RU2258103C1 - Method for production of chitosan-containing fiber - Google Patents

Abstract

FIELD: artificial fibers manufacturing, in particular chitosan-containing fiber with antifungal and antibacterial activity.

SUBSTANCE: chitosan is dissolved in acetic acid solution and passed through sputtering dryer. Then obtained activated chitosan with porous structure in form of microparticles is brought into reactions of mercerization, xantation and wet extrusion.

EFFECT: chitosan-containing fiber with antibacterial activity and good biodegradability.

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Description

The invention relates to the field of production of artificial fibers having antibacterial and antifungal activity.

Chitin (poly-2-acetamido-2-deoxy-β-D-glucan) is one of the most common biopolymers in nature. Chitin is widely distributed in nature as a structure-forming material mainly in arthropods, annelids and mollusks, especially the external skeletons of arthropods.

Chitosan (poly-2-amino-2-deoxy-β-D-glucan) obtained on its basis has antimicrobial and antifungal activity, which determines the possibility of its use in medicine (RAAMuzzarelli "Chitin", Pergamon, 1977, RAAMuzzarelli "Chitosan per os ", Atec, 2000).

Products based on chitosan viscose have biocompatibility, antimicrobial activity, good biodegradability and can be used for the production of fiber materials, knitted and textile products, non-woven materials, films and other types of products.

Of practical interest are chitosan-containing and chitosan fibers and films obtained on the basis of viscose chitosan, which have biocompatibility, antimicrobial activity and good biodegradability.

There are a number of patents describing methods for processing chitosan into textile fibers and films. The possibility of obtaining fibers from acid solutions of chitosan was presented by Kunike back in 1926 (Kunike G., "Chemiefasern" 8, 126).

In 1936, Clark and Smith showed the possibility of forming chitosan fibers from lithium thiocyanate aqueous solutions of chitosan (J. Phys. Chem. 40, 863).

There are a number of patents for producing chitosan fibers by using chitosan solvents.

So, in US patent 4651725, 1987, the dissolution of chitosan is carried out in the system of dimethylformamide lithium chloride, followed by spinning the fiber into butyl alcohol.

Unitika, a Japanese company, also uses the dimethylformamide – lithium chloride system as a chitosan solvent, followed by molding into isobutyl alcohol (Japan, Patent 59068347, 1984).

There is information on the use of such solvents as chitosan solvents as a solution of acetic acid, trichloroacetic acid or an aqueous solution of sodium thiocyanate (USA Patent 4464321, USA Patent 5897821).

The production of chitosan-containing fibers using direct chitosan solvents, in contrast to the viscose method, is complicated by the need to create complex regeneration of chitosan solvents and components of the precipitation bath.

In this regard, under certain conditions, it is preferable to use the traditional method for producing chitosan-containing fibers according to a viscose scheme, mercerizing and xanthogenizing the initial product, followed by molding into a precipitation bath containing sulfuric acid, sodium and zinc salt of sulfuric acid.

A known process for producing chitin-chitosan viscose and products based on it (United States Patent Yoshikawa et al. 5756111, Int. CL. A 01 N 25/34; A 61 L 15/16; US CL. 424/402; 424/443 ; 424/445; 424/446; 424/447; 604/289; 604/304, May 26, 1998).

The process consists in the fact that the crushed chitin is subjected to double immersion in a 30-40% solution of sodium hydroxide in water (deacetylation) and squeezed up to 3-5 times the weight of the weight of the original chitin.

The obtained chitin-chitosan is ground and a xanthogenation reaction is carried out by adding carbon disulfide to chitin-chitosan in an amount of 30-80% by weight of the starting chitin. Then crushed ice is added and the chitin-chitosan is dissolved to obtain viscose chitin-chitosan, which is used to form fibers, films and sponges by the traditional wet method.

Obtaining chitosan from chitin, as a rule, includes a number of stages, the last of which is deacetylation, carried out with a 50% solution of sodium hydroxide in water at high temperature, followed by washing (RF patents No. 2211811, No. 2157590, No. 2159253).

In all the mentioned patents, the obtained chitosan is a solid dense substance with a characteristic pearlescent shine, therefore, the penetration of any reagent into chitosan is very difficult, and the implementation of mercerization and xanthogenation reactions is difficult due to the low diffusion rate of the reagent under heterogeneous conditions. Therefore, to carry out the reactions of mercerization and xanthogenization, chitosan is subjected to grinding. The disadvantage of the methods is the use of expensive, low-productivity and energy-intensive equipment, which carry out grinding of chitosan, while only about 10% of the grinding has the necessary degree of grinding and can ensure the occurrence of mercerization and xanthogenation reactions.

The objective of the invention is to obtain chitosan in the form of microparticles with a porous structure, which leads to an increase in the diffusion rate of the reagent and provides a higher reaction rate of mercerization and xanthogenation.

The task is achieved as follows.

A 1000 cps chitosan is dissolved in an acetic acid solution and passed through a spray dryer. Chitosan, obtained in the form of microparticles with a porous structure and thus activated, is subjected to mercerization and xanthogenation reactions.

The invention provides a more efficient implementation of the reactions of mercerization and xanthogenesis under heterogeneous conditions.

The chitosan-containing fiber obtained from chitosan viscose has antibacterial and antifungal activity.

The authors determined the dependence of the biocidal activity of samples of chitosan-containing fibers on the content of chitosan in the fibers. The results of the tests are shown in table 1.

