RU2315774C1 - Chitosanium perchlorate, method for its preparing and power-consuming composition comprising thereof - Google Patents

Abstract

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention describes chitosanium perchlorate of the following formula: C₆O₄H₉NH₃ClO₄. This compound shows such properties as explosion-proof, absence of toxicity, resistance to moisture and heating, mechanical effects and possesses high oxidizing and binding properties. This allows its using in power-consuming compositions in mixture with chitosanium dodecahydro-clozododecaborate wherein it functions as a binding agent. The quantitative ratio between chitosanium dodecahydro-clozododecaborate in the composition is determined by required regimen of combustion: the more content of chitosanium perchlorate the higher activity of the composition.

EFFECT: improved preparing method, valuable properties of composition.

3 cl, 1 dwg, 4 ex

Description

The invention relates to the chemistry of chitosan and polyhedral closo-hydroborates, which can be used as active components in energy-intensive compositions, the method for their preparation and use.

Salts of chitosan, C ₆ O ₄ H ₉ NH ₂ , with acetic, hydrofluoric, hydrochloric, sulfuric and other acids are known. Their formation is due to the donor – acceptor interaction of a pair of nitrogen electrons of the NH ₂ groups of chitosan with the free 1S orbital of the H ⁺ cations of these acids with complete proton transfer to the amino group and the formation of the molecular chitosan cation, C ₆ O ₄ H ₉ NH ₃ ⁺ . Some of the salts of chitosan are quite soluble in water (acetate, fluoride, chitosania), some poorly (chloride, chitosan sulfate). Soluble salts form viscous, clear solutions that are shelf stable. Upon evaporation of the solvent, chitosan salts form a solid compact product (in the form of films, plates, bulk materials), easily crushed into powder. It does not contain crystalline hydrate water, is slightly hygroscopic, thermally stable enough, insensitive to mechanical stress (shock, friction, pricking, etc.), non-toxic. (Plisko E.A., Nudga L.A., Danilov S.N. // Advances in Chemistry. 1977. T. XLVI. Issue 8. P.1470).

Known salts of chitosan are obtained by its interaction with acids or metabolic reactions between salts of chitosan and acids or salts of the corresponding acids.

For example, a highly soluble chitosan acetate is obtained by dissolving chitosan in acetic acid, taken in a molar ratio of 1 to 1, according to the following reaction equation:

C ₆ O ₄ H ₉ NH ₂ + CH ₃ COOH = C ₆ O ₄ H ₉ NH ₃ CH ₃ COO

The resulting solution was evaporated to dryness and solid chitosan acetate was obtained.

Poorly soluble chitosan sulfate is obtained by the exchange reaction between chitosan acetate and sulfuric acid or soluble sulfate, according to the following reaction equation:

2C ₆ O ₄ H ₉ NH ₃ CH ₃ COO + H ₂ SO ₄ (Na ₂ SO ₄ ) = (C ₆ O ₄ H ₉ NH ₃ ) ₂ SO _{4 ↓} + 2CH ₃ COOH (2CH ₃ COONa)

The precipitated chitosania sulfate is separated by filtration, washed with water and dried.

A disadvantage of the known chitosan salts is the low oxygen content and the absence of even weakly expressed oxidizing properties. Apparently, for this reason, nothing is known about their use as active oxidizing components of energy-intensive compositions.

A fairly wide range of metal perchlorates and molecular cations (ammonium, hydrazonium, hydroxylammonium, nitronium, etc.) are known that are used as solid oxygen sources in energy-intensive compositions for various purposes (V.Ya. Rosolovsky. Anhydrous perchlorates and perchloromethalates: synthesis, structure, properties In the collection of scientific papers of IONKh under the editorship of N. Kuznetsov, Chemistry of Inorganic Hydrides. - M.: Nauka, 1990. P.126).

Perchlorates are prepared by reacting perchloric acid, HClO ₄ , with oxides, hydroxides, carbonates and chlorides of metals and molecular cations; electrochemical oxidation of chlorates; metabolic reactions of NaClO ₄ with the corresponding salts (Chemical Encyclopedic Dictionary. Editor-in-chief IL Knunyants - M .: Soviet Encyclopedia, 1983. 435 pp.).

The disadvantages of the known perchlorates are hygroscopicity and the formation of crystalline hydrates (LiClO ₄ × 3H ₂ O, NaClO ₄ × H ₂ O, Mg (ClO ₄ ) ₂ × 6H ₂ O), rather low thermal stability, explosiveness and sensitivity to mechanical stress and heat, toxicity (perchlorates of hydrazonium, hydroxylammonium, nitronium). Although known perchlorates have a high oxygen content, the listed disadvantages lead to the complication of their use in energy-saturated materials.

