Chitosan chromate, synthesis method thereof and energy-intensive composition containing said chitosan chromate
SUBSTANCE: method of producing chitosan chromate involves reaction of soluble chitosan salts with metal chromates in ratio of 2 moles of the chitosan cation to 1 mole of chromate anion or with metal bichromates in ratio of 4 moles of the chitosan cation to 1 mole of the bichromate anion. The solid chitosan chromate residue formed is then separated and dried at temperature not higher than 150°C. The invention discloses an energy-intensive composition based on chitosan dodecahydro-closo-dodecaborate containing an effective amount of chitosan chromate. The quantitative ratio in the energy-intensive composition is by the required combustion mode: the higher the content of chitosan chromate, the higher the activity of the composition.
EFFECT: invention enables to obtain a chemical compound having sufficiently high oxidative properties and suitable for use in energy-intensive compositions which burn without emitting harmful gaseous products.
3 cl, 5 ex
The invention relates to the chemistry of carbon, specifically to obtain the chromate chitosane, which may find application as an active oxidizing component in a variety of energetic condensed systems (ECS), such as powders, pyrotechnic and explosive compositions and composite solid rocket fuels.
It is known that chitosan C6O4H9NH2as the base, due to the presence in its composition of amino groups capable of protonemata when interacting with acids with the formation of singly charged cation chitosane C6O4H9NH3+forming soluble and water-insoluble salts (Chitin and chitosan: synthesis, properties and applications / edited Kgosana, Gasiorowski, Wepfeemia. - M.: Nauka, 2002. 366 C.).
Soluble salts of chitosan is produced by interaction of chitosan with the appropriate acid taken in a stoichiometric ratio according to the following reaction equation:
where a is CH3Soo-, Cl-, NO3-and others.
Formed as a result of interaction of initial substances, the solution is evaporated to dryness and the solid residue salt of chitosan.
Insoluble salts, such as sulfate, chitosan, obtained by interaction of a solution containing a soluble salt of chitosan, rest the rum, containing sulfate anion, taken in a stoichiometric ratio according to the following reaction equation:
The precipitation of chitosan sulfate is filtered off, washed with water and dried.
The disadvantage of most salts of chitosan is relatively low oxygen content and the lack of even a mild oxidizing properties, which is an obstacle to the use of salts of chitosan as an active oxidizing components of the energy-intensive structures.
Know the use of chromates and bichromates as oxidizers in various FORMER, in particular pyrotechnic and match the compositions in solid fuels for generators and rocket engines. Education in the combustion products of chromium oxide (III) increases the speed and completeness of combustion of the primary fuel (Energy condensed systems. Brief encyclopedic dictionary. Edited Bpeuropa. M: the Janus-K. 2000. S).
Chromates is produced by interaction of solutions of chromic acid (H2CrO4or chromium oxide CrO3with oxides, hydroxides, carbonates of the respective metals or ammonium, as well as deposition from solutions of salts of chromate sodium Na2CrO4or oxidation of chromium compounds lower valences. Bichromate, salt darmowej acid (H2Cr2O7
Sufficiently high oxidative properties of chromates and bichromates metals or ammonium caused not only by the oxygen content in the corresponding anions, but also the ability of chromium in oxidation state (VI), in which he is chromates and bichromate, move under certain conditions (pH, presence of reducing agents and their resilience in chrome compounds with oxidation state (III) or (0).
The prior art perchlorate chitosane composition C6O4H9NH3ClO4the method of its production and energy-intensive composition containing the perchlorate chitosane (U.S. Pat. Of the Russian Federation No. 2315774, publ. 27.01.2008), which is the closest to the claimed invention.
According to this invention, the perchlorate chitosane get the interaction of chitosan with a solution of chloric acid HClO4when the molar ratio of the initial reagents 1 to 1. From the reacted mixture of the target product are evaporation, followed by drying.
Due to the high oxidizing properties perchlorate chitosane can be used in energy-intensive structures.
However, a significant shortcoming of the perchlorate chitosane as oxidant in energy-intensive part is the selection in the process of combustion of the gaseous Gloria hydrogen chloride, represents an environmental hazard.
Object of the invention is a receipt containing the chromate anion new chemical compounds that have high enough oxidizing properties and is suitable for use in energy-intensive structures, without burning the selection of environmentally harmful gaseous products.
