Throwing explosives are. Initiating cc
Propellant explosives include gunpowder and solid propellant. The main form of their explosive transformation is combustion. Gunpowder is a substance capable of regular combustion in parallel layers without oxygen access from the outside, while combustion occurs without turning into detonation under the conditions of a shot.
Gunpowder is divided into smoky and smokeless.
Smoke powder is used for the manufacture of expelling charges in fragmentation (jumping) and signal mines, for the manufacture of a igniter cord and igniters for reactive charges, fuses for hand grenades, remote fuse tubes, equipment for hunting ammunition, making firecrackers and other pyrotechnic products. The composition of the gunpowder is a mechanical mixture of potassium nitrate (75%), charcoal (15%) and sulfur (10%). Powder grains are black or slightly brown grains with a shiny surface. Depending on the size of the grains, gunpowder is divided into fine-grained and coarse-grained. Smoke powder is highly hygroscopic, dampens under the influence of moisture and becomes unsuitable for use at a moisture content of more than 2%. Dried (after dampening) gunpowder has reduced qualities. When storing and using black powder, due to its high flammability, special precautions must be observed.
Rice. 1. Forms of grains of smokeless powder (plates, tape, tube, cylinder with seven channels)
Smokeless powders are divided into pyroxylin, ballistic and cordite. They are used for the manufacture of charges for firearms: pyroxylin powders are mainly used in small arms cartridges, ballistic powders, as more powerful ones, are used in various artillery ammunition, as well as rocket launchers (solid jet fuels). In some cases, gunpowder is used (in the form of internal charges) for demolition work. The detonation of powder charges occurs if they are initiated by a sufficiently powerful intermediate detonator.
The shape of the grains of smokeless powder used in ammunition can be different: spherical, lamellar, ribbon, single-channel or multi-channel tubular, cubic or cylindrical with or without internal channels.
Stabilizers can be added to smokeless powders - to protect against chemical decomposition during long-term storage; phlegmatizers - to slow down the burning rate of the outer surface of the powder grains; graphite - to achieve flowability and eliminate grain sticking.
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Initiating explosives possess high sensitivity to external influences (impact, friction and fire). The explosion of relatively small amounts of initiating explosives in direct contact with blasting explosives causes the latter to detonate.
Due to these properties, initiating explosives are used exclusively for equipping means of initiation (detonator caps, igniter caps, etc.).
Initiating explosives (BBs) include:
· mercury fulminate(mercury fulminate) ;
· lead acid ( lead nitrate) ;
· teneres - lead trinitroresorcinate TNRS.
They are highly sensitive to external influences and require very careful handling.
EXPLOSIVES
Rice. 1. Classification of explosives
Initiating explosives are finely crystalline substances, as a rule, poorly soluble in water.
Mercury fulminate (mercury fulminate) is a fine-grained free-flowing substance of white or gray color. It is poisonous, poorly soluble in cold and hot water. When mercury fulminate is moistened, its explosive properties and susceptibility to the initial impulse decrease (for example, at 10% humidity, mercury fulminate only burns, and at 30% humidity it does not burn and does not detonate). It is used to equip primers - detonators and primers - igniters.
Explosive mercury in the absence of moisture does not interact chemically with copper and its alloys. With aluminum, it interacts vigorously with the release of heat and the formation of non-explosive compounds (aluminum is corroded). Therefore, the shells of explosive primers are made of copper or cupronickel, and not aluminum.
lead azide (nitric acid lead) is a finely crystalline substance white color, slightly soluble in water.
Lead azide is less sensitive to impact, friction and fire than mercury fulminate. Lead azide does not lose its ability to detonate when moistened at low temperatures, its initiating ability is much higher than that of mercury fulminate. It is used to equip caps - detonators.
Lead azide does not chemically interact with aluminum. But it actively interacts with copper and its alloys, so primer cases equipped with lead azide are made of aluminum, not copper.
Teneres (TNRS)- is a fine-crystalline non-flowing substance of dark yellow color; its solubility in water is negligible. The shock sensitivity of teneres is lower than that of mercury fulminate and lead azide; in terms of sensitivity to friction, it occupies a middle place between mercury fulminate and lead azide.
High explosives are used as intermediate and main charges in demolition work or for loading ammunition. The relatively low sensitivity of brisant explosives to mechanical and thermal effects, their sufficient safety, led to the convenience of their practical application.
Brisance is understood as the ability of an explosive to crush objects in contact with it (metal, rocks etc.)
By power, blasting explosives are divided into three groups:
· increased power;
· normal power;
· reduced power.
To explosives of increased power relate:
TEN; hexogen; tetryl.
They are crystalline substances that are insoluble in water.
TEN(tetranitropentaerythritol, penthrite) is used to equip blasting caps and detonating cords. Of all explosives, it is the most sensitive to mechanical influences, it explodes from a bullet shot, combustion can turn into detonation.
RDX(trimethylenetrinitroamine) is a finely crystalline substance of white color according to appearance difficult to distinguish with sugar; it has neither taste nor smell, it is non-hygroscopic, it does not dissolve in water. RDX in its pure form is poorly compressed, so it is often used with the addition of a small amount of a phlegmatizer (an alloy of paraffin with ceresin), which improves the compression of RDX and at the same time reduces its sensitivity to mechanical stress. It can be used in its pure form to equip detonator caps, the sensitivity to influences is slightly lower than that of Ten. In an alloy with tetryl, it is used in shaped charges; aluminum is added to the mixture to increase energy.
Shaped charge - an explosive charge with a conical, spherical or cone-shaped notch, the action of which is based on the cumulative effect.
Cumulative effect - (from the Latin - comulo I collect, accumulate) the concentration of the explosion in one direction.
Tetryl(trinitrophenylmethylnitroamine) is a bright yellow, odorless crystalline substance with a salty taste. Tetryl is non-hygroscopic and insoluble in water; it is quite easily pressed to a density of 1.60-1.65. It is used to equip blasting caps and intermediate detonators in various ammunition. The sensitivity is lower than in RDX, but a bullet can also explode from a shot, and combustion can turn into a detonation.
To explosives of normal power relate :
TNT; picric acid; plastic explosives (plastite-4).
TNT(trinitrotoluene, tol, TNT) - the main blasting explosive, used for demolition work and equipment of most ammunition. It is a crystalline substance from light yellow to light brown in color, bitter in taste. TNT is non-hygroscopic and practically insoluble in water; in production, it is obtained in the form of a powder (powdered TNT), small flakes (flaked TNT) or granules (granulated TNT). Flaked TNT is well pressed, up to a density of 1.6. It is practically safe to use.
The combustion of TNT in a confined space can turn into detonation. On the outdoors burns with a yellow, strongly smoky flame without explosion. Pressed and cast TNT does not explode and does not catch fire from the lumbago of an ordinary rifle bullet, it does not chemically interact with metals, pressed TNT detonates from a detonator cap.
TNT is insensitive to impact, friction and heat.
To perform demolition work, TNT is used in the form of pressed TNT blocks (Fig. 2):
large - 5x5x10 cm in size and weighing 400 gr.
small - 5 x 2.5 x 10 cm and weighing 200 gr;
drilling (cylindrical) - d = 3 cm, h = 7 cm, weighing 75 gr.
Each TNT stick has an incendiary socket for a detonator cap. To protect the checkers from external influences, they are covered with a layer of paraffin and wrapped in paper, on which another layer of paraffin is then applied. The location of the incendiary nest is marked with a black dot.
