) and free space for workers in accordance with the volume of production. General standards for production premises:

  1. Ceiling height from 3.5 meters.
  2. Non-combustible materials should be used in wall decoration.
  3. Floors should be concrete or tiled.

If the production of polymer products is planned in a large city (Moscow, St. Petersburg), then rent per square meter is up to 5,000 rubles. per year. Therefore, at least 2,000,000 rubles must be included in the expenses part of the business plan.

Purchase of equipment and materials

Production process cycles can be complete or incomplete. The costs of purchasing equipment on which polymer products will be produced depend on this.

The full cycle involves melting the granules, forming a film and creating a finished product from it. Mandatory equipment includes:

  • granulator;
  • extruder (apparatus for producing film from raw materials);
  • crushing units.

For additional processing of polymer products in Russia, a special printer for applying drawings and inscriptions, an apparatus for bending edges, and a packaging machine may be required. Partial cycle – working with finished film. To complete the lines, you will need to purchase special shaping presses, a laying and packaging machine. Approximate costs of equipment for a plant producing polymer products with a full cycle:

Equipment costs will be at least 300,000 rubles. Costs for setting up the production line are not included. The main raw material for a variety of household products is plastic granules. They are made from recycled plastic. Purchasing your own plant for processing feedstock is unprofitable. Most factories purchase ready-made granules. The cost of 1 ton of material is about 15,000 rubles.

Recruitment

There are craftsmen who are able to make polymer products with their own hands, without outside help. For example, in a garage or basement of a house.

However, high income can only be obtained with large-scale production. The quality of products and financial results depend on the professionalism of employees. The employee must have experience and know production technology. To start a line, you can limit yourself to the following vacancies:

  • general workers (2 people with a salary of 25,000 rubles);
  • technologist (RUB 40,000–50,000);
  • machine control specialist (from RUB 35,000);
  • loader (RUB 20,000–30,000).

Monthly expenses for paying wages will be from 150,000 rubles.

Sales organization procedure

Polymer film is used everywhere - from packaging goods to creating greenhouses and greenhouses. Large retailers are always in need of such materials. You can enter into contracts with them for the wholesale supply of film, offering more favorable conditions than competitors.

One of the popular areas is the production of polymer forms for concrete. The plant can also produce polymer-sand products (paving slabs, tiles, facing stones). In this case, simple compositions are used - polymer, sand, dye. Such production solves the environmental problem of cities. Household waste (plastic, bags, bottles) is used as raw material.

By offering the city administration a waste disposal plan, your ideas and products, you can get good orders and create a positive image.

An approximate estimate of the profitability of a project for the production of polymer materials is from 50,000 to 100,000 rubles. per month. Full payback can be achieved within a year.

Polymer materials are chemical high-molecular compounds that consist of numerous low-molecular monomers (units) of the same structure. Often, the following monomer components are used to make polymers: ethylene, vinyl chloride, vinyldene chloride, vinyl acetate, propylene, methyl methacrylate, tetrafluoroethylene, styrene, urea, melamine, formaldehyde, phenol. In this article we will take a detailed look at what polymer materials are, what their chemical and physical properties are, classification and types.

Types of polymers

The peculiarity of the molecules of this material is large, which corresponds to the following value: M>5*103. Compounds with a lower level of this parameter (M=500-5000) are usually called oligomers. Low molecular weight compounds have a mass of less than 500. The following types of polymer materials are distinguished: synthetic and natural. The latter usually include natural rubber, mica, wool, asbestos, cellulose, etc. However, the main place is occupied by synthetic polymers, which are obtained as a result of the process of chemical synthesis from low-molecular-level compounds. Depending on the method of manufacturing high-molecular materials, there are polymers that are created either by polycondensation or by addition reaction.

Polymerization

This process is the combination of low molecular weight components into high molecular weight ones to produce long chains. The level of polymerization is the number of “mers” in molecules of a given composition. Most often, polymeric materials contain from one thousand to ten thousand of their units. The following commonly used compounds are obtained by polymerization: polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polybutadiene, etc.

Polycondensation

This process is a stepwise reaction, which consists of combining either a large number of monomers of the same type, or a pair of different groups (A and B) into polycapacitors (macromolecules) with the simultaneous formation of the following by-products: carbon dioxide, hydrogen chloride, ammonia, water, etc. When Using polycondensation, silicones, polysulfones, polycarbonates, aminoplasts, phenoplasts, polyesters, polyamides and other polymer materials are obtained.

Polyaddition

This process is understood as the formation of polymers as a result of multiple addition reactions of monomer components that contain saturated reaction compounds to monomers of unsaturated groups (active rings or double bonds). Unlike polycondensation, the polyaddition reaction occurs without the release of byproducts. The most important process of this technology is the curing and production of polyurethanes.