The problem is solved offered by the chromate chitosane composition (C6O4H9NH3)2CrO4and the method of its production, including the interaction of soluble salts chitosane with metal chromates, taken in the ratio of 2 moles of the cation chitosane on 1 mol of the chromate anion, or bichromate metals in relation to 4 mol of the cation chitosane on 1 mol of the bichromate-anion, subsequent separation of the resulting target product - chromate chitosane solid and drying at a temperature not higher than 150°C.
The claimed compound, its properties and how to obtain it accessible to the applicant the information sources described previously were not.
Chromate chitosane is non-toxic, explosion-proof, resistant to moisture, heat and mechanical stress connection. The Tg shows that its decomposition at temperatures above 150°C flows smoothly (without explosion or flash). Test impact-testing machine (Horst A.G. Gunpowder and explosive substances is TBA. M: Barongis, 1975. 187 C.) showed that the connection is stable when the drop weight 10 kg from a height of 400 mm (maximum height, which is achieved using existing impact-testing machine). Keeping the chromate chitosane in a humid atmosphere leads to a slight increase in weight (within 5%), without decomposition or hydrolysis, and the absorbed moisture can be easily removed by drying. While the chromate chitosane has a sufficiently high oxidizing properties that enable its use as a component of the energy-intensive compositions which burn without releasing harmful gaseous products of its decomposition.
The development of the method of production of new chemical compounds, chromate chitosane composition (C6O4H9NH3)2CrO4preceded experimental studies on the interaction of chitosan with the chromate and bichromate-anions, razyasnenie a number of questions, the answers to which could not be deduced only from logical reasoning. First, because CrO42-and Cr2O72-anions are, in most cases, oxidative properties, it was necessary to test the stability of chitosan against these oxidants, as it is known, that under action of chitosan some oxidants, such as periodate or sodium peroxide, is a polymer chain that is alglucosidase with the formation of the oxidized chitosan (VI Chursin Properties and application of oxidized chitosan. // Proc. Dokl. Ninth international conference "Modern perspectives in the study of chitin and chitosan. Stavropol, 2008. M: VNIRO. 2008. P.113-115.). Secondly, in the absence of redox interactions and the formation of salts was difficult to state unequivocally whether they dissolve in water, which is necessary to develop a method of synthesis of these compounds.
As a result of investigations of the interaction of chitosan with anions CrO42-and Cr2O72-it is established that in both cases, high yield is the formation of water-insoluble chromate chitosane according to the following equations:
Based on theoretical notions one might expect the formation of chromate and bichromate of chitosane respectively, however, experimental studies have confirmed theoretical assumptions about the educational opportunities of bichromate of chitosane.
The formation of the chromate chitosane in both cases is confirmed by the chemical analysis of the precipitate formed and output, as well as acidification of the solution due to the formation of the acid (proton) in the case of bichromate in accordance with the equation (4).
the Method of producing the chromate chitosane as follows. Prepare soluble salt of chitosan, such as the acetate chitosane. To do this, dissolve a portion of chitosan in acetic acid. To the resulting solution was added a solution of chromate or bichromate of sodium containing reagents in the required quantities for the formation of the chromate chitosane according to equations (3) or (4). The combined solution is thoroughly mixed, the precipitation of chromate chitosane filtered off, washed from side products of the reaction and dried to constant weight by heating to a temperature not exceeding the decomposition temperature of the chromate chitosane. According to differential thermal analysis of the decomposition of the target product - chromate chitosane with mass loss begins at temperatures above 150°C.
In appearance and properties of the chromate chitosane sharply differs from the original chitosan and chromium, or bichromate used for its synthesis. Chromate chitosane is a brittle solid product, breaking up breaking them into pieces of irregular shape, shiny on the breaks. Color plate pieces dark brown, three-dimensional - almost black. When grinding the pieces of the chromate chitosane with crunch and scatter fray in fine brown powder.
According to diffraction (DRON - 3,0, λCuKα) new connection rangeroamer is about, which is typical of the salts of chitosan, and reflection, which gives the original chitosan, are absent. IR-spectrum (IFS EQUINOX-55S) chromate chitosane (C6O4H9NH3)2CrO4contains band in the range of 1518, 1616, 3187 and 3519 cm-1characterizing the cation chitosane (Wealden, Lnegative, Umiliana. The reaction of dodecahydro-closo-dodecaborane acid with chitosan. // Journal of structural chemistry. 2006. T. No. 1. P.41-46.). According to IR spectroscopy the presence of absorption bands in the region 892 cm-1related to the stretching vibrations of CrO42-anion, confirms its occurrence in the structure of the claimed compounds, but not Cr2O72-anion, because the absorption bands in the region 949 and 762 cm-1characterizing the bichromate-anion, in the IR spectrum are missing.