Supplied in wooden boxes. Each box contains 30 large and 65 small or 250 drill pieces. Such a box can be used as a concentrated charge weighing 25 kg without removing the lid. The lid has a hole covered with a removable bar, against which a large threaded checker is laid.
a - large (400 g);b - small (200 g);
c - drilling (75 g);
g - socket for detonator cap
Picric acid(trinitrophenol, melinite) is a yellow crystalline substance, bitter in taste. Picric acid dust is highly irritating to the respiratory tract. The sensitivity of picric acid to impact, friction and heat is slightly higher than that of TNT; from shooting with a rifle bullet, it can explode, and combustion turns into detonation. It is used to equip some ammunition.
Explosives according to the nature of their action are divided into the following groups.
· initiating explosives.
· Blasting (or crushing) explosives.
· Gunpowder.
· Pyrotechnic compositions.
Initiating explosives are such explosives that have a very high sensitivity and explode from a slight external mechanical (impact, friction) or thermal (laser beam, flame, heating, electricity) impact. These substances always detonate and cause the detonation of other explosives. Initiating explosives are used in small quantities to equip primers that create the initial impulse of the explosion.
High explosives are such explosives that, during an explosion, crush surrounding objects. They are much less sensitive to external influences than initiating explosives, and are usually detonated by the explosion of another explosive - a detonator. The detonator is an explosive charge that is more sensitive than the explosive of the main charge. The explosion of the detonator is carried out by the explosion of the primer with the initiating explosive (Fig. 3.1). First, the primer explodes from mechanical or thermal effects. The resulting shock wave causes an explosion of the detonator, which, exploding, causes the detonation of the main charge. High explosives are used as bursting charges for equipping mines, shells, explosive cartridges and serve to destroy and crush various objects and obstacles.
Rice. 3.1. High explosive detonation scheme:
1 - primer (initiating explosive); 2 - detonator;
3 - the main charge of high explosive
Gunpowders are such explosives, the nature of the explosion of which allows them to be used as a source of energy for the movement of projectiles, mines, bullets and rockets. The main type of explosive transformation of gunpowder under normal conditions is faster combustion. Gunpowder is not sensitive to external mechanical influences. The difference in the action of gunpowder and high explosive can be explained simple example shown in fig. 3.2. With the rapid burning of gunpowder (Fig. 3.2, a), the gas pressure increases gradually, the projectile moves with acceleration, crashing into threaded channels (which serve to give the projectile rotational motion in order to stabilize its trajectory). When a high explosive is detonated (Fig. 3.2, b) under the same conditions, gas formation occurs almost instantly, and the resulting gases destroy the barrel and chamber.
Rice. 3.2. Scheme of the action of an explosive on a projectile during combustion:
A - gunpowder; b - high explosive
Pyrotechnic compositions are mixtures of explosive and non-explosive substances. Their explosive properties are much less pronounced than those of conventional explosives. Pyrotechnic compositions have special properties (bright glow, smoke formation, flame color). They are used in lighting and incendiary cartridges, in salutes and fireworks, in smoke bombs, etc. Let us consider in more detail the main types of explosives.
Initiating explosives
Mercury fulminate, lead azide, and lead styphnate are most widely used as initiating explosives.
Mercury fulminate - mercury fulminate, is a finely crystalline white or gray powder. Resulting from an action ethyl alcohol to a solution of mercury in nitric acid. Unpressed mercury fulminate is extremely dangerous to handle because it is very sensitive. In compressed form, this substance is less dangerous and less sensitive to initial excitation. Under the influence of moisture, mercury fulminate easily loses its explosive properties. At 5%moisture, explosive properties decrease, at 10% - it only burns out, at 30% - it turns into an inert substance.
Lead azide is a lead salt of hydronitrous acid, is a white powder. It is less sensitive than mercury fulminate, but has an initiating power 10 times greater than mercury fulminate. It is not hygroscopic and does not dissolve in water. It is used in aluminum casings, as it does not react with aluminum. When interacting with copper, it forms copper azide, a very sensitive explosive.
Lead styphnate (THPC) is the lead salt of styphnic acid. THPC is a yellow crystalline solid. It is not hygroscopic, does not dissolve in water and does not interact with metals. Shock sensitivity is lower than lead azide, and higher to flame. Very sensitive to electrical discharges. Its initiating ability is lower than that of other initiating explosives.
Initiating explosives in mixtures with other substances form percussion compositions that are used to equip igniter caps and detonator caps. The recipes of some shock compositions are given in table. 3.2.
Explosive mercury in shock compositions gives an initial flash, antimonium is combustible and serves to enhance the force of the flame, Berthollet salt is an oxidizing agent that supports combustion. Primers-igniters are divided into cartridge and tube.
Cartridge primers-igniters are used in cartridges and primer bushings for small arms and artillery shells. They are ignited by the impact of the striker and give the initial impulse to ignite the warhead. The diagram of the cartridge primer-igniter is shown in fig. 3.3.
Table 3.2
Recipes of percussion compositions for rifle and pistol
primer igniters
Primer igniter |
Explosive mercury, wt.% |
Bertoletova salt, wt.% |
Antimonium, wt.% |
Mass, Mr. |
Pistol |
0.02 |
|||
Rifle |
0.03 |
|||
capsule sleeve |
0.025 |
Rice. 3.3. Scheme of a cartridge primer-igniter
It consists of a metal shell (cap) 1, made of brass or copper, into which the impact composition is pressed 2. From above, the impact composition is closed with a foil or paper circle 3. Tube igniters are used in tubes and fuses and serve to initiate the detonation of the detonator capsule .
The scheme of the tubular primer-igniter is shown in fig. 3.4.
Rice. 3.4. Scheme of the tubular primer-igniter:
1 - cap with a hole; 2 - shock composition;
3 - foil cup; 4 - foil diaphragm
To equip tubular igniter primers, the same percussion composition is used as for cartridge igniter primers, but its mass is (5 ÷ 10) times greater and amounts to (0.08 ÷ 0.2) g.
Detonator caps are divided into artillery and subversive. Artillery blasting caps are used in fuses of various shells, mines, air bombs and hand grants. The purpose of the blasting cap is to cause the detonator of the explosive charge of the high explosive with which the charge is equipped to detonate.
According to the nature of the initial impulse that excites the explosion, blasting caps can be of the following types.
· Nakolnye, act from pricked with a sting.
· Radiation, act from the beam (force) of fire of the igniter primer.
· Explosive blasting caps are designed to initiate the detonation of explosive charges. They operate from the force of fire (fickford cord) or from an electric fuse. The scheme of the explosive detonator cap is shown in fig. 3.5.
Rice. 3.5. Scheme of a subversive detonator capsule:
1-sleeve; lead 2-styphnate; 3-azide lead; 4-tetryl
High explosives
High explosives are used to equip artillery shells, mines, hand grenades, aerial bombs, and also to prepare subversive weapons. The main high explosives currently used are pyroxylin, nitroglycerin, TNT, melanite, RDX, dynamite, as well as various mixtures and alloys.
Pyroxylin (nitrocellulose) is a fibrous solid. It is obtained by processing plant fiber (cotton, flax, wood) with a mixture of nitric and sulfuric acid - nitration or nitration of fiber. Depending on the degree of nitration, the nitrogen content in pyroxylin may be different. The higher the nitrogen content, the higher the explosive properties of pyroxylin. Pyroxylin is highly hygroscopic. With a moisture content of up to 3%, pyroxylin is called dry, with a moisture content of more than 3% - wet. Dry pyroxylin is very dangerous - it explodes on impact and friction. With a moisture content of more than 25%, it is insensitive and safe to handle and store. Pyroxylin is used to make smokeless gunpowder and for demolition work. To equip ammunition - pyroxylin No. 1 (13% nitrogen), pyroxylin No. 2 (12% nitrogen) is used.
Nitroglycerin is a toxic clear oily liquid. It is obtained by treating glycerin with nitric and sulfuric acids. Very sensitive to shock, friction, concussion. It is not used in its pure form. It is used in the manufacture of smokeless powders as a solvent and for the preparation of dynamite in demolition work.
