Method for isolating purified chitosan from reaction mixture (variant)
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
The invention relates to the field of chitosan and clearing the components of the reaction mixture of low molecular weight reaction products and excess alkali (sodium hydroxide or other alkali metals). In traditional methods of production of chitosan by dezazetilirovanie chitin with concentrated solutions of sodium hydroxide using 10-20-fold molar excess of NaOH . More environmentally friendly and cost-effective is the solid-state method , which requires only a 5-fold molar excess of alkali. However, in this case, the obtained reaction mixture, only 33% consisting of chitosan, and 67% are CH3COONa and excess NaOH. Therefore, purification of chitosan from low molecular weight components of the reaction mixture is an important stage of the technological process of its receipt.
A known method of extraction of chitosan from the reaction mixture by washing with water, in which it is necessary to use a large amount of deionized water 300 to 700 liters per 1 kg of chitosan . The washing water containing alkali, sodium acetate and degradation products of chitin, in the best case, neutralized before discharge into the sewer.
Closer and adopted for the prototype is a method of extraction with alcohol or azeotropic mixture of isopropanol - water . The disadvantage of this method is the low solubility of sodium hydroxide in the extractant and incomplete (to a residual content of more than 1%) the removal of alkali, polluting product and initiating processes leading to loss of chitosan solubility with the long-term storage.
The aim of the proposed method of extraction of chitosan from the reaction mixture is getting a product that does not contain traces of alkali, with ash content less than 1% and not lose solubility during storage.
This goal is achieved by the fact that apply:
the method of purification of chitosan from alkali and sodium acetate, which consists in the extraction of the powdered reaction mass obtained solid way to dezazetilirovanie, an extractive agent consisting of water, ethanol and ethyl acetate, the saponification of which sodium hydroxide is formed ethanol and sodium acetate, extragenomic further, when the boiling point of the extractant 68-74°and the ratio of the components: water - 3,3-20,0%ethyl acetate - 32,2-57,1% and ethanol - 28,6-64,5%;
the method of purification of chitosan from alkali and sodium acetate, which consists in processing wrung the reaction mass obtained suspension method, ethyl acetate, taken in stoichiometric quantity with respect to the content of sodium hydroxide, and subsequent extraction of the formed sodium acetate at the boiling point of the extractant 68-74°and the ratio of its components: water - 6,2-25,0%, ethyl acetate, 12.5 to 62.5 percent and ethanol 31,3-62,5%.
Thus, the reaction mass containing chitosan, alkali and the Etat sodium, extracted with a mixture of ethyl alcohol, ethyl acetate and water, taken in a certain ratio. The proposed method of purification of chitosan is especially useful when conducting dezazetilirovanie chitin solid-state method. But it can be used for isolation of chitosan from the reaction mass obtained traditional suspension method. In this case, when calculating the ratio of components of the extractant should be factored into the amount of water contained in the squeezed reaction mass. Best cleaning results wrung the reaction mass obtained if prior to the extraction process stoichiometric with respect to the remaining alkali amount of ethyl acetate. After extraction, the extractant regenerate, removing the crystallized when cooled sodium acetate and ethanol and the ethyl acetate separated by distillation and re-used for the extraction.
The advantage of the proposed method of purification of chitosan is the lack of alkali and discharge the wash water. In addition, the practical elimination of water usage that causes the crystallization of the polymer, and the more amorphous and porous chitosan provide a high rate of dissolution and reactivity of chitosan, including sorption and sulfation . Diffraction patterns of chitosan, purified by pre the proposed method (see curve 1 in the figure), and chitosan, purified by washing with water (curve 2), confirm the most amorphous of the first.
The technical result achieved by the application of the inventive method the selection of the pure chitosan is a complete transformation of an excess of sodium hydroxide in sodium acetate and removal of the last content in the finished product less than 1%, as well as maintaining a high level of reactivity and solubility of the polymer during storage.
Table 1 presents the composition of two species of the reaction mass of:
1 is obtained by solid-state technology from a mixture of caustic soda 50% and chitin 50% (5:1 mol/mol)
2 is obtained by suspension technology from a mixture of caustic soda 22,7%, chitin 7.8% and water 69,5% (14,8:1:100 mol/mol).
The reaction mass may contain an antioxidant, bleach or other additives that are acceptable for the process and introduce, if necessary.
The method of purification of chitosan illustrated by the examples presented in table 2.
Thus, the proposed method of purification of chitosan from low molecular weight components (NaOH, CH3COONa)remaining in the reaction mass after the process of dezazetilirovanie, allows you to:
- clear chitosan to a residual ash content of less than 1%;
- to obtain a chitosan containing no alkali;
- save rastvorimosti with long-term (>2 years) storage;
to obtain chitosan with more porous and amorphous structure, especially when using solid-state technology to dezazetilirovanie chitin;
to obtain sodium acetate as an additional commercial product.