Salt of the chromate chitosane does not contain crystallohydrates water, inert to atmospheric moisture, does not explode upon impact, friction and other mechanical effects, is non-toxic. When heated pure individual chromate chitosane ranging from 150°C, it is quiet decomposition without flares and explosive emission. After annealing in air at 800 to 900°C To form the remainder of a dark green colour, which according to diffraction is an oxide of chromium (III) Cr2O3. Atomic absorption analysis method (spectrophotometry is the EPR AA-780) solution Cr 2O3sulfuric acid is found that the chromate anion quantitatively transferred into the chromium oxide.
The proposed chromate chitosane exhibits sufficiently high oxidative properties. In mixtures of the chromate chitosane with such well-known combustible components and pyrotechnic incendiary compositions, as red phosphorus, sulphur, sulphide of antimony Sb2S3and others get actively oxidizing materials. However, depending on the ratio of the chromate chitosane and the combustible component decomposition can be in the form of rapid combustion, and flash (explosion).
The advantage of the chromate chitosane compared with the perchlorate chitosane is the absence of toxic gaseous emissions of chlorine-containing compounds.
It is known that in some cases the presence of soot in the combustion products of the FORMER improves the conditions for oxidation of the primary fuel.
The advantage of the chromate chitosane (C6O4H9NH3)2CrO4compared with other known oxidants, including chromates and bichromates metals or ammonium, used in the composition of the FORMER, is the allocation of sooty residue, which improves the combustion efficiency of fuel.
The chemical composition of the claimed chromate chitosane (C6O4H9NH3)2CrO4determine using shadowshadow.
Analysis for carbon, hydrogen and nitrogen is carried out by the known methods of microanalysis of organic substances (Mazor L. Methods of organic analysis. M.: Mir, 1986. S). The content of the chromate ion is calculated based on the weight of the resulting residue, which is a chromium oxide Cr2O3. The oxygen content chitosanase cation find the difference.
The objective of the invention is solved also offer energy-intensive composition containing the chromate chitosane.
It is known the use of compounds of dodecahydro-closo-dodecaborate chitosane composition (C6O4H9NH3)2In12H12as energy-intensive component of high-energy materials (U.S. Pat. Of the Russian Federation No. 2158221, publ. 27.10.2000). Due to the specific structure of this compound is thin at the molecular level, the distribution of fuel (B12H122--anions) and oxidant (oxygen-containing groups of chitosan), the flow of oxygen and air to the combustion, expansion when heated with a sharp increase in the volume of the burning material, creates favorable conditions for rapid and full flow terrogation the combustion reaction. When ignited (C6O4H9NH3)2In12H12ignites and burns vigorously with the formation of black residue, representing the cm is camping soot and boric anhydride and/or boric acid. However, because the compound has a relatively high flash point (300°C), this limits the possibility of its use as an energy-intensive component of energy-efficient materials.
Closest to the claimed energy-intensive composition is a composition based on dodecahydro-closo-dodecaborate chitosane (C6O4H9NH3)2B12H12containing the perchlorate chitosane C6O4H9NH3ClO4the effective amount (U.S. Pat. Of the Russian Federation No. 2315774, publ. 27.01.2008).
A disadvantage of known composition are harmful chlorine-containing gaseous emissions in the combustion process energy-intensive structure.
To eliminate this drawback is proposed energy-intensive structure on the basis of dodecahydro-closo-dodecaborate chitosane (C6O4H9NH3)2B12H12containing the chromate chitosane (C6O4H9NH3)2CrO4in effective amounts, determined the required character burning.
Unlike the individual components of the structure - (C6O4H9NH3)2CrO4and (C6O4H9NH3)2In12H12, the claimed composition is generally characterized by a much higher energoactivity and complete combustion. As studies have shown, SOS is AB has a lower flash temperature (about 240°C) compared to the individual components. This is due to the structure of the resultant composition, which is a uniformly distributed mixture of oligomers of chitosan salts B12H122and CrO42-anions.