Closest to the claimed compound is hydrazonium perchlorate composition N ₂ H ₅ ClO ₄ . The compound is a colorless crystal, readily soluble in water and polar non-aqueous solvents. With rapid heating, it decomposes with a flash or explosion, and with slow heating in a vacuum it dissociates into the starting compounds. Very toxic. Used in rocket fuel as an oxidizing agent. Hydrazonium perchlorate is obtained by the interaction of hydrazine and perchloric acid, taken in a molar ratio of 1 to 1 (Chemical Encyclopedia. T.1. Editor-in-chief IL Knunyants - M .: Soviet Encyclopedia, 1988. 547 S.). Isolation from solutions is carried out either by drying at moderate temperatures, because the compound is sufficiently thermally unstable, or by salting out with a suitable solvent.

The objective of the invention is to obtain a non-toxic, explosion-proof, resistant to moisture, heat and mechanical stress and at the same time possessing high oxidizing properties of the compound, which can be used in energy-intensive compositions.

The problem is solved by chitosan perchlorate of the composition C ₆ O ₄ H ₉ NH ₃ ClO ₄ and a method for its preparation, including interaction in an aqueous solution of chitosan and perchloric acid, HClO ₄ , taken in an equimolar ratio, and subsequent isolation of the compound by drying the resulting solution at a temperature of 105 -110 ° C to constant weight or salting out with a suitable solvent.

The method is carried out according to the following reaction equation:

C ₆ O ₄ H ₉ NH ₂ + HClO ₄ = C ₆ O ₄ H ₉ NH ₃ ClO ₄

A viscous solution is obtained, which is then dried in air at ordinary temperature or at a temperature of 105-110 ° C.

The implementation of the method under conditions of an excess of perchloric acid leads to contamination of the obtained compound with perchloric acid, since it is noticeably non-volatile, removing its excess is difficult, and strong heating can lead to decomposition and flash of the mixture. The lack of acid leads to contamination of the resulting compound with chitosan, which must be separated, since impurity chitosan plays the role of ballast and lowers the oxidizing properties of chitosan perchlorate.

As studies have shown, chitosanium perchlorate - C ₆ O ₄ H ₉ NH ₃ ClO ₄ - has an extremely high solubility in water. For example, when the diluted solution is dried, a syrupy liquid is formed, which, upon further drying, passes into a colorless, uniform, transparent, cellophane-like film, without the formation of crystals or particles of chitosan perchlorate in it. Chitosania perchlorate can be isolated in the form of hard coatings, films, plates, bulk materials, easily crushed into powder. The salt does not contain crystalline hydrate water, is slightly hygroscopic, does not explode upon impact, friction, or other mechanical impact, and is non-toxic. When heating pure chitosan perchlorate, its quiet decomposition occurs without flares and explosive emissions, starting from 180 ° C. According to diffractometry data (DRON - 3.0, λCuK _α ), the compound is X-ray amorphous, which is typical for chitosan salts, and there are no reflections that the initial chitosan gives.

The drawing shows the IR spectra (IFS EQUINOX-55S) "a" - pure chitosan; "B" - chitosania perchlorate; "C" - dodecahydro-closo-dodecaborate chitosania. It can be seen that the spectrum of chitosanium perchlorate, taken from a film of chitosanium perchlorate (see drawing, b), contains a number of bands in the region of 1518, 1616, 3187 and 3519 cm ^-1 , characterizing the anion of chitosania (see drawing, c) (V.I. .Saldin, L.N. Ignatyev, Yu.M. Nikolenko. Reactions of dodecahydro-closo-dodecaborate acid with chitosan. // Journal of Structural Chemistry. 2006. V.47. No. 1. P.41-46) and which are absent in IR spectrum of pure chitosan (see drawing, a). The band in the region of 1098 cm ^-1 refers to the stretching vibrations of the ClO ₄ ^- anion, confirming its occurrence in the structure of the claimed compound.

Chitosania perchlorate exhibits the properties of an oxidizing component. So when grinding a mixture of chitosanium perchlorate in the form of its concentrated solution with such well-known combustible components of pyrotechnic and incendiary compositions as red phosphorus, and / or sulfur, and / or antimony sulfide, Sb ₂ S ₃ and subsequent drying, actively oxidized compact materials are obtained. Moreover, depending on the ratio of chitosan perchlorate to the combustible component, decomposition can take place both in the form of rapid combustion and explosion.

The advantage of C ₆ O ₄ H ₉ NH ₃ ClO ₄ over other known oxidizing agents, including perchlorates used in oxidizing mixtures, is the combination of oxidizing properties with the properties of a binder in this compound. Wet mixtures of chitosan perchlorate with flammable components are safe to use. A uniform distribution of the components is achieved by grinding the components and provides a sufficiently high viscosity of the concentrated solution With ₆ O ₄ H ₉ NH ₃ ClO ₄ , which eliminates the sedimentation of solid particles of the components. It is easy to form the product of the desired shape from the obtained plastic material. When these mixed compositions dry, a dense material is formed, which eliminates such an unsafe operation as pressing.