Classification of polymers

Based on their composition, all polymer materials are divided into inorganic, organic and organoelement. The first of them (mica, asbestos, ceramics, etc.) do not contain atomic carbon. They are based on oxides of aluminum, magnesium, silicon, etc. Organic polymers constitute the largest class; they contain atoms of carbon, hydrogen, nitrogen, sulfur, halogen and oxygen. Organoelement polymer materials are compounds that contain, in addition to those listed, atoms of silicon, aluminum, titanium and other elements in their main chains that can combine with organic radicals. Such combinations do not occur in nature. These are exclusively synthetic polymers. Typical representatives of this group are organosilicon-based compounds, the main chain of which is built from oxygen and silicon atoms.

To obtain polymers with the required properties, technology often uses not “pure” substances, but their combinations with organic or inorganic components. A good example is polymer building materials: metal-plastics, plastics, fiberglass, polymer concrete.

Polymer structure

The unique properties of these materials are due to their structure, which, in turn, is divided into the following types: linear-branched, linear, spatial with large molecular groups and very specific geometric structures, as well as ladder-like. Let's look briefly at each of them.

Polymer materials with a linearly branched structure, in addition to the main chain of molecules, have side branches. Such polymers include polypropylene and polyisobutylene.

Materials with a linear structure have long zigzag or spiral chains. Their macromolecules are primarily characterized by repetitions of sections in one structural group of a link or chemical unit of a chain. Polymers with a linear structure are characterized by the presence of very long macromolecules with a significant difference in the nature of the bonds along the chain and between them. This refers to intermolecular and chemical bonds. The macromolecules of such materials are very flexible. And this property is the basis of polymer chains, which leads to qualitatively new characteristics: high elasticity, as well as the absence of brittleness in the hardened state.

Now let’s find out what polymer materials with a spatial structure are. When macromolecules combine with each other, these substances form strong chemical bonds in the transverse direction. The result is a mesh structure, which has a non-uniform or spatial basis of the mesh. Polymers of this type have greater heat resistance and rigidity than linear ones. These materials are the basis of many structural non-metallic substances.

The molecules of polymeric materials with a ladder structure consist of a pair of chains that are connected by a chemical bond. These include organosilicon polymers, which are characterized by increased rigidity, heat resistance, and in addition, they do not interact with organic solvents.

Phase composition of polymers

These materials are systems that consist of amorphous and crystalline regions. The first of them helps reduce rigidity and makes the polymer elastic, that is, capable of large, reversible deformations. The crystalline phase helps to increase their strength, hardness, elastic modulus, and other parameters, while simultaneously reducing the molecular flexibility of the substance. The ratio of the volume of all such areas to the total volume is called the degree of crystallization, where polypropylenes, fluoroplastics, and high-density polyethylenes have the maximum level (up to 80%). Polyvinyl chlorides and low-density polyethylenes have a lower level of crystallization.

Depending on how polymer materials behave when heated, they are usually divided into thermosetting and thermoplastic.

Thermoset polymers

These materials primarily have a linear structure. When heated, they soften, but as a result of chemical reactions occurring in them, the structure changes to spatial, and the substance turns into a solid. In the future, this quality is maintained. Polymers are built on this principle. Their subsequent heating does not soften the substance, but only leads to its decomposition. The finished thermosetting mixture does not dissolve or melt, so its re-processing is unacceptable. This type of materials includes epoxy organosilicon, phenol-formaldehyde and other resins.

Thermoplastic polymers

When heated, these materials first soften and then melt, and upon subsequent cooling they harden. Thermoplastic polymers do not undergo chemical changes during this treatment. This makes this process completely reversible. Substances of this type have a linearly branched or linear structure of macromolecules, between which there are small forces and absolutely no chemical bonds. These include polyethylenes, polyamides, polystyrenes, etc. The technology of thermoplastic polymer materials involves their production by injection molding in water-cooled molds, pressing, extrusion, blowing and other methods.

Chemical properties

Polymers can be in the following states: solid, liquid, amorphous, crystalline phase, as well as highly elastic, viscous and glassy deformation. The widespread use of polymer materials is due to their high resistance to various aggressive environments, such as concentrated acids and alkalis. They are not affected. In addition, with an increase in their molecular weight, the solubility of the material in organic solvents decreases. And polymers with a spatial structure are not at all affected by the mentioned liquids.

Physical properties

Most polymers are dielectrics; in addition, they are non-magnetic materials. Of all the structural materials used, only they have the lowest thermal conductivity and the highest heat capacity, as well as thermal shrinkage (about twenty times more than metal). The reason for the loss of tightness of various sealing units under low temperature conditions is the so-called vitrification of rubber, as well as the sharp difference between the expansion coefficients of metals and rubbers in the vitrified state.