CrO42-anions are more rich in oxygen and stronger oxidant than oxygen-containing groups of the chitosan. Therefore, by heating such compounds ignition (C6O4H9NH3)2In12H12occurs at lower temperatures, and its combustion is much more intensive than in individual form. The activity of compounds is determined by the ratio of In12H122-anions, which act as fuel and CrO42-anions of the chromate chitosane exhibiting oxidative properties. Since dodecahydro-closo-dodecaborate chitosane very deficient in oxygen, when the number of the chromate chitosane activity of the claimed compounds is growing. The specific composition is determined depending on the desired combustion mode (slow, fast, or explosion): if necessary, explosive character increase concentration in a mixture of chromate chitosane, and to provide a more relaxing type of combustion - the concentration of dodecahydro-closo-dodecaborate chitosane.
According to the invention C is demonstrate the composition of a common deposition of the chromate chitosane with dodecahydro-closo-dodecaborates chitosane, taken in a predetermined ratio. Uniform distribution of salts is due to the fact that In12H122-anions are electron-deficient systems, unlike CrO42-anions containing in its structure a large number of donor atoms of oxygen with the unshared pair of electrons. Therefore, when the evaporation of water is the convergence of oligomers of salts due to donor-acceptor interaction B12H122-and CrO42-anions.
Compared to energy-intensive composition containing the perchlorate chitosane (U.S. Pat. Of the Russian Federation No. 2315774, publ. 27.01.2008), the proposed energy-intensive composition during combustion does not emit into the atmosphere of harmful impurities, due to the presence in its composition of the chromate chitosane.
The properties of the proposed structure: flash point (about 240°C), the activity and the completeness of combustion, comparable with the properties of known composition.
Thus, the technical result of the claimed invention to provide new chemical compounds, chromate chitosane that has a sufficiently high oxidizing properties and is suitable for use in energy-intensive structures, burn without releasing harmful gaseous products, due to the presence of energy-intensive part of the chromate chitosane.
The opportunity to undertake the surveillance of the invention is illustrated by examples, which describes the obtaining of the chromate chitosane (examples 1-3) and the energy-intensive preparation of the composition (examples 4, 5).
As a source of chitosan to obtain soluble salts of chitosan, which are then used in the synthesis of the chromate chitosane taken the product produced by LLC "Biopolymers" (bartizans Primorsky Krai) TU 9283-174-200472012-03 with a degree of dezazetilirovanie 75,0%, having the following elemental composition, wt.%: WITH AND 45.5; H - 6,8; N - 8,1; 39,6. This corresponds to the gross formula C6,5O4,25H9,5NH2.
Example 1. To 200 ml of a solution containing 1,03365 g (6,02 mg-mol) of the hydrochloride chitosane6,5O4,25H9,5NH3Cl, poured with vigorous stirring to 200 ml of a solution containing 0,70450 g (3,01 mg-mol) 4-water chromate sodium Na2CrO4×4H2O. This corresponds to their molar ratio of 2 to 1, i.e. the stoichiometry of reaction (3). The resulting fine precipitate of brown-yellow filtered, washed with water prior to the absence in the lavage Na+and dried at a temperature of about 105°C to constant weight. Get 1,26390 g (2,74 mg-mol) of the chromate chitosane (C6,5O4,25H9,5NH3)2CrO4that corresponds 91,0%increase yield of the target compound.
Calculated for (C6,5O4,25H9,5NH3)2CrO4, wt.%: With - 33,9; 5,5; N - 6,0; Cr - 11,3; O - 43,3.
Nai is prohibited for (C 6,5O4,25H9,5NH3)2CrO4, wt.%: With To 33.8; H - 5,5; N - 5,9; Cr - 11,3; 43,5.
Example 2. Spend the interaction between 1,18340 g (6,17 mg-mol) hydrohloride chitosane C6,5O4,25H9,5NH3F and 0,72090 g (is 3.08 mg-mol) 4-water chromate sodium Na2CrO4×4H2O, which corresponds to a small excess chitosan salt, and allocate the sediment, as described in example 1. Get 1,28615 g (2,79 mg-mol) of the chromate chitosane (C6,5O4,25H9,5NH3)2CrO4that corresponds to its 90,5%final output.
Calculated for (C6,5O4,25H9,5NH3)2CrO4, wt.%: With - 33,9; 5,5; N - 6,0; Cr - 11,3; O - 43,3.
Found for (C6,5O4,25H9,5NH3)2CrO4, wt.%: With - 33,9; N - 5,4; N - 6,1; Cr - 11,4; 43,2.
Example 3. Spend the interaction between 1,15000 g (5,52 mg-mol) of the hydrochloride chitosane C6,5O4,25H9,5NH3Cl and 0,40600 g (1,38 mg-mol) of potassium bichromate K2Cr2O7that corresponds to the stoichiometry of reaction (4), then allocate the sediment, as described in example 1. Get 1,23510 g (1.24 mg-mol) of the chromate chitosane (C6,5O4,25H9,5NH3)2CrO4that corresponds to its 89,9%final output.