TNT (trinitrotoluene, tol, TNT) is a dark yellow solid fine-crystalline substance. It is obtained by processing toluene (a product of the dry distillation of coal) with nitric and sulfuric acid. TNT is insensitive to shock and heat, safe to handle and has a high storage stability (thin pieces retain the ability to explode even after decades of storage). In the open air, it burns with a smoky flame without explosion. TNT is the most common explosive. It is used to equip shells, mines, bombs and in demolition work.
Melinite (picric acid) is a dense crystalline mass of yellow-lemon color. It is obtained from carbolic acid by treating it with nitric and sulfuric acids. It is a stronger explosive than TNT. Disadvantage - the ability to form at the junction with metal shells chemical compounds(salts) - picrates, very sensitive to impact and friction. Used to prepare demolition charges.
RDX is obtained by treating urotropine and pentaerythritol with nitric acid. It is the most powerful high explosive. Hexogen - crystalline white matter, melts well and does not interact with metals. This is a more powerful explosive than TNT and melinite, but also more sensitive to mechanical stress. Phlegmatized RDX is used to equip armor-piercing and anti-aircraft shells and to make additional detonators.
Ammonites (explosives based on ammonium nitrate) are surrogate explosives that are made up of a mixture of ammonium nitrate, TNT, aluminum powder and other fillings. In terms of explosive action, they are inferior to TNT, are of little use for storage and are usually used only in war time(cheapness of raw materials). in the USSR during the Great Patriotic War ammonites were the main types of explosives. In peacetime, they are used in the national economy (undermining ice jams, coal seams in mines, etc.). For hand grenades, two types of ammonites are used - ammotol (a mixture of ammonium nitrate and TNT) and ammonal - a mixture of ammonium nitrate, high explosive and aluminum powder.
Plastite-4 (C-4) is a pasty mass of a cream or brown hue (less often bright orange). It consists of 80% powdered RDX and 20% plasticizer (which determines its properties). In appearance it resembles plasticine or wax, oily to the touch, plastic in temperature conditions from -30 ° C to +50 ° C. Just like TNT, it is very resistant to external influences - it can be crushed, cut, dropped, hit without dangerous consequences. The special properties of plastite determine its use for terrorist purposes - a plastite charge can be placed in any slot, rolled out in a thin layer into a letter, hidden in a structure of any configuration. It is used, most often, in some kind of shell (paper, bag) and attached with adhesive tape or tape to the object being exploded. Plastit-4 is supplied in standard 1 kg briquettes wrapped in paper. Plastite charges are used in the active armor of tanks, as well as for equipping anti-personnel mines MON-50.
Gunpowder
Gunpowder, or propellant explosives, are explosives for which the main form of explosive transformation is rapid combustion at a speedu in» (1÷10) m/s. Gunpowder is used as a source of energy for the movement of projectiles, bullets, mines, rockets. In addition, gunpowder is used as auxiliary means - igniters, gas generators, etc.
Gunpowder is divided into two groups - mechanical mixtures and colloidal type gunpowder.
Mechanical mixtures include the following compositions.
· Smoky (black) powder.
· Ammonium powder.
· Mixed high-energy materials and solid propellants.
The basis of all colloidal powders is pyroxylin. Depending on the nature of the solvent, colloidal powders are divided into the following groups.
· Pyroxylin gunpowder (on a volatile solvent).
· Nitroglycerin gunpowder (on a non-volatile solvent).
· TNT gunpowder (on a non-volatile solvent).
· Viscose powder (no solvent).
Mechanical mixtures
Smoky or black powder is a mechanical mixture of potassium nitrate, sulfur and charcoal (S, KNO3, C). For more than 500 years, black powder was the only explosive used in military affairs for the manufacture of charges in artillery and small arms and for demolition work. It was only in the second half of the 19th century that pyroxylin gunpowder was used instead of black powder for combat charges. The most optimal composition of smoky gunpowder was established in late XVIII century based on the works of M.V. Lomonosov. The composition of black powder is given in table. 3.3.
Table 3.3 Composition of black powder
|
This composition has not changed significantly to date. Saltpeter, when heated, easily releases oxygen, which is necessary for the combustion of coal and sulfur. With an increase in the content of saltpeter (up to 80%), the strength of the gunpowder and its burning rate increase. Coal in the composition of gunpowder is a combustible substance. |
With an increase in its content, the burning rate of gunpowder decreases. Sulfur is a cementing agent that binds saltpeter to coal, as well as a combustible substance that facilitates the flammability of black gunpowder (sulfur ignites at a lower temperature than coal). With an increase in the sulfur content, the burning rate and the strength of the gunpowder decrease. Smoky gunpowder is obtained by thoroughly mixing the crushed constituent parts, pressing the mixture and crushing the pressed cake into grains of various sizes. Gunpowder is sensitive to all types of mechanical impact (impact, friction, spark, etc.). When a bullet hits a powder charge, it almost always explodes. However, black powder does not detonate. During the combustion of smoky gunpowder, 45% of gaseous and 55% of solid products (smoke, soot in the bore) are formed. Currently, smoky gunpowder is not used in combat charges (low power of gunpowder, unmasking by smoke, danger in handling, hygroscopicity). It is used for the manufacture of igniters, as well as in the fuses of hand grenades.
Ammonium powder consists of ammonium nitrate (90%) and charcoal (10%). It is obtained by mixing the components and pressing in the form of elements of a given shape (rings, segments). Ammonium powder is a gray solid. Unlike black powder, all of its combustion products are gaseous. Sensitivity to mechanical influences is weak. Very hygroscopic and unsuitable for storage. It is used in wartime to replace (25÷35)% of the charge of pyroxylin gunpowder.
Mixed high-energy materials and mixed solid propellants (STRTs) are a wide class of energy-intensive substances used as energy sources in gas generators for various purposes and in solid propellant rocket engines. The composition of STRT includes a polymeric fuel-binder (butyl rubber), an oxidizing agent (ammonium perchlorate or ammonium nitrate) and a metallic fuel (aluminum powder).
colloidal gunpowder
Pyroxylin smokeless powder is made from a mixture of two grades of pyroxylin - No. 1 and No. 2 in different ratios. A mixture of these varieties is dissolved in an alcohol-ether mixture. The resulting homogeneous jelly-like mass is pressed through special filters. After cutting and drying, powder grains are obtained (tape, tubular, cylindrical, multi-channel gunpowder). Up to 3% of impurities are introduced into the composition of pyroxylin gunpowder - stabilizers, phlegmatizers and flame arresters. Stabilizers (diphenylamine) slow down the decomposition of gunpowder and increase the shelf life up to 20 years (without stabilizers, gunpowder is stored for 10 years). Phlegmatizers (camphor) reduce the burning rate. Flame arresters (rosin, dibutyl phthalate) reduce the flame when fired. They absorb some of the energy of the gunpowder and reduce the temperature of the combustion products. A great contribution to the development of smokeless powders was made by D.I. Mendeleev. Pyroxylin powder has a number of advantages over smoky gunpowder.
· Has higher energy.
· When burned, it does not form smoke and soot in the gun barrel (98.5% - gaseous products).
· Allows you to make charges of various sizes and shapes, which makes it possible to control the duration of the burning of the charge.
· It has low hygroscopicity.
· Retains its properties during long-term storage, insensitive to impact.
Nitroglycerin smokeless powder is made from pyroxylin, and nitroglycerin is used as a solvent. Depending on the brand of pyroxylin, ballistites (pyroxylin No. 2) and cordites (pyroxylin No. 1) are distinguished. The advantages of nitroglycerin powders over pyroxylin powders are as follows:
· Higher gunpowder strength values.