Mechanical properties

Polymer materials have a wide range of mechanical characteristics, which strongly depend on their structure. In addition to this parameter, various external factors can have a great influence on the mechanical properties of a substance. These include: temperature, frequency, duration or speed of loading, type of stress state, pressure, nature of the environment, heat treatment, etc. A feature of the mechanical properties of polymer materials is their relatively high strength with very low rigidity (compared to metals).

Polymers are usually divided into hard ones, the elastic modulus of which corresponds to E = 1-10 GPa (fibers, films, plastics), and soft, highly elastic substances, the elastic modulus of which corresponds to E = 1-10 MPa (rubber). The patterns and mechanism of destruction of both are different.

Polymer materials are characterized by a pronounced anisotropy of properties, as well as a decrease in strength and the development of creep under conditions of prolonged loading. At the same time, they have a fairly high fatigue resistance. Compared to metals, they are distinguished by a sharper dependence of mechanical properties on temperature. One of the main characteristics of polymer materials is deformability (compliance). It is customary to evaluate their basic operational and technological properties using this parameter over a wide temperature range.

Polymer flooring materials

Now let's consider one of the options for the practical use of polymers, revealing the entire possible range of these materials. These substances are widely used in construction and repair and finishing work, in particular in floor coverings. The enormous popularity is explained by the characteristics of the substances in question: they are resistant to abrasion, have low thermal conductivity, have low water absorption, are quite durable and hard, and have high paint and varnish qualities. The production of polymer materials can be divided into three groups: linoleum (rolled), tile products and mixtures for creating seamless floors. Now let's briefly look at each of them.

Linoleums are made on the basis of different types of fillers and polymers. They may also contain plasticizers, processing aids and pigments. Depending on the type of polymer material, there are polyester (glyphthalic), polyvinyl chloride, rubber, colloxylin and other coatings. In addition, according to their structure, they are divided into baseless and with a sound- and heat-insulating base, single-layer and multi-layer, with a smooth, fleecy and corrugated surface, as well as single- and multi-colored.

Materials for seamless floors are the most convenient and hygienic to use, they are highly durable. These mixtures are usually divided into polymer cement, polymer concrete and polyvinyl acetate.

Polymers surround us everywhere; most common objects are made from them. There are several types of polymer materials. We will talk about their features, properties and characteristics further.

Classification of polymer materials and products

Polymer materials combine several groups of plastics of synthetic origin. Among them we note:

  • polymeric substances;
  • plastic compounds;
  • PCM - polymer composite materials.

In each of the listed groups there is a polymer substance with which you can determine the characteristics of a particular composition. Polymers are high-molecular substances into which special additives are introduced, that is, stabilizers, plasticizers, lubricants, etc.

Plastic is a composite material based on a polymer. In addition, they contain dispersed or short-fiber filler. Fillers do not tend to form continuous phases. There are two types of plastic substances:

  • thermoplastic;
  • thermal assets.

The first version of plastic is prone to melting and further use, the second version of plastic is not prone to melting under the influence of high temperature.

Depending on the polymerization method, plastics are produced using:

  • polyconcentration;
  • polyadditions.

Considering the types of polymer substances, we highlight:

1. Type of polyoefins - polymers with the same chemical nature belong to this type of polymer. They contain two substances:

  • polyethylene;
  • polypropylene.

Every year, more than one hundred and fifty tons of such polymers are produced in the world. Among the advantages of polyester substances, we note:

  • resistance to oxidizing agents and tearing;
  • mechanical resistance;
  • no shrinkage;
  • change properties if necessary.

If we compare polyoefins with other types of polymer substances, the former are characterized by the greatest environmental safety. Their production and processing of materials requires a minimal amount of energy.

2. Polyethylene is widely used in the packaging process of any product. Among the advantages of using this material, we note a wide range of applications and excellent performance characteristics.

The structure of polyethylene is quite simple, so it crystallizes easily.

High pressure polyethylene substances. This material is distinguished by the presence of a light matte sheen, plasticity, and the presence of a wavy texture. This type of film is characterized by high mechanical resistance, resistance to impacts and tearing, and strength even in frost. To soften it, you will need a temperature of about one hundred degrees.

Low pressure polyethylene substances. Films of this type have a rigid, durable base, which is less wavy compared to the previous version of polyethylene. Steam is used to sterilize this substance, and its softening temperature is more than one hundred and twenty-one degrees. Despite the presence of high resistance to compression, the film has lower characteristics of resistance to impact and tearing. However, their advantages also include resistance to moisture, chemicals, grease, and oil.

Using polyethylene at room temperature results in a softer, more flexible texture. However, in frosty conditions, these characteristics are maintained. Therefore, polyethylenes are used for storing frozen products. However, when the temperature rises to one hundred degrees Celsius, the characteristics of polyethylene change and it becomes unsuitable for use.