Calculated for (C6,5O4,25H9,5NH3)2CrO4, wt.%: With - 33,9; 5,5; N - 6,0; Cr - 11,3; O - 43,3.
Found for (C6,5O4,25H9,5NH3)2CrO4, wt.%: With - 33,8; N - 5,4; N - 6,1; Cr - 11.4; - 43,3.
Example 4. To 10 ml creamy solution containing 0,73090 g (1,50 mg-mol) their fine (C6,5O4,25H9,5NH3)2B12H12) add 10 ml creamy solution containing 0,23070 g (0.50 mg-mol) their fine (6,5O4,25H9,5NH3)2CrO4(molar ratio 3:1) and mix thoroughly. The resulting mixture is filtered and dried at a temperature of 100-110°C. Receive 0,96160 g brown product in the form of a curved towards the edges of the compact round brown pill. The flash point of 240°C. the Decomposition takes place in the form of rapid combustion.
Example 5. Cook the mixture 0,50365 g (1,03 mg-mol) (C6,5O4,25H9,5NH3)2B12H12and 0,47525 g (1,03 mg-mol) (C6,5O4,25H9,5NH3)2CrO4(molar ratio 1:1), as described in detail in example 4. The flash point of 240°C. the Decomposition takes place in the form of a bright flash with a Bang and scattering decomposition products.
1. Chromate chitosane composition (C6O4H9NH3)2CrO4.
2. The method of obtaining the chromate chitosane composition (C6O4H9NH3)2CrO4including mutual the action of soluble salts chitosane with chromates metals in the ratio of 2 moles of the cation chitosane on 1 mol of the chromate anion or bichromate metals in the ratio of 4 moles of the cation chitosane on 1 mol of the bichromate-anion, subsequent separation of the resulting solid precipitate of the chromate chitosane and drying at a temperature not exceeding 150°C.
3. Energy-intensive structure on the basis of dodecahydro-closo-dodecaborate chitosane (C6O4H9NH3)2B12H12,containing the chromate chitosane (C6O4H9NH3)2CrO4in an effective amount.
SUBSTANCE: method involves taking a certain weighed amount of chitosanium chromate which is first purified from extraneous impurities and reduced to constant weight. The weighed amount is then turned into a stable weighted form through thermal treatment on air at temperature 800-900°C to form chromium oxide Cr2O3. The weight of the formed chromium oxide is then determined. Content of chromic acid in the initial weighed amount of chitosanium chromate is then calculated from the weight of chromium oxide. The degree of deacetylation of chitosan is calculated using defined formulae.
EFFECT: invention enables to increase accuracy of determining degree of deacetylation of chitosan.
SUBSTANCE: invention relates to a method of extracting and stabilising ultra low-molecular aminoglycans from eggshell wastes. Aminoglycan extract is used to produce cosmetic creams with skin moisturising and anti-wrinkle properties. The method of extracting low-molecular aminoglycan compound of formula I from a natural source of eggshell wastes, which consists of alternating glucuronic acid and N-acetylglucosamine units, where M can be one or more of Na, Ca, K, Mg; and n is a whole number from 20 to 40, involves the following steps: (a) preparing eggshell wastes for extraction of embryonic low-molecular aminoglycan compound of formula I using a polar organic solvent in water, (b) extracting low-molecular aminoglycan compound of formula I in form of a water-soluble salt, for which the eggshell from step (a) is vigorously shaken with aqueous polar salt solution at 10°C - 35°C for 6-12 hours, then filtered or centrifuged in order to collect an aqueous layer containing a dissolved aminoglycan compound of formula I; (c) extracting a purified low-molecular aminoglycan compound of formula I by forming a gel from an aqueous mixture of salts using a polar organic solvent, for which the solution from step (b) is successively and step-by-step mixed with an organic solvent mixed with water while gently stirring and then cooled to maintain temperature from 20°C to 25°C, and the formed gel is left for 2-24 hours for complete precipitation, then filtered or centrifuged in order to extract a semidry aminoglycan compound of formula I; (d) the extracted aminoglycan compound of formula I from step (c) is stabilised via gradual addition of organic oils to the semidry gel to form aminoglycan compound of formula I. In order to prepare a composition having anti-wrinkle properties, at least one pharmaceutically acceptable filler is added to the stabilised aminoglycan compound of formula I obtained at step (d).
