Most organic thermal insulation materials are manufactured in the form of slabs, usually large-sized, which simplifies and speeds up the work and helps to reduce the cost of construction.

The main raw material for their manufacture is wood in the form of waste (sawdust, shavings, slab, lath) and other plant raw materials of a fibrous structure (reeds, straw, low-decomposed high-moor peat, flax and hemp).

Wood is a porous material (porosity - 60-70%). In addition, wood chips and wood fibers in some heat-insulating products (fiberboard, chipboard) are located so that the heat flow in the structure is directed not along, but across the fibers, and this creates additional resistance to heat leakage. At the same time, shavings and fibers of wood or other plant raw materials create a kind of reinforcing cage in thermal insulation products. Finally, the use of wood and other plant waste for the mass production of thermal insulation materials is cost-effective and contributes to solving the environmental problem, i.e. helps to reduce environmental pollution.

To increase fire resistance, biostability and water resistance, fire retardants, antiseptics and water repellents are introduced into organic-based thermal insulation materials.

Fiber boards

Fiberboard is made from non-commercial wood, sawmill and woodworking industry waste, paper waste, straw stalks, corn, cotton and some other plants.

In order to increase the strength, durability and fire resistance of wood-fiber products, special additives are used: water emulsions of synthetic resins, emulsions of paraffin, rosin, bitumen, antiseptics and fire retardants, as well as asbestos, alumina and gypsum.

Plant raw materials are crushed in various units in the presence of a large amount of water, which facilitates the separation of wood into individual fibers, and mixed with special additives. Thereafter, the free-flowing pulp is transferred to a casting machine consisting of an endless metal mesh and a vacuum unit. Here the mass is dewatered, compacted and cut into individual slabs of a given size, which are then pressed and dried.

The density of fiberboard insulation and insulation finishing boards is 150-350 kg / m3, thermal conductivity is 0.046-0.093 W / (m · K), ultimate strength in bending is not less than 0.4-2.0 MPa.

The advantage of the slabs is their large size - up to 3 m in length, up to 1.6 m in width. this contributes to the industrialization of construction and installation works and a decrease in labor costs.

Insulation boards are used for heat and sound insulation of walls, ceilings, floors, partitions and interfloor ceilings, roof insulation (especially in wooden housing construction), acoustic decoration of special rooms (radio studios, typing bureaus, concert halls).

Standard insulation boards are used for additional insulation of walls, ceilings and floors, as well as to increase the strength of wall frames. They can be applied to interior walls and ceilings prior to final finishing.

Windproof insulation boards are used to seal and reinforce external walls, ceilings and roofs of buildings.

Floor insulation boards are used as floating underlays for parquet and laminate floors. The slab evens out the surface under the parquet, insulates the floor and significantly increases sound insulation.

Along with the advantages, fiberboards also have disadvantages. They have high water absorption (up to 18% per day), are distinguished by significant hygroscopicity (up to 15% under normal conditions), change their size when the ambient humidity changes, and wood-destroying fungi can develop in them. Such boards are more flammable than ordinary wood.

The introduction of antiseptics and fire retardants into their composition allows to reduce the decay of wood-fiber boards, to increase their fire resistance.

Chipboards

These materials are products obtained by pressing wood chips with the addition of synthetic resins.

Like fiberboards, they have different densities. For thermal insulation, so-called light slabs are used, while for structural and finishing purposes, light and heavy slabs are used.

Lightweight boards are made from the same raw materials and using the same technology as lightweight and heavy boards. The only difference is that in the manufacture of lightweight boards less polymer consumption (by 6-8%) and lower pressure during pressing than in the manufacture of structural and finishing.

Chipboards are obtained by hot pressing of a mass containing about 90% organic fibrous raw materials (most often - fine wood chips) and 8-12% synthetic resins.

Chipboards are produced in single and multi-layer. For example, in a three-layer board, the porous middle layer consists of relatively large chips, and the surface ones are made of thin flat chips of the same thickness.

Lightweight particle boards are mm long, mm wide and 13 to 25 mm thick. The average density is 250-400 kg / m3. Their advantage over fiberboard is a simpler manufacturing technology, they are more durable, but have a slightly higher density. Other properties of particle boards and their areas of application are the same as those of fiberboards. They cost about the same as fiberboard.

This thermal insulation material is a type of lightweight concrete made from a well-chosen mixture of cement, organic aggregates, chemical additives and water. Organic aggregates can be of various origins and with different particle shapes (crushed wood waste, reeds, hemp or flax fire, sunflower husk). Portland cement is more often used as a binder, less often other inorganic binders. The manufacturing technology of arbolite products is in many respects similar to that in the production of products from ordinary concrete.

Distinguish between heat-insulating wood concrete (density up to 500 kg / m3) and structural and heat-insulating (density up to 700 kg / m3). The thermal conductivity of wood concrete is 0.1-0.126 W / (m · K). The material belongs to the category of materials that are difficult to attack by mushrooms and hardly combustible.

Arbolit is used for the construction of curtain and self-supporting walls and partitions, and also as a heat-insulating material in walls, partitions and coatings of buildings for various purposes.

Fibrolite

This board material is usually made from special wood shavings (wood wool) and an inorganic binder. Wood wool is obtained on special machines in the form of thin and narrow ribbons. Portland cement is used as a binder, less often a magnesian binder.

Wood wool is first mineralized with a solution of calcium chloride, water glass or sulphurous alumina, and then mixed with cement and water. Plates are molded under a pressure of 0.5 MPa and sent for hardening into steam chambers. The hardened boards are dried to a moisture content of no more than 20%.

The slabs are 240 and 300 cm long, 60 and 120 cm wide, and 3-15 cm thick. According to their density, they are divided into grades F-300 (heat-insulating fiberboard) and F-400, F-500 (heat-insulating and constructive fiberboard). Thermal conductivity - 0.08-0.1 W / (m · K).

Fiberboard does not burn with an open flame, it is easily processed: it can be sawed, drilled and nails driven into it. Water absorption of cement fiberboard - no more than 35-45%. At a humidity above 35%, it can be attacked by a house fungus, therefore it must be protected from moisture - in particular by plastering. The rough surface of the fiberboard promotes good adhesion to the plaster.

Magnesian fibrolite is made without special mineralization, since caustic magnesite is mixed with aqueous solutions of magnesian salts, which bind water-soluble substances contained in wood.

Peat insulating products

This thermal insulation material is obtained from peat by molding and heat treatment.

The raw material for the production of peat products is poorly decomposed moss - sphagnum (“white moss”) from the upper layers of peatlands, which retained its fibrous structure and is not used as fuel and agricultural fertilizer. About 50% of the world's peat reserves are located in Russia. Peat insulating products can be made in two ways - wet and dry.

Peat insulation boards are characterized by a homogeneous fibrous structure of a fine-pored structure with open communicating pores. The absolute values \u200b\u200bof the porosity of peat slabs range from 84 to 91%.

During the production of peat slabs, the structure of peat is slightly disturbed, and their average density is close to that of raw peat. Peat slabs are produced with a density of 170-260 kg / m3. The ultimate bending strength of peat slabs is 0.3-0.5 MPa, which provides satisfactory conditions for their transportation and installation.

The water absorption of peat slabs is quite high. The highly porous structure of this type of TIM promotes capillary and hygroscopic moistening. So, the water absorption of ordinary plates (by weight) for 24 hours is 190-180%, and of special waterproof ones - 50%.

The thermal conductivity of peat slabs in the dry state is low due to the mixed fine-pored structure and organic origin of the solid phase and amounts to 0.052-0.075 W / (m · K).

Peat slabs are a combustible material. The ignition temperature is about 160 ° C, and auto-ignition is about 300 ° C.

The maximum temperature for storage and operation of peat slabs is 100 ° C; however, it can be increased if flame retardants are introduced into their composition.

There are about 10 enterprises producing peat slabs in our country.

The dimensions of peat slabs are usually 1000x500x30 mm.

Depending on the purpose, they can be:

• Waterproof - B,
• Hardly combustible - Oh,
• Biostable - B,
• Complex, having 2 or 3 of the above properties,
• · Ordinary.

These heat-insulating products are used for thermal insulation of the enclosing structures of buildings of the 3rd class and surfaces of industrial equipment with an operating temperature of - 60 ° C to 100 ° C.

Ecowool is a wood material made from waste paper. 80% of ecowool consists of newsprint, and 20% is non-volatile, safe for health additives that serve as antiseptics and fire retardants.

building assembly heat-insulating

Ecowool allows the building to "breathe". It does not contain volatile chemicals hazardous to human health. Boron and boric acid contained in ecowool, thanks to their antiseptic properties, protect ecowool and wooden structures in contact with it from rotting and fungal diseases. Boron compounds with insecticidal properties do not allow insects and rodents to enter heat-insulating materials.

Ecowool belongs to the group of non-combustible materials. In the event of a fire, boron compounds of ecowool release crystallization water: the insulation is moistened and retards the spread of the fire. When ignited, ecowool does not emit any toxic gases.

The average density in structures is 35-65 kg / m3. Thermal conductivity - 0.041 W / (m · K).

Building felt

The characteristic features of felt materials are their fibrous structure, organic origin (synthetic fibers, animal fibers - wool - or vegetable origin).

The most effective from the point of view of thermal insulation qualities are waste padding polyester (clothing insulation), shevelin (linen tow), construction felt (cloths made of rolled animal hair, plastic film mats stuffed with synthetic fur waste, thread waste or felt made of synthetic fibers). The average density of such materials is 10-80 kg / m 3, thermal conductivity is 0.03-0.07 W / (m · K).

To prevent the appearance of moths, the felt is impregnated with a 3% solution of sodium fluoride and dried well. After mechanical processing, the felt looks like 2x2 m sheets.

This material is flammable, and it is used mainly in wooden buildings: for insulating external doors, window frames, for thermal and sound insulation of walls and ceilings under plaster, for insulating outside corners in log houses, for window and door work.

Felts impregnated with clay mortar are used for fire-fighting purposes in ovens.

It is a heat-insulating material in the form of slabs pressed from the stems of common reeds.

Depending on the location of the stems, the plates are transverse and longitudinal. Reed slabs are made from reed or reed of autumn-winter felling. For the production of reeds, mobile installations are used, equipped with high-performance presses, on which pressing, as well as wire broaching and trimming of plates, is carried out.

The density of reeds, depending on the degree of pressing, is 175-250 kg / m3, the thermal conductivity is 0.046-0.093 W / (m K), the ultimate strength in bending is 0.5-0.1 MPa.

Reeds rots when moistened, does not hold nails, is capable of catching fire, and is prone to damage by rodents. These disadvantages can be reduced by impregnating the boards with antiseptics or plastering.

Slabs are produced with a length of mm, a width of mm, and a thickness of 30-100 mm. Density grades - 175, 200 and 250, bending strength - up to 0.5 MPa.

Reed is used for filling the walls of frame buildings, arranging partitions, insulating floors and coatings in low-rise construction, for thermal insulation of small industrial premises in agricultural construction. This is one of the cheapest TIM.

Cork slabs

Cork thermal insulation boards are produced on the basis of cork oak bark. It is a natural natural ageless material. The cell that the cork consists of (there are approximately 40 million in 1 cm3) consists of a minimum amount of solid and a maximum amount of air.

Another feature of the cork is the composition of the cell walls. Each wall consists of 5 layers: 2 layers of fiber, to which the air in the cell adjoins, 2 dense and fat layers; impermeable to water, and a final woody layer that stiffens the cell and forms the final structure.

Cork materials are lightweight, strong in compression and bending. In addition, this material does not lend itself to shrinkage and decay. The cork is also not exposed to alkalis. It is easy to cut to ensure clean and fast work. The cork is chemically inert and very durable. It never becomes moldy, and its physical properties practically do not change over time, it resists attacks by rodents well. If this material is installed, for example, on walls (ceiling) or on the floor in a workroom, it protects people from radiation exposure. The plug does not conduct electricity and does not build up static electricity.

Materials from the cork do not burn, but only smolder (in the presence of an open fire source), after processing with fire-resistant compounds, they belong to the BT flammability class. When smoldering, the cork does not emit phenols and formaldehydes.

Heat-insulating material RAIV

The material is made on the basis of cellulose fibers and has excellent thermal insulation properties.

RIVE does not retain moisture and does not transfer it into the structure. It does not evaporate and does not collapse in rooms with high humidity and high temperatures (baths, saunas). The fibers do not emit harmful substances, do not dust the air, do not cause allergic reactions in the user. Insulation RAIV - lightweight, it fits easily and is attached to the grooves and openings when assembling the structure.

In terms of its physical properties, such TIM is similar to wood, has a long service life, does not require maintenance during the entire period of operation of a wooden structure, and most importantly, a house with RAIV insulation breathes. This material has excellent soundproofing and dustproof properties, reduces background noise and keeps indoor air clean.

Thermal conductivity - 0.023 W / (m · K).

Block insulation RAIV:

Thermal conductivity - 0.03 W / (m · K).