· Less time spent on their production - (5÷7) hours instead of several days.
· Low cost.
· Better preservation of properties during storage.
· They are used for mortars, multiple rocket launchers, solid fuel rocket engines.
TNT gunpowder is made from a mixture of pyroxylin and TNT. Gunpowder is obtained by special treatment at elevated temperature and under high pressure. It does not contain a volatile solvent, so TNT gunpowder is more stable in quality than pyroxylin and nitroglycerin gunpowder. AT recent times is gaining more and more use.
Viscose powder (solvent-free powder) is nitrated and stabilized pre-compacted cellulose. These gunpowders are still poorly understood. They are used to make charges for rifles and pistols.
Pyrotechnic compositions
Pyrotechnic compositions are used to equip special projectiles, bullets, rockets, and so on. Many pyrotechnic compositions are explosives, but their explosive properties are much less pronounced than those of conventional explosives. The energy released during the combustion of pyrotechnic compositions is spent not on the production of mechanical work, but on the formation of a pyrotechnic effect (illumination of the area, initiation of a fire, etc.). Pyrotechnic compositions are mechanical mixtures of fuel, oxidizing agent, cementing agent and special impurities. Aluminum, magnesium, their alloys, gasoline, kerosene, oil, turpentine, starch, etc. are used as fuel. Salts of nitric, perchloric and chloric acids, metal oxides (iron oxide, barium peroxide, manganese dioxide and etc.). As cementing agents - drying oil, rosin, shellac, artificial resins (bakelite, etc.). They serve to bind the composition and give it mechanical strength. Special impurities serve to color the flame or smoke.
According to the nature of the application, pyrotechnic compositions are divided into the following groups.
· Lighting.
· Incendiary.
· Signal.
· Smoke.
· Tracers.
Lighting compositions are used to equip lighting cartridges, shells and bombs and serve to illuminate the area or individual objects. The most commonly used composition is 18% aluminum, 4% magnesium, 75% barium nitrate, 3% drying oil. Lighting compositions are pressed into a cylindrical shell, on one side of which an igniter composition (smoke powder) is pressed. The diagram of the lighting cartridge is shown in fig. 3.6. The characteristics of some lighting compositions are given in table. 3.4.
Table 3.4
Characteristics of some lighting compositions
ammunition |
Power of light, thousand candles |
Action time, s |
Cartridge |
||
projectile |
||
aerial bomb |
Incendiary compositions are used to equip bullets, shells and bombs. They are divided into three groups.
· Thermite-incendiary compositions containing metal oxides as an oxidizing agent.
· Incendiary compositions - oxygen-containing mixtures (salts).
· Incendiary compositions that do not contain an oxidizing agent.
Rice. 3.6. Scheme of the lighting cartridge:
1-sleeve; 2-capsule; 3-charge of black powder;
4-igniter composition; 5 – lighting composition; 6-wad
Thermite-incendiary compositions are made on the basis of thermite (a mixture of 25% aluminum and 75% iron oxide) with a combustion temperature of about 2500 ° C. In its pure form, thermite is not used, since it has a small ignition radius. An example of a thermite incendiary composition for a 76 mm projectile is given in Table. 3.5.
Table 3.5
Composition of thermite incendiary projectile
Substance |
barium nitrate |
Potassium nitrate |
iron oxide |
Aluminum |
Magnesium |
Cementer |
Incendiary compositions with an oxidizing agent in the form of various salts give high temperature burning and flammable. These compositions are used to equip incendiary small-caliber projectiles and bullets. Incendiary compositions without an oxidizing agent burn due to atmospheric oxygen. As an example, let's take an aerial bomb with an electron body (an alloy of 92% magnesium and 8% aluminum) filled with a thermite composition. When such a bomb burns, a temperature of up to (700 ÷ 900) ° C develops and hot sparks are formed, which scatter over a long distance.
Incendiary compositions include hardened fuel (napalm) - a gelatinous mass obtained by mixing stearic acid and an alcoholic solution of caustic soda with petroleum products. Easily ignited and gives a bright volumetric flame.
Self-igniting substances - white phosphorus and mixtures with it ignite easily in air ( T » 1000°C). An example of the use of this substance are bottles for setting fire to tanks, which were widely used during the Great Patriotic War ("Molotov Cocktail"). They contain fuel and phosphorus dissolved in carbon disulfide. When the solvent evaporates, phosphorus ignites in air, and carbon disulfide vapors are ignited first, and then the main fuel.
Signal compositions give when burning a colored flame, for example, red, yellow, green, white. Signal trains with flames of blue color do not apply because blue flame hard to see at a distance. To obtain a red flame, strontium compounds are introduced into the composition, green flame - barium compounds, yellow - sodium salts, white - barium and potassium salts. To increase the brightness, up to 5% aluminum or an aluminum-magnesium alloy is added to the signal compositions. Signal compositions are used in 26 mm cartridges (rocket launchers). The height of the rocket is 90 m, the burning time of the charge is 6.5 s, the luminous intensity of the flame is 10,000 candles.
Smoke compositions are designed to mask objects and smoke enemy battle formations. They are used to equip smoke bombs, shells, mines. According to the nature of the smoke formation process, they are divided into three groups.
· Smoke formation as a result of combustion.
· Smoke formation as a result of the interaction of the composition with air moisture.
· Smoke generation as a result of thermal sublimation.
The first group includes white phosphorus. At a temperature of +50°C, it ignites and burns with the formation of thick white smoke. The second group includes sulfur trioxide, tin tetrachloride, chlorosulfonic acid. The third group includes smoke bombs (Ershov's bombs), which consist of potassium nitrate (10%), ammonium chloride (40%), bartholite salt (20%), charcoal (10%), naphthalene (20%). During the combustion of the Ershov mixture, ammonium chloride and naphthalene are sublimated, the condensation of the vapors of which leads to the formation of smoke.
Tracer compositions serve to indicate the flight path of a bullet or projectile (white or red trace). Examples of tracers are given in table. 3.6.
Pyrotechnic compositions, along with the examples of military applications discussed above, are widely used as charges for equipping rockets and pyrotechnic devices during salutes, organizing colorful fireworks and other festive spectacles. Used in this pyrotechnic charges are a combination of different compositions.
Table 3.6
Composition of tracer mixtures
tracer composition |
Substance |
|
White track |
barium nitrate |
|
Magnesium |
||
Shellac |
||
Red track |
Strontium nitrate |
|
Magnesium (aluminum) |
||
Cementer |
47. Depending on the application, explosives are separated
Depending on the application, explosives are divided into three large groups: initiating, crushing, propelling (gunpowder).
Initiators Explosives differ in that the usual form of their explosive transformation is complete detonation. Initiating explosives are the most sensitive to external influences and easily explode from a minor impact, prick, flame beam, etc. They are mainly used for the manufacture of various igniters and the equipment of capsules used to initiate explosive transformations of other explosives. For equipping cartridge igniter primers for the most part an impact composition is used (a mixture of mercury fulminate, berthollet salt and antimony).
Initiating explosives include:
Explosive mercury;
lead azide;
TNRS (lead trinitroresorcinate, lead styphnate).
Crushing (blasting) Explosives are called those that, with relative safety in circulation, detonate without fail. They are blown up with capsules of initiating explosives. The rate of explosive transformation of blasting explosives reaches several hundred meters per second. They are used as explosive charges for shells, aerial bombs, mines and grenades.
Brisant explosives are divided into 3 groups:
a) High power explosives ( TEN (tetranitropentaerythritol, pentrite); hexogen (trimethylenetrinitroamine); tetryl (trinitrophenylmethylnitroamine);
b) BB normal power(trotyl (trinitrotoluene, tol, TNT); picric acid (trinitrophenol); plastic explosives (plastids);
in) Low power explosive(ammonium nitrate; ammonium nitrate explosives (ammonites, dynamites).
