RU2392972C2 - Method of obtaining polysaccharide material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining polysaccharide fibre for making materials, specifically for making surgical suture materials absorbable in a human and a mammal body, absorbable and non-absorbable dressing material and absorbable textile matrix materials. The method is characterised by that 2.4-4.0 wt % solution of polysaccharide in dimethylacetamide which contains 4.56-10.00 wt % lithium chloride is mixed with 1.0-5.0 wt % poly-N-vinylpyrrolidone with molecular weight of 8-35 kDa or a metallopolymer complex - fine-grained silver stabilised by poly-N-vinylpyrrolidone in such an amount that, content of fine-grained silver relative polysaccharide dissolved in spinning solution ranges from 0.07 to 0.87 wt %. Mass ratio of polysaccharide: metallopolymer complex equals 88.0-99.0:1.0-12 wt %. The mixture is intensely stirred, held, filtered, degassed and the obtained spinning solution is extruded at room temperature into an alcohol deposition tank in form of water-soluble aliphatic C₂ and C₃ alcohols. The fibre is then processed in plastification and washing tanks and dried.

EFFECT: obtaining fibre with good deformation and strength properties.

1 dwg, 4 tbl, 29 ex

Description

The invention relates to a method for producing polysaccharide fibers for the manufacture of materials with enhanced deformation and strength properties, such as monofilament and polyfilaments, films, powders from natural high molecular weight polymers, including chitin and cellulose. The resulting polysaccharide materials can be additionally given antimicrobial activity due to the formation of complexes with highly dispersed silver.

The invention can be used to obtain absorbable and non-absorbable in the human and mammalian body surgical sutures, dressings, films and powders with prolonged antimicrobial activity, as well as absorbable woven matrix materials to obtain grafts (dermal equivalents) necessary in the treatment of extensive skin lesions with extensive burns and trophic ulcers. The claimed method for producing polysaccharide fibers for the manufacture of materials with increased deformation-strength properties is characterized by a combination of the following essential features:

1. The polysaccharide is dissolved by heating in dimethylacetamide containing 4.56-10.00 wt.% Lithium chloride, to obtain a 2.4-4.0 wt.% Solution.

2. 1.0-5.0 wt.% Poly-N-vinylpyrrolidone (PVP) with a molecular weight of 8-35 kDa or the metal-polymer complex PVP - finely dispersed silver in such an amount that the content of finely dispersed silver relative to the dissolved polysaccharide is added to the solution in the final spinning solution is from 0.07 to 0.87 wt.%, while the mass ratio of polysaccharide: metal-polymer complex is 88.0-99.0: 1.0-12 wt.%, the mixture is intensively mixed, kept, filtered and degassed.

3. The resulting dope at room temperature is extruded into an alcohol precipitation bath containing aliphatic water-soluble C ₂ -C ₃ alcohols; the resulting fiber is passed through plasticizing and washing baths and dried.

Fibers from natural polysaccharides have long attracted the attention of surgeons. So, in the so-called papyrus Edwin Smith (Internet), whose age is estimated at 4000 years, describes the use of flax as a suture material.

It is known that suture threads can be non-absorbable, for example, flax and other types of celluloses of various origin and absorbable ([1] Buyanov VM, Egiev VN, Udotov OA Surgical suture - 2000-2005, site Endosurgery , section “History of suture materials”).

Currently, a set of the following requirements is presented to surgical suture materials. They must be biocompatible, preserving strength over time, ensuring complete healing of the wound. They should not have allergenic properties, not have wickiness (that is, the ability to filter liquids through themselves), and be resistant to various infections.

If the surgical suture thread has antimicrobial activity, then disadvantages such as wickness, and resistance to infections can be neglected. ([2] Kuzmina N.L., Biber B.L., Abakumov G.A. et al. Chemical and natural sutures for surgical suture materials. - M .: NIITEKHIM, 1988. P. 82).

The mechanical strength of the fiber used for surgical sutures should exceed the strength of the damaged tissue at all stages of its regeneration and provide good handling properties of the suture during suturing. In this case, the fiber should not have cutting edges that could injure stitched fabrics. Materials must be sterilized by simple, generally accepted methods ([3] Kuzin MI, Adamyan AA, Vinokurova TI Surgical absorbable suture materials. // Surgery. 1990. No. 9, S.152-157).