Average density is about 25 kg / m3.

CHAPTER 2.

ORGANIC BUILDING MATERIALS

Depending on the chemical composition, all building materials can be conditionally divided into organic and inorganic. Organic materials include: wood, organic binders, which can occur both in nature and be obtained by deep oxidation of oil, as well as synthesized polymers.

2.1. Wood

Wood has been used for a long time in construction due to a number of its inherent positive properties: high strength with a low average density (CCC \u003d 0.7 - 0.8), low thermal conductivity, ease of processing and decorativeness. Both coniferous and deciduous species are used in construction. The area of \u200b\u200btheir rational use is presented in table. 2.1.

Table 2.1

The use of softwood and hardwood in construction

Application in construction	Tree species
			deciduous
	Pine,	larch			birch, aspen	beech, hornbeam
Plywood production
Bridge building
Hydraulic engineering
building
Sleepers manufacturing
Parquet production
Wall finishing materials

The tree consists of a trunk, crown and roots. The trunk is the main and most valuable part; from 60 to 90% of commercial timber is obtained from it.

By its structure, wood is a fibrous porous material, consisting of living and dead cells. Cells are subdivided into conductive nutrients, storage and mechanical. The macrostructure of wood is studied in transverse and two longitudinal sections: radial and tangential (Fig. 2.1).

Figure: 2.1. Tree trunk sections:

a - end; b - tangential; c - radial;

Wood elements: 1 - core; 2 - core; 3 - sapwood; 4 - bark

On the cross-section, conifers have annual rings. Each ring, in turn, consists of a light ring of early wood and a darker ring of late wood. Early wood formed in spring or early summer, it consists of large thin-walled cells, is prone to decay, has high porosity and low strength. The wood formed in summer and early fall (late) has a dark color due to saturation with resinous substances, high density and strength. Therefore, the more late wood is formed, the higher its overall strength and water resistance.

Due to its fibrous structure, wood is classified as anisotropic material, that is, all of its physical and mechanical properties are different in different directions.

2.1.1. General properties

Each wood species has a characteristic color and texture (picture). Conifers generally have a simple and uniform pattern, while hardwoods have a complex pattern. Due to the richness and variety of textures, a number of species - oak, beech, walnut, chestnut - are highly valued in carpentry and finishing works.

The true density of wood, consisting mainly of cellulose, is 1540 kg / m3 and practically does not depend on the type of wood. The average density ranges from 450 kg / m3 (cedar, fir) to 900 kg / m3 and more (hornbeam, ironwood, boxwood, dogwood) and depends on the total porosity, which for conifers equals 46 - 81%, deciduous - 32 - 80%.

Due to its hydrophilic nature and fibrous porous structure, wood easily absorbs and gives up moisture when the temperature and humidity conditions change. Depending on moisture content (degree of saturation with water in%), wood is divided into wet - freshly cut (more than 35%), air-dry (15 - 20%) and room-dry (8 - 12%). The moisture acquired by wood during prolonged exposure to constant temperature and humidity conditions is called equilibrium.The total humidity (when immersed in water) can reach up to 200%. Since moisture affects all physical and mechanical properties of wood (dimensions increase, electrical and thermal conductivity increases, strength decreases), in order to analyze the area of \u200b\u200bapplication, they introduce standard humidity indicator - 12% and all properties are recalculated taking it into account using special formulas. Moisture in wood it is in three types: chemical, which is part of the basic substance of cellulose, hygroscopicadsorbed on the cell walls, and freefilling cells and intercellular spaces.

Fluctuations in humidity lead to changes in the size and shape of products. Due to the heterogeneity of the structure, wood dries out in different directions differently. Shrinkage along the fibers is 1 cm per 1 m
(1%), in the radial direction 3 - 6 cm per 1 m (3 - 6%), in the tangential direction 6 - 12 cm per 1 m (6 - 12%). Uneven shrinkage and, as a result, warping lead to the appearance of internal stresses and cracking of lumber and logs. To prevent warping and cracking of wooden products, they are made from wood that has been pre-dried to the equilibrium moisture content that will be during use. For joinery used indoors, humidity 8 - 10%, for outdoor structures 15 - 18%. To protect the wood from subsequent moisture, it is covered with waterproof paints, polymer films. In round wood and sawn timber, shrinkage cracks are formed primarily at the ends. To reduce cracking, the ends of the logs, beams are coated with a mixture of lime, salt and glue or other protective compounds.

Under wet operating conditions, the wood is exposed to the destructive action of microorganisms - it rots. They protect wood from destruction and extend the service life of structures and products in buildings and structures by providing ventilation, preliminary natural or artificial drying, painting with waterproof paint and paste compounds and antiseptic treatment. Drying is carried out either in a well-ventilated warehouse under a canopy for 2-3 months to one and a half years, or using special equipment. For artificial drying, special drying chambers of continuous and periodic action with natural and forced air circulation are used. The heat carrier is first water vapor with a temperature of 70 - 80 ° C, and then air heated to 50 - 60 ° C. Drying time - 3 - 6 days.

To accelerate the drying process up to 8-12 hours, a package of wooden products is immersed in a bath with petrolatum heated to 130 ° C, which is a hydrophobic oil refinery product. Drying of especially valuable wood is carried out in the field of high frequency currents. The method is based on converting the energy of an alternating electric current into thermal energy, which causes wood heating and water evaporation.

Antiseptic treatment carried out using special substances - antiseptics,which are subdivided into water-soluble (sodium fluoride and silicofluoride, zinc chloride, copper sulfate), used for indoor operating conditions, and oily (anthracene, coal, shale oil), used for wood outdoors, in the ground or in water. Antiseptic pastes based on bitumen and water glass have a similar purpose. The latter are not waterproof and therefore they are protected from above with such waterproofing roll materials as roofing felt, roofing felt.

The following requirements are imposed on antiseptics: possibly high toxicity in relation to wood-destroying microorganisms; long-term preservation of toxic properties; no harmful effect on the strength of wood and metal fastening (bolts, nails); the ability to penetrate as deeply as possible into the thickness of the wood; harmlessness to people.

Impregnation of wood with antiseptics can be carried out by several methods: surface treatment with brushes to a depth of 1 - 2 mm; alternate immersion of products in hot-cold baths with a temperature of 90 - 20 ° C, respectively; under pressure of 0.6 - 0.8 MPa in autoclaves; saturation in a high-temperature bath at 160 - 170 ° C.

Thermal conductivity and electrical conductivitywood depends on its porosity, moisture content and the direction of the flow of heat or electric current. When dry, wood is an insulating material and a good dielectric.

By fire resistancewood is a combustible material, it ignites at a temperature of 250 - 300 ° C. The norms allow the use of wood for the manufacture of beams, columns, arches, trusses, frames, provided that the material is impregnated with special fire retardants - fire retardants.The most effective method is pressure treatment. Traditional means of fire protection for wooden structures are coatings based on cement-sand, clay and other plasters. Various paints are also widely used for fire protection of wood - non-expanding and intumescent, inorganic and organic. Coatings and paints protect the material from ignition by emitting gases when heated, which impede the combustion process and absorb the released heat, or water, which maintains the temperature at 100 ° C. For fire protection of wooden structures, plate and sheet materials are also used. The most widespread are gypsum plasterboard and asbestos-cement sheets. Their use makes it possible to increase the fire resistance of wooden structures by 20 - 30 minutes at a thickness of 10 mm.

Chemical resistancewood depends on the concentration and duration of exposure to solutions of acids and alkalis. Organic acids (acetic, lactic, etc.) do not destroy this material, as well as slightly alkaline solutions. Inorganic acids (sulfuric, phosphoric) dehydrate wood, causing it to char.

Mechanical propertieswood depends on the direction of the applied load in relation to wood fibers, average density and moisture.

The compressive strength is determined along and across the fibers on samples in the form of a rectangular prism measuring 20x20x30 mm. Compression strength of wood along the grain is 4 - 6 times greater than across. For example, for pine along the grain - 100 MPa, across - 20 - 25 MPa. Due to its organic origin and fibrous structure, wood has great resistance to bending, therefore it is used in the manufacture of beams, rafters, trusses. Strength, which ranges from 50 to 100 MPa, is determined on specimen beams 20x20x300 mm. The tests are carried out according to the scheme of a beam freely lying on two supports with a span of 240 mm and loaded with two concentrated loads at a distance of 80 mm.

On chippingwood works in roof trusses. This strength is 6 - 13 MPa when shearing along the fibers and 24 -
40 MPa across the grain.

Static hardnessis numerically equal to the load required to press half a metal ball of a certain mass and diameter into the sample surface. Depending on this indicator, all tree species are subdivided into soft (pine, spruce, alder) -
35 - 50 MPa, solid (oak, hornbeam, birch) - 50 - 100 MPa, very hard (dogwood, boxwood) - more than 100 MPa. The hardness of wood decreases with increasing moisture content.

Along with static hardness, determine dynamic hardnessby the diameter of the indentation obtained as a result of falling from a given height of a metal ball of a certain mass and diameter. This indicator is important for assessing the quality of materials used for flooring.

When working beams, arches, trusses, a property such as dynamic modulus of elasticity material, which is calculated from the deflection of the sample-beam. For example, for pine and spruce, the dynamic modulus of elasticity is 1000 - 15000 MPa. This indicator increases with increasing density and decreases with moisture.

One of the promising ways to significantly improve the properties of wood is to modify it with synthetic polymers. The essence of the modification lies in the fact that natural wood is impregnated with a liquid monomer, which is then cured under the influence of heat, chemical reagents or ionizing radiation. The peculiarity of the modification is that the synthetic polymer not only fills the free space between the fibers, but interacts with the wood components. As a result, disadvantages such as swelling and shrinkage, warping and cracking, decay and combustion are eliminated. At the same time, wood retains its positive qualities: low density, high strength, heat and sound insulating ability, chemical resistance. The greatest effect from the modification is obtained if wood with low physical and mechanical properties is used as a starting material, i.e. low-value wood, which does not yet have a sufficiently wide technical application, for example, aspen.

2.1.2. Materials and wood products

Wood materials are used in construction as structural, finishing, heat-insulating, acoustic and joinery products.

To construction materialsinclude round timber, lumber, plywood, wood laminated plastics, fiberboard, wood concrete, cement-particle boards.

Round timberobtained by cleaning from bark and sawing tree trunks. Depending on the diameter of the upper end, they are subdivided into logs (not less than 14 cm), a pod (8-13 cm) and poles
(3 cm). Thick short timber with a diameter of more than 200 mm is called ridges, they are used for the manufacture of wood veneer, plywood; logs - for the production of lumber, the construction of log houses, the manufacture of piles, hydraulic structures, bridge elements, supports for communication lines, radio and power transmission; toolbox and poles - for auxiliary and temporary structures.

When cutting logs, they receive lumberof various types and sizes (beams, sleepers, boards) (Fig. 2.2). Glued structures are made of logs, boards and beams: frames, arches, trusses, beams, piles, the strength, rigidity and bearing capacity of which are increased by reinforcement with steel rods, wire, mesh or fiberglass reinforcement.

Plywoodis a sheet material glued from three or more layers of peeled veneer so that the direction of fibers in adjacent layers is mutually perpendicular. This structure increases the uniformity of the product in terms of properties, excludes shrinkage deformations and warpage.

Veneer- thin sheet material obtained by peeling or planing on special machines of steamed logs.

Figure: 2.2. Lumber:

a - plates; b - quarters; c - croaker; g, f - edged board; d - board

semi-edged; g - four-way bar; z - clean-cut timber

In construction, plywood is used for cladding internal partitions on a wooden frame, spatial structures in the form of vaults and domes, as well as glued beams, arches and trusses. In order to increase the strength, hardness and rigidity in the manufacture of plywood, a metal mesh is laid between its layers. In this case, plywood is called reinforced and can be used in particularly critical structures. Pipes play an important role in the production of plywood products. Depending on the technology, plywood pipes can be extruded or produced by roll winding - twisted. These products have increased anticorrosive resistance and are intended for the transportation of waste water, oil, oils, as well as slightly aggressive industrial solutions. Plywood pipes are used as a structural material for columns, masts, supports, trusses.

Wood Laminatesare sheet material obtained by pressing several layers of veneer, impregnated at high temperature with high molecular weight resins. The technology of plastic production includes the preparation of wood veneer, its impregnation with polymers, drying of the impregnated veneer, assembly into packages, pressing, and cutting to specified dimensions. Plastics are used for cladding of cooling towers, structures of rigid spatial shells for covering large aisle premises (indoor stadiums, circuses, markets), external and internal finishing of industrial premises.