Low-density polyethylene is used in the manufacture of bottles and for packaging various types of substances. It has excellent performance characteristics.

High-density polyethylene is more widely used as a packaging polymer. It has low crystallinity, softness, flexibility and affordable cost.

3. Polypropylene - a material that has excellent transparency, high melting point, chemical resistance and resistance to moisture. Polypropylene is capable of transmitting steam and is unstable to oxygen and oxidizing agents.

4. Polyvinyl chloride is a rather fragile and inelastic material, which is most often used as an additive to polymers. It is characterized by low cost, high-viscosity melt, thermal instability, and when heated, it tends to release toxic substances.

Technology for the production of polymer materials

The production of polymers is a rather complex process, for which many technical aspects of working with these materials must be taken into account. There are several types of technologies for manufacturing polymer-based materials. Polymer materials, products, equipment, technologies, methods:

  • roller-calender method;
  • application of three-component technology;
  • use of extrusion of thermoplastic products;
  • method of casting polymers of large, medium and small shapes;
  • formation of polystyrene substances;
  • production of polystyrene foam boards;
  • blow molding method;
  • manufacturing of products based on polyurethane foam.

The most popular methods for producing products from polymer materials are blowing and thermoforming. To perform the first method, the main starting materials are polyethylene and polypropylene compounds. Among the main characteristics of polyethylene, we note rapid shrinkage and resistance to temperature instability. By means of blowing, products of three-dimensional shape are formed.

Using thermal molding, it is possible to make plastic dishes. In this case, the product manufacturing procedure consists of three stages. First, the amount of plastic is determined, then it is placed in a pre-prepared mold, and then it is melted. The plastic is installed under the press, then it is closed. In the forming station, the product is brought to the desired shape; at the next stage, it is cooled and hardened. Next, the product is removed from the mold and thrown into a special tank.

The use of modern equipment for the manufacture of plastic products allows us to obtain a substance that is durable and long-lasting.

There is automated equipment that is also used to produce polymer substances. In this case, in the process of working on polymer products, the human factor is practically absent; all work is carried out by special robots.

Using automated equipment, it is possible to obtain substances of higher quality, a wider range of products and reduced production costs.

There are a huge number of products made from polymer materials. They differ in size, manufacturing method, composition. For the manufacture of polymers, substances are used in the form of:

  • natural polyamides containing glass fiber;
  • polypropylenes, which make products resistant to frost;
  • polycarbonates;
  • polyurethane;
  • PVC, etc.

Roofing polymer materials and products in the construction industry

Any roof must be durable and reliable. Quite popular finishing materials for roofing are products based on polymer materials. Among the advantages of their use we note:

  • high degree of elasticity;
  • reliability;
  • excellent strength;
  • resistance to stretching and mechanical damage;
  • installation in almost any climatic region;
  • easy installation and simple operation;
  • duration of operation.

The use of membrane roofing of a polymer composition is based on the mechanical fastening of first the thermal insulation and waterproofing layers. Using a membrane, it is possible to create roofs of buildings of various shapes and configurations.

There are several types of polymer membranes depending on their composition and main characteristics:

  • polyvinyl chloride membranes, which contain additional fillers;
  • membranes based on plastic polyesters;
  • membranes containing ethylene propylene diene polymer.

The first version of the membrane is particularly popular. The main component of the membrane is polyvinyl chloride and various additives. With their help, the composition becomes more stable at low temperatures. Polyester mesh is used as film reinforcement. It makes the product more durable and tear-resistant. It is with the help of these characteristics that it is possible to ensure mechanical fastening of the film.

If we consider the disadvantages of PVC membranes, it is worth noting the loss of their elasticity after a certain period of operation. Since the additives present in their composition lose their properties over time. In addition, this material should never be used with bitumen-based waterproofing materials; they are incompatible with each other. The service life of PVC membranes is no more than thirty years.

Membranes based on thermoplastic polyesters contain rubber and special substances that improve their fire safety. This material successfully combines plasticity and rubber. Among their advantages we note:

  • compatibility with bitumen-based substances;
  • Duration of operation, do not require repairs up to forty years;
  • there is the possibility of surface repair, if necessary;
  • easy to install;
  • longer service life compared to PVC-based materials.

Among the disadvantages, we note only the higher cost of such a roof. Which is completely covered by all its advantages.

Membranes based on EPDM are characterized by excellent resistance to climate change, elasticity and long service life.

Among the large number of polymer building materials and products, cash polymer roofing belongs to a special group. Among the advantages of its use are noted:

  • excellent waterproofing characteristics;
  • high level of strength;
  • resistance to temperature changes;
  • high level of frost resistance;
  • lack of joints;
  • high resistance to mechanical damage and wear;
  • resistance to rotting;
  • variety of color solutions;
  • ease of installation work;
  • service life is about fifteen years.