In recent years, publications have appeared on the use of chitin, a natural polysaccharide, as a surgical suture material. Chitin is characterized by biological compatibility with tissues of the human and animal body. It has immunomodulating, antimicrobial, fungistatic, antitumor, radioprotective, wound healing and hemostatic effects ([4] K.D. Zhogolev, V.Yu. Nikitin, Yu.I. Bulankov. Study of chitin and chitosan preparations during the wound healing process. // Actual problems of purulent-septic infections. - SPb. 1996, S.36-37). Chitin accelerates tissue repair without scarring and loss of functionality. It initiates the restoration of blood vessels without any side effects ([5] Shigemasa A., Minami S. The use of chitin and chitosan in medicine. // Kobunsi kako. - 1997. 46. No. 2. P.27-33, [6 ] Dinesh K. Singh and Alok R. Ray. Biomedical applications of chitin and chitosan, and their derivatives. // J. of macromol. Sci.-Reviews in chemistry and physics. 2000, V.C40, N.1, p. 60-83).

Biologically active polysaccharides can immobilize growth factors and regulate cell proliferation, which opens up wide possibilities for the regeneration of not only the skin integument, but also other vital cellular systems of the human body.

The stabilization of finely dispersed metal particles in polymer matrices opens up wide possibilities for combining the properties of inorganic components and polymers.

The production of spongy membranes from chitosan and a chitin-chitosan mixture containing silver sulfodiazine ([6] K. Tachira, Onishi H., Machida Y., Preraration of silver sulfadiazine-containing spongy membranes of chitosan and chitin-chitosan mixture and their evaluation as burn wound dressings / -Yakuzaigaku, 1997, 57 (3), 159-167 (Japan), Nippon Yakuzai Gakkai. (Dep. Clinical Pharm., Hoshi Univ., Tokyo, Japan). Chem. Abstr. vol. 128, No. 5, 1998).

The closest in technical essence to the claimed solution is a method for producing polysaccharide fibers ([7] RF Application 2006124131 A, publication date 01/20/2008). This method is implemented by the following set of essential features: “A 2.4-4.0 wt.% Solution of polysaccharide in dimethylacetamide containing 4.56-10.0 wt.% Lithium chloride is extruded at room temperature into an alcohol precipitation bath, which is used as a water-soluble aliphatic C ₂ and C ₃ alcohols, treat the obtained fiber in plasticizing and washing baths and dry. ”

However, the resulting surgical suture material was not strong enough and flexible. The reason for this was the increased fragility of the threads and low tensile elongation.

The objective of the invention was to obtain from natural high molecular weight polysaccharides such materials as absorbable and non-absorbable fibers (monofilament and polyfilaments), with increased deformation and strength properties necessary for a surgical suture material, and absorbable woven matrix materials.

The claimed method for producing polysaccharide fibers for the manufacture of materials with increased deformation-strength properties is characterized by a combination of the following essential features;

1. The polysaccharide is dissolved by heating in dimethylacetamide containing 4.56-10.00 wt.% Lithium chloride, to obtain a 2.4-4.0 wt.% Solution of the polysaccharide.

2. 1.0-5.0 wt.% Poly-N-vinylpyrrolidone (PVP) with a molecular weight of 8-35 kDa or the metal-polymer complex PVP - finely dispersed silver in such an amount that the content of finely dispersed silver relative to the dissolved polysaccharide is added to the solution in the final spinning solution is from 0.07 to 0.87 wt.%, while the mass ratio of polysaccharide: metal-polymer complex is 88.0-99.0: 1.0-12 wt.%, the mixture is intensively mixed, kept, filtered and degassed.

3. The resulting dope at room temperature is extruded into an alcohol precipitation bath containing aliphatic water-soluble C ₂ -C ₃ alcohols; the resulting fiber is passed through plasticizing and washing baths and dried.

Isolation and purification of chitin from chitin-containing raw materials is carried out according to the following method. The crushed shells of crab, shrimp, krill are repeatedly treated with dilute hydrochloric acid, cooled to 4-10 ° C, followed by washing with water; then the material is treated once with a dilute aqueous solution of sodium hydroxide at 35-45 ° C, washed with water, treated with an aqueous solution of synthetic detergent at a temperature of 35-45 ° C and pH = 11, washed with water, an aqueous solution of 1-5 wt.% acetic acid , water, acetone and dried in vacuum at a temperature not exceeding 60 ° C.

The selection of purified pulp is also carried out by known methods.