EFFECT: method enables to obtain an aminoglycan compound of formula I with the necessary viscosity and skin penetrating properties for reducing skin wrinkles, as well as excellent softening and moisturising effects.
8 cl, 9 ex
SUBSTANCE: method involves feeding wastes to be treated into artificial containers, biotreatement, tapping the filtrate and removing the obtained biomass. Biotreatement is carried out by culturing hoverfly larvae from the freshly laid eggs phase to the pupation phase in the fermented wastes to be treated, placed in artificial meshed containers the bottom and walls of which are covered with filter cloth. The apparatus has artificial containers, devices for feeding the wastes to be treated, outputting the filtrate and collecting the biomass. The artificial containers have a meshed bottom and walls covered with filter cloth.
EFFECT: invention enables to combine biotreatment of methane wastes with production of chitin containing biomass.
8 cl, 1 dwg
SUBSTANCE: method of producing nanoparticles of low-molecular chitosan involves preparing a solution of pre-purified low-molecular chitosan in filtered 1-2 wt % aqueous acetic acid, adding solutions of hydroxides of alkali metals or ammonia for 2 hours, dispersing the system using a mechanical mixer at a rate of 200-300 rpm at temperature 20°C to pH 6.9-7.0. Further, the dispersion is centrifuged at 10000 rpm. The obtained solid residue is redispersed in bidistillate while mechanically mixing at a rate of 200-300 rpm at temperature 20°C.
EFFECT: invention simplifies the method of producing nanoparticles of low-molecular chitosan and apparatus design without formation of undesirable harmful substances.
SUBSTANCE: starting high-molecular chitosan is dissolved in acid solution. The chitosan dissolved in the acid is then precipitated by adding alkali solution. The re-precipitated high-molecular chitosan is washed from the formed salt and excess alkali using a coarse-porous filter. The re-precipitated chitosan is dissolved in acid solution until achieving pH 5.5. An enzyme preparation is then added and hydrolysis is carried out. The reaction is stopped after formation of low-molecular chitosan.
EFFECT: method is characterised by avoiding the need to remove salts from the enzymatic mixture and the end product, as well as low level of loss of material.
2 dwg, 7 tbl, 6 ex
SUBSTANCE: method for the recovery of high-purity and completely soluble partially deacetylated chitin polymer of deacetylation degree (DD) 30-60 % involves the stages: neutralisation of partially deacetylated chitin; dissolution of partially deacetylated chitin in an acid; removal of undissolved particles by sequential filtration stages; pH reduction of the solution to 8 and more; precipitation of completely dissolved and purified partially deacetylated chitin by temperature rise and salt addition where the precipitate is removed and rinsed after precipitation by filtration or centrifugation and where rinsing water and deposit temperature is 40°C and higher. Also the invention refers to a neogenesis composition containing therapeutically active N-acetylglucosamine (A) and glucosamine (D) chitooligomers where the composition contains heterochitooligomers which shall meet the following criteria: said oligomers have a chain length in the range 5-20 monomer residues; each oligomer chain can have two residues of N-acetyl-D-glucosamine (AA) on any or both ends of the oligomer chain, the remained inside of the oligomer has a maximum number of the residues A; the sequence of said inside of the chain is such that the N-acetyl-D-glucosamine residue (A) does not adjoin to the other N-acetyl-D-glucosamine (A) residue (such as, e.g. AA).
EFFECT: biomaterial based on said compositions intensifies the bone repair and hemostasis in healing of a fractured or seriously injured bone.
21 cl, 32 dwg, 9 tbl, 9 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention relates to field of medicine, cosmetology and to production of biologically active substances. In order to isolate glycosaminoglycans from skins, extraction, proteolysis and sedimentation are carried out. For extraction used is 0.9% NaCl solution, for fermentative proteolysis used is papain enzyme, for sedimentation used is 4% alcohol solution of potassium acetate.
EFFECT: method application makes it possible to obtain target product with the least expenditures for its production.
1 dwg, 1 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to producing chitin and its derivatives, namely to methods for producing low-molecular chitosan. Low-molecular chitosan is produced by dissolving high-molecular chitosan in 1% aqua acetic acid. It is added with hydrogen peroxide in amount 0.5-1.5 wt % to total solution in the presence of catalytic amounts of manganese oxide (IV). The solution is kept at temperature 18-50°C for 30 min. Upon completing reaction time, it is added with an aqueous solution of ammonia, with reducing pH of the reaction mixture to 6.9-7.0. After setting of sediment, acetone is added, and the solution is kept for 2 hours. The sediment is filtered, washed with distilled water and acetone, dried.