Fibrolitecalled a panel material made of thin long wood shavings and a mineral binder (more often Portland cement). The production technology includes chemical treatment of wood waste, mixing them with water and cement to obtain homogeneous mass, form filling and product hardening. Fiberboard slabs can be sawn and drilled with ordinary woodworking tools, it is easy to hammer in nails and screw in screws; they are well plastered and painted; firmly adhere to unhardened concrete and reliably attach to the surface of concrete and stone structures. Fibrolite is frost-resistant, does not decay, is not affected by rodents. In terms of fire resistance, the material is classified as hardly combustible. The physical and mechanical properties of the material depend on its density, which is controlled by the amount of mineral binder and the degree of compaction. Structural, heat-insulating and acoustic fiberboard is produced depending on the density. Structural fiberboard plates are used as ceilings, partitions and coverings of agricultural and warehouse buildings, as well as walls of standard wooden houses, heat-insulating and acoustic - to ensure comfortable living and working conditions in residential and public buildings.

Arbolitis a light wood concrete based on mineral binder. For the manufacture of wood concrete, crushed waste from sawmilling and wood processing of various species, as well as crushed branches, branches, tops, slabs, slats are used. Portland cement is more often used as a mineral binder, less often lime with hydraulic additives, in some cases magnesia binders and gypsum. Manufacturing technology is similar to fiberboard. Hinged and self-supporting panels of external and internal walls, cover plates are made of wood concrete. The surface of the panels is protected with asbestos-cement sheets on screws, cement mortar, and ceramic tiles. It is not allowed to use wood concrete products for basements, basement walls.

A promising material for wooden housing construction are cement-bonded particle boards.In contrast to fiberboard and wood concrete, these boards are pressed at increased pressure, so they have a high density and strength. Cement particle boards are used for external cladding of wall panels of residential buildings, for the manufacture of sanitary cabins.

Selection of materials for interior decorationdepends on the purpose of the premises, operating conditions and capital of buildings. At the same time, not only decorativeness and durability of the material itself are taken into account, but also the convenience of its operation, conditions of sanitary and hygienic maintenance. So, for wall decorationin living rooms, lining is used, in public premises - cement-bonded, chipboard, hard fibreboards with decorative paintwork, polymer films, plastic or veneer of valuable wood species.

Chipboard(Chipboard) and fiberboard(Fiberboard) slabsobtained by flat pressing of wood waste (shavings, sawdust), mixed with hot synthetic resins or adhesive binder. Waste board materials similar in properties are produced on the basis of flax processing (fires) or fires in combination with wood fibers.

For facing the internal walls of public administrative and industrial buildings, decorative plywood is used with a front surface finishing with special paper imitating the texture of valuable wood or fabric, a film coating, and sliced \u200b\u200bveneer. If the project provides for an improved or high-quality finish, wood laminates are used. In the production of finishing works, wallpapers have found wide application, which are used for pasting walls and ceilings. It is a paper-based roll material with a printed or embossed pattern. When protecting the paper surface with transparent film compounds (washable, moisture resistant), they can be used in rooms that require wet cleaning (kitchens, toilets, bathrooms).

For floor coverings in residential and public buildings, floorboards, parquet, parquet boards, chipboard and hard fiber boards are used. These materials must not be used in rooms with a humid operating mode (humidity over 60%) and high pedestrian traffic (floors in lobbies, sales areas, dining rooms).

Materials such as heat insulatingfibrolite, wood concrete, soft fibreboards with an average density of 175 - 500 kg / m3 are used to insulate thin brick and concrete walls in agricultural buildings, enclosing wall structures of residential, public and industrial buildings with a dry mode of operation.

Acousticfiberboard and soft fibreboard are used in the construction of airport buildings, lobbies of theaters, cafes, restaurants, using them to make sound-absorbing suspended ceilings. To improve the acoustic properties, special volumetric plasters are applied to their surface or perforated.

To joineryinclude window and door blocks, window boards, wooden gates. The nomenclature of molded products is shown in Fig. 2.3. Materials and products used in construction are presented in table. 2.2.

Table 2.2

Application of materials and wood products

Materials and products	Application area
1
Round timber: long (logs)	Receiving lumber, erecting log houses, making piles, bridge elements, communication line supports, radio and power transmission
short with a diameter of more than 200 mm (ridges)	Obtaining wood veneer for the manufacture of plastics plywood and decorative finishes for chipboard and fiberboard

The end of the table. 2.2
Long timber (beams, sleepers, boards)	Manufacturing of glued structures (frames, arches, beams, trusses). Wall cladding during the construction of prefabricated frame individual houses, roof sheathing, floor covering (boards)
	Interior and exterior decoration
Large sheet products:	Implementation of frame internal partitions; erection of rigid vaults; production of glued structures; pipe making
wood plastic	Framed interior partitions, rigid shells, interior and exterior wall decoration
Large size slabs: fibrolite, wood concrete	Execution of enclosing structures of walls and internal partitions. Low density slabs are used as thermal insulation and acoustic materials
cement-bonded (DSP)	External cladding of wall panels; manufacturing of sanitary cabins; interior wall decoration, subject to the additional use of decorative coatings: film, paint and varnish
particle board (chipboard), fiberboard (fiberboard)	Floor covering, wall decoration when using decorative coatings; execution of frame partitions (fiberboard-solid). Soft fibreboard is used as thermal insulation and acoustic when making suspended ceilings
Small-piece products (parquet)	Floor covering in rooms with humidity no more than 60%
Joinery	Window and door blocks, window boards, gates

Figure: 2.3. Molded products:

a - grooved boards; b - seam boards; в - plinth;

g - platband; d - handrail

2.2. Polymer materials and products

Even in ancient times, natural polymer materials such as bitumen (asphalts) were known. For 700 years BC. e. In Babylon, natural polymer bitumen was used as a cementitious and waterproof material in the construction of a canal under the Euphrates River. Subsequently, these materials received further development only from the second half of XIX century. It was during this period that work was carried out on the chemical processing of such natural materials as cellulose, rubber and protein. At the beginning of the 20th century, new high-molecular substances were artificially synthesized not on the basis of existing natural polymers, but on the basis of substances with simple chemical composition. At the same time, the works of the founder of the theory of structure organic matter Russian chemist Butlerov, in particular, the synthesis of isobutylene and the study of the process of its polymerization.

Since the 30s of the last century, polymerization plastics (polystyrene, polyvinyl chloride, polymethyl methacrylate) have acquired great importance. New types of polycondensation polymers have appeared: polyamide, polyurethane, organosilicon.

2.2.1. Obtaining and properties of polymeric materials

Currently, high-molecular-weight resins, the basis of all polymeric materials, are obtained chemically by polymerization of simple molecules or by polycondensation of various organic compounds.

Process polymerizationcarried out without the isolation of by-products by breaking double, triple chemical bonds and combining molecules into long linear or branched structures. For example, ethylene (CH2 \u003d CH2) n upon polymerization forms linear polyethylene (-CH2-CH2-) n. To increase the reaction rate, heat or pressure is used, as well as ultraviolet rays, catalysts, initiators. Polymerization polymers that are widely used in construction include: polyvinyl chloride, polystyrene, polyisobutylene, high and low pressure polyethylene. As a result of the polycondensation reaction, in which several substances participate, polymers with complex composition are formed with a linear (polyamides, polycarbonates) or spatial structure (phenol-formaldehyde, epoxy). When polycondensation along with the resulting polymer, by-products such as gas or water are released. Depending on the raw material used, polymeric materials are divided into artificial and synthetic... Artificial ones are obtained by chemical modification of natural high-molecular compounds (cellulose), synthetic ones - from various monomers. The raw materials for obtaining building materials are complex plasticswhich consist of a mixture of several components: binder polymer, designed to ensure the plasticity of the mixture in the heated state and hardness in the cooled state (synthetic resins, rubbers, cellulose); filler (finely ground asbestos, sand, rubber waste) to reduce cost, increase crack resistance, heat resistance, hardness; plasticizer - to increase the elasticity of the finished product; hardener - to accelerate the set of strength; pigment - to add color.

The properties of polymeric materials and products, like any others, depend on their composition and structure. The microstructure is determined to a greater extent by the substance itself, and the macrostructure is determined by the method of production.

Products from plastics get several methods: direct pressingbase impregnated with hot resins (fabric, wood veneer, paper) in several layers (sheet plastics) or polymer press powder (tiles for flooring); injection moldingviscous molten mixture (tile and sheet material with a volumetric pattern for finishing walls and ceilings); extrusionor forcing the plastic mass through a nozzle of a certain size and shape (baseboards, handrails for stairs, slats, sealing and sealing gaskets for windows and doors, roll cloth for finishing floors and walls); smearsthe upper surface of the base cloth (paper, fabric, fiberglass) with a pasty polymer mass followed by deep application of a relief pattern; roller-calendermethod , which consists of thorough mixing of the components on the rollers, subsequent rolling of the plastic mass between two rollers rotating in opposite directions with a gap that determines the thickness of the future rolled product, and applying a three-dimensional or flat pattern to the surface. In the last two ways, roll materials are obtained for finishing vertical and horizontal surfaces in rooms for various purposes.

Heat insulatingpolymer materials get in several ways. The first is through preliminary foamingplastic polymer mass due to intensive mechanical stirring in combination with the action of superheated steam (110 ° C) or introduction of foaming additives, subsequent pouring the mixture into a mold, quickly cooling it to fix the porous structure and cutting to size ( foams).

The second one provides for the use as part of a polymer mass gas-forming components, mold filling, heating to improve gassing, rapid cooling to fix the structure and, if necessary, cutting to size ( poroplasts).

The third is due to gluing by contacts corrugated sheets hot resin impregnated paper, fabric or wood veneer ( honeycomb).

Fourth - a decrease in average density due to introduction into polymeric mass highly porous aggregates (perlite) or fibrous components.

The widespread use of polymeric materials (plastics) in construction is based on their positive properties: low true density, high water resistance, hydrophobicity. These are materials that work successfully under abrasive loads. Mechanical strength is well combined in them with plasticity and elasticity. High corrosion resistance ensured their use as anticorrosive materials for the protection of concrete and metal structures. With an inexhaustible color palette, plastics can successfully imitate materials such as wood, natural stone, ferrous and non-ferrous metals. An important positive property of plastics is their good workability. They can be easily cut, welded, sanded and polished. The ability of plastics to combine with other organic and inorganic materials makes it possible to create new progressive composite materials and structures for various purposes on their basis.

Plastics also have a number of disadvantages... Most of them have a high coefficient of thermal expansion, increased creep, and non-fire resistance. Polymers age under the influence of atmospheric factors and especially sunlight. This process is accompanied by a decrease in strength and elasticity. The materials have a relatively low hardness and heat resistance. With respect to heating, polymers are classified into thermoplastic (polyethylene, polystyrene, polyvinyl chloride) and thermosetting (based on epoxy and polyester resins). For thermoplastic, the transition from a plastic state (upon heating) to a solid state (upon cooling) is not accompanied by a change in the composition and structure of the product and, as a consequence, in its physical and mechanical properties. Heating thermosetting polymers leads to structural changes at the microlevel, which has a significant effect on their properties, they become hard and brittle.

2.2.2. Application of polymeric materials and products

Analysis of all the properties of polymeric materials showed that in construction it is economically expedient to use them in the manufacture of load-bearing structures of high corrosion resistance, flooring, wall decoration, thermal insulation of enclosing structures and technological equipment, sealing joints and seams in large-panel buildings, waterproofing roofs and foundations, manufacturing sanitary - technical equipment and pipes, as well as for anti-corrosion work.

TO load-bearing structures include walls, shells and slabs, columns, beams, road slabs, floor coverings of industrial buildings. An example is multilayer panels, which are used as enclosing structures for walls and coverings. They represent a wooden or aluminum frame, sheathed on both sides with solid fiberboard and chipboard with a water-resistant polymer coating or sheet plastic, the gap between the skins is filled with heat-insulating foam or foam plastic plates. Such structures are widely used in industrial construction.

Of great interest are pneumatic structures (soft shells), which perform the enclosing functions of the vault. The preset shape of the dome and its bearing capacity are provided by the injected air at a pressure of 0.1 - 1.0 kPa. The material for pneumatic structures is unreinforced and reinforced with mesh (nylon, lavsan, metal) polymer films, fabrics coated or impregnated with polymers, high-strength steel ropes. Soft shells are used to cover markets, sports halls. When filled with water or water in combination with air, these structures are used as dams.

The advantages of rigid shells are that they can have both positive and negative surface curvatures. The spans covered by the shells can reach 90 - 110 m, the mass of 1 m2 of the coating is 7 - 20 kg. The material for the rigid shells is fiberglass sheets, aluminum and steel profiles, glued wooden beams, and foam plastic to provide thermal insulation.

During the construction of workshops for the chemical, food, pulp and paper industries, the question arises of ensuring the corrosion resistance of load-bearing and self-supporting structures. The only material that meets the set of specified properties is polymer concrete.It is obtained by intensive mixing in a concrete mixer of heated aggregates (sand, crushed stone), polymer resin and additives. The resulting mass is placed in a mold, compacted and kept at temperatures up to 100 ° C. Polymer concretes have high mechanical strength (Rсzh \u003d 90 - 110 MPa, Rras \u003d 9 - 11 MPa), chemical resistance, dust-free, hygienic, and water resistance. All these properties predetermine the use of these materials for the manufacture of columns, floor slabs, piece materials for flooring. In the production of polymer solutions, there is no large aggregate (crushed stone) in the composition.