The lignin residues from flax, cotton, and other types of industrial celluloses are first removed by boiling the polysaccharide in an aqueous solution of sodium hydroxide with sodium thiosulfate. The cellulosic feed is desalted with a dilute aqueous solution of hydrochloric acid and washed with water to pH = 6-6.5. The isolated cellulose is included with acetone or ethanol and dried in vacuum at a temperature not exceeding 60 ° C.

It should be noted that the fibers obtained from various types of chitin and cellulose possess deformation-strength characteristics characteristic of their nature.

Distinctive from the prototype method, an essential feature is the introduction of a poly-N-vinylpyrrolidone (PVP) polysaccharide solution with a molecular weight (M) of 8-35 kDa, in an amount of 1.0-5.0 wt.% Of the polysaccharide mass or PVP metal-polymer complex - finely divided silver in such an amount that the content of finely divided silver relative to the dissolved polysaccharide in the final dope is from 0.07 to 0.87 wt.%, while the mass ratio of polysaccharide: metal-polymer complex is 88.0-99.0: 1.0-12 wt.%.

Note: when using methyl alcohol as a precipitation bath, good deformation and strength characteristics of polysaccharide fibers both containing PVP and additionally containing a complex of polysaccharide - highly dispersed metallic silver were also obtained. However, due to the high toxicity of methanol, its use in the formation of fibers is unacceptable.

The most effective effect on the properties of shrimp chitin fibers is exerted by small PVP additives from 1 to 5.0%. The PVP with M = 8-35 kDa turned out to be the best modifier. With the introduction of 2.5% PVP with M = 12 kDa, a fiber strength of 718 MPa was achieved in the dope, and the elongation at break was 6.8%. Such a fiber retains up to 40% of the initial strength in a knot. The results are shown in table No. 1.

Obtained from solutions of sulfite cellulose, using a 1 / 0.4 die, in accordance with the claimed method, fibers modified with polyvinylpyrrolidone are characterized by tensile strength (σ _p ) 475-735 MPa; elongation at break (ε) of 7.9-9.2%, the preservation of strength in the node (σ _y ) 32-40.8%. The results are shown in table No. 2.

Modification of the polysaccharide solution by the PVP complex - highly dispersed silver in accordance with the claimed invention is carried out by adding to the solution a metal-polymer complex synthesized by a known method. (8. RF patent No. 2088234 "Water-soluble bactericidal composition and method for its preparation" with priority dated November 25, 1994). The known composition is a system containing silver nanoparticles stabilized by poly-N-vinylpyrrolidone.

Composite fibers of crab chitin — monofilaments obtained by using a 1 / 0.4 die in accordance with the claimed method — are characterized by strength of 700–916 MPa, elongation at break of 5.0–8.1%, and maintenance of strength in a knot of 8.9–25% . The results are summarized in table 3.

Polyfilament crab chitin fibers obtained by using dies with a number of holes up to 300 and a hole diameter of up to 0.08 mm in accordance with the claimed method are characterized by a strength of 600 to 868 MPa (63.4 cN / tex), and a knot strength of 40% is maintained up to 69.8% and elongation at break from 5.0% to 8.5%. The results are presented in table 4.

The tests also showed that the fibers obtained by the claimed method are biocompatible, absorbable during the time necessary for complete healing of the wound, are not allergenic, their mechanical properties fully comply with the existing requirements for matrix and surgical suture materials. Radiation, as well as conventional heat-vapor sterilization, do not change the deformation-strength characteristics of the fibers. Tests have shown that fibers containing highly dispersed silver have high antimicrobial activity against both gram-positive and gram-negative bacteria.

The analysis of the scientific and technical level did not allow us to find a known method that matches the entire set of essential features with the declared one. This allows us to claim compliance of the claimed invention with such a condition of patentability as novelty.

An analysis of the known scientific and technical level showed the novelty of such essential features of the claimed method as the modification of polysaccharide solutions in the dimethylacetamide - lithium chloride system by the addition of PVP, as well as the PVP - Ag metal-polymer complex containing silver nanoparticles. It unexpectedly turned out that in this case the deformation-strength characteristics of the modified fiber are improved. It was first discovered that small additions of PVP or PVP - Ag complex slow down the crystallization of chitin during fiber formation, which increases the strength and tensile elongation. T.O. new non-obvious functions of PVP and PVP-Ag complex were discovered: first, polymer additives combine well with polymers such as polysaccharides in the same solution (this was impossible to predict), and secondly, this combination improves the deformation-strength characteristics of the composite fiber ( it was also impossible to predict) without deterioration of compatibility with the body, thirdly, the interaction of the polysaccharide with the introduced metal-polymer complex is also accompanied by an increase in the deformation-strength x teristics fibers thus formed chelate complexes is accompanied by the discoloration of the spinning solution. The resulting final material is homogeneous and maintains a high dispersion of silver nanoparticles. It also turned out to be unexpected and unobvious.