1. Muzzarelli R.A.A. Chitin. Oxford-N.Y.-Toronto-Sydney-Paris-Frankfurt: Pergamon Press. 1977. 309 p.
2. A.C. 1760749 A1 / Enikolopov NS, galbraikh PS, Rogovin SZ, Vikhoreva GA and other Way of chitosan. 1989.
3. Stolboushkin P.P. preparation, structure and properties of low molecular weight sulfated aminopolysaccharide. Diss. c.ch.s. - M.: Moscow state technical University n.a. An Kosygin. - 2003. - S.
|# example||no reaction mass||The composition of the extractant,.%*||The time of extraction, h||Characterization of chitosan||Output acetate Na||The consumption of acetate by saponification|
|Ethanol||The ethyl acetate||Water||The ash content of chitosan, %||The content of NaOH in the chitosan, %||The solubility of chitosan after storage for 2 years %||The output of chitosan|
|kg/kg reaction mass||% of theory||kg/kg of the reaction mixture.||% of theory||kg/kg reaction mass||% of theory|
|5**||2||31,3||62,5||6,2||24||9,9||0||-||was 0.138||108,6||0,81||of 87.3||0,902+0,05||101,3|
|*Excluding regeneration flow rate of the extractant is 6 kg/kg reaction mass.|
|**Before extraction to the reaction mass 2 added ethyl acetate in the amount of 0,902 kg/kg|
1. The method of purification of chitosan from alkali and sodium acetate, characterized in that it includes the extraction of the powdered reaction mass obtained solid-state method, the extractant consisting of 3,3-20,0% water, 32,2-57,1% ethyl acetate and 28.6-64,5% ethanol, at the boiling point of the extractant.
2. The method of purification of chitosan from alkali and sodium acetate, characterized in that it includes processing wrung the reaction mass obtained suspension method, ethyl acetate, taken in stoichiometric quantity with respect to the content of alkali and subsequent extraction with an extractant consisting of a 6.2-25,0% water, 12.5 to 62.5% of ethyl acetate and 31.3-62.5% of ethanol, at the boiling point of the extractant.
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: 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: 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: 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: 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: 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: 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: 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: 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: flavoring industry; pharmaceutical industry; perfumery industry; equipment for extraction of valuable components from vegetable and animal raw material.
SUBSTANCE: the invention is pertaining to the means of the flavoring industry, pharmaceutical and perfumery industry and is intended for extraction of valuable builders from vegetable and animal raw material. The extractor contains: the body (1),the barrel (2) arranged coaxially to the body with the upper open part; the cover (3); the alternating pressure generator and the alternating pressure branch-pipes (4); the extract collector (5); the low pressure receivers (7) and the high-pressure receivers (8); the controlled valves (9) and (10); the tank with the store volume of the fresh extractant (11); the plunger pump (12) for injections of the extractant; the extractant injection jets (13); the sources of the microwave emissions (14); the oscillator of the microwave oscillations (15); the power supply unit and the control unit (19). The alternating pressure oscillator is of impulse type as the plunger pump for pumping in - pumping out of the alternating pressure. The barrel is made out of a dielectric material with the perforated lateral and bottom parts. The controlled valves are connected by the branch-pipes to the body and the receivers. The injection jets inlets are connected through the branch-pipes to the outlets of the plunger pump of the extractant injection and to the tank with the store of the fresh extractant, and their outlets are connected to the internal volume of the body. The power supply unit is connected to the plunger pumps and the microwave oscillator, output of which is connected to the inputs of the microwave emitters. The emitters of the microwave emissions are arranged on the different horizon levels of the body. The control unit is connected to he plunger pumps, the microwave oscillator and the valves. The invention ensures the increased efficiency of the extractor, acceleration of the process and deepening of extraction of the extractives.
EFFECT: the invention ensures the increased efficiency of the extractor, acceleration of the process and deepening of extraction of the extractives.
FIELD: solvent extraction.
SUBSTANCE: device comprises extraction chamber made of cylindrical housing (1), cooler (2), and screen (5). Openings (4) and (3) are made in the bottom and top sections of the extraction chamber. The bottom section of the extraction chamber is provided with changeable screens (5). The cooler is made of a cylinder and provided with funnel and flange in the bottom section. The funnel is connected with the housing of the extraction chamber. The cylindrical section of the cooler receives the vertical pipes (6) secured to plates (7) that are flush-mounted with respect to the top plate and project out of the bottom plate. The top of the cylindrical section of cooler (2) is provided with opening (8) with thread for control of pressure.
EFFECT: enhanced efficiency.
FIELD: cosmetology, in particular cream production.