Depending on the type of polymer binder, polymer concretes can be furan, polyester, epoxy; containing reinforcement are called armopolymer concrete. Depending on the material of the reinforcement, there are steel-polymer concrete (steel reinforcement) and glass-polymer concrete (fiberglass reinforcement). The reinforcement can be in the form of rods, wire or individual fibers, evenly distributed throughout the volume - dispersed reinforcement. Short thin threads and fibers (fibers) made of metal, glass, rocks and polymers are used as dispersed reinforcement. If dispersed reinforcement is used in polymer concrete, then concrete is called fiber polymer concrete.

Fiberglass reinforcement is obtained by twisting resin-impregnated glass threads into a bundle and applying a special protective polymer film coating on the surface of the resulting rods. Fiberglass reinforcement has high strength, chemical resistance, therefore it is used in reinforced concrete structures operated under the action of solutions of acids and salts.

It is possible to increase the durability of finished reinforced concrete structures by impregnating them with a monomer, which, polymerizing in the pores of concrete, provides high density and corrosion resistance of structures. Impregnation is carried out in special sealed chambers under pressure to a depth of 3 cm. This material is called concrete polymer,and structures and products are made of concrete-polymer.

Structures that experience a load during operation also include formwork.Formwork is used to obtain concrete and reinforced concrete elements and structures at the construction site. For her the manufacture uses chipboards, waterproof plywood, plastics. Due to its hydrophobicity, the surface of the plastic formwork has little adhesion to concrete and does not require special lubrication. Forms for the production of precast concrete at the plant can be all-polymer or combined. The latter are obtained by cladding wooden surfaces with plastic sheets. In addition to the above, there is another option for the manufacture of fiberglass formwork (forms) - by spraying a mixture of fiberglass with resin onto the enclosing surface made of fiberboard, chipboard or plywood. In addition to fiberglass, sheet rigid polyvinyl chloride, paper-laminated plastics, polyethylene, rubber are used for formwork.

For floor coveringsin construction they use polymer solutions, roll (linoleums), tile materials and pile carpets, which are used as a secondary coating. Seamless monolithic coatingsfrom polymer mastics, mortars and concretes are used in industrial buildings where corrosion resistance is required or there are increased requirements for floors in terms of hygiene and dust-free coatings. The coating is made in two layers: the lower one is made of polymer concrete, the upper one is made of polymer mortar. Leveling and compaction is carried out with special vibrators or rollers.

The most common flooring material is rolled linoleum... Linoleum floors are comfortable, as they are resilient, drown out the noise of footsteps, have low thermal conductivity, are decorative, easy to clean, resist wear well, and are durable. The quality of linoleum is assessed by three main indicators: elasticity, hardness and abrasion. According to the type of basic raw material used, linoleums can be divided into polyvinyl chloride, rubber and alkyd. The main volume is polyvinyl chloride(PVC) linoleums, which are produced baseless (by extrusion methods, roller-calender) and basic (coated method) with a smooth or embossed texture of the front surface. As a basis, jute fabrics, fiberglass and fiberglass are used, as well as non-woven needle-punched material, which gives linoleum heat and sound insulating properties. Similar products are obtained by applying a foamed polymer mass to a substrate. These materials are used for flooring in residential, public and industrial buildings with medium traffic.

Rubber linoleums(Relins) are made on the basis of synthetic rubbers, fillers (finely ground rubber waste, rocks) and additives. By design, they can be single-layer or multi-layer on a heat and sound insulating base. This type of material has proven itself well for covering the floors of livestock, medical premises; it is used to a limited extent in mass housing construction. Exposure to acids, alkalis, fats, solvents and petroleum products is not recommended.

Alkyd linoleumsused in residential premises, public, medical and industrial buildings.

Linoleum canvases are welded in workshops with high-frequency currents, hot air or infrared rays to obtain a room-sized carpet, which reduces the complexity of finishing work at the construction site. Linoleum is laid on a carefully made even, dry and clean substrate and glued with special polymer compounds.

Carpet pile heat and sound insulating coatings, which are used in residential and public buildings, can also be referred to roll materials. They are obtained from a synthetic pile material on a backing. Pile-stitched (tufted), needle-punched felt carpets and pile linoleums - nap is used for flooring in hotels, theaters, libraries, etc.

The second place in terms of volume of products for flooring is occupied by tiled polymeric materials... Depending on the binder used, they can be divided into coumarone, polyvinyl chloride, rubber... Tiles are obtained by pressing or cutting to size from baseless linoleum linen. The main purpose is to cover the floors of kitchens, corridors, staircases.

Advantages tile coatings: increased production efficiency by reducing the consumption of polymer binder, high durability of products and the repairability of the coating. disadvantages: low decorative effect, a large number of seams that reduce the solidity of the coating, increased labor intensity when installing floors. Compared to tile materials advantages of linoleums - in their industrialism, manufacturability and greater solidity, as well as in their low labor intensity when laying.

For wall decorationapply film baseless and basic materials, as well as large-sized sheets and small-piece tiles. They can be painted in different colors with a smooth, embossed or embossed surface. The decoration of kitchens, hallways, sales areas, cafes is carried out using PVC film on a paper backing with various printed and embossed color patterns (polyethylene, isoplastic). Devilon, imitating leather, has a high decorative effect, while texoplen is a fabric with a printed pattern impregnated with a special organosilicon composition.

In the decoration of residential (corridors, hallways) and public premises, roll foamed foam on a paper base is increasingly used. This material is prohibited from using in child care facilities, hospitals, as it belongs to the group of combustible materials. The possibility of using polymer roll materials is assessed by their surface water absorption, flexibility and tensile strength.

Facing with tilessanitary facilities, halls, sales areas are performed using special adhesive polymer compounds (mastics). Tiles produce decorative polystyrene and PVC relief, imitating the texture of valuable wood species, stucco patterns. Due to their low fire resistance, these materials are prohibited from using in rooms with open fire heating devices, in child care facilities and in stairwells. The quality of the products is assessed according to the conformity with GOST for the appearance and heat resistance.

Found widespread for wall decoration sheet paper-layered plastic,which is produced in one-color and multi-colored with imitation of valuable species of wood and stone. Facing embossed polyvinyl chloride polydecor panels are used for finishing walls and ceilings of public and industrial buildings. Sheets are made with a relief pattern, one-color and multi-color, with a printed pattern, a smooth or embossed front surface.

TO special purpose materials include acoustic, thermal insulation, roofing, waterproofing, sealing and anti-corrosion.

Acoustic soundproof materials are used in structures between ceilings and walls in the form of flexible, resilient pads made of polyurethane foam or sponge rubber. For the same purpose, elastic mineral wool mats and slabs are used, which are large-sized products, which include stone, slag or glass fibers bonded with polymer resins, as well as polyurethane foam and foam vinyl chloride boards located under the floor covering.

Sound absorbing materials are needed to reduce noise in industrial workshops, auditoriums, classrooms, television and radio studios. The effect of sound absorption is ensured by a high through porosity of the material (mineral wool, glass wool boards on phenol-formaldehyde, bitumen or starch binder) or artificially made perforation. Laminate can be used as a perforated cover. Foamed or gas-filled plastics with open porosity form the basis of polymer products (plates).

Heat insulatingmaterials based on plastics are made from various polymers: polystyrene, polyurethane, polyvinyl chloride, polyethylene, etc. Foam plastics are characterized by high thermal insulation properties in combination with good strength indicators. One of the highly effective thermal insulation materials is mipora obtained by foaming a urea-formaldehyde resin. It is used in the form of blocks with a density of 10 - 20 kg / m3 for thermal insulation of brick walls and three-layer frame panels.

In terms of structure, heat-insulating foam plastics have predominantly closed pores. The properties of materials, depending on the type of polymer and the method of production, fluctuate within wide limits: density 10 - 150 kg / m3; thermal conductivity at a temperature of 20 ± 5 ° С - 0.023 -
0.052 W / (m · K), strength 0.05 - 4 MPa, volumetric water absorption - 2 - 70%. In terms of fire resistance, the products are classified as non-combustible and combustible materials.

Foam plastics are widely used for thermal insulation of pipelines and equipment, for thermal insulation of building enclosing structures and protection of refrigeration units. The temperature of application of foamed plastics, depending on the type of resin, ranges from –180 to +100 ° С.

The problem of improving the thermotechnical properties of enclosing structures is solved through the use of multilayer wall and roof panels, the middle layer of which is made of effective plate insulation or the method of foaming the polymer directly in the cavity of building structures is used. According to this technology, polymer granules are heated with steam or high-frequency currents, poured between the layers of the panel and cooled to a certain temperature.

Due to their high water resistance, water resistance, often combined with hydrophobic properties, polymers have found wide application in roofing and waterproofingbuilding structures. Sheet and roll products, mastic compositions are used as roofing.

Most widespread among leafyof roofing materials received flat and corrugated polyester fiberglass. These materials have high strength, resistance to weathering, increased light transmission (up to 85%). The main purpose of roofing fiberglass is the construction of roofs for unheated buildings - pavilions, verandas, warehouses, as well as greenhouses and greenhouses.

Roll materialssimultaneously play the role of roofing and waterproofing. These include reinforced with glass mesh and unreinforced polymer films, base materials, which include rubber mixtures in combination with fillers and special additives (hydrobutyl, butisol, buterol) or obtained on the basis of glass mesh and glass cloth impregnated and coated on both sides with polymer mastic compositions (armobitep, elastosteklobite, etc.).

It is interesting to use a new polymer material for roofing, which is a mastic composition based on chlorosulfonated polyethylene. To obtain a durable waterproof top coat, the composition is applied with the help of rollers to the surface of a reinforced concrete or asbestos-cement slab in several layers, where it dries up and turns into a resilient elastic rubber carpet that successfully works at temperatures from -45 to +120 ° C.

For the production of new roll waterproofing materials, synthetic polyamide and polyethylene fibers are used, connected by synthetic resins, latexes. Sometimes fusible fibers are added to the mass, which, when melted and rolled, form a continuous web. Synthetic fibers with the addition of mineral fibers (glass, slag) and a binder are widely used for the production of nonwoven synthetic fabrics. There are various combinations of organic fibers with inorganic (metal, slag, glass, basalt), which increase the strength and durability of roll materials. Vinyl acetate, phenolic resins, polyacrylic acid esters, organosilicates and latexes are used as a binder.

An important task in construction is joint sealingbetween building blocks and panels, as joints are the most vulnerable point in buildings. Sealing materials for durable and reliable ensuring the solidity of the structure must be weather and moisture resistant, resistant to multiple seasonal and daily temperature changes, have good heat and sound insulation properties. The materials used are mastic compounds, elastic gaskets in the form of porous or dense rubber-like polymer bundles (poroizol, hernite, etc.).

Mastic compositions are obtained by mixing organic binders with finely ground fillers and special additives that increase the material's resistance to ultraviolet rays, slow down the aging process, etc. Powdered or finely ground fibrous inorganic materials (sand, slag, asbestos) are used as fillers that reduce the consumption of the binder and increase the operational properties. When introduced, shrinkage deformations are reduced during the curing of the compositions, and heat resistance and mechanical strength increase. Finely dispersed rubber waste is used to increase resilience and elasticity. By the type of binder used, mastics are classified into polymer, bitumen-polymer and bituminous. According to the technology of application - on hot, requiring heating before applying to the surface, and cold, the plasticity of which is provided by water (emulsion) or a solvent. In addition to the sealing purpose, mastics are used for gluing roll materials for roofing, steam and waterproofing of pipelines and building structures, as well as to protect them from corrosion.

Anti-corrosionpolymeric materials produced in the form of paints and varnishes, putties, mastics, mortars and concretes, as well as products such as tiles and sheets. Their main purpose is to protect building structures and technological equipment from destruction.

Polymer mortars and polymer concretes based on furan resins are used for flooring under the action of acids, alkalis and organic solvents. On the basis of thermoplastic resins (polystyrene, polyvinyl chloride, polyethylene, polyisobutene), products and materials in the form of sheets, tiles and films are produced for gluing anti-corrosion protection of building structures. Special adhesives, putties, and mastics based on chemically resistant high molecular weight resins are used as fixing compositions.

Colorful compositions used to protect the surface of building structures from corrosion, decay, moisture absorption, as well as to make them decorative. Depending on the purpose of the coating, the following types of paint compositions are distinguished: primers,providing adhesion of the coating to the surface; putties,intended for filling pores, cavities and leveling the painted surface; paint compositions,giving decorative and protective functions in relation to the surface of the product and structure.

The choice of paints and varnishes used to protect concrete, reinforced concrete and metal structures is carried out taking into account the operating conditions, the type and degree of aggressiveness of the environment, the required durability of the coating. To brand varnishes, enamels, paints are included figures, conventionally denoting their purpose, letters - type of polymer binder. For example, EP-225 enamel is limitedly weather-resistant, based on epoxy resin.