Finding new, non-obvious functions of a previously known substance gives the claimed solution as a whole compliance with such a patentability condition as inventive step (non-obviousness).

The fiber formation in accordance with the claimed invention is carried out by the "wet method" (on a device for studying the processes of fiber formation PFV-01).

Functional diagram of the device shown in the drawing. Use a syringe dispenser or a metering pump and dies: 1 / 0.4 (one hole with a diameter of 0.4 mm); and also dies with the number of holes up to 300 and with hole diameters from 0.06 to 0.08 (40 / 0.06; 40 / 0.07; 40 / 0.08, etc.).

Films are prepared by pouring a diluted spinning solution of a polysaccharide onto a drum or substrate, followed by precipitation, washing with water, and drying.

The production of powder materials is carried out by grinding the obtained fibers.

The fabric for absorbable matrices was made by hand weaving.

The drawing shows a functional diagram of the device PIFV-01 to study the processes of orientational forming of fibers from polymer solutions. The device includes the following components:

1. A syringe spinning assembly, which consists of a control unit, an electric motor, a gearbox, a metering syringe, a filter, and a spinneret assembly.

2. A replaceable spinning unit with a metering pump, which consists of a motor control unit, an electric motor, a gearbox, a metering pump, a spinning tank, a filter and a spinneret unit.

3. Precipitation bath with a jacket to maintain the desired temperature of the coagulant.

4. The first plasticizing bath with a jacket to maintain the required temperature.

5. The second plasticizing bath with a jacket to maintain the required temperature.

6. A flushing unit that includes a control unit for an electric motor, electric motor, gearbox, thermostat, bathtub and feed pump.

7. The drying unit, which consists of an electric motor control unit, an electric motor, a gearbox, a heat chamber with a temperature regulator.

8. Fiber receiving unit with twist and control unit.

A - Sweeping units, including control units for electric motors, electric motors, gearboxes.

The electric motors of the metering devices, sweeping units, twists, and winders are equipped with stroboscopic sensors that are connected to the control units of the units and to the recording device.

Studies have shown that solutions of polysaccharides in aprotic solvents containing lithium chloride and PVP, as well as PVP-Ag, in the absence of moisture in the air for several years, maintain a constant viscosity and the ability to form fibers with constant deformation and strength characteristics.

Tests have shown that the obtained modified polysaccharide fibers used as a suture material are biocompatible, absorbable during the time required for complete healing of the wound. They are not allergenic, non-toxic, their mechanical properties are fully consistent with existing requirements for surgical suture materials. Radiation sterilization does not change the deformation-strength characteristics of the fibers.

To prove the conformity of the claimed solution to the condition of patentability, industrial applicability and to better understand the essence of the invention, we give examples of its specific implementation, which cannot exhaust the essence of the technical solution.

Obtaining polysaccharide fibers modified with polyvinylpyrrolidone

Example 1

Chopped chitin - containing raw materials (shrimp shell - krill chitin) is repeatedly treated with dilute hydrochloric acid, cooled to 4-5 ° C, washed with water; once treated with a dilute aqueous solution of sodium hydroxide at 35-45 ° C, washed with water, twice with a synthetic detergent at 35-45 ° C and pH = 1, washed with water, an aqueous solution of 1-5 wt.% acetic acid, water, acetone and dried in vacuum at a temperature not exceeding 60 ° C. Isolated chitin does not contain ash, protein and has M = 120 kDa.

A portion of chitin - 10.1 g is poured with a hot solution of 21.91 g of lithium chloride dissolved in 300 ml of dimethylacetamide (T = 80 ° C), stirred until complete dissolution, filtered, degassed under vacuum. The resulting solution contains 3.2 wt.% Chitin and 7 wt.% LiCl. Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. Precipitation bath - isopropanol, temperature - room. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled and dried.

The strength of the obtained filament 300 MPa, elongation at break of 1.8%.

The data of examples 2-10, performed under the conditions of example 1, but with the addition of PVP, are presented in Table 1, which shows the dependence of the tensile strength properties of composite chitin fibers on M and the concentration of poly-N-vinylpyrrolidone (PVP).