Self-leveling polymer roofing is very similar to a membrane, however, they differ in the technology of material installation. Depending on the roofing technology, it can be:

  • polymer;
  • polymer-rubber.

The first option is more common due to the huge number of advantages it has. To apply this type of roofing, you will need to pour the composition onto the surface and distribute it evenly with a brush or roller. The main advantage of this roof is its complete tightness, elasticity and solidity.

In relation to the technology for installing self-leveling roofing, it can be:

  • reinforced;
  • unreinforced;
  • combined.

Self-leveling roofing with reinforcement contains a solid bitumen emulsion and additional reinforcement with fiberglass. Non-reinforced coating consists of an emulsion material that is applied directly to the roof, about 1 mm thick. The combined option involves the use of polymer mastics, roll-type waterproofing materials, a top layer that contains stone chips, gravel and moisture-resistant paint. The bottom layer of the roof contains a lining in the form of inexpensive rolled material. At the same time, reinforcement is provided by a top layer of stone chips.

The polymer self-leveling roofing contains:

  • polymer-type compositions;
  • fillers that increase the performance characteristics of the material;
  • primer, which is used to prepare the base before applying the roof;
  • reinforcing composition - polyester fiber or fiberglass.

A fairly common option is to use polyurethane-based roofing. It fits perfectly on the surface and is easily installed in difficult areas near a chimney or television antenna. Polyurethane makes the roof similar to rubber; it gives it such qualities as resistance to temperature changes and durability.

Another option for an organic-based polymer used in the process of repairing and manufacturing self-leveling roofing is polyurea. Among its advantages we note:

  • very fast polymerization, to walk on the roof it is enough to wait one hour after applying the material;
  • ability to carry out work at temperatures down to -16 and high humidity;
  • excellent electrical insulation characteristics;
  • resistance to ultraviolet radiation;
  • fire safety and resistance to high temperatures;
  • duration of operation;
  • environmental safety.

The use of polymer materials and products is associated with various industries and the public. The use of polyurea is especially important in regions with an unstable climate and sudden changes in temperature.

The production of products from polymer materials is a complex and responsible task, since half of household items, appliances, cosmetics and furniture are made from polymers today.

Technologies for the production of products from polymer materials

The following technologies can be used in the production of products from polymer materials:

  • Roller-calender technology.

  • Three-component technology.

  • Extrusion of thermoplastics.

  • Casting of small, medium and large parts from polymers.

  • Production of polyethylene film.

  • Formation of polystyrene.

  • Production of polystyrene foam boards.

  • Blow molding.

  • Molding of products from polyurethane foam.

The most common methods are the blow molding method and the thermoforming method. In the first case, polypropylene and polyethylene are used as raw materials.

Polyethylene has certain properties, in particular, rapid shrinkage and temperature resistance, which makes it the most common material for the manufacture of various types of parts. Typically this method is used to create three-dimensional products.

The thermoforming method is used to create bottles and dishes. In this case, the process contains 3 stages. First, the dose of plastic is determined, it is sent into a semi-closed mold, then it is melted.

The plastic is brought under the press and the mold is closed. Next, the mold is opened and the product enters the forming station. To maintain the resulting shape, the station is cooled and the product hardens.

At the final stage, the supporting element opens, the product is released and thrown into a special container.

In the modern world, the production of polymer plastics is carried out using the latest equipment, which allows us to obtain high-quality, strong and durable products.

Thanks to the availability of a large selection of equipment, the product range and its characteristics have also improved.

All new products in the field of equipment for the production of products from polymer materials will be presented at the exhibition, which will be held at the end of October at the Expocentre Fairgrounds. The exhibition will be dedicated to chemical engineering, science and technology, where you can get acquainted with the products of the world's leading brands.

Automated equipment for polymer production

The use of automated equipment has many advantages, since due to the use of special robots in the technology, the subjective and human factor completely disappears.

An automated casting or extrusion process allows you to obtain better production results, expand the range of products, and reduce labor and material costs for production.

The equipment is used to produce a wide variety of parts in shape and size. Polymer products can be both large and small and have different compositions.

A production complex of equipment that is suitable for the manufacture of various parts usually contains the following components:

  • Injection molding machines. Such equipment can have different characteristics; the force of the device ranges from 50 to 2700 tons, that is, the device is suitable for the manufacture of any parts.

  • Blow molding machines. The force for normal operation is 60 tons.

  • Automated robots of different sizes. The purpose of robots can be the supply of raw materials, their loading and processing. All processes are carried out automatically.

  • A set of devices for the production of polystyrene foam products.

  • Various molding machines.

  • Embossing calender.

  • Mixer operating in several stages. As a rule, there are two of them.

In the production of polymer products, high-quality raw materials must be used.