Paint compositionsare viscous-flowing compositions that form, when applied to the surface of products and curing, film-like dense elastic protective coatings.

The main component of these materials are binders (film-forming substances), providing the plasticity of the mixture, strength and durability of the coating. In polymer paint compositions, high-molecular resins are used as a binder, and drying oils are used in oil compositions. Oils can be obtained by processing vegetable oils (linseed, hemp, etc.) - natural and based on polymer resins.

Depending on the plasticity, oil paints are divided into thick grated and ready to eat (with an increase in the consumption of drying oil). To accelerate the curing of the film, oil paints are introduced driers.

Binder quality assessed by viscosity, color and speed drying out... When the polymer binder is dissolved with an organic solvent (gasoline, white spirit, toluene, turpentine), varnish,forming a transparent protective coating when applied to the surface, by introducing a pigment into the varnish - enamel.

Pigmentis a finely milled colored powder, insoluble in water, binder and solvent. By origin, pigments can be organicwith high color intensity but reduced durability, and mineral - weather resistant. The quality of pigments is assessed by the degree of their grinding - the fineness of grinding (dispersion), hiding power (color intensity) and oil absorption (the minimum consumption of the binder required to obtain a homogeneous plastic mass of a certain molar consistency).

The paint composition includes a binder, pigment, solvent (or thinner), and filler.

Fillerused in the form of a slightly colored finely ground mineral material (quartz sand, chalk, talc, dolomite, kaolin). The main purpose of this component is to increase the viscosity of the composition, strength, density, temperature resistance and reduce the deformability of the protective film coating, as well as reduce the consumption of expensive pigment.

Thinnersused to reduce the viscosity of the paint composition, in contrast to solvent they do not dissolve the binder. The thinner can be water in water-based paints, drying oil - in oil paints.

When tested colorful compositions define them viscosity, film hardness, strength at impact and bend.

The materials used in construction are presented in table. 2.3.

Table 2.3

Application of polymeric materials

Materials and products	Application area
Polymer concrete, concrete polymers	Columns, beams, floor slabs, floors in chemical workshops with aggressive media
Sheet plastics	Sheathing of hinged panels; installation of translucent roofs (fiberglass), rigid shells; finishing of facades and internal walls; execution of suspended ceilings; production of molds in the production of reinforced concrete products and structures
Large-sized slabs highly porous:	Soundproofing of intermediate floors

The end of the table. 2.3

	Thermal insulation of enclosing structures (wall panels, coating slabs). If perforated, sound-absorbing materials for false ceilings
Fiberglass rods	As reinforcement in the production of concrete structures operated under conditions of acid and salt-containing media
Tiled - small-piece (cut and pressed) (PVC, coumarone, rubber polystyrene, etc.)	Covering floors, walls in rooms with wet operation
Roll basic and baseless:	Execution of soft roofs
linoleums (PVC, alkyd, rubber, etc.)	floor covering in residential, public areas
smooth and embossed films	Execution of soft shells, protection of roofing and waterproofing roll materials, interior wall decoration
Long harnesses, cords, gaskets made of polyurethane, rubbers and soft foam	Sealing of joints, sound insulation of building structures
Viscoplastic mastic compositions based on bitumen-polymer and polymer binders	Making mastic roofs, sealing joints, anti-corrosion protection of building structures, gluing roll, tile and large-sized materials to the base
Viscous colorful	Giving decorative effect and protecting the surface from destruction

2.3. Bituminous and tar binders, materials based on them

Bitumen and tar are organic materials of amorphous structure, which include high molecular weight hydrocarbons and their derivatives. Bituminous materials include natural bitumens - a product of natural oil oxidation and artificial ones obtained by refinery oil refining. Tar is produced by dry distillation of solid fuels: coal, peat or oil shale.

The use of bitumen has been known for a long time, but for a long time the literature almost did not mention bitumen or asphalt. In 1300, the Italian traveler Marco Polo first pointed to the deposits of "liquid asphalt" in Baku. In 1601, an attempt was made to classify bituminous materials, and only in 1777 did Le Saze give a more or less complete classification of asphalt (bitumen), including oil. In Russia, asphalt began to be used in the forties years XIX centuries, first in road construction, then in the production of varnishes, paints and waterproofing materials. Bitumen and tar are united by the similarity of composition and structure and, as a consequence, by the similarity of basic properties.

2.3.1. Properties of organic binders

All organic binders are black or dark brown in color, which is why they are also called black astringents.

Possessing an amorphous structure, bitumens, unlike crystalline materials, do not have a specific melting point. Gradual transition from solid state in a viscous flow is reversible and occurs without changing the basic properties, therefore, bitumens are classified as thermoplastic organic materials. Tar - a dark colored liquid product with low weather resistance. To increase the viscosity, atmospheric and temperature resistance, fillers (limestone, sand) are introduced into the tar composition. Since organic binders are absolutely dense, their average and true density are numerically equal and fluctuate, depending on the composition, from 800 to 1300 kg / m3.

In construction practice, they have found the greatest application bitumens... They are hydrophobic (not wetted with water), water-resistant, their porosity is practically zero, so they are waterproof and frost-resistant. These properties make it possible to widely use bitumen in the production of waterproofing and roofing materials. The service life of bitumen products in air is short, since under the influence of sunlight and oxygen in the air, bitumen aging occurs, accompanied by an increase in hardness and fragility. In this regard, petroleum bitumens are transported in closed containers or paper bags and stored in special closed warehouses, protected from the action of sunlight and atmospheric precipitation.

Due to the fact that the technology of obtaining materials and products using bitumen is based on its property of transition when heated from a solid to a plastic state, and also taking into account the operating conditions of roofing materials, for bitumen, according to GOST, the following definitions are provided. thermotechnical indicators: softening temperature on the device "ring-ball", which characterizes the heat resistance and the degree of softening of bitumen when heated; flash points of gaseous products released from bitumen when heated. The latter indicator is necessary to develop a safe technology for obtaining materials and products using bitumen.

The quality of bitumen is also assessed by viscosity and tensile properties. Viscositydetermined by the depth of penetration of the needle into the bitumen for a certain time under the action of a fixed load at a test temperature of 25 ° C (penetration) Viscosity is expressed in degrees, with 1 ° corresponding to the needle penetration depth of 0.1 mm. Extensibility(ductility) - the ability of bitumen to stretch into thin threads that break under the action of an applied tensile load. Stretch is measured in centimeters. These three main properties of bitumen are interrelated. Hard bitumens have a high softening point, but low elongation, i.e. relatively fragile. Soft bitumens soften at low temperatures, can stretch strongly - they have high plasticity. According to the above properties, a brand is determined for bitumen, the symbol of which includes letters that determine the use of bitumen, and numbers that characterize its main properties. For example, grades BN-90/10, BNK-90/40 are petroleum bitumen for construction and roofing, the softening temperature of which is 90 ° C, viscosity is 10 and 40 °, respectively, BND-130/220 is oil road bitumen with a viscosity of 131 - 220 °.

Bitumen corrosion resistant in relation to aqueous solutions of many acids, alkalis, salts and most corrosive gases, but they dissolve partially or completely in various organic solvents (alcohol, acetone, turpentine). This property allows them to be used for the preparation of anticorrosive mastics, varnishes and paints.

Mechanical propertiesbitumen depend on the ambient temperature. At normal (20 ° C) temperature, these are, as a rule, solid, relatively plastic materials, when the temperature drops to negative ones, they are brittle. In order to increase elasticity, heat resistance, mechanical strength, polymeric and mineral additives are introduced into organic binders. Bitumen-based materials cannot be used in action hot water and liquid organic media (oils, solvents, petroleum products).

2.3.2. Materials and products based on organic binders

Considering the specific properties of organic binders, bitumen and tar are used to obtain materials and products for special purposes: waterproofing, sealing, anticorrosive and road.

Depending on the working conditions of the building structure, various kinds waterproofing,and, consequently, the materials used for its implementation.

So, to protect against destruction of the roof, underground structures, foundations for equipment, reinforced concrete berths and piles, they use paint waterproofing.It is performed in several layers using bituminous, tar and bitumen-polymer mastics.

Mastics are plastic or viscous-flowing compositions, which include the organic binder itself: roofing, road bitumen or mixtures thereof, high molecular weight resins to increase plasticity and finely ground mineral filler (sand, limestone, asbestos, talc) to increase the durability, strength, temperature resistance of the coating and saving bitumen. In order to facilitate the application of the composition to the protected surface, the mastic is either heated ( hot mastic), or an organic solvent ( cold mastic).

The disadvantages of hot mastics include instability of properties, high energy consumption for production, the possibility of getting burns during their use, difficult working conditions, relatively low performance under atmospheric influences. When working with cold mastics, a solvent harmful to human health evaporates.

In recent years, more and more applications are found bitumen emulsion mastics,which are fine particles of bitumen evenly distributed in water, covered with a layer of solid (cement, clay, lime) or liquid (soap, sulfite-alcohol stillage) emulsifier and filler. The emulsifier ensures the uniformity and stability of the emulsion, the shelf life of which does not exceed several months. These mastics do not contain toxic solvents, are hygienic, explosion-proof and fire-safe, easily applied to the protected surface, including wet ones, by spraying with compressed air. The protective coating is formed by the evaporation of water. Bitumen-emulsion mastics are intended for installation and repair of roofs, external waterproofing of underground parts of buildings and structures, walls, floors at temperatures not lower than 5 ° C. The quality of mastics is assessed by the same indicators as bitumen.

The following mastic compositions have found the greatest application in construction for roofing and waterproofing of building structures: MBK-G-55 (65, 75, 85, 100) - bituminous mastic, hot roofing with heat resistance 55 - 100 ° С; MBR-G-55 (65, 75, 85, 100) - bituminous with crumb rubber filler; MBBG-90 (80) - hot bitumen-butyl-rubber; VK-X-60 - cold bitumen-kukersolny. For the same purpose, rubber-bitumen mastic isol is used, which can be either hot or cold (MRB-X).

Wrapping waterproofingused to protect roofs, pipelines, prefabricated and monolithic reinforced concrete foundations. To perform this type of waterproofing, use roll main(roofing material, glass roofing material, foil-roofing material, hydroisol) and baseless(isol) bituminous and bitumen-polymer materials.

According to STB 1107-98, the main rolled roofing (K) and waterproofing (G) materials are obtained on glass fiber (CX), glass fabric (ST), polyester canvas (PX), polyester fabric (PT) and foil (foil ruberoid, foil insol). Bitumen (B) and bitumen-polymer compositions: elastomeric (BE) or plastomeric (BP) compositions with increased elasticity, chemical resistance and weather resistance are used as a binder for impregnating the base and obtaining a mastic coating composition applied to surfaces on both sides. To exclude sticking of the material in rolls, as well as in order to strengthen and protect its surface from temperature, ultraviolet rays and mechanical damage, sprinkles are used: coarse-grained (colored) - K (C), fine-grained - M, dusty - P, metal foil - MF and a polymer film - PP. The grade of the material is designated as follows: K-ST-B-K / PP-3.0 STB 1107-98 - roofing material on fiberglass using bituminous binder and coarse-grained dressing (or film coating) with a coating composition weight of 3001-3500 g / m2 ... Depending on the technology of laying roll materials, they can be glued to the base using special mastics and weldable... The latter have a thickened layer of the coating composition on the lower side of the roll, which is heated for gluing, giving the adhesive ability, with a gas-flame burner. When used as a base board impregnated with bitumen and a bituminous mastic coating composition, the material is called roofing material, if the basis was fiberglass - glass roofing material. Roll material quality assessed by flexibility on a bar of a certain radius at zero or negative temperatures, heat resistance, tensile strength and water absorption... A soft roll roof is a multi-layer coating, therefore, cover materials protected by a polymer film or dust-like dressing, as well as non-cover materials, which are a cardboard base impregnated with bitumen - glassine, are used as a sublayer. In addition to roll materials, sheet materials - "Ondulin" and tiles "Shingles" (bituminous tiles) are used to protect the roof and the entire building as a whole. The first is corrugated elastic sheets formed from cellulose fibers impregnated with bitumen. On the front side, the sheets are covered with a protective and decorative paint layer based on a thermosetting polymer and lightfast pigments. The second material is obtained on the basis of fiberglass or asbestos board impregnated with bitumen. A self-adhesive layer of rubber-bitumen composition is applied to the lower surface, which ensures the absolute tightness of the roof due to its heating and partial melting by solar energy. The top mastic coating is protected by stone cuttings of a certain size and color.

Lubricating waterproofingare made of asphalt plasters. It is recommended for rigid, non-deforming horizontal and vertical concrete surfaces. The composition of asphalt plasters, which can be cold and hot, includes, respectively, bitumen emulsion paste or heated bitumen, filler and quartz sand. Bituminous paste is a thick creamy mass obtained by intensive mechanical grinding of bitumen in water in the presence of an inorganic emulsifier (lime), which increases its uniformity and stability.