The deformation-strength properties of the fibers of krill chitin obtained with the addition of PVP (according to examples 1-10)
Table 1 Example The molecular weight of PVP, ^x 10 ³ The composition of the solution Chitin - PVP,% Breaking strength, MPa Elongation at break,% one Source Chitin 100-0 300 1.8 2 8.0 99.0-1.0 384 3.7 3 97.5-2.5 370 4.4 four 95.0-5.0 366 3.8 5 12.0 99.0-1.0 773 4.0 6 97.5-2.5 718 6.8 7 95.0-5.0 577 6.1 8 35.0 99.0-1 573 5.5 9 97.5-2.5 528 3.1 10 95.0-5.0 484 5.1

From the data of Table 1 it can be seen that the most effective effect on the properties of shrimp chitin fibers is exerted by small PVP additives - from 1.0 to 5.0%. The modification effect is achieved with PVP with M = 8.0-35 kDa. With the introduction of 2.5% PVP with M = 12 kDa into the dope, the fiber strength increased to 718 MPa, and the elongation at break was 6.8%. Such a fiber retains up to 40% of the initial strength in a knot.

With an increase in the PVP concentration in the dope solution of more than 5.0%, a decrease in all the mechanical characteristics of the fiber is observed, the values of which are also significantly affected by the molecular weight of the PVP. The use of low molecular weight PVP with M less than 8.0 kDa and high molecular weight with M more than 50 kDa leads to a noticeable decrease in strength and elongation at break, while the elastic modulus remains almost unchanged, however, when using PVP with M more than 800 kDa, a sharp drop is observed.

Example 11

Sulphite cellulose is desalted with a dilute aqueous hydrochloric acid solution and washed with water to pH = 6-6.5. Anesthetized cellulose is included with acetone and dried in vacuum at a temperature not exceeding 60 ° C.

A sample of sulfite cellulose - 10.1 g is poured with a hot solution of 21.91 g of lithium chloride dissolved in 300 ml of dimethylacetamide (T = 80 ° C), stirred until complete dissolution, filtered, degassed under vacuum. The resulting solution contains 3.2 wt.% Cellulose and 7 wt.% LiCl.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. Precipitation bath - isopropanol, room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The deformation-strength characteristics of a fiber conditioned at a relative humidity of 65% (pH = 65) were determined using an Instron-110 instrument. The base of the test samples was 50 mm, the loading speed was 10 mm / min. In each definition of strength, the characteristic is the average value obtained on 5 parallel samples. The strength of the obtained filament is 370 MPa, the elongation at break of 7.0%, the preservation of strength in the node 28.9%, the initial module (Young's modulus) 19.2 GPa, linear density 1.37 tex.

Example 12

In 100 g of the cellulose solution obtained under the conditions of Example 11, 0.0337 g of poly-N-vinylpyrrolidone, 1.00 wt.%, PVP of the polysaccharide contained in the solution is dissolved with stirring. Use PVP with M = 12 kDa. The solution is filtered, degassed, and a cellulose dope is obtained to form the fiber.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The obtained fiber is characterized under the conditions of Example 11. The strength of the obtained yarn is 735 MPa, the elongation at break is 8.1%, the preservation of the strength in the knot is 32.0%, the initial modulus is 20 GPa, and the linear density is 1.37 tex.

Example 13

In a solution of cellulose (100 g) obtained under the conditions of Example 11, 0.0840 g of PVP (2.5%) was dissolved. The resulting solution is filtered, degassed and used to form the fiber. The conditions for forming the fiber and determining the deformation-strength properties are also similar to the conditions of example 11.

Fiber strength at break 685 MPA, elongation at break 9.2%; initial module 19.5 GPa; preservation of strength in the node - 40.8%; linear density 1.37 tex.

Example 14

0.1683 g of PVP (5.0%) is dissolved in 100 g of the cellulose solution prepared according to the conditions of Example 11. The solution is filtered, degassed and spun. The resulting fiber is characterized by a strength of 576 MPa; elongation at break 9.0%; initial module 19.2 GPa; preservation of strength in the node - 40.0%; linear density 1.37 tex.

Example 15

0.5017 g of PVP (10.0%) is dissolved in 100 g of the cellulose solution obtained under the conditions of Example 1. The solution is filtered, degassed and spun. The resulting fiber is characterized by a strength of 457 MPa; elongation at break 7.9%; initial module 19.0 GPa; preservation of strength in the node - 38.0%; linear density 1.37 tex.