The use of compounds of closo-hydroboric anions, including dodecahydro-closo-dodecaborate of chitosania (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ (paragraphs of the Russian Federation No. 2158221), is known as energy-intensive components of energy-saturated materials. Due to the structural features of this compound — a fine molecular distribution of fuel (B ₁₂ H ₁₂ ^2- anions) and oxidizer (oxygen-containing chitosan groups), free access of oxygen and air to the combustion centers, swelling when heated with a sharp increase in the volume of burning material — are created favorable conditions for the rapid and complete occurrence of a solid-gas-phase combustion reaction. When ignited (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ ignites and burns vigorously with the formation of a black residue, which is a mixture of soot and boric anhydride and / or boric acid. However, since the compound has a relatively high flash point (about 300 ° C), this limits the possibility of its use as an energy-intensive component of energy-saturated materials.

To lower the flash point and increase the activity and completeness of combustion of energy-saturated compositions, a composition based on dodecahydro-closo-dodecaborate of chitosania (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ and chitosan perchlorate C ₆ O ₄ H ₉ NH ₃ ClO _{4 is} proposed. in an effective ratio determined by the desired nature of combustion.

Unlike individual C ₆ O ₄ H ₉ NH ₃ ClO ₄ and (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H _{12, the} claimed composition exhibits much higher energy activity. As the studies showed, the composition has a lower flash point (about 240 ° C) and a higher rate and completeness of combustion compared with the individual components. This is explained by the structure of the resulting composition, which is a uniformly distributed mixture of oligomers of chitosan salts B ₁₂ H ₁₂ ² - and ClO ₄ ^- anions.

ClO ₄ ^- anions are richer in oxygen and more active oxidizing agents than oxygen-containing chitosan groups. Therefore, when heating such compositions, the ignition of (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ occurs at a lower temperature, and its combustion is much more intense than in an individual form. The activity of the compounds is determined by the ratio of B ₁₂ H ₁₂ ^2- anions, which act as fuel, and ClO ₄ ^- anions of chitosanium perchlorate, which exhibit oxidizing properties. Since chitosania dodecahydro-closo-dodecaborate is very oxygen deficient, with an increase in chitosan perchlorate, the activity of the claimed compounds increases. The specific composition of the composition is determined depending on the desired combustion mode (slow, fast or explosion): if necessary, explosive in nature increases the concentration of chitosanium perchlorate in the mixture, and to ensure a more relaxed nature of combustion, increase the concentration of chitosan dodecahydro-closo-dodecaborate.

The compositions are prepared by jointly concentrating a solution of chitosanium perchlorate with a finely divided powder of chitosan dodecahydro-closo-dodecaborate. Uniform distribution of the salts is achieved not only by the high viscosity of the resulting solution, but also because the B ₁₂ H ₁₂ ^2- anions are electron-deficient systems, unlike ClO ₄ ^- anions containing in its structure a large number of oxygen donor atoms having unshared electron pairs. Therefore, when water evaporates, the oligomers of the salts approach each other due to the donor – acceptor interaction of B ₁₂ H ₁₂ ² and ClO ₄ ^- anions, which is confirmed by a shift in the characteristic bands of stretching vibrations of the initial anions in comparison with individual compounds. As a result, a uniform polymer composition with a uniform distribution of oxidizing agent and fuel is formed.

The chemical composition of the claimed chitosan perchlorate C ₆ O ₄ H ₉ NH ₃ ClO ₄ is determined as follows.

The chlorine content is found by calcining samples with an excess of sodium peroxide, Na ₂ O ₂ in a nickel bomb (Babko AK, Pyatnitsky IV Quantitative analysis. - M .: Higher school, 1968. P.419). The reaction product is leached with water and the Cl ^- anion ^is determined in the form of AgCl by a known method (Babko A.K., Pyatnitsky I.V. Quantitative analysis. - M.: Higher School, 1968. P. 19).

For analysis of the remaining elements and groups that are part of chitosanium perchlorate, a parallel sample of the sample is treated with an excess of sodium hydroxide, as a result of which chitosan precipitates and sodium perchlorate passes into the solution according to the following reaction equation:

C ₆ O ₄ H ₉ NH ₃ ClO ₄ + NaOH = C ₆ O ₄ H ₉ NH _{4 ↓} + NaClO ₄ + H ₂ O (4)

The chitosan precipitate was separated by filtration, washed with water and dried at 105 ° C to constant weight. Analysis of the obtained chitosan for carbon, hydrogen and nitrogen is carried out by known methods of microanalysis of organic substances (Mazor L. Methods of organic analysis. M .: Mir, 1986. P.147).

The invention is illustrated by the following examples.