The strength and reliability of the future product depends on its characteristics. Typically, the following materials are used to produce modern polymer products:

  • Polyamides of natural origin, containing talc and glass fiber.

  • Polypropylenes, as well as compounds that are resistant to frost and shock, as well as any mechanical stress.

  • Polycarbonates.

  • Polyurethane.

  • Polyvinyl chloride.

  • Natural ABS and polycarbonate compounds.

Modern technologies for the production of products from polymer materials are demonstrated at the Chemistry exhibition, held annually at the Expocentre Fairgrounds.

Polymer materials and products

Polymers are materials that contain high-molecular organic binders (polymers) as the main component..

Due to their ability to take the required shape during processing and retain it after the forces are removed, polymeric materials are also called plastics (plastics or plastics). Plastics used in construction are complex compositions consisting of a polymer binder, fillers, stabilizers, plasticizers, hardeners and other components.

Polymers(from the Greek ʼʼpolyʼʼ - many, ʼʼmerosʼʼ - part, share) - high molecular weight substances, the molecules of which consist of a large number of units of the same structure, interacting with each other through covalent bonds to form macromolecules.

By main chain composition Macromolecule polymers are divided into three groups: a) carbon-chain polymers - macromolecular polymer chains consist only of carbon atoms; b) heterochain polymers, the chains of which include, in addition to carbon atoms, atoms of oxygen or sulfur, nitrogen, phosphorus, etc.; c) organoelement polymers, the main chains of which may include atoms of silicon, aluminum, titanium and other elements having silicon-oxygen, siloxane bonds.

Polymers can have a linear, branched or network (three-dimensional) structure, which determines the physical, mechanical and chemical properties of polymers. Macromolecules of polymers linear the structures are elongated in the form of chains interconnected by weak forces of intermolecular interaction (Fig. 9a). For branched Polymers are characterized by the presence of monomer units branched from the main chain of the macromolecule (Fig. 9b). Mesh (three-dimensional) polymer structures are characterized by the fact that strong chemical bonds between chains (cross-linking of individual linear or branched polymer chains) lead to the formation of a single spatial framework (Fig. 9c).

Polymers with macromolecules of a linear or branched structure melt when heated with a change in properties and dissolve in an appropriate organic solvent, and when cooled they solidify again. Such polymers, which can repeatedly soften when heated and harden when cooled, are called thermoplastics (thermoplastics). On the contrary, polymers with macromolecules of a three-dimensional structure have increased resistance to thermal and mechanical stress, do not dissolve in solvents, but only swell. Such polymers cannot soften reversibly when reheated and are called thermoset polymers (thermosets).

High molecular weight compounds are characterized not only by the structure of their molecules, but also molecular weight. Polymers typically have molecular weights greater than 5000; High molecular weight compounds with lower molecular weight are called oligomers. As the molecular weight of the polymer increases, its solubility in organic solvents decreases, elasticity decreases somewhat, but strength increases significantly.

The properties of many polymers are inextricably linked to the molecular weight and intermolecular forces, which are weaker than conventional valence bonds. As the molecular weight of the polymer increases, the total effect of intermolecular forces becomes noticeable, since each atom is their source. In this regard, the increasing role of intermolecular forces with increasing molecular weight qualitatively distinguishes polymers from low-molecular compounds.

V
A
b

Rice. 9. Schematic structure of polymer macromolecules with linear (a), branched (b), network (c) structure

For polymer production main raw materials serve as monomers, ᴛ.ᴇ. substances that can combine with each other to form polymers. Monomers are obtained by processing natural and petroleum gases, coal, ammonia, carbon dioxide and other similar substances. Taking into account the dependence on the production method, polymers are divided into polymerization, polycondensation and modified natural ones.

Polymerization Polymers are obtained during the polymerization of monomers due to the opening of multiple bonds (or ring opening) and the joining of elementary monomer units into long chains. Since atoms and their groups are not split off during the polymerization reaction, by-products are not formed, the chemical composition of the monomer and polymer is the same.

Polycondensation polymers are obtained through the polycondensation reaction of two or more low-molecular substances. During this reaction, along with the main polycondensation product, side compounds (water, alcohols, etc.) are formed, and the chemical composition of the polymer differs from the chemical composition of the initial polycondensation products.

Modified polymers are obtained from natural high-molecular substances (cellulose, casein) by chemical modification to change their original properties in a given direction. Cellulose acetate is used to produce durable and waterproof varnishes for painting wood and metal.