To fill seams of various design and purpose in order to impart solidity to the structure, to protect against soaking and freezing, elastic sealing bituminous and bitumen-polymer mastics (sealants) with the addition of crumb rubber. An example of sealing mastics can be bitumen-rubber - resoplast (brands RK and RG), consisting of crumb rubber, bitumen, polymer component, plasticizer, and bitumen-butyl rubber, including bitumen in combination with butyl rubber, talc and plasticizer - MBBP-65. Sealing bitumen materials must meet the following requirements: be flexible and resilient; moisture and gas tight; have weather resistance and anti-corrosion properties; preserve physical-chemical and physical-mechanical properties during operation; have a strong adhesion to the material of construction; do not emit toxic substances.

Corrosion resistance metal, concrete, reinforced concrete structures are provided by means primary and secondary protection... The primary measures include all those technological measures that ensure the resistance of the material itself (composition selection). Secondary protection is used if the required durability of the structure is not achieved when using the primary one.

Secondary protection measures include: paint and varnish coatings, pasting and plaster (coating) coatings based on bitumen. In addition to bitumen, colorful compositions contain modifying polymer additives and organic solvents, during the evaporation of which a resistant coating is formed. The disadvantages of coatings include their porosity, slow curing, low heat, frost and radiation resistance. However, the availability and relatively low cost of bitumen have provided them with widespread use in construction.

Asphalt concrete and mortarsare the most important materials for the construction of road and airfield pavements, floors in industrial plants, irrigation canals, flat roofs.

Asphalt concrete- an artificial building material obtained as a result of hardening of compacted asphalt concrete mass, consisting of carefully mixed components: crushed stone (gravel), sand, mineral filler powder and bitumen. Asphalt concrete without coarse aggregate is called asphalt mortar.

By the type of coarse aggregate, asphalt concrete is divided into crushed stone and gravel... Depending on the brand of bitumen used and the laying temperature - on hot (120 °), warm (70 °) and coldprepared on liquid bitumen or bitumen emulsions, which are used at an ambient temperature of at least 5 ° C.

By the largest grain size of crushed stone or gravel hot and warm asphalt concrete is divided into coarse-grained - the largest grain size up to 40 mm; fine-grained - up to 20 mm, sandy - with the largest grain size up to 5 mm. Cold asphalt concrete can only be fine-grained or sandy... In addition, hot and warm asphalt concrete, depending on their use in the road structure, are divided into dense - for the upper layers of road surface with residual porosity from 2 to 7% by weight, porous (7 - 12%) - for the top layer and base of road surfaces, highly porous (12 - 18%). The technology of asphalt concrete mixture preparation provides for heating aggregates and bitumen to a predetermined temperature, thoroughly mixing them in a mixer. By technological signs asphalt concrete mass is divided into tough, plasticand cast... To compact hard and plastic masses, heavy and medium rollers are used. The cast asphalt concrete mass is compacted with special rollers, a light roller or not at all.

Quality asphalt concrete coverings assessed by strength, wear resistance and water resistance... The technical properties of asphalt concrete vary significantly with temperature. At normal temperatures (20 .. - 25 ° С) it has elastic-plastic properties, at high temperatures - viscoplastic, and at low temperatures it becomes brittle. In this regard, mechanical strength tests are carried out at temperatures 0, 20, 50 ° Сat constant speed load supply. Depending on the temperature, the flexural strength is respectively equal to 1.0 - 1.2; 2.5 - 3 and 10 - 15 MPa.

A distinctive feature of asphalt concrete is its ability to resist tough impact and wear. It was found that in urban traffic conditions, wear is from 0.2 to 1.5 mm per year. Since asphalt concrete is sensitive to fluctuations in the temperature of the environment, structural changes constantly occur in it, leading to the destruction of the pavement. Especially intensively destructive processes occur with a sharp change in temperature. This process is accelerated by the action of water and aging of the organic binder itself. The use of materials based on bitumen is presented in table. 2.4.

Table 2.4

Application of materials based on bitumen

Application area	Materials and products used
Waterproofing of building structures: painting	Mastics (hot, cold) bituminous, bitumen-polymer, bitumen-emulsion
lining	Roll basic (on cardboard, fiberglass and fabric) and baseless fused and glued
coating	Cold and hot asphalt plasters
Roof coverings	Sheet - "Ondulin", tiled - bituminous tiles ("Shingles"), roll and mastic materials
Sealing seams	Bituminous-rubber mastics, bitumen-rubber
Corrosion protection of building structures	Colorful and mastic bituminous and bitumen-polymer compositions, roll products
Coverings of roads, floors, flat roofs	Asphalt concrete and asphalt mortars

REGULATORY LITERATURE USED

1.GOST 11047-90. Wooden products.

2. STB 4.208-95. Product quality indicators system. Building. Glued wooden structures and parts. Nomenclature of indicators.

3. STB 4.223-96. System of indicators of product quality. Building. Parquet products. Nomenclature of indicators.

4. STB 1074-97. Profile parts made of wood and timber materials for construction. Technical conditions.

5. STB 1105-98. Wall blocks made of wood concrete for low-rise construction. Technical conditions.

6. STB 1116-98. Campfire and wood-edged stoves. Technical conditions.

7. SNB 5.05.01-2000. Wooden structures.

8. CH 549-82. Manufacturing and application of structures and products from wood concrete.

9.GOST 4598-86. Fiber boards.

10. GOST 19222-84. Fibrolite.

11. CH 525-80. Instructions on the technology of manufacturing polymer concrete and products from it.

12. STB 4.230-98. Polymeric finishing materials and products. Nomenclature of indicators.

13. STB 1064-97. Thermoplastic floor tiles. Technical conditions.

14. STB 1092-97. Bitumen-elastomeric sealing mastic. Technical conditions.

15. STB 1103-98. Fiberglass fittings. Technical conditions.

16. STB 1161-99. Thermal insulation boards made of synthetic fibers. Technical conditions.

17. STB 1240-2000. Roll fiberglass. Technical conditions.

18. STB 1246-2000. Thermal insulation foam based on urea-formaldehyde resin. Technical conditions.

19.GOST 7251-77. Linoleum, polyvinyl chloride on a fabric basis. Technical conditions.

20. GOST 11529-86. Polyvinyl chloride materials for floors. Control methods.

21. GOST 18108-80. Polyvinyl chloride linoleum on a heat and sound insulating base. Technical conditions.

22. GOST 26149-84. Roll floor covering based on chemical fibers. Technical conditions.

23. GOST 30307-95. Construction polymer adhesive latex mastics. Technical conditions.

24. GOST 22950-95. Mineral wool slabs of increased rigidity on a synthetic binder. Technical conditions.

25. STB 4.224-95. Materials and products polymer construction, sealing and sealing. Nomenclature of indicators.

26. STB 1033-96. Road, airfield and asphalt concrete mixtures. Technical conditions.

27. STB 1062-97. Petroleum bitumens for the upper layer of the road surface.

28. STB 1093-97. Roofing glassine. Technical conditions.

29. STB 1107-98. Roll roofing and waterproofing materials based on bitumen and bitumen-polymer binders. Technical conditions.

30. STB 1220-2000. Modified road bitumens. Technical conditions.

31. STB 1245-2000. Bituminous cationic emulsions. Technical conditions.

32. GOST 7415-86. Hydroizol. Technical conditions.

33. GOST 10296-79. Isol. Technical conditions.

34. GOST 10923-93. Roofing material. Technical conditions.

35. GOST 15879-70. Glass roofing material. Technical conditions.

36. GOST 20429-84. Folgoizol. Technical conditions.

37. GOST 30547-97. Roll roofing and waterproofing materials. General technical conditions.

Resistor base materials

General information about aging

Aging is an irreversible change in the properties of materials under the influence of external and internal factors. According to statistics, on average for resistors, the change in contact resistance occurs per year by 1%.

The causes of aging are processes occurring in real operating conditions of EA, such as: crystallization, electrochemical oxidation, electromigration, breaking of bonds in molecules, sorption processes, etc.

Sorption - absorption of various substances by the material from the outside.

Absorption - absorption of various substances by volume.

Adsorption - absorption of various substances by the surface.

The most resistant to aging are resistors containing inorganic materials and wire REs. Among the non-wire resistors, thin-film resistors, as a rule, do not contain organic additives, are more or less aging. And the less resistant ones are composite with an organic dielectric - lacquer.

The change in resistance of the subsequent resistor depends on the ratio between the different components in terms of aging rate. For thin-film resistors, the resistance usually increases with aging; for thick-film resistors, aging is determined by the stability of the binder dielectric materials that make up the resistive paste (composition). Aging of wirewound resistors is determined by the resistance of resistive alloys to oxidative processes other than temperature, moisture and radiation. Aging is affected by atmospheric pressure over 3 atmospheres. At a reduced pressure, due to a decrease in the dielectric strength of the air, it is necessary to reduce the operating voltage across the resistors in order to avoid overheating them (due to the deterioration of the heat sink).

Organic and inorganic materials are used as dielectric bases of the resistor.

Benefits of organic material:

Organic material has the highest manufacturability. Manufacturability - a set of properties of an object of production that ensure the minimum cost of the object (simple and cheap synthesis at a temperature< 1000 0 С). Органический материал является дешевым сырьем, возможность варьировать свойства, путем введения в массу добавок, как органических, так и неорганических.

Disadvantages of organic material:

Low heat resistance, for polyimide and fluoroplastic the heat resistance is +250 0 С. Also, the lack of organic materials is low thermal conductivity.

From organic materials, fiberglass (fiberglass impregnated with epoxy resin with modifiers) is used as the base of the resistors. Modifiers give the organic mixture plasticity, vibration strength and other properties as intended, the heat resistance is +150 0 С.

Also used textolites (cotton fabric, impregnated with phenol-formaldehyde resin with the necessary additives) heat resistance is +105 0 C.

Getinax paper impregnated with phenolic resin is also used as organic materials, the heat resistance is +100 0 C. The last two materials are used for resistors in micropower circuits.

Organic thermal insulation materials and products are made from various plant materials: wood waste (shavings, sawdust, slabs, etc.), reeds, peat, flax, hemp, animal hair, and also on the basis of polymers.

Many organic heat-insulating materials are subject to rapid decay, damage by various insects and are flammable, so they are pre-processed. Since the use of organic materials as backfills is ineffective due to inevitable precipitation and the ability to decay, the latter are used as raw materials for the manufacture of plates. In slabs, the base material is almost completely protected from moisture, and, consequently, from decay, in addition, during the production of slabs, it is treated with antiseptics and fire retardants, which increase its durability.

Thermal insulation materials and products from organic raw materials. Among the wide variety of thermal insulation products made from organic raw materials, the most interesting are fibreboard, reed, fiberboard, peat, natural cork thermal insulation, as well as thermal insulation foam.

Fiber boards used for heat and sound insulation of enclosing structures. They are made from loose wood or other plant fibers - non-business wood, waste from the timber processing industry, fires, straw, reeds, cotton. The most widespread are fibreboards obtained from wood waste, which are made by hot pressing a pulp consisting of wood fibers, water, fillers, polymer and additives (antiseptics, fire retardants, hydrophobic substances). For the manufacture of insulating boards, a casting machine is used, equipped with an endless metal mesh and a vacuum unit, where the mass is dehydrated, compacted and cut into plates of the required dimensions.

A photo. 11.6. Fiber boards

Fiber boards are produced in five types: superhard, solid, semi-solid, insulating and finishing and insulating. Fiberboard insulation has a length of 1200 ... 3600 mm, a width of 1000 ... 2800 mm and a thickness of 8 ... 25 mm, a density of 250 kg / m 3, a flexural strength of 1.2 MPa and a thermal conductivity of no more than 0.07 W / (m ° C).

Along with insulating boards, insulation and finishing boards with a front surface painted or prepared for painting are used.

Reed slabs , or simply reeds, are used for thermal insulation of enclosing structures of low-rise residential buildings, small industrial premises, in agricultural construction.

A photo. 11.7. Reed slab

It is a heat-insulating material in the form of slabs pressed from reed stalks, which are then fastened with galvanized steel wire. For the manufacture of reed slabs, mature annual stems with a diameter of 7 ... 15 mm are used. The harvesting of the stems should be done in the autumn-winter period. The plates are pressed on special presses. Depending on the location of the reed stems, slabs are distinguished with a transverse (along the short side of the slab) and longitudinal arrangement of the stems. Plates are produced with a length of 2400x 2800 mm, a width of 550 ... 1500 mm and a thickness of 30 ... 100 mm, grades in density D175, 200 and 250, with a bending strength of at least 0.18 ... 0.5 MPa, thermal conductivity 0.06 ... 0.09 W / (m ° C), humidity not more than 18% by weight.

Peat thermal insulation products are manufactured in the form of plates, shells and segments and are used for thermal insulation of the enclosing structures of buildings of the III class and surfaces of industrial equipment and pipelines at temperatures from -60 to -100 ° C.