Example 1. The starting material used was chitosan synthesized according to the technology of Combio LLP (Vladivostok, TU 15-01 482-88) in the form of a powder (lamellar particles not more than 0.3 mm across) product. Its elemental composition after drying at 105 ° C to a constant weight is (wt.%): C - 44.8; H - 6.9; N - 8.6; O is 39.7. This corresponds to a 98% degree of chitin deacetylation and a conditional molecular weight of 162.02 a.u. To 300 ml of a solution containing 1.06 g (10.52 mg mol) of perchloric acid, 1.72 g (10.62 mg mol) of chitosan was added. After dissolving the bulk of chitosan, which takes several minutes, a viscously colorless solution is heated to accelerate the diffusion of acid to unreacted chitosan particles. Then the heated solution is filtered, separating a small excess of chitosan and mechanical impurities. For a higher yield of the target compound, the precipitate formed is washed with 50 ml of water, since the solution is viscous and remains in the form of a film both on the walls of the glass and in the porous partition of the glass filter. Part of the solution is poured with a thin layer (1.5-2 mm) into a glass Petri dish and evaporation is carried out at 100 ° C. As the solution is concentrated, its viscosity increases. The target chitosania perchlorate is obtained in the form of a transparent, colorless thin coating with high adhesion to glass. When evaporating solutions poured with a thick layer (more than 8 mm), the coating is quite easily separated from the surface in the form of a sufficiently strong and flexible colorless transparent film. In total, as a result of the final drying at 105 ° C to constant weight, 2.76 g (10.50 mg mol) of C ₆ O ₄ H ₉ NH ₃ ClO ₄ are obtained, which corresponds to its 99.8% yield in perchloric acid. The resulting compound decomposes calmly, without flash and explosive emissions, at temperatures above 180 ° C.

Calculated for С ₆ O ₄ Н ₉ NH ₃ ClO ₄ , wt.%: С - 27.54, Н - 4.63, N - 14.01, Cl - 13.55, O - 48.92.

Found for С ₆ O ₄ Н ₉ NH ₃ ClO ₄ , wt.%: С - 27.51, Н - 4.66, N - 14.05, Cl - 13.58.

Example 2. To 20 ml of a creamy solution containing 1.44 g (3.04 mg mol) of freshly obtained finely divided (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ , add 0.40 g (1.52 mg mol) C ₆ O ₄ N ₉ NH ₃ ClO ₄ (molar ratio 2: 1) and mix thoroughly. A homogeneous viscous white solution resulting from the dissolution of solid chitosanium perchlorate is poured into a Petri dish and dried to constant weight at a temperature of 110 ° C. Obtain 1.82 g of a whitish translucent product. Flash point 240 ° C. Decomposition takes place in the form of rapid burning with a spread of burning material.

Example 3. 1.17 g (2.50 mg mol) of dry fine (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H _{12 is} poured into 20 ml of a viscous solution containing 0.66 g (2.50 mg mol) C ₆ O ₄ H ₉ NH ₃ ClO ₄ (molar ratio 1: 1), thoroughly mixed and dried, as described in detail in example 1. Obtain 1.82 g of the product, which corresponds to 100% yield of the target product. Flash point 240 ° C. Compared with the composition obtained in example 1, the combustion is more vigorous.

Example 4. 5 g of a wet pasty product containing 1.30 g (2.76 mg mol) of freshly obtained finely divided (C ₆ O ₄ H ₉ NH ₃ ) ₂ B ₁₂ H ₁₂ is added to 40 ml of a viscous solution containing 1.45 g (5.52 mg mol) With ₆ O ₄ H ₉ NH ₃ ClO ₄ (molar ratio 1: 2), and mix thoroughly. The resulting creamy, homogeneous, viscous white solution is poured into a Petri dish and dried to a constant weight, as described in detail in Example 1. 2.75 g of product are obtained, which corresponds to almost 100% yield of the target product. Flash point 240 ° C. The resulting composition demonstrates the fastest and most energetic combustion compared with the compositions obtained in the two previous examples.

Claims (3)

1. Chitosan perchlorate composition With ₆ O ₄ H ₉ NH ₃ ClO ₄ . 2. A method of producing chitosanium perchlorate of composition C ₆ O ₄ H ₉ NH ₃ ClO ₄ , comprising reacting in an equimolar ratio of perchloric acid and chitosan and then isolating the compound in solid form by drying the resulting solution at a temperature not exceeding 110 ° C or salting out with a suitable solvent. 3. Composition for energy-saturated compositions based on dodecahydro-closo-dodecaborate chitosania (C ₆ O ₄ H ₉ NH ₃ ClO ₄ ) ₂ B ₁₂ H ₁₂ , characterized in that it further comprises chitosanium perchlorate C ₆ O ₄ H ₉ NH ₃ ClO ₄ in an effective amount.

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