TO polymerization polymers(thermoplastics) include polyethylene, polypropylene, polyisobutylene, polyvinyl chloride, polystyrene, polymethyl methacrylate (organic glass), polyvinyl acetate, etc.
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Polyethylene[-CH 2 -CH 2 -] n– a product of ethylene polymerization. Available in the form of granules measuring 3–4 mm or white powder. The technical properties of polyethylene depend on molecular weight, chain branching and degree of crystallinity. Polyethylene is one of the lightest polymers - its density is less than the density of water (0.92-0.97 g/cm 3). It is characterized by high tensile strength (12-32 MPa), low water absorption (0.03-0.04%), high chemical resistance and frost resistance. It is necessary to take into account the features of polyethylene that are characteristic of all polymers with a linear structure: a relatively low elastic modulus (150-800 MPa), low hardness, limited heat resistance (108-130 ° C), and a high coefficient of thermal expansion. Polyethylene is used for the production of pipes, films, heat-insulating gas-filled materials, containers and plumbing equipment.

Polyvinyl chloride(PVC) is a polymerization product of vinyl chloride (CH 2 =CHCl). The high mechanical properties of polyvinyl chloride have determined the main areas of its application in construction. Waterproofing and finishing materials, baseboards, handrails, window and door frames, linoleum, etc. are made from polyvinyl chloride.
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A valuable property of polyvinyl chloride is its resistance to acids, alkalis, alcohol, gasoline, and lubricating oils. For this reason, it is widely used for the production of pipes used in water supply, sewerage and process pipelines.

The disadvantages of polyvinyl chloride are a sharp decrease in strength with increasing temperature, as well as creep under prolonged load.

Polystyrene[-CH 2 -SNS 6 H 5 -] n– solid product of polymerization of styrene (vinylbenzene). At ordinary temperatures, polystyrene is a solid, transparent material similar to glass, transmitting up to 90% of the visible spectrum. Polystyrene is produced in the form of granules (6-10 mm), fine and coarse-grained powder, and also in the form of beads (using the suspension production method) with a moisture content of up to 0.2%.

Polystyrene has high mechanical properties (compressive strength 80-110 MPa), water-resistant, well resistant to concentrated acids (except nitric and glacial acetic acids), and resistant to alkali solutions (concentrations up to 40%). The disadvantages of polystyrene that limit its use include: low heat resistance, fragility, which manifests itself under shock loading.

Used for the manufacture of waterproofing films, facing tiles, thermal insulation materials, water pipes, etc.

Among polycondensation polymers(thermosets), the most significant are phenol-formaldehyde, urea (urea-formaldehyde), epoxy, organosilicon polymers, polyurethanes, etc.
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Phenol-formaldehyde polymers are obtained by polycondensation of phenol with formaldehyde. These polymers combine well with fillers - wood chips, paper, fabric, glass fiber, resulting in plastics that are stronger and less fragile than the polymers themselves. For this reason, phenol-formaldehyde polymers are widely used as a binder in the manufacture of particle boards, laminated plastics, fiberglass and various mineral wool products. At the same time, they are used for the production of adhesives, waterproof plywood, and alcohol varnishes.

Macromolecules organosilicon polymers consist of alternating silicon and oxygen atoms, and carbon is only part of the groups framing the main CH 3 chain. The presence of a siloxane bond imparts properties inherent to silicate materials (strength, hardness, heat resistance), and hydrocarbon radicals CH 3 - to organic polymers (elasticity, etc.).

Polymers are characterized by the following technical properties: thermal (softening point and heat resistance, glass transition temperature and fluidity), mechanical (strength, deformability and surface hardness), chemical (weather resistance and resistance to destruction).

In general, along with the positive properties of polymers - low average density (about 1 g/cm3), low thermal conductivity, water and gas impermeability, chemical resistance, high structural quality factor, practically unlimited raw material base, etc.
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– they also have a number of disadvantages. These include: low heat resistance, low modulus of elasticity, significant creep, tendency to aging, which ultimately determines insufficient durability. At the same time, it is extremely important to take into account the flammability and certain toxicity of polymers. Thus, in the production of many polymeric materials, phenol-formaldehyde resins are used as a binder, containing up to 9% free phenol, up to 11% free formaldehyde and 1.5-2.0% methanol. During the production and operation of products, a significant part of these highly toxic substances is released into the air. Expanded polystyrene under normal operating conditions (and especially during combustion) releases highly toxic styrene. When burned, polyurethane foam thermal insulation materials produce many volatile, highly toxic compounds, including hydrocyanic acid.

Fillers in plastics, reducing polymer consumption, making plastics cheaper. At the same time, by structuring the polymer binder, they improve a number of technical properties of plastics: strength, hardness, heat resistance, resistance to shrinkage and creep, etc.

Based on their chemical nature, fillers are divided into organic and inorganic; based on shape and structure - powdery and fibrous. Organic and inorganic materials are widely used in the production of polymer composite materials. powdery fillers (wood flour, pulp production waste - lignin, micromica, quartz flour, talc, etc.).

Fibrous The fillers are cellulose, asbestos and glass, as well as synthetic (nylon, nylon, lavsan, etc.) fibers.