Also, brisant explosives include nitroglycerin and others.
Nitroglycerine is an oily colorless liquid. The properties are rather unstable and can detonate on impact, so it is used infrequently.
Dynamite is an absorbent material soaked in nitroglycerin. After that, it is wrapped in glossy paper. Over time, drops of liquid nitroglycerin appear on its surface, and it becomes less stable. When the nitroglycerin starts to leak out of it, the bars turn into a greasy mess and become very dangerous to handle. Most other explosives also "sweat", and wet spots on the bag are a sure sign that it may contain an explosive device.
Throwable BB, or gunpowder , are called those whose explosive transformations are in the nature of rapid combustion, occurring mostly at a speed of several meters per second. Gunpowder is used in all types of firearms as a source of energy needed to communicate the bullet (projectile) movement. Therefore, of all types of explosives, gunpowder is of the greatest interest for shooting, which requires, at least in general terms, familiarization with their properties and features.
Gunpowder composition, physical and chemical properties are divided into smoky(mechanical mixtures) and smokeless(colloidal).
Smoky, or black powder, in comparison with other types of currently known propellant explosives, is ballistically disadvantageous and unproductive in terms of work; after the explosion, its powder gases increase their volume only 280-300 times compared to the initial volume of the charge.
Can also be used as charges. TNT checkers (75 g, 200 g and 400 g), boxes with TNT blocks weighing 25 kg, plastic explosive briquettes or other standard military charges (concentrated, elongated, cumulative). Depending on the purpose of the explosive device, containers with smoky and smokeless powder can be used as a charge.
abstract
New initiating explosives free of lead and mercury
Introduction
initiating explosive azide oxydiazo compound
Initiating explosives are those explosives that have a very high sensitivity and explode from a slight external mechanical (impact, friction) or thermal (laser beam, flame, heat, electric current) impact. These substances always detonate and cause the detonation of other explosives. Initiating explosives are used in small quantities to equip primers that create the initial impulse of the explosion. For initiating explosives, the transition from combustion to detonation occurs quickly, at a distance not exceeding a few millimeters from the place of ignition. The efficiency of initiating explosives is the higher, the shorter the section of transition from combustion to detonation and the higher the detonation velocity. If you place a little initiating explosive on top of a high explosive charge and set it on fire, then its explosion will produce such a strong blow, as a result of which the high explosive will also explode.
There are two main areas of application of TRS:
) For excitation of detonation in BVV charges.
) For sensitization of igniter compositions intended for ignition of powder charges or initiation of detonation in the charges of the main IVV.
As initiating explosives, mercury fulminate, lead azide and lead styphnate are most widely used, but the abstract deals exclusively with explosives that do not contain lead and mercury.
1.
Diazonium salts
Diazonium salts with oxidizing anions have explosive properties, and almost all aryldiazonium perchlorates are IVV. High initiating ability, combined with satisfactory performance characteristics, has 2,4 - dinitro-diazobenzene perchlorate (2,4 - dinitrophenyldiazonium perchlorate).
The starting product for its production is 2,4-dinitroaniline.
4 - Dinitrodiazobenzene perchlorate is an effective IVV, having the following properties: t flash, 5 sec = 215 about C; \u003d 1.65 g / cm 3, the minimum charge on tetryl is 0.007 g (for comparison: explosive mercury - 0.35 g, and lead azide - 0.025 g).
4 - Dinitrodiazobenzene perchlorate decomposes in the light, however, photodecomposition products form a light-protective film, therefore only the surface layer decomposes and the initiating ability of the charge does not change. The product is thermally stable: the explosive properties of the substance were preserved after holding charges for two years at 80 ° C. In the 40s of the last century, dinitrodiazobenzene perchlorate successfully passed experimental testing as a TRS for industrial CD. In subsequent decades, repeated attempts were made to find practical applications for this phenyldiazonium perchlorate, including as a low-toxic IVV for commercial CD and ED. However, the widespread use of 2,4 - dinitrodiazobenzene perchlorate is hampered by two significant drawbacks: hygroscopicity, the technical product is overpressed.
2. Oxydiazo compounds
Many oxydiazophenols exhibit explosive properties. The greatest practical importance as an IVV in the series of diazophenols is 2-diazo - 4,6 - dinitrophenol, C 6 H 2 N 4 O 5 , (diazodinitrophenol, DDNP, DDNP ) . Molecular weight 210.1, oxygen balance -60.9%.
Diazodinitrophenol is not hygroscopic, slightly soluble in water, soluble in methanol and ethanol, freely soluble in acetone, nitroglycerin, nitrobenzene, aniline, pyridine and acetic acid. On the sunlight getting dark. Density of DDNF min. \u003d 1.719 g / cm 3, heat of formation 321 kJ / mol.
In the literature, both open and cyclic structures of the diazophenol fragment have been proposed for DDNF.
According to quantum chemical calculations, the most probable for this compound in the gas phase is the following open structure:
The brisance of DDNF is ~95% of the brisance of TNT, the explosiveness in the lead block is 326 cm 3 /10 g. the minimum charge on tetryl is 0.13 g, that is, less than that of mercury fulminate. DDNP is less sensitive to shock than lead azide. The detonation velocity of DDNF is 4400 m/s at a charge density of 0.9 g/cm 3 , 6600 m/s at a charge density of 1.5 g/cm 3 , 6900 m/s at a charge density of 1.6 g/cm 3 . The explosive decomposition of DDNF is described by the following equation:
C 6 H 2 N 4 O 5 à 42 CO + 2.52 CO 2 + 2.94 H 2 O +
3.15 H 2 + 7.67 C + 7.87 HCN + 16.1 N 2
Diazodinitrophenol is obtained by diazotization of picramic acid with sodium nitrite in 10% sulfuric acid according to the scheme:
The target product precipitates from the reaction mass in the form of a red-brown precipitate. The disadvantage of the method of synthesis of DDNP is the presence of a large number of toxic Wastewater. The raw material base of DDNP is quite wide, since the starting material - picramic acid, which is synthesized by partial reduction of picric acid with sodium sulfide, is a commercial product (it is used in the synthesis of a number of dyes).
DDNF as an IVV has the following disadvantages: it is overpressed, it does not have a high enough heat resistance, the compound quickly darkens in sunlight, and it also stimulates the immune response, which contributes to the development of an allergic syndrome.
Diazodinitrophenol has found application as an IVV for industrial initiation agents in the United States and China, as well as a component of low-toxic shock compositions for small arms igniter primers, including sports and hunting weapons in Europe and North America
. Azides
Silver azide
,
AgN 3 - mol. weight 149.9. Initiating explosive. It darkens under the influence of light. Insoluble in water and organic solvents. Non-hygroscopic. Soluble in aqueous ammonia and hydrogen fluoride. Crystallizes from aqueous ammonia. Destroyed by nitric acid. The density of silver azide crystals is 5.1 g/cm 3 . The energy of the crystal lattice is 857.69 kJ/mol. The enthalpy of formation (DH f o) is + 279.5 kJ / mol, according to other sources + 311 kJ / mol. The detonation velocity at maximum density is 4.4 km/s. The volume of gases during detonation is 244 l / kg. The explosiveness is 115 cm 3 /10 g. Silver azide is sensitive to impact and friction. The product is not repressed. In terms of initiating ability, silver azide is noticeably superior to lead azide. The speed of detonation of silver azide is 3830 m/s at a density of 2.0 g/cm 3 . The change in the detonation velocity of silver azide with increasing charge density is described by the equation:
D r \u003d D 0 + 770 (r - r 0) m / s, where r 0 \u003d 2 g / cm 2.