A photo. 11.8. Peat plate

The raw material for their production is low-decomposed high-moor peat, which has a fibrous structure, which favors the production of high-quality products from it by pressing. Plates are made with a size of 1000x500x30 mm by pressing in metal molds with subsequent drying at a temperature of 120 ... 150 ° C. Depending on the initial moisture content of the peat mass, two methods of making slabs are distinguished: wet (moisture content 90 ... 95%) and dry (moisture content about 35%). With the wet method, excess moisture is squeezed out of the peat mass during the pressing period through fine metal nets. In the dry method, such meshes are not placed in the molds. Peat insulating boards are divided by density into D 170 and 220 grades with a bending strength of 0.3 MPa, a dry thermal conductivity of 0.6 W / (m ° C), and a moisture content of no more than 15%.

Fiber-cement boards are thermal insulation material obtained from a hardened mixture of Portland cement, water and wood wool.

Wood wool plays the role of a reinforcing frame in fiberboard. In appearance, thin wood shavings up to 500 mm long, 4 ... 7 mm wide, 0.25 ... 0.5 mm thick are prepared from non-commercial coniferous wood on special wood-wool machines.

A photo. 11. 9. Cement-fiberboard plate

The wool is pre-dried, impregnated with mineralizers (calcium chloride, liquid glass) and mixed with cement paste by the wet method or with cement by the dry method (wood wool is sprinkled or dusted with cement) in various types of mixing machines. At the same time, make sure that the wood wool is evenly covered with cement. Slabs are formed in two ways: by pressing and on conveyors, where fiberboard is molded in the form of a continuously moving belt, which is then cut into separate slabs (similar to vibratory rolling of reinforced concrete products). When pressing plates, the specific pressure for heat-insulating fiberboard is taken up to 0.1 MPa, and for constructive - up to 0.4 MPa. After molding, the plates are steamed for 24 hours at a temperature of 30 ... 35 ° C. Cement-fiberboard plates are produced with a length of 2400 ... 3000 mm, a width of 600 ... 1200 mm, a thickness of 30, 50, 75, 100 and 150 mm. Cement fiberboard is produced in three grades in terms of density: Ф300, 400 and 500, thermal conductivity 0.09 ... 0.15 W / (m ° С), water absorption no more than 20%. Fiberboard slabs F300 grades are used as heat-insulating material, F400 and 500 grades are used as structural and heat-insulating material for walls, partitions, ceilings and coatings of buildings.

Arbolite plates They are also obtained by molding and heat treatment (or without it) of organic short-wavy raw materials (crushed machine shavings or flails, straw or reeds, sawdust, fires, etc.), treated with a solution of a mineralizer.

F
oto. 11 .10. Arbolite plates

Chemical additives are calcium chloride, soluble glass, alumina sulfate. Portland cement is the second component in the manufacture of wood concrete slabs. Plates are formed in lengths and widths of 500, 600 and 700 mm, thicknesses of 50, 60 and 70 mm. The density in the dry state is 500 kg / m 3, the compressive strength is 0.3 ... 3.5 MPa, the ultimate strength in bending is not less than 0.4 MPa, the thermal conductivity in the dry state is not more than 0.12 W / (m ° C), humidity not more than 20% by weight.

Cement particle boards the domestic industry produces two grades: TsSP-1 and TsSP-2. Plates are made by pressing wood particles with cement binder and chemical additives.

CBPBs belong to the group of hardly combustible materials with increased biostability. They are produced with a length of 3200 ... 3600 mm, a width of 1200, 1250 and a thickness of 8 ... 10, 12 ... 16, 18 ... 28 and 30 ... 40 mm with a polished and non-polished surface. CBPB is produced with a density of 1100 ... 1400 kg / m 3, humidity up to 9%, water absorption in 24 hours no more than 16% and swelling in thickness no more than 2%.

A photo. 11.11. Cement particle boards

Plates have a sufficiently high bending strength, for plates with a thickness of 8 ... 16 mm it is 9 ... 12 MPa, and for plates with a thickness of 26 ... 40 mm - 7 ... 9 MPa, thermal conductivity - 0.26 W / (m ° C). CBPB is used in wall panels, "slabs of coatings, in elements of suspended ceilings, ventilation ducts, in the construction of floors, as sill boards, cladding, facing and other building products.

Cork thermal insulation materials and products (slabs, shells and segments) are used for thermal insulation of building envelopes, refrigerators and surfaces of refrigeration equipment, pipelines at a temperature of insulated surfaces from -150 to + 70 ° C, for insulating ship hulls. They are made by pressing crushed cork chips, which are obtained as a waste in the production of closures from the bark of cork oak or the so-called velvet tree.

Due to its high porosity and the presence of resinous substances, cork is one of the best thermal insulation materials and is used for the production of plates, shells and segments.

A photo. 11.12. Cork slabs

Thermal insulation foams in the form of gas-filled plastics , as well as mineral wool and glass wool products are made using a polymer binder.

According to their physical structure, gas-filled plastics can be divided into three groups: cellular or foamy (foamed plastics), porous (foamed plastics) and honeycomb (honeycomb plastics). Polyfoam and honeycomb-based plastics are not only heat-insulating, but also a structural material. Thermal insulation materials made of plastics by the type of polymers used for their manufacture are divided into: polystyrene - porous plastics based on suspension (bead) or emulsion polystyrene; polyvinyl chloride - porous plastics based on polyvinyl chloride; phenolic - porous formaldehyde-based plastics.

Porization of polymers is based on the use of special substances that intensively emit gases and swell the polymer crushed when heated. Such intumescent substances can be solid, liquid and gaseous.

A photo. 11.13. Foam boards

Solid blowing agents of the greatest practical importance include carbonates, sodium and ammonium bicarbonates, which release CO 2 during decomposition. Liquid foaming agents include benzene, light fractions of benzene, alcohol, etc. Gaseous foaming agents include air, nitrogen, carbon dioxide, ammonia. To give elasticity to porous plastics, plasticizers are introduced into polymers - phosphates, phthalates, etc.

Porous and cellular plastics can be obtained in two ways: press and non-press. In the manufacture of porous plastics by the pressing method, a finely ground polymer powder with a blowing agent and other additives is compressed under a pressure of 15 ... 16 MPa, after which the sample taken (usually 2 ... 2.5 kg) is foamed, resulting in a material with a cellular structure.

In the manufacture of porous plastics by a non-pressurized method, a polymer with additives of a blowing agent, a hardener, etc. other components are heated in molds to an appropriate temperature. Heating melts the polymer, the blowing agent decomposes, and the evolved gas foams the polymer. A cellular material is formed with fine pores evenly distributed in it.

Plates, shells and segments of porous plastics are used for thermal insulation of building envelopes and surfaces of industrial equipment and pipelines at temperatures up to 70 ° C.

Products made of porous plastics on suspension polystyrene by density in a dry state, they are divided into grades D 25 and 35 with a bending strength of at least 0.1 ... 0.2 MPa, thermal conductivity of 0.04 W / (m ° C), humidity of no more than 2% by mass.

The same products on emulsion polystyrene have grades D 50 ... 200 in terms of density, ultimate strength in bending not less than 1.0 ... 7.5 MPa, thermal conductivity not more than 0.04 ... 0.05 W / (m ° С), humidity not more than 1% by weight. Porous plastic plates; made with a length of 500 ... 1000 mm, a width of 400 ... 700 mm, a thickness of 25 ... 80 mm.

A photo. 11.14. Cellular plastic

The most common thermal insulation materials made from plastics are polystyrene foam, mipora, etc.

Polystyrene foam - an excellent insulation in laminated panels, which goes well with aluminum, asbestos cement and fiberglass. It is widely used as an insulating material in the refrigeration industry, shipbuilding and railroad car building for the insulation of walls, ceilings and roofs in construction. Polystyrene foam made of beaded (suspension) polystyrene is a material consisting of fine-mesh spherical particles sintered together. There are voids of various sizes between the particles. The most valuable properties of polystyrene foam are its low density and low thermal conductivity. Polystyrene cellular plastic is produced in the form of plates or various shaped products, it is produced with a density of up to 60 kg / m 3, strength at 10% compression up to 0.25 MPa and thermal conductivity of 0.03 ... 0.04 W / (m ° C ). The most common slab size is 1200x1000x100 (50) mm.

Polyurethane foam used for thermal insulation of building envelopes and surfaces of industrial equipment and pipelines at temperatures up to 100 ° C.

It is obtained from polyester polymers by introducing pore-forming and other additives. Polyester polymers - This is a large group of artificial polymers obtained by condensation of polyhydric alcohols (glycol, glycerin, pentaerythritol, etc.) and mainly dibasic acids - phthalic, maleic, etc.

By density in a dry state, mats made of porous polyurethane are divided into grades D 35 and 50, their thermal conductivity in a dry state is 0.04 W / (m ° C), humidity is not more than 1% by weight. On the basis of porous polyurethane, hard and soft plates with a density of 30 ... 150 kg / m 3 and a thermal conductivity of 0.022 ... 0.03 W / (m ° C) are also produced. Mats made of porous polyurethane are manufactured in the form of plates 2000 mm long, 1000 mm wide, 30 ... 60 mm thick.

Photo 11.15. Polyurethane foam

M ipora is a porous material based on a urea-formaldehyde polymer. The raw material for the production of mipora is a urea-formaldehyde polymer and a 10% solution of sulfanaaphthenic acids (Petrov's contact), as well as fire retardant additives (a solution of ammonium phosphate of 20% concentration).

Photo 11.16. Mipora

Miporu used for thermal insulation of building structures, industrial equipment and pipelines at temperatures up to 70 ° C.

To obtain mipora, an aqueous solution of a urea-formaldehyde polymer and a foaming agent are loaded into an apparatus with a stirrer, which are vigorously stirred. The resulting foam is lowered into metal molds, which are sent to chambers, where the mass hardens at a temperature of 18 ... 22 ° C in 3 ... 4 hours.

The resulting blocks are sent for 60 ... 80 hours to a dryer with a temperature of 30 ... 50 ° C. Mipora is produced in the form of blocks with a volume of at least 0.005 m 3, ultimate compressive strength 0.5 ... 0.7 MPa, specific impact strength 400 MPa, water absorption 0.11% in 24 hours, thermal conductivity 0.03 W / (m ° C).

Sovelite thermal insulation materials.

P litas are made from dolomite lime and chrysolite asbestos. They withstand aging well and retain their thermal insulation properties for many years. They belong to the group of non-combustible substances, do not ignite and do not rot. Products do not contain corrosive agents.

The products are environmentally friendly.

Photo 11.17. Sovelite slabs

Sovelite heat-insulating plates are intended for thermal insulation of industrial equipment and pipelines, lining of steam boilers, thermal power plants, state district power plants, nuclear power plants, metallurgical and coke and gas industry enterprises, as well as pipes of large diameters at temperatures of insulated surfaces up to +600 ° C. This plate is a universal material. They can also be used for domestic purposes (protection of heating elements, grills, ten), etc.

Vermiculite (from Latin vermiculus - worm) - a mineral from the group of hydromica, which has a layered structure. It is a lightweight, free-flowing, odorless, highly porous material. Large lamellar crystals (vermiculite slabs) are golden yellow or brown in color. When heated to a temperature of 900–1,000 ° C, vermiculite swells, showing one of its most remarkable qualities: it increases in volume 4.5–12 times, turning into swollen vermiculite. This phenomenon is explained by the fact that when calcined, molecular water in the flakes and packs of vermiculite turns into steam, under the pressure of which the mica leaves always move apart in one direction, perpendicular to the cleavage of the mica.

AT
the vermiculite coalesced in this way, when cooled, retains the volume acquired by it with the thinnest gaskets of air instead of water vapor between the mica leaves, which gives the mineral many of its valuable properties, for example:

durability. The indisputable advantage of vermiculite is that its shelf life and action are not limited!

Photo 11.18. Vermiculite gravel

- lightness (0.065-0.130 g / cm 3 ), porosity and flowability ... When backfilling in the course of building insulation, it fills all voids of small diameter and any irregular shape;

- heat resistance. Melting point of vermiculite: 1350 ° C, operating temperature range: –260 ° C to + 1200 ° C. The material is resistant to high temperatures and open fire. When exposed to high temperatures, it does not emit gases, which is an undoubted advantage compared to other heaters;

- biological and chemical resistance ... The material is odorless. It is not subject to decomposition and rotting under the influence of microorganisms, prevents the formation of mold, and the appearance of insects and rodents is also excluded. Vermiculite does not interact with active chemicals in the environment.

- radiation protection. Vermiculite has the ability to reflect gamma radiation, as well as absorb radioactive substances - strontium-90, cesium-137, cobalt-58;

- environmental friendliness. Expanded vermiculite is absolutely non-toxic, environmentally friendly and radiation-safe modern material, free from carcinogenic impurities;

- low hygroscopicity and high water absorption ... Vermiculite has a high coefficient of moisture absorption (the volume of a material weighing 100 grams absorbs 400 ml of water) and, when wet, slightly loses its mechanical strength. After drying, the expanded vermiculite restores its previous heat and sound insulation and fire protection properties.