SUBSTANCE: claimed method includes preparation of fresh vegetable juice or mixture thereof, filtering, concentration at temperature up to 40°C followed by dissolution in structured water, obtained from plants, plant raw materials, slush, or in structured water, ionized, for example, with copper ions and optionally aseptic treatment of obtained product not causing denaturation, such as by membrane filtration method.
EFFECT: new matters for cosmetic products.
SUBSTANCE: method involves extraction of total lipids from the rice grains processing waste. Lipids are separated by method of two-dimensional thin layer chromatography by using the following solvent mixtures: by the first direction - chloroform, acetone, benzene, formic acid, water, and by the second direction - acetone, benzene, formic acid, water. Invention provides enhancing purity of product.
EFFECT: improved isolating method, enhanced quality of product.
2 tbl, 2 dwg, 1 ex
FIELD: reprocessing of larch wood, in particular methods for production of arabinogalactan.
SUBSTANCE: arabinogalactan is obtained by extraction of ground larch wood with water at room temperature followed by extract separation, stripping thereof, cooling and reprecipitation of target product in organic solvent. Larch extraction with water is carried out simultaneously with microwave treatment for 0.5-1.0 min.
EFFECT: increased arabinogalactan yield; simplified method for production thereof.
SUBSTANCE: extractor-separator comprise housing, extracting module, separating module, electric drive, and unit for control and temperature control. The extracting module and separating module are movably mounted parallel inside the housing on supports in the vertical plane. The separating module is coaxially mounted in the housing. The extracting module is made of ring stand with the sockets for changeable sleeves. The separating module comprises rotating hollow, cylindrical rotor for receiving changeable sleeves and provided with the changeable collector of extract and ring chamber with drain pipeline. The changeable sleeves are provided with the separating lid.
EFFECT: expanded functional capabilities.
FIELD: chemical industry; methods of extraction of fullerenes.
SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the method of extraction of fullerenes. The method provides that the fullerene-containing soot is mixed with the natural vegetable essential oil. The preferable ratio is 1:(50-200) accordingly. It is possible to use a turpentine oil, camphoric or menthol oil. The mixture is placed in the ultrasonic bath and in the volume of the indicated mixture find a resonant frequency, for example, within 20-50 kHz. It is possible to use the ultrasonic radiation with the sinusoidal, rectangular or sawtooth form of impulses and to affect on the mixture by the selected frequency for no less than 20 minutes at the temperature of 40-80°C. The formed slurry is subjected to centrifuging, preferably, during 30-40 minutes at 20 000-40 000 g, where g is the acceleration of gravity. The supernatant liquid is filtered through the membrane filter with the pores diameter of no more than 0,2 microns. The solution is subjected to evaporation up to a permanent weight, for example, at the temperature of 130-140°C. The invention allows to extract effectively fullerenes, using nontoxic natural extractants.
EFFECT: the invention ensures effective extraction of fullerenes using the nontoxic natural extractants.
11 cl, 2 dwg, 4 ex
FIELD: leather industry.
SUBSTANCE: method comprises extracting tannins from oak raw using hot water and subsequent drying of plastic-state product at temperature not higher than 90°C until crystalline state is attained. Extraction is carried out at 75-85°C when using pulsar and thickening membrane filter.
EFFECT: enabled environmentally appropriate preparation of tannins at lowered power consumption and avoiding use of chemicals.
FIELD: methods of materials treatment by the multiple extension-compression of a dissolvent in different processes.
SUBSTANCE: the invention is pertaining to the methods of materials treatment by the multiple extension-compression of a dissolvent in processes of recrystallization, extraction, deposition of coatings, sedimentation, impregnation, removal of contaminants and at realization of various chemical reactions. A liquid consisting of a dissolvent, a soluble substance and a gaseous fluid is expanded by its passing through a retaining medium containing a filtering screen, which holds the undissolved particles of the soluble substance. Let the gaseous fluid to dissolve up to concentration at which the liquid extends until it will not lose its capacity to dissolve the soluble substance, which at that is settling. The settlings are held by the retaining medium containing the filtering screen. Then the pressure in the liquid is reduced up to the pressure, at which the main amount of the gaseous fluid may leave it and so forming the liquid possessing a capacity to dissolve a soluble substance. The produced liquid may be optionally added with some amount of a soluble matter. In the result of repetition of the cycles of the extension and compression the mixture of the dissolvents and the gaseous fluids is transformed from the dissolvent into an antidissolvent at the minimal losses of the dissolvent. At that one and the same dissolvent is used multiply. The invention allows to treat a big amount of the soluble material by the minimal amount of the dissolvent.
EFFECT: the invention allows to process a big amount of the soluble material by the minimal amount of the dissolvent.
26 cl, 5 ex, 10 dwg, 1 tbl