EFFECT: use of the method provides producing the end-product with a smaller degree of polydispersity and composition heterogeneity.
2 dwg, 2 tbl, 5 ex
SUBSTANCE: invention relates to synthetic polymer chemistry. The nanocomposite contains a matrix in form of a cross-linked salt of hyaluronic acid which is modified with sulphur-containing compounds and nanoparticles of a noble metal as filler. A film of the cross-linked salt of hyaluronic acid which is modified with sulphur-containing compounds is obtained through chemical reaction of the salt of hyaluronic acid with a mixture of two sulphur-containing compounds and with a cross-linking agent, under conditions with pressure between 50 and 300 MPa and shear deformation in a mechanical reactor at temperature between 20 and 30°C. The reactor used to obtain the film is a Bridgman anvil.
EFFECT: invention enables to obtain a range of new bioactive nanocomposites with quantitative output and in the absence of a liquid medium, where the method does not require high energy, labour and water consumption and significantly increases efficiency of the composite; in particular, resistance to decomposition in the presence of hydroxyl radicals is 2-3 times higher compared to the control result.
16 cl, 7 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention relates to novel group of chemical-pharmaceutical bioconjugates, which can be obtained by indirect synthesis by means of molecular spacer between hyaluronic caid and/or its derivatives and medications with anti-tumour activity, belonging to different groups, method of their obtaining. Invention also relates to anti-tumour pharmaceutical compositions and three-dimensional biomaterials based on said conjugate.
EFFECT: novel derivatives, depending on bond type and substitution degree, have different physical-chemical properties, which improve their tolerance and efficiency and ensure possibility of more accurate modulating dosage by using mechanism of active targeting.
31 cl, 4 dwg, 16 ex
FIELD: fish industry.
SUBSTANCE: method involves providing deacetylation of raw material with the use of preliminarily cooled alkaline solution; washing and drying. Deacetylation process is performed in three stages, first stage being performed for 7 days and subsequent two stages being performed for 2 hours each, combined with thermal processing at temperature of 55-590C. Washing process is provided after each deacetylation stage.
EFFECT: provision for producing of chitosan from chitin of cancerous with increased extent of deacetylation, while native properties of natural polymer being kept, without breaking of glycoside binding chain.
FIELD: organic chemistry.
SUBSTANCE: claimed method includes subsequent chitosane-containing raw material with non-polar liquefied gas, water, alkali, water, acid, water, alkali, and water to produce target product in form of solid residue, wherein in at least first extraction step pressure in reaction mixture is periodically released to provide extractant boiling, and than increased up to starting value.
EFFECT: method with reduced energy consumption.
FIELD: chemical technology of natural compounds.
SUBSTANCE: invention describes a method for preparing water-soluble derivatives of chitosan. Method involves treatment of chitosan with acid medium up to its swelling wherein vapor medium water-acid is used as acid medium. Treatment of chitosan is carried out with vapor of monobasic acid aqueous solution taken among the group including hydrochloric acid, formic acid and acetic acid. Method allows simplifying technology in preparing water-soluble derivatives of chitosan.
EFFECT: improved preparing method.
4 cl, 1 tbl, 9 ex
FIELD: chemistry and technology of derivatives of polysaccharides, chemical technology.
SUBSTANCE: invention relates to methods for preparing chitosan esters. Invention describes a method for preparing chitosan polyethylene glycol ester that involves dissolving chitosan in acetic acid followed by alkalization. Then the reaction mixture is subjected for effect of ethylene oxide under pressure 1-3 atm and temperature 60-100°C, and the concentration of reaction mass is corrected by addition of distilled water up to the density value of solution 1.030-1.032 g/cm3. Then the reaction mass is purified by electrodialysis at the rate value of solution in treatment chambers 3.0 cm/s, not less, temperature 20-45°C, the current density value 0.25-0.75 A/dm2 and the constant volume of the reaction mass. Method provides enhancing the effectiveness of purification by electrodialysis due to reducing energy consumptions. Chitosan esters can be used in medicine, cosmetics, food and chemical industry.
EFFECT: improved preparing method.
FIELD: organic chemistry of natural compounds, chemical technology, medicine.
SUBSTANCE: invention relates to the group of chitosan-containing compounds. Invention relates to synthesis of modified chitosan of the following structure: wherein n = 150-1400. The modified chitosan possesses the bactericidal activity, in particular, antituberculosis activity.