For a better understanding, the results of examples 11-15 are summarized in table 2.

Characterization of Polyvinylpyrrolidone Modified Sulphite Cellulose Fibers
Table number 2 № / № п / п Solution composition
Cellulose - PVP,% σ, MPa E, GPa ε,% σ _p ,% eleven 100.0-0.0 370 19.2 7.0 28.9 12 99.0-1.0 735 twenty 8.1 32,0 13 97.5-2.5 685 19.5 9.2 40.8 fourteen 95.0-5.0 576 19.2 9.0 40,0 fifteen 90.0-10.0 457 19.0 7.9 38,0

An analysis of the results given in Table 2 shows that, as in the cases with low molecular weight shrimp chitin, the modification of spinning solutions of low molecular weight sulfite cellulose (SP = 220) leads to an increase in the deformation and strength characteristics of the fibers obtained from these solutions. The maximum increase in strength characteristics is observed with small additives of 1.0-5.0% PVP with M = 12 kDa. It should be noted that in table No. 1, which also shows the effect of the molecular weight of PVP on the change in the deformation-strength characteristics of modified chitin fibers, the maximum increase in strength corresponds to PVP with M = 12 kDa.

Obtaining fibers upon modification of the dope solution with the PVP-Ag metal-polymer complex

Example 16

The crushed chitin-containing raw materials (crab shells) are repeatedly treated with dilute hydrochloric acid, cooled to 4-5 ° C, washed with water; once treated with a diluted aqueous solution of 5 wt.% sodium hydroxide at 35-45 ° C, washed with water, an aqueous solution of synthetic detergent at 35-45 ° C and pH = 11, washed with water, included with acetone and dried in vacuum at a temperature of 60 ° FROM. Isolated chitin does not contain ash, protein and has M = 180 kDa.

A portion of chitin - 10.1 g is poured with a hot solution of 21.91 g of lithium chloride dissolved in 300 ml of dimethylacetamide (T = 80 ° C), stirred until complete dissolution, filtered, degassed under vacuum. The resulting solution contains 3.2 wt.% Chitin and 7 wt.% LiCl.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. Precipitation bath - isopropanol, room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried.

The strength of the obtained filament is 645 MPa, elongation at break of 7.0%, the preservation of strength in the site of 16.0%, a linear density of 1.35 tex.

Example 17

In 100 g of a solution of chitin obtained under the conditions of Example 16, 0.00224 g of silver stabilized with poly-N-vinylpyrrolidone and 1.00 wt.% PVP-Ag of the chitin in solution are dissolved with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.0320 g of PVP-Ag, the modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried.

The strength of the obtained yarn is 895 MPa, the elongation at break of 8.1%, the preservation of strength in the node 25,0%, linear density of 1.37 tex.

Example 18

In 100 g of a solution of chitin obtained under the conditions of Example 16, 0.0056 g of silver stabilized with poly-N-vinylpyrrolidone and 2.5 wt.% PVP-Ag of the polysaccharide (chitin) contained in the solution are dissolved with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolution, 0.0800 g of PVP-Ag modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless. Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried. The strength of the obtained yarn is 916 MPa, the elongation at break of 8.0%, the preservation of strength in the node 24.1%, linear density 1.37 tex.

Example 19

In 100 g of a solution of chitin obtained under the conditions of Example 16, 0.0112 g of silver stabilized with poly-N-vinylpyrrolidone, 5.00% by weight of PVP-Ag from the polysaccharide (chitin) contained in the solution was dissolved with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.1600 g of PVP-Ag, the modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried.

The strength of the obtained yarn is 884 MPa, elongation at break of 6.7%, the preservation of strength in the node 19.2%, linear density of 1.38 tex.

Example 20

0.0224 g of silver stabilized with poly-N-vinylpyrrolidone, 10.00 wt.% PVP-Ag from the polysaccharide (chitin) contained in the solution is dissolved in 100 g of a chitin solution obtained under the conditions of Example 16. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.3200 g of PVP-Ag, the modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried. The strength of the obtained yarn is 845 MPa, the elongation at break of 6.7%, the preservation of strength in the site of 18.5%, a linear density of 1.40 tex.

Example 21

000269 g of silver stabilized with poly-N-vinylpyrrolidone, 12.00 wt.% PVP-Ag from the polysaccharide (chitin) contained in the solution is dissolved in 100 g of a chitin solution under the conditions of Example 16 with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.3840 g of PVP-Ag, the modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried.