The detonation pressure of silver azide depends on the charge density:
P = (40r - 61) . 10 2 MPa
The softening point of silver azide is 250 0 C. Silver azide completely melts at 300 0 C (with decomposition). Rapid heating to 300 0 C causes an explosion of silver azide. The disadvantage of silver azide is poor compatibility with antimony sulfide (Sb 2 S 3) and tetrazene, which are included in most formulations of prick compositions. Silver azide is obtained by mixing solutions of sodium azide and water-soluble silver salts. In a number of countries (Great Britain, Sweden), silver azide is produced in small quantities by the reaction
AgNO 3 + NaN 3 AgN 3 + NaNO 3
An alternative technology for the production of bulk silver azide by the reaction
3 + N 2 H 4 + NaNO 2 AgN 3 + NaNO 3 + 2H 2 O
Silver azide is used to a limited extent as a TRS in small-sized initiation devices, where lead azide is not effective, and in heat-resistant blasting caps. With an increase in the dimensions of the initiating charge of the capsule, the picture changes: silver azide becomes less effective compared to IVV lead azide, since its detonation velocity is significantly lower. The practical use of silver azide is constrained by high friction sensitivity, difficulty in obtaining in bulk form, and high cost.
cadmium azide
, Cd(N 3) 2 mol. weight 196.46 - white crystalline substance initiating explosives. It dissolves and hydrolyzes with water. Hygroscopic. The density of single crystals is 3.24 g/cm 3 . The heat of explosion, according to various estimates, is in the range of 2336-2616 kJ / kg, T pl. \u003d 291 0 С (with decomp.), T aux. (5 s) = 360 0 C. The detonation velocity of cadmium azide is 3760 m/s at a density of 2.0 g/cm 3 . The change in the detonation velocity of lead azide with increasing charge density is described by the equation:
D r \u003d D 0 + 360 (r - r 0) m / s, where r 0 \u003d 2 g / cm 2.
The detonation pressure of lead azide depends on the charge density:
P = (59r - 106).10 2 MPa
Cadmium azide is sensitive to impact and friction. The initiating ability of cadmium azide is greater than that of lead azide. Cadmium azide is obtained by reacting cadmium hydroxide or carbonate with an excess of HN 3 .
Cd(OH) 2 + 2 HN 3 à Cd(N 3) 2 + 2 H 2 O 3 + 2 HN 3 à Cd(N 3) 2 + CO 2 + H 2 O
thallium azide
,
TlN 3 , they say. weight 246.41 - yellow crystalline powder. Initiating BB. It is poorly soluble in water and organic solvents. The energy of the crystal lattice is 685.1 kJ / mol, the enthalpy of formation (DH f o) = 234 kJ / mol, Tm = 334 0 C, Tvsp. (1 s) = 500 0 C. Thallium azide is less sensitive to impact and friction than lead azide. The initiating ability of thallium azide is noticeably less than that of lead azide. Toxic. Poor compatibility with nitro compounds. A convenient laboratory method for obtaining thallium azide is the reaction of aqueous solutions of thallium perchlorate and sodium azide.
TlClO 4 + NaN 3 à TlN 3 + NaClO 4
Thallium azide is poisonous. Thallium azide is not used in industry as IVV. Finds limited use in scientific research.
. organic peroxides
Acetone peroxide (acetone diperoxide, 1,1,4,4 - tetramethyl - 2,3,5,6 - tetraoxacyclohexane)
, (C 3 H 6 O 2) 2 - mol. mass 148, white crystalline primer. Acetone diperoxide dissolves well in organic solvents: benzene, acetone, chloroform, diethyl ether, petroleum ether. Density \u003d 1.33 g / cm 3, T pl. \u003d 132 - 133 0 C, T aux. (5 s) about 180 0 C. Very volatile substance. The vapor pressure of acetone diperoxide is 17.7 Pa at 25 0 C. Acetone diperoxide is less sensitive to impact than lead azide.
Its initiating ability is greater than that of mercury fulminate, but less than that of lead azide. According to other data, a charge of 0.5 g of acetone diperoxide, pressed into a sleeve from KD No. 8 at a pressure of 30 MPa, did not initiate a RDX charge.
Acetone diperoxide is obtained by reacting acetone with Caro's acid (a solution of hydrogen peroxide in concentrated sulfuric acid) in an acetic anhydride medium.
Tricycloacetone peroxide (cyclotriacetone peroxide, 1,1,4,4,7,7-hexamethyl-2,3,5,6.8.9-hexaoxacyclononane)
, C 9 H 18 O 6 , mol. mass 222.1 - initiating explosive.
(CH 3) 2 C - O - O - C (CH 3) 2
Cyclotriacetone peroxide forms colorless crystals in the form of prisms. The density of the crystal is 1.272 g/cm 3 (X-ray), it dissolves well in benzene, acetone, chloroform, ether, petroleum ether, pyridine, glacial acetic and nitric acids. It dissolves in ethyl alcohol when heated, does not dissolve in water and aqueous solutions of ammonia. Forms at least six polymorphic forms. Hydrolyzed by dilute acids. T pl. is 97 0 C. The energy of formation of cyclotriacetone peroxide is 90.8 kJ/mol. Oxygen balance -151.3%. Heat of explosion 5668 kJ/kg. Explosiveness 250 cm 3 /10 g. Detonation velocity at a density of 0.92 g / cm 3 3750 m / s, at a density of 1.18 g / cm 3 - 5300 m / s, explosiveness in a lead block 250 cm 3 /10 d. Cyclotriacetone peroxide does not corrode copper, aluminum, zinc, tin, iron; lead corrodes. The impact sensitivity of cyclotriacetone peroxide is higher than that of lead azide; in terms of initiating ability, cyclotriacetone peroxide is inferior to lead azide: its minimum charge for hexogen is 0.1 g (compression pressure 30 MPa) and 0.16 g for TNT.
The product is obtained from acetone, acidified with sulfuric acid, which is treated with perhydrol (a dilute solution of hydrogen peroxide).
Cyclotriacetone peroxide is a kinetic product of acetone oxidation, and acetone diperoxide is a thermodynamic product, that is, during storage, a trimer can turn into a dimer. Because of their high volatility and tendency to sublimation, acetone peroxides have no practical value as IVV.
5. Acetylides
In a neutral or slightly acidic medium, mixed salt Ag 2 C 2 . AgNO 3 - initiating explosive, molecular mass 409.7, density 5.369 g / cm 3 (X-ray), decomposition temperature about 220 0 C, explosiveness in a lead block 136 cm 3 / 10 g, heat of explosion 1888 kJ / kg. The detonation velocity is 2250 m/s at a density of 2.51 g/cm 3 and 4540 m/s at a density of 3.19 g/cm 3 . The initiating ability is greater than that of mercury fulminate and depends on the method of obtaining the double salt. Minimum charge Ag 2 C 2 . AgNO 3 equal to 0.005 g for heating element, 0.07 g for tetryl and 0.25 g for TNT. Salt is not overpressed. In practice, it is not used as a TRS.
. Salts of dinitrobenzfuroxan
(KDNBF) is a low-toxic "pseudo-initiating" substance.
6 - Potassium dinitro-7-hydroxy-7-hydrobenzfuroxanide
The melting temperature of the potassium derivative is 174 0 C, the flash point with a 5-second delay of KDNBF is 207 - 210 0 C, the temperature of the beginning of intensive decomposition is about 190 0 C. The density of a single crystal is 2.21 g/cm 3 . The friction sensitivity of KDNBF is the same as that of TNRS. In terms of shock sensitivity, the adduct (Meisenheimer's s-complex) is superior to lead azide, but inferior to mercury fulminate.