EFFECT: valuable medicinal properties of modified chitosan.
1 tbl, 1 dwg, 3 ex
FIELD: natural compounds technology.
SUBSTANCE: chitosan preparation process comprises breaking naturally occurring chitin-containing material, charging it into reactor, demineralization with 6-7% aqueous hydrochloric acid, deproteination with sodium hydroxide solution at 85-95°C, deacetylation with sodium hydroxide solution on heating, decoloration, and washing with water after each stage to pH 6.5. Process is characterized by that chitin-containing material broken to achieve fraction 0.5-6 mm is fed simultaneously into a number of reactors, wherein demineralization is effected with aqueous hydrochloric acid stream at 85-95°C for 1.5 h while controlling pH in each reactor exit to achieve acid concentration in each reactor exit the same as concentration of the initial acid by way of feeding it in a continuous manner. In addition, deproteination is carried out with 6-7% sodium hydroxide solution stream for 1.5 h followed by discharging treated material into autoclave to perform deacetylation simultaneously with decoloration using 50% sodium hydroxide solution at 130-140°C in inert gas environment and in presence of 3-5% hydrogen peroxide solution used in amount 3-5% of the total volume of mixture.
EFFECT: enhanced process efficiency.
FIELD: chemical technology.
SUBSTANCE: invention relates to methods for preparing water-soluble saline complexes (associates) of hyaluronic acid with d-metals of IV, V and VI periods of Mendeleyev's periodic system of elements that can be used in pharmacology and cosmetology. Invention describes a method for preparing water-soluble saline complexes of hyaluronic acid involving preparing an aqueous solution of salt of d-metal of IV, V and VI periods of periodic system and its mixing with hyaluronic acid sodium salt, holding the mixture, its stirring, dilution with water and isolation of the end product. For mixing method involves using the amount of aqueous salt of abovementioned d-metal that is equivalent to the amount of carboxy-groups of hyaluronic acid sodium salt or in the limit from 0.95 to 1.10. After dilution with water the solution mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with aqueous salt solution of abovementioned d-metal firstly and then with deionized water followed by concentrating the product. By another variant for mixing the method involves the amount of aqueous solution of d-metal salt lesser of the equivalent amount of carboxy-groups in hyaluronic acid sodium salt. After dilution with water the mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with deionized water followed by concentrating the product also. Method is characterized by the decreased time of processes and simplicity.
EFFECT: improved preparing method.
2 cl, 1 tbl
FIELD: medicine, food processing industry, in particular production of depolymerized chitosane and products based on the same.
SUBSTANCE: claimed method is based on using of chitosanase in acetic acid medium and spray drying of and depolymerized chitosane and is characterized in that obtained depolymerized chitosane is preliminary converted in non-ionized form by neutralizing of bound acetic acid with ammonium hydroxide followed by precipitation in ethanol and air drying. Further interaction is carried out with ammonium lipoate or glutathione in aqueous medium. Claimed products may be used individually or in combination with other components.
EFFECT: new products for food processing industry and medicine.
4 cl, 2 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing modified glycosaminoglycans possessing analgesic properties. Method involves interaction of glycosaminoglycans with 1-phenyl-2,3-dimethyl-4-aminopyrazolone-5-(4-aminoantipyrine) in aqueous medium at pH = 4.7-4.8 in the presence water-soluble 1-ethyl-3-[3-(dimethlamino)propyl]carbodiimide as a condensing agent at room temperature followed by purification from low-molecular reagents. Method involves a single step that simplifies technology in preparing modified glycosaminoglycans.
EFFECT: improved preparing method.
FIELD: natural substances, chemical technology.
SUBSTANCE: invention relates to a method for preparing chitosan and purification from components of the reaction mixture - low-molecular products of deacetylation and alkali excess. Invention relates to a method for purifying chitosan prepared by solid-state method involving treatment of reaction mass with extractant consisting of 3.3-20.0% of water, 32.2-57.1% of ethyl acetate and 24.6-64.5% of ethanol at the extractant boiling point. Also, invention relates to a method for purifying chitosan prepared by suspension method and involving treatment of the reaction mass with ethyl acetate and the following treatment with extractant consisting of 6.2-25.0% of water, 12.5-62.5% of ethyl acetate and 31.3-62.5% of ethanol at the extractant boiling point.
EFFECT: improved isolating and preparing method.
3 cl, 2 tbl, 1 dwg