- high heat and sound insulation properties ... Due to its porous structure, expanded vermiculite is an excellent heat and sound insulator (sound absorption coefficient at a frequency of 1000 Hz in the range of 0.7–0.8), which allows it to be successfully used as a bulk insulation for floor and roof processing.

- profitability. Thermal insulation with the use of vermiculite provides significant cost savings, since expanded vermiculite in its energy-saving properties is 7–10 times superior to such traditional building materials as concrete or brick.

All of these properties determine the unusually wide possibilities of its use as a raw material for multipurpose purposes.

Expanded vermiculite has been successfully used in more than 200 industrial areas around the world. Due to the above qualities, expanded vermiculite is widely used in construction, nuclear, food and chemical industries, agriculture, metallurgy, shipbuilding.

The effect of using vermiculite as a non-combustible bulk material with excellent heat and sound insulation qualities has already been appreciated in construction.

The use of vermiculite in construction has clear advantages over the use of traditional materials. Thanks to this material, it is possible not only to reduce the weight of individual structures and improve their quality, but also to reduce the consumption of valuable materials, reduce the cost of foundations and increase the usable area of \u200b\u200bbuildings due to thin walls and partitions.

Expanded vermiculite possesses one of the lowest thermal conductivity indices among thermal insulation materials –0.04–0.062 W / m o C. A layer of backfilled vermiculite, having a thickness of only 12 cm, in brickwork provides thermal insulation that meets modern requirements.

Backfill insulation of attic and floor.

A 5 cm layer of vermiculite covering the attic floors reduces heat loss by 75%, and a 7.5 cm layer - 85%. A layer of vermiculite 10 cm thick will increase thermal protection by 92%! Often in attics, vermiculite is packed in bags, which makes it easy to dismantle the insulation if necessary.

Materials based on expanded vermiculite are effective in solving problems of fire and fire protection. The high melting point (1350 ° C), significant reflectivity and high heat resistance of vermiculite have become decisive factors in the creation of fire retardant vermiculite boards and blocks. This is an environmentally friendly material that, in addition to high fire resistance, has excellent sound absorption and thermal insulation performance.

The use of vermiculite at different stages of construction and in different qualities can solve several problems at once. Protection of structures from fire, preservation of heat, sound insulation both outside the building and inside between rooms and their improvement - in a word, today the range of application of vermiculite in construction is quite wide, and in the future, with the development of construction technologies, it will significantly increase.

Expanded perlite.

Perlite (obsidian hydroxide) is a rock of volcanic origin (in fact, glass of volcanic origin). Chemical composition: SiO 2 -75.5; A1 2 O 3 -13.6; Fe 2 About 3 - 1.0; CaO -1.0; MgO - 0.3; Na 2 O - 3.8; K 2 O - 4.8. A distinctive feature of perlite from other volcanic glasses is that when heated to a certain temperature in the range of its softening, it increases in volume from four to twenty times against its original volume.

This swelling process occurs due to the presence of two to six percent of bound water in natural perlite. When this rock heats up quickly above 870 ° C, it bursts like<поп корна>, as the bound water evaporates and creates countless tiny bubbles in the softened glazed particles. Since perlite is a form of natural glass, it is chemically inert and has a pH of approximately 7.

P erlite slabs-PC products are used for thermal insulation of building structures of residential, public and industrial buildings and structures.

Perlite-cement slabs are designed for thermal insulation of structures of public and industrial buildings and structures, as well as for thermal insulation of industrial equipment at an insulated surface temperature of up to 600 ° C (including boilers DKVR and DE).

Photo 11.19. Perlite slab

Perlite cement slabs are packaged in 8 slabs per pack. 1 cubic meter contains 80 slabs \u003d 10 packages.

Physical and mechanical characteristics of the plates: 1.Density, kg / m 3 320 ± 25;

2. Flexural strength, kgf / cm 2 2.5; 3. Thermal conductivity, W / m о С 0.070-0.120; 4. Temperature, ° C up to 600; 5. Size, mm 500x500x50.

Expanded clay gravel. Expanded clay is a lightweight porous building material obtained by firing clay or shale. Expanded clay gravel has an oval shape. Expanded clay crushed stone differs only in that its grains are mainly cubic in shape with sharp edges and corners. It is also produced in the form of sand - expanded clay sand (see Ch. 3).

Shungizite gravel. Shungizite is obtained by swelling of crushed schungite-containing rocks containing 1, 2 - 5% of shungite substance. This is a special form of carbon, consisting of particles with a size of 0.2 microns, evenly distributed in the silicate mass.

In the past, scientists divided all substances in nature into conditionally inanimate and living ones, including the kingdom of animals and plants among the latter. Substances of the first group are called mineral. And those that entered the second, began to be called organic substances.

What does this mean? The class of organic substances is the most extensive among all chemical compoundsknown to modern scientists. The question of which substances are organic can be answered as follows - these are chemical compounds that include carbon.

Please note that not all carbon-containing compounds are organic. For example, corbides and carbonates, carbonic acid and cyanides, carbon oxides are not included in their number.

Why are there so many organic substances?

The answer to this question lies in the properties of carbon. This element is curious in that it is able to form chains from its atoms. And yet the carbon bond is very stable.

In addition, in organic compounds, it exhibits a high valence (IV), i.e. ability to educate chemical bonds with other substances. And not only single, but also double and even triple (otherwise - multiples). As the bond multiplicity increases, the chain of atoms becomes shorter and the bond stability increases.

And carbon is also endowed with the ability to form linear, flat and three-dimensional structures.

That is why organic substances in nature are so diverse. You can easily check it yourself: stand in front of a mirror and look carefully at your reflection. Each of us is a walking aid for organic chemistry... Think about it: no less than 30% of the mass of each of your cells is organic compounds. The proteins that built your body. Carbohydrates that serve as a "fuel" and source of energy. Fats that store energy stores. Hormones that control organs and even your behavior. Enzymes that start chemical reactions inside you. And even the "source code", the DNA strands are all organic carbon-based compounds.

Composition of organic substances

As we said at the very beginning, the main building material for organic matter is carbon. And almost any element, combining with carbon, can form organic compounds.

In nature, hydrogen, oxygen, nitrogen, sulfur and phosphorus are most often present in the composition of organic substances.

The structure of organic substances

The variety of organic substances on the planet and the variety of their structure can be explained by the characteristic features of carbon atoms.

Remember that carbon atoms are capable of forming very strong bonds with each other by connecting in chains. The result is stable molecules. How exactly the carbon atoms are connected in a chain (arranged in a zigzag) is one of the key features of its structure. Carbon can combine both in open chains and in closed (cyclic) chains.

It is also important that the structure of chemicals directly affects their chemical properties. The way the atoms and groups of atoms in a molecule affect each other also plays a significant role.

Due to the structural features, the account of the same type of carbon compounds goes to tens and hundreds. For example, consider hydrogen carbon compounds: methane, ethane, propane, butane, etc.

For example, methane is CH 4. Such a combination of hydrogen with carbon under normal conditions is in a gaseous state of aggregation. When oxygen appears in the composition, a liquid is formed - methyl alcohol CH 3 OH.

Not only substances with different qualitative composition (as in the example above) exhibit different properties, but substances of the same qualitative composition are also capable of this. An example is the different ability of methane CH 4 and ethylene C 2 H 4 to react with bromine and chlorine. Methane is capable of such reactions only when heated or under ultraviolet light. And ethylene reacts even without lighting and heating.

Consider this option: the qualitative composition of chemical compounds is the same, the quantitative composition is different. Then the chemical properties of the compounds are different. As is the case with acetylene C 2 H 2 and benzene C 6 H 6.

Not the least role in this diversity is played by such properties of organic substances, "tied" to their structure, as isomerism and homology.

Imagine that you have two seemingly identical substances - the same composition and the same molecular formula to describe them. But the structure of these substances is fundamentally different, from which follows the difference between chemical and physical properties... For example, the molecular formula C 4 H 10 can be written as two different substances: butane and isobutane.

We are talking about isomers - compounds that have the same composition and molecular weight. But the atoms in their molecules are arranged in a different order (branched and unbranched structure).

Concerning homology - This is a characteristic of such a carbon chain in which each subsequent member can be obtained by adding one CH 2 group to the previous one. Each homologous series can be expressed by one general formula. And knowing the formula, it is easy to determine the composition of any of the members of the series. For example, homologues of methane are described by the formula C n H 2n + 2.

As the "homological difference" CH 2 is added, the bond between the atoms of the substance is enhanced. Take the homologous series of methane: its first four members are gases (methane, ethane, propane, butane), the next six are liquids (pentane, hexane, heptane, octane, nonane, decane), and then substances in a solid state of aggregation follow (pentadecane, eicosan, etc.). And the stronger the bond between carbon atoms, the higher the molecular weight, boiling point and melting point of substances.

What classes of organic substances are there?

Organic substances of biological origin include:

• proteins;
• carbohydrates;
• nucleic acids;
• lipids.

The first three points can also be called biological polymers.

A more detailed classification of organic chemicals covers substances not only of biological origin.

Hydrocarbons include:

• acyclic compounds:
  • saturated hydrocarbons (alkanes);
  • unsaturated hydrocarbons:
    • alkenes;
    • alkynes;
    • alkadienes.
• cyclic connections:
  • carbocyclic compounds:
    • alicyclic;
    • aromatic.
  • heterocyclic compounds.

There are also other classes of organic compounds, in the composition of which carbon combines with substances other than hydrogen:

• alcohols and phenols;
• aldehydes and ketones;
• carboxylic acids;
• esters;
• lipids;
• carbohydrates:
  • monosaccharides;
  • oligosaccharides;
  • polysaccharides.
  • mucopolysaccharides.
• amines;
• amino acids;
• proteins;
• nucleic acids.

Formulas of organic substances by class

Examples of organic substances

As you remember, in the human body, various kinds of organic substances are the basis of the foundations. These are our tissues and fluids, hormones and pigments, enzymes and ATP, and much more.

In the bodies of humans and animals, proteins and fats are prioritized (half of the dry mass of animal cells is proteins). In plants (about 80% of the dry mass of a cell) - for carbohydrates, primarily complex ones - polysaccharides. Including cellulose (without which there would be no paper), starch.

Let's talk about some of them in more detail.

For example, about carbohydrates... If it were possible to take and measure the masses of all organic substances on the planet, it would be carbohydrates that would win this competition.

They serve as a source of energy in the body, are building materials for cells, and also carry out a supply of substances. Starch serves for this purpose for plants, glycogen for animals.

Moreover, carbohydrates are very diverse. For example, simple carbohydrates. The most common monosaccharides in nature are pentoses (including deoxyribose, which is part of the DNA) and hexose (glucose you are familiar with).

As from bricks, on a large construction site of nature, polysaccharides are built from thousands and thousands of monosaccharides. Without them, or rather, without cellulose, starch, there would be no plants. And animals without glycogen, lactose and chitin would have a hard time.

Let's take a close look at proteins... Nature is the greatest master of mosaics and puzzles: from just 20 amino acids in the human body, 5 million types of proteins are formed. Proteins also have many vital functions. For example, construction, regulation of processes in the body, blood clotting (there are separate proteins for this), movement, transport of certain substances in the body, they are also a source of energy, in the form of enzymes they act as a catalyst for reactions, provide protection. Antibodies play an important role in protecting the body from negative external influences. And if a disorder occurs in the fine tuning of the body, antibodies, instead of destroying external enemies, can act as aggressors to the body's own organs and tissues.

Proteins are also divided into simple (proteins) and complex (proteids). And they have properties inherent only to them: denaturation (destruction, which you have noticed more than once when you boiled a hard-boiled egg) and renaturation (this property has found wide application in the manufacture of antibiotics, food concentrates, etc.).

We will not ignore and lipids (fats). In our body, they serve as a reserve source of energy. As solvents, they help the course of biochemical reactions. They participate in the construction of the body - for example, in the formation of cell membranes.

And a few more words about such curious organic compounds as hormones... They are involved in biochemical reactions and metabolism. These small, hormones make men men (testosterone) and women women (estrogen). They make us happy or sad (thyroid hormones play an important role in mood swings, and endorphins give a feeling of happiness). And they even determine whether we are "owls" or "larks." Whether you are willing to study late or prefer to get up early and do your homework before school, it is not only your daily routine that decides, but also some adrenal hormones.

Conclusion

The world of organic matter is truly amazing. It is enough to delve into its study just a little to take your breath away from the feeling of kinship with all life on Earth. Two legs, four or roots instead of legs - we are all united by the magic of Mother Nature's chemical laboratory. It forces carbon atoms to chain together, react and create thousands of such diverse chemical compounds.

You now have a quick guide to organic chemistry. Of course, not all possible information is presented here. You may have to clarify some points yourself. But you can always use the route outlined by us for your independent research.

You can also use the definition of organic matter, classification and general formulas of organic compounds given in the article and general information about them to prepare for chemistry lessons at school.

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