The strength of the obtained filament is 805 MPa, the elongation at break is 6.0%, the preservation of strength in the knot is 13.7%, the linear density is 1.40 tex.

Example 22

0.03136 g of silver stabilized with poly-N-vinylpyrrolidone, 14.00 wt.% PVP-Ag from the polysaccharide (chitin) contained in the solution, is dissolved in 100 g of a chitin solution obtained under the conditions of Example 16. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.4480 g of PVP-Ag, the modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Obtaining fiber is carried out using a syringe dispenser and a die 1 / 0.4. The solution is extruded into an alcohol precipitation bath — isopropanol, and room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried. The strength of the obtained filament is 709 MPa, the elongation at break is 5.0%, the preservation of strength in the knot is 8.9%, and the linear density is 1.42 tex.

Example 23

A solution of chitin containing finely divided silver and obtained under the conditions of Example 17 is extruded into an alcohol precipitation bath — ethanol, and temperature — room temperature. The fiber is formed using a metering syringe and a 1 / 0.4 die. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control) and dried. The strength of the obtained yarn is 886 MPa, the elongation at break of 8.1%, the preservation of strength in the node 25.1%, linear density of 1.37 tex.

The results of these examples are summarized in table No. 3.

The deformation and strength characteristics of composite fibers from crab chitin containing fine silver
Table 3 No. / No. of examples The composition of the dope, wt.% Fiber indicators, monofilament. Die-1 / 0.4 chitin LiCl PVP-Ag Ag content Linear density tex Tensile strength, MPa Elongation at break,% Strength in a knot,% of the initial 16 3.2 7.00 0.00 0.00 1.35 17 3.2 7.00 1.00 0,07 1.37 895 8.1 25.0 eighteen 3.2 7.00 2,50 0.17 1.37 916 8.0 24.1 19 3.2 7.00 5.00 0.38 1.38 884 6.7 19.2 twenty 3.2 7.00 10.00 0.70 1.40 845 6.7 18.5 21 3.2 7.00 12.00 0.84 1.40 805 6.0 13.7 22 3.2 7.00 14.00 0.97 1.42 709 5,0 8.9 23 * 3.2 7.00 1.00 0,07 1.37 886 8.1 25.1 * - Coagulant - ethyl alcohol

Getting multifilament yarns

Example 24

A solution of chitin containing finely divided silver obtained under the conditions of Example 18 is extruded into a precipitation bath through a 300 / 0.08 die in isopropanol at room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The strength of the obtained filament is 641 MPa (46.8 cN / tex), elongation at break of 8.0%, preservation of strength in the knot 68.0%, linear density of 13.7 tex.

Example 25

A solution of chitin containing finely divided silver obtained under the conditions of Example 19 is extruded into a precipitation bath through a 300 / 0.08 die in isopropanol at room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The strength of the obtained filament is 601 MPa (43.6 cN / tex), elongation at break of 6.9%, preservation of strength in the node 69.8%, linear density of 13.8 tex.

Example 26

Bacterial cellulose is included with acetone, dried in vacuum at 60 ° C to constant weight. A portion of cellulose 9.17 g (3%) is poured with a hot (80 ° C) solution of 21.91 g LiCl (7%) in 300 ml of dimethylacetamide. Stir until completely dissolved, filtered, degassed under vacuum. The resulting dope solution contains 3.0 wt.% Bacterial cellulose and 7 wt.% LiCl.

The preparation of the fiber is carried out using a syringe dispenser and a die 300 / 0.08. Precipitation bath - isopropanol, temperature - room. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The strength of the obtained filament is 734 MPa, elongation at break of 7.2%, the preservation of strength in the node 41.1%, linear density of 1.36 tex.

Example 27

In 100 g of a solution of bacterial cellulose obtained under the conditions of Example 20, 0.00560 g of silver stabilized with poly-N-vinylpyrrolidone, 2.5 wt.% PVP-Ag of the polysaccharide (cellulose) contained in the solution was dissolved with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolution, 0.0800 g of PVP-Ag modified chitin solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless.

Dies 300 / 0.08. Precipitation bath - isopropanol, room temperature. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The strength of the obtained yarn is 868 MPa (63.4 cN / tex), the elongation at break of 8.5%, the preservation of the strength in the node of 60.0%, the linear density of 1.37 tex.