Table 1
Biocidal activity of samples of chitosan-containing fibers (radius of inhibition zone, mm) Test culture The content of chitosan in the fiber,% (wt.) 10.1 23.3 50,4 100 Staphylococcus aureus 3 6 7 10 Streptococcus salivarius 1 3 3 4 Pseudomonas aeruginosa - 2 2 3

The justification for the suitability of the claimed invention is the experience of its implementation on an industrial scale.

Examples of specific implementation of the method.

Example 1

Crab chitosan with a deacetylation degree of 95% and a viscosity of 1000 cps (mol. Weight 24 × 10 ⁴ ) is dissolved in a 5% solution of acetic acid. The concentration of the solution is 0.5% wt. The resulting solution is passed through a PC-1.8 spray dryer with a solution feed rate of 50 l / h, the temperature of the incoming hot air is 160-170 ° C, and the temperature of the exhaust air is 60-70 ° C. The number average diameter of the obtained chitosan microparticles is 3.97 microns. Chitosan obtained in the form of microparticles is subjected to mercerization with a 17.5% aqueous solution of sodium hydroxide at 20 ° C for 1 hour in a liquid module 20. After vacuum pressing on a suction filter, alkali-containing chitosan contains 25.4% (wt.) Of chitosan and 11% (wt.) Sodium hydroxide.

The obtained mercerized chitosan is subjected to xanthogenation, for which carbon disulfide is added to the mercerized chitosan. The amount of carbon disulfide is 60% of the initial weight of chitosan.

Xanthogenation proceeds at a temperature of 20 ° C for 24 hours.

After filtration, viscose chitosan contains 3.3% (wt.) Chitosan.

The obtained viscose of chitosan is mixed with viscose pulp in an apparatus with a stirrer in a ratio of 1: 3.

The formation of chitosan viscose fiber is carried out in the traditional wet way.

After finishing and drying, the 25.8 tex chitosan viscose fiber contains 10.1% by weight chitosan and has bactericidal activity against staphylococcus aureus and streptococcus salivarius.

Tests for bactericidal activity were carried out in vitro. The test material was placed on the surface of an agarized Chapek-Dox medium inoculated with appropriate test cultures.

Fiber strength - 96.5 mN / tex, elongation at break - 15.5%.

Example 2

Crab chitosan with the indicators of example 1, activated in the conditions of example 1, is subjected to mercerization in the conditions of example 1.

The alkali-containing chitosan obtained after vacuum pressing on a nutsche filter contains 25.4% (wt.) Chitosan and 11% (wt.) Sodium hydroxide.

The obtained mercerized chitosan is subjected to xanthogenation under the conditions of example 1. After filtration, the viscose chitosan contains 3.3% (wt.) Chitosan.

The obtained viscose of chitosan is mixed with viscose pulp in an apparatus with a stirrer in a ratio of 0.8: 1.

The formation of chitosan viscose fiber is carried out in the traditional wet way.

After finishing and drying, the 16.6 tex thick chitosan viscose fiber contains 23.3% chitosan and has bactericidal activity against staphylococcus aureus and streptococcus salivarius. The bactericidal test was carried out under the conditions of example 1.

Fiber strength - 105 mN / tex, elongation at break - 11%.

Example 3

The crab chitosan with the parameters of Example 1, activated under the conditions of Example 1, is subjected to mercerization with a 24% sodium hydroxide solution at 60 ° C for 3 hours in a liquid module 20.

The alkali-containing chitosan obtained after vacuum pressing on a nutsche filter contains 27.2% (wt.) Chitosan and 14.1% (wt.) Sodium hydroxide.

The obtained mercerized chitosan is subjected to xanthogenation, for which carbon disulfide is added to the mercerized chitosan in an amount of 80% of the initial weight of chitosan.

After filtration, viscose chitosan contains 2.58% (wt.) Chitosan.

The obtained viscose of chitosan is mixed with viscose pulp in an apparatus with a stirrer in a ratio of 3: 1.

The formation of chitosan viscose fiber is carried out in the traditional wet way.

After finishing and drying, the chitosan viscose fiber with a thickness of 16.6 tex contains 50.4% (wt.) Chitosan and has bactericidal activity against staphylococcus aureus and streptococcus salivarius. The bactericidal test was carried out under the conditions of example 1.

Fiber strength - 115 mN / tex, elongation at break - 12%.

Example 4

The crab chitosan with the parameters of Example 1, activated under the conditions of Example 1, is mercerized under the conditions of Example 3. The mercerized chitosan obtained after vacuum pressing on a suction filter contains 27.2% chitosan and 14.1% sodium hydroxide.

Mercerized chitosan is xanthogenized under the conditions of example 3.

After filtration, viscose chitosan contains 2.58% chitosan. To form a fiber, viscose chitosan is used.

The formation of fiber from viscose chitosan is carried out in the conditions of example 1.

The obtained chitosan fiber with a thickness of 16.6 tex contains 100% (wt.) Chitosan and has bactericidal activity against staphylococcus aureus, streptococcus salivarius and pseudomonas aeruginosa.

Fiber strength - 110 mN / tex, elongation at break - 12%.

Claims (1)

A method of producing chitosan-containing fiber from chitosan by grinding chitosan, mercerization, xanthogenization and wet molding, characterized in that chitosan is activated by dissolving it in acetic acid, followed by drying in a spray dryer to form microparticles with a porous structure, and then subjected to mercerization and xanthogeny molding.