You can get KDNBF from o-nitroaniline according to the following scheme:
KDNBF is used in low-toxic igniter pyrotechnic compositions instead of TNRS together with a non-toxic oxidizing agent KNO 3 and additives that increase the susceptibility of compositions to impact and friction. Pilot production of the KDNBF product began in the United States shortly after World War II. A significant disadvantage of the KDNBF compound is its insufficiently high heat resistance.
At the beginning of the 21st century, it was obtained and studied as a possible low-toxic substitute for TNRS potassium salt
4,6 - dinitro-7-hydroxybenzofuroxan
(KDNGBF),
Potassium salt 4,6 - dinitro-7-hydroxybenzofuroxan
Unlike the KDNBF compound , which is the Meisenheimer complex, the substance KDNGBF is a simple salt.
Potassium salt exists in monohydrate and anhydrous form. The density of KDNGBF lies in the range of 1.94 - 2.13 g/cm 3 . The temperature of the start of intensive decomposition of the salt KDNGBF is about 270 0 C, the substance retains its operational properties after heating at 120 0 C for 90 days. The substance KDNGBF is a fast-burning compound with good heat resistance and fairly safe handling.
KDNGBF is obtained from the available meta-bromoanisole according to the following scheme:
At the final stage of the reaction, the azide ion replaces bromine, and the methoxy group is replaced by hydroxyl.
Since the beginning of 2009, in the USA, KDNGBF salt has been approved for use in low-toxic pyrotechnic compositions for initiation agents.
7. Coordination metal complexes with an outer sphere
The increased requirements for technological, operational and environmental safety of initiating explosives have led researchers to search for energy-intensive compounds in the series complex salts of d-metals .
In the United States, it was proposed to use as an explosive for safe means of initiation perchlorate pentaammine (5-cyano-2H-tetrasolato-N 2) cobalt (III)
(CP)
Perchlorate pentaammine (5-cyano-2H-tetrasolato-N 2) cobalt (III), CP
The density of single crystals of the CP complex is 1.97 g/cm . The section of the transition from combustion to detonation (with a charge diameter of 5 mm) is approximately 4.5 mm, the time for the transition from combustion to detonation is about 75 μs, the detonation velocity is 7.18 km/s at a density of 1.75 g/cm 3 . The dependence of the detonation velocity of the SR on the charge density is described by the following equation:
D = 0.868 + 3.608r,
where D is the detonation velocity (km/s),
r is the initial charge density of the CP (g/cm3).
All measurements were made for a charge diameter of 6.35 mm.
The sensitivity to shock of the SR complex is less than the sensitivity of the heating element. The metal complex is poorly compatible with standard BVV - octogen. SR is slightly hygroscopic.
The technological process for obtaining SR, developed by Unidinamic (USA), consists of a number of stages.
First, carboxypentaamminecobalt (III) nitrate (CPCN) is obtained by the reaction:
2 Co(NO 3) 2 + NH 3 (H 2 O) + 2 (NH 4) 2 CO 3 + 1/2O 2 a
à 2 NO 3 + 2 NH 4 NO 3 + H 2 O
The CPCN synthesis process involves bubbling air through a stirred pasty mass of ammonium carbonate and cobalt nitrate in ammonia solution for 96 hours to oxidize Co 2+ to Co 3+ . After aeration is completed, the bright red reaction mass is heated to 70-75 0 C to dissolve the CPCN salt, filtered from impurities and cooled to 0 0 C. The precipitated product is washed with alcohol and dried.
The resulting substance does not have explosive properties.
To obtain aquapentaamminecobalt (III) perchlorate (APCP), the CPCN complex is treated with a large excess of perchloric acid.
NO 3 + 3 HClO 4 à (ClO 4) 3 + CO 2 + HNO 3
The process takes place in two stages.
Purification of the complex CP-raw produced from acidified with perchloric acid solution of ammonium perchlorate. Purification removes the main part of the "amide complex" and almost all unreacted cyantetrazole, as well as residues nitric acid. The desired fractional composition of SR is obtained by adding a hot aqueous solution of purified SR to chilled propanol-2. After filtration, the product is sieved and dried at 60 - 65 0 C for several hours. For one deposition, about 1 kg of commercial SR is obtained, suitable for equipping means of initiation.
This reaction is the key one in the entire process of SR synthesis.
The substance SR is proposed for use in electric detonators. However, the complex is toxic, which prevents its widespread use.
Perchlorate
pentaammine (5-nitrotetrazolato-N 2) cobalt (III)
(NCP, NCT) has found limited use in Russia as an explosive for safe initiation. The tubing material, in comparison with traditional TRS, has a reduced sensitivity to static electricity discharges. Density of monocrystals of the NKT complex is 2.03 g/cm 3 , the temperature of the beginning of intensive decomposition is 265 0 С (TG/DTA). Thermostating in sealed conditions at 200°C for 6 hours does not change its properties. The section of the transition from combustion to detonation at the tubing with a diameter of 6.25 mm at r = 1.60-1.63 g/cm 3
is about 4.5 mm. The detonation velocity of the tubing substance is 6.65 km/s at a density of 1.61 g/cm 3 . The minimum charge for hexogen in the sleeve from KD No. 8 is 0.15-0.20 g. The sensitivity to impact of the tubing complex is less than the sensitivity of the heating element. The product is non-hygroscopic. The NCT compound is less toxic than the SR complex.
Perchlorate pentaammine (5-nitrotetrazolato-N 2) cobalt (III), tubing
The technological process of obtaining tubing is similar to the technological process of preparing CP. The target complex is synthesized from the complex salt of АРСР and the sodium salt of 5-nitrotetrazole in an aqueous perchloric acid solution at 95 - 100 0 C for three hours. The process of cleaning the tubing complex from impurities does not fundamentally differ from the method of preparing commercial CP.
As one of the most promising explosives for safe means of initiation, including laser ones, is considered perchlorate tetraammine-cis-bis (5-nitro-2H-tetrazolato-N 2) cobalt (III)
(BNCP):
Perchlorate tetraammine-cis-bis (5-nitro-2H-tetrazolato-N 2) cobalt (III), (BNCP)
The density of a single crystal of the BNCP substance is 2.05 g/cm 3
, detonation velocity at a density of 1.79 g/cm 3
equal to 7117 m / s, the temperature of the beginning of intensive decomposition (at a heating rate of 20 ° C / min.) 269 ° C (DSC). The minimum RDX charge in the cartridge case from CD No. 8 is 0.05 g, the time for the transition from combustion to detonation is about 10 μs. The impact sensitivity of the BNCP complex is greater than that of the SR substance, but less than that of the PETN. The BNCP substance is obtained by the reaction:
The reaction takes place at a temperature of about 90°C and a holding time of about 3 hours. In the synthesis of BNCP, the starting cobalt tetraamminate was used in the form of ClO 4 perchlorate or NO 3 nitrate, the synthesis and properties of which are described in detail in the literature. The sodium salt of 5-nitrotetrazole was prepared either by the Sandmeyer reaction in the presence of copper salts (see Section 6.2) or by the following non-catalytic process:
The reaction is carried out in two stages. At the first stage, 5-aminotetrazole is diazotized with an excess of sodium nitrite in sulfuric acid. At the second stage, the reaction mass is neutralized with sodium carbonate, water is distilled off, and the target product is extracted with acetone from a mixture of salts. Sodium nitroterazolate is isolated as a crystalline hydrate, which is less hazardous to handle than the anhydrous salt.
The yield of the BNCP complex was 50-60%, considering the complex cobalt carbonate. The BNCP complex has found application in the pyroautomatic systems of missile systems in the United States as part of semiconductor and optical detonators.