Additives. Introduction plasticizers(esters of aliphatic and aromatic acids and aliphatic alcohols, glycol ethers and phosphoric acid esters, epoxidized and chlorinated compounds) allows to improve the conditions for processing polymer compositions and reduce their fragility. Additives- stabilizers(antioxidants, heat and light stabilizers) contribute to the long-term preservation of the properties of plastics during their operation. Hardeners(cross-linking and vulcanizing agents) provide the process of curing of polymers (formation of their spatial structure). To obtain colored plastics they use pigments. The fire resistance of plastics is increased flame retardants. The creation of gas-filled (cellular) plastics is achieved using porogens.

All variety of plastics based on appointments in construction they are reduced to groups: structural, roofing, waterproofing and sealing; heat and sound insulating; finishing (floor and wall coverings, varnishes, paints, adhesives, etc.) materials, as well as materials for engineering communications. Main structural Polymer-based materials are polymer concrete. Structural and finishing materials include fiberglass, laminated paper, carbon and other plastics; wood fiber and particle boards (which can also be structural and thermal insulation materials).

Polymer concrete– composite materials made primarily on the basis of thermosetting polymers: polyester, epoxy, phenol-formaldehyde, furan, etc.
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Fillers are selected based on the type of aggressive operating environment. For acidic environments, polymer concrete is produced using acid-resistant fillers - quartz sand and crushed stone from quartzite, basalt or granite. Acid-resistant brick scrap, coke, anthracite, and graphite are also used. Polymer concretes based on epoxy resins have the highest physical and mechanical properties. To reduce the consumption and cost of epoxy resins, they are modified with coal tar (up to 35-50%). Polymer concretes based on furan polymers, which are modified with epoxy resins to improve the properties of the compositions, have become widespread.

The binder consumption is 100-200 kg per 1 m 3 of polymer concrete with a ratio of polymer to filler of 1:5-1:12 by weight. The technology for preparing and compacting polymer concrete is the same as cement concrete. Heat treatment at 40-80 °C significantly accelerates the hardening process. Polymer concretes (polymer solutions) adhere well to cement concrete, and therefore they are used for repairing reinforced concrete structures. To reduce the fragility of polymer concrete, fibrous fillers are used - asbestos, fiberglass, etc.
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Polymer concrete differs from conventional cement concrete not only chemical resistance(especially in relation to acids), but also high strength indicators, especially in tension (7-20 MPa) and bending (16-40 MPa). Compressive strength reaches 60-120 MPa. The frost resistance of polymer concrete can last 200-300 or more freezing and thawing cycles; heat resistance 100-200 °C (up to 300 °C). But their cost is several times higher than cement concrete.

Polymer concretes are used for chemically resistant structures, wear-resistant coatings, where the high cost of polymer concretes will be justified. The negative properties of polymer concrete are their high creep and aging, which increases under the action of alternating heating and cooling. It is necessary to observe special labor protection rules when working with polymers and acidic hardeners that can cause burns. In particular, good ventilation, provision of workers with safety glasses, rubber gloves, and protective clothing are necessary.

Fiberglass- ϶ᴛᴏ composite sheet materials made from glass fibers or polymer-bonded fabrics. The binders in fiberglass plastics are usually phenol-formaldehyde, polyester and epoxy polymers. Three types of fiberglass are produced: based on oriented fibers, chopped fibers and fabrics or mats. Fiberglass with oriented fibers(such as SVAM - glass fiber anisotropic material) have great strength (tensile up to 1000 MPa), lightness (their density is 1.8-2 g/cm 3), which, combined with chemical resistance, makes them an effective material for building structures, containers and pipes Fiberglass with chopped glass fiber manufactured in the form of fibrous or flat sheets on a polyester binder that is translucent. These products are used for roofing, fencing of balconies, loggias and partitions. Fiberglass made on the basis of glass fabric (fiberglass laminates), are obtained by hot pressing of fabric panels impregnated with a thermosetting polymer at high pressure and temperature. Fiberglass is used for the outer layers of three-layer wall panels. The same material is used for constructing shells and other building structures. Fiberglass laminates are also produced by pressing a paste-like mass of polyester polymer, fiberglass, asbestos and powder filler. Window and door blocks, fittings, and sanitary products are formed from this material.

Laminates made from several layers of special paper impregnated with phenol-formaldehyde or urea polymer. Plastic is produced in the form of sheets 1000-3000 mm long, 600-1600 mm wide, 1-5 mm thick. Paper-laminated plastics are varied in color and pattern, they are well processed - they can be sawed and drilled. Plastic up to 1.6 mm thick is fixed with bitumen-rubber and other mastics, epoxy and resorcinol-formaldehyde adhesives. Thicker sheets of plastic are fastened mechanically.

Polymer materials and products - concept and types. Classification and features of the category "Polymer materials and products" 2017, 2018.