Example 28

Residual lignin is removed from a wax-free cotton linter by boiling in an aqueous solution of sodium hydroxide (5%) and sodium thiosulfate (20%). Next, the linter is washed with distilled water, the excess moisture is squeezed out, included with acetone and dried in vacuum at 60 ° C to constant weight.

A portion of purified cotton linter 9.17 g (3%) is poured with a hot (80 ° C) solution of 21.91 g LiCl (7%) in 300 ml of dimethylacetamide. Stir until completely dissolved, filtered, degassed under vacuum. The resulting dope solution contains 3.0 wt.% Cellulose and 7 wt.% LiCl.

The preparation of the fiber is carried out using a syringe dispenser and a die 300 / 0.08. Precipitation bath - isopropanol, temperature - room. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried.

The strength of the obtained yarn was 618 MPa (44.8 cN / tex), the elongation at break was 5.0%, the strength was maintained at a knot of 40.8%, and the linear density was 1.38 tex.

Example 29

In 100 g of a cotton linter solution obtained under the conditions of Example 28, 0.00560 g of silver stabilized with poly-N-vinylpyrrolidone, 2.5 wt% PVP-Ag of the polysaccharide (cellulose) contained in the solution, is dissolved with stirring. To stabilize silver, PVP with M = 12 kDa is used. The Ag content in the PVP-Ag composition is 7%. After dissolving 0.0800 g of PVP-Ag, the modified cellulose solution is left overnight to complete the chelation reaction. The end of the process is judged by the discoloration of the system - the brown solution becomes colorless. The solution is filtered, degassed and a spinning solution is obtained to form the fibers.

The preparation of the fiber is carried out using a syringe dispenser and a die 300 / 0.08. Precipitation bath - isopropanol, temperature - room. Plasticizing and washing baths - distilled water with a temperature of 50 ° С. Fiber intake speed - 3 m / min. The resulting fiber is washed with water at a temperature of 85 ± 5 ° C from lithium chloride (silver nitrate control), cooled, treated with acetone and dried. The strength of the obtained yarn is 911 MPa (65.1 cN / tex), elongation at break of 5.5%, the preservation of strength in the node 59.2%, linear density of 1.40 tex. The results of examples 24-29, obtaining multifilament yarns (300 / 0.08 spinneret was used) from solutions of various polysaccharides (chitin, cellulose from cotton linter and bacterial cellulose) are summarized in table No. 4 for a better understanding.

The deformation and strength characteristics of composite polysaccharide fibers containing fine silver
Table 4 No. / No. of Examples * The composition of the dope, wt.% Fiber indicators. Die - 300 / 0.08 Polysaccharide LiCl PVP-Ag Ag content,
wt.% Linear density tex Tensile strength, MPa Elongation at break,% Strength in a knot,% of the initial 24 3.2 7.00 2,50 0.17 1.37 25 3.2 7.00 5.00 0.38 1.38 601 6.9 69.8 26 3.0 7.00 0.00 0.00 1.36 734 7.15 41.1 27 3.0 7.00 2,50 0.17 1.37 868 8.5 60.0 28 3.0 7.00 0.00 0.00 1.38 618 5,0 40.8 29th 3.0 7.00 2,50 0.17 1.40 911 5.5 59.2 * examples: 24, 25 - crab chitin; 26 and 27 - bacterial cellulose;
28 and 29 — cellulose of cotton linter.

Films are prepared by pouring a diluted spinning solution of a polysaccharide onto a drum or substrate, followed by precipitation, washing with water, and drying. Powder materials are obtained by grinding the fibers.

Claims (1)

A method of obtaining polysaccharide fibers for the manufacture of materials, characterized in that in a 2.4-4.0 wt.% Solution of polysaccharide in dimethylacetamide containing 4.56-10.00 wt.% Lithium chloride, add 1.0-5.0 wt.% poly-N-vinylpyrrolidone (PVP) with a molecular weight of 8-35 kDa or the metal-polymer complex is finely dispersed silver stabilized by poly-N-vinylpyrrolidone in such an amount that the content of finely dispersed silver relative to the dissolved polysaccharide in the dope is from 0 , 07 to 0.87 wt.%, While mass co the polysaccharide: metal-polymer complex ratio is 88.0-99.0: 1.0-12 wt.%, the mixture is intensively mixed, aged, filtered, degassed and the resulting dope is extruded at room temperature in an alcohol precipitation bath, which is water-soluble. aliphatic C ₂ and C ₃ alcohols, then the resulting fiber is treated in plasticizing and washing baths and dried.

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