Complex perchlorates of cobalt (III) aminates with tetrazole ligands are heat-resistant, non-hygroscopic, and safer than regular IVVs. These substances do not contain highly toxic heavy metals: mercury, lead, cadmium. The complex cation of amminecobalt (III) has low toxicity. But the composition of these cobalt complexes includes a biologically dangerous perchlorate anion, which is probably a teratogen (causes deformities during the prenatal development of a child) and acts on the thyroid gland. Therefore, complex perchlorates of cobalt (III) aminates with azole ligands cannot be classified as "green" initiating substances.
Meanwhile, the search for low-toxic energy-saturated substances for initiation agents led researchers from the Los Alamos National Laboratory (USA) at the beginning of the 21st century to obtain copper and iron complex salts of 5-nitrotetrazole, presented as ideal "green" initiating substances. The complexes have the following gross formula:
(Cat) 1-4 [M II (NT) 3-6 (H 2 O) 3-0],
where Cat \u003d NH 4, Na, M \u003d Fe, Cu
The authors of the study argue that the performance properties of these metal complexes are easily controlled by the nature of Cat and M, as well as the content NT - in a molecule. It was found that the complexes
Na 2 and Na 2
are safer TRS than AC and THRS. Some Characteristics of Complex Nitrotetrazoles FeII and Cu II are given in the table.
Properties of metal complex nitrotetrazolates Fe II and Cu II
At high pressures complexes are repressed. Tests have shown that the experimental CD and ED, containing the initiating charges of the Na 2 complex or Na 2 salt, did not differ in their characteristics from the regular ones equipped with lead azide. industrial production these metal complexes apparently do not exist at present. The fact that nickel hydrazinates with oxidizing anions have a short combustion-to-detonation transition region and can be used to initiate energy-saturated organic substances has been known for about a hundred years. However, these compounds are inferior in efficiency to lead azide, so until recently the possibility of their practical application in CD and ED has not been considered. The search for environmentally friendly energy-rich compounds that do no harm environment, forced researchers to return to this class of metal complex salts. One of the promising "green" energy-saturated compounds capable of replacing lead azide in industrial hydrazine nickel(II) nitrate
Ni(N 2 H 4) 3 (NO 3) 2 .
The density of a single crystal of the complex is 2.129 g/cm 3 . The density of the pressed charge of the Ni(N 2 H 4) 3 (NO 3) 2 complex is 1.55 g / cm 3 (at a pressing pressure of 20 - 40 MPa) and about 1.70 g / cm 3 (at a pressing pressure of 60 - 80 MPa). Charges of complex nickel nitrate are repressed at a pressure of more than 60 MPa. The flash point of complex nickel hydrazinate at a 5-second delay is 167°C. The onset temperature of decomposition and the onset temperature of intense decomposition, determined by differential thermal analysis (DTA), are 210°C and 220°C, respectively. The activation energy for the thermal decomposition of complex nickel nitrate is 78 kJ/mol (according to the results of TG/DTA analysis) and 89 kJ/mol (based on T flash). The detonation velocity of the metal complex is 7.0 km/s at a charge density of 1.7 g/cm 3 . The minimum charge of Ni (N 2 H 4) 3 (NO 3) 2 in the sleeve from KD No. 8 according to the heating element is 0.15 g. Complex nickel nitrate is obtained from available raw materials, in standard equipment in aquatic environment at a temperature of 65 0 C according to the equation: Ni(NO 3) 2 *6H 2 O + 3N 2 H 4 *H 2 O à Ni(N 2 H 4) 3 (NO 3) 2 + 9H 2 O Hydrazine nickel(II) nitrate Complex nitrate Ni(N 2 H 4) 3 (NO 3) 2 (pink substance) is not hygroscopic and practically insoluble in water, it is compatible with structural materials. The metal complex is resistant to sunlight and X-rays, insensitive to static electricity charges. China has developed an industrial technology for the production of complex nickel hydrazine. Complex nickel nitrate Ni(N 2 H 4) 3 (NO 3) 2 is used in China in environmentally friendly industrial CA and ED. Complex hydrazine nickel(II) azide
(N 3) 2 is another candidate to replace lead azide in "green" industrial PDs and EDs. The density of a single crystal of the complex is 2.12 g/cm 3 . The flash point of complex nickel azide at a 5-second delay is about 193 0 C. The temperature of the start of decomposition is 186 0 C (DTA). The product decomposes in two macrokinetic steps. The activation energy of the first stage of thermal decomposition is 142.6 kJ/mol, the second stage is 109.2 kJ/mol. The detonation velocity of the metal complex is 5.42 km/s at a charge density of 1.497 g/cm 3 . The minimum charge (N 3) 2 in the sleeve from CD No. 8 for hexogen is 0.045 g. The sensitivity to impact of the nickel azide complex is less than the sensitivity of the heating element. Complex azide is obtained from nickel nitrate or acetate, hydrazine hydrate and sodium azide according to the equation: Ni(NO 3) 2 *6H 2 O + 2N 2 H 4 *H 2 O + 2NaN 3 а (N 3) 2 + 8H 2 O + 2NaNO 3 Hydrazine nickel(II) azide Ni(CH 3 COO) 2 *4H 2 O+2N 2 H 4 *H 2 O+2NaN 3 a (N 3) 2 +6H 2 O+2CH 3 COONa Hydrazine nickel(II) azide Complex nickel azide is a green polycrystalline product. The technical product is not hygroscopic, insoluble in water. In China, a pilot-industrial technology for obtaining complex nickel azide has been developed, which makes it possible to safely obtain up to 5 kg of the product in one deposition. Tests of EDs containing hydrazinenickel(II) azide as a primary charge ,
showed that they are not inferior in reliability to regular EDs and can be used in the mining industry. Conclusion
There are many TRS that do not contain lead and mercury, but in our time they are not so widely used (they cannot be standard) due to various shortcomings. But in some cases they have more advantages, and their use is the most beneficial and appropriate. In conclusion, it should be said that all over the world they are striving to find low-toxic energy-saturated substances. For example, the substance SR is proposed for use in electric detonators. However, the complex is toxic, which prevents its widespread use. The widespread use of 2,4 - dinitrodiazobenzene perchlorate is hampered by two significant drawbacks: hygroscopicity, the technical product is overpressed. DDNF as an IVV has the following disadvantages: it is overpressed, it does not have a high enough heat resistance, the compound quickly darkens in sunlight, and it also stimulates the immune response, which contributes to the development of an allergic syndrome. List of used literature
1. Ilyushin M.A. Energy-saturated substances for means of initiation: tutorial/ M.A. Ilyushin, I.V. Tselinsky, A.A. Kotomin, Yu.N. Danilov - St. Petersburg: SPbGTI(TU) - 2013 -177 p. Ilyushin M.A. Metal complexes in high-energy compositions (monograph) / ed. I.V. Tselinsky / M.A. Ilyushin, A.M. Sudarikov, I.V. Tselinsky and others - St. Petersburg: Leningrad State University named after A.S. Pushkin, 2010. - 188 p. 3. Loskutova L.A. Sensitivity of energetic materials to detonation impulse: guidelines/ L.A. Loskutova, M.A. Ilyushin, A.V. Smirnov, I.V. Bachurin - St. Petersburg: SPbGTI (TU), 2011. - 23c. Loskutova L.A. Flash point of condensed energy-intensive substances: guidelines / L.A. Loskutova, A.S. Kozlov, M.A. Ilyushin, I.V. Bachurin - St. Petersburg: SPbGTI (TU), 2007. - 20 p. Loskutova L.A. Sensitivity of solid explosive systems to mechanical influences: guidelines / L.A. Loskutova, A.S. Kozlov - St. Petersburg: SPbGI (TU), 2007 - 22 p.
- The displacement is called the vector connecting the start and end points of the trajectory The vector connecting the beginning and end of the path is called
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