CN102199810B - Method for preparing chitosan fibers - Google Patents

Abstract

The invention discloses a method for preparing chitosan fibers, which comprises the following steps: mixing 2.0 to 6.0 weight percent of chitosan, 4.0 to 6.0 weight percent of lithium hydroxide, 0.5 to 4.0 weight percent of urea, 0.1 to 3.0 weight percent of glycerol and the balance of water, and swelling to prepare chitosan spinning solution; and spinning by a wet-process spinning method, coagulating and precipitating in a coagulating bath to form protofilaments, washing, drawing, and drying to obtain the chitosan fibers. In the invention, the spinning solution is prepared by dissolving chitosan in an alkaline solvent, the chitosan macromolecular chains exist in a high-swelling state, the arrangement of the chitosan macromolecular chains is more compact, the high instability of the chitosan in acidic solution is overcome, the hydrolysis of the chitosan macromolecular chains and the breakage of the glucosidic bonds are avoided, the oriented arrangement of the macromolecular chains is promoted, and the mechanical properties of the chitosan fibers are improved.

Description

A kind of preparation method of chitosan fiber

technical field

The invention relates to a novel preparation method of chitosan fiber.

Background technique

Chitosan fiber has the advantages of broad-spectrum antibacterial, high antibacterial efficiency and non-toxicity; at the same time, it has biodegradability, bioactivity and the ability to adsorb metal ions, and it has been clinically proven to promote new skin generation and accelerate healing. Speed, reduce pain and other functions, can be used in medical sutures, medical non-woven fabrics, hemostatic cotton, artificial skin and tissue engineering and other fields. With the expansion of the scope of application, the demand for chitosan fiber is bound to increase. However, the mechanical properties of chitosan fibers are still poor at present, and one of the important reasons is the acidic solvent used. Commonly used solvents at home and abroad are various dilute acids, and chitosan is extremely unstable in acidic solutions, which will cause partial hydrolysis of chitosan long chains and cleavage of glycosidic bonds, resulting in reduced molecular weight and polydispersity of chitosan. Thereby resulting in insufficient performance of chitosan fiber.

Contents of the invention

The purpose of the present invention is to provide a preparation method of chitosan fiber with good mechanical properties, stability and biocompatibility, so as to expand the application range of chitosan fiber.

The preparation method of chitosan fiber of the present invention, step is as follows:

1) Take the components according to the weight percentage: chitosan 2.0~6.0%, lithium hydroxide 4.0~6.0%, sodium hydroxide 0.5~4.0%, urea 6.0~9.0%, glycerin 0.1~3.0%, and the rest It is water; the above components are mixed and swelled for 3 hours, the swelling solution is frozen at -60°C~-20°C for 1-4h, and then thawed at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) Inject the chitosan spinning solution into a coagulation bath with a temperature of 30°C to coagulate into silk, coagulate and precipitate to form primary fibers, wash and stretch at 5~30°C, and dry at 20~50°C to obtain chitosan fiber.

The above coagulation bath can be H ₂ SO ₄ with a mass fraction of 2.0~18.0%, or a mixture of H ₂ SO ₄ and ethanol with a mass fraction of 2.0~18.0% in a volume ratio of 1:8~8:1, or It is a mixture of H ₂ SO ₄ with a mass fraction of 2.0~18.0%, ethanol and NaCl with a mass fraction of 2.0~8.0% in a volume ratio of 3:6:1.

The advantages of the present invention are:

The present invention dissolves chitosan in an alkaline solvent as the spinning solution, so that the macromolecular chains of chitosan exist in a highly swollen state, and the macromolecular chains of chitosan are arranged more tightly instead of the macromolecular chains of chitosan in an acid solution. The existence of chitosan salt overcomes the extremely unstable state of chitosan in acidic solution, ensures that the macromolecular chain of chitosan is not hydrolyzed and the glycosidic bond is not broken, and is more conducive to the alignment of the macromolecular chain, making the shell The mechanical properties of polysaccharide fibers are improved.

Detailed ways

Below in conjunction with example further illustrate the present invention.

Example 1:

1) Take each component according to the weight percentage content: 9.0g chitosan, 12.0g lithium hydroxide, 1.5g sodium hydroxide, 18.0g urea, 0.3g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -60°C for 1 hour, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) inject the chitosan spinning solution into a coagulation bath with a temperature of 30°C to coagulate into filaments to form fibers, and the coagulation bath used is H ₂ SO ₄ with a mass fraction of 18.0% to obtain primary chitosan fibers;

4) After the chitosan primary fiber was washed with water at 25°C, it was air-dried at 20°C. White chitosan fibers were obtained.

Example 2:

1) Take each component according to the weight percentage content: 9.0g chitosan, 15.0g lithium hydroxide, 3.0g sodium hydroxide, 18.0g urea, 1.5g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -40°C for 2 hours, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) Inject the chitosan spinning solution into a coagulation bath with a temperature of 30°C to form fibers. The coagulation bath used is a mixture of H ₂ SO ₄ and ethanol with a mass fraction of 10.0% in a volume ratio of 2:7. solution to obtain chitosan fibrils;

4) After the chitosan primary fiber was washed at 5°C, it was dried at 50°C to obtain white chitosan fiber.

Example 3:

1) Take each component according to the weight percentage content: 9.0g chitosan, 15.0g lithium hydroxide, 1.5g sodium hydroxide, 21.0g urea, 1.5g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -30°C for 3 hours, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) The chitosan spinning solution was injected into a coagulation bath with a temperature of 30 ° C to form fibers. The coagulation bath used was H ₂ SO ₄ with a mass fraction of 8.0%, ethanol and NaCl with a mass fraction of 5.0% According to the mixed solution with a volume ratio of 3:6:1, the primary chitosan fiber is obtained;

4) Washing the primary chitosan fibers with water at 10°C and drying at 30°C to obtain white chitosan fibers.

Example 4:

1) Take each component according to the weight percentage content: 12.0g chitosan, 15.0g lithium hydroxide, 4.5g sodium hydroxide, 24.0g urea, 6.0g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -20°C for 4 hours, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) Inject the chitosan spinning solution into a coagulation bath with a temperature of 30°C to form fibers. The coagulation bath used is a mixture of H ₂ SO ₄ and ethanol with a mass fraction of 4.0% in a volume ratio of 4:5. solution to obtain chitosan fibrils;

4) Wash the primary chitosan fiber at 15° C. and dry at 20° C. to obtain white chitosan fiber.

Example 5:

1) Take each component according to the weight percentage content: 12.0g chitosan, 12.0g lithium hydroxide, 4.5g sodium hydroxide, 21.0g urea, 6.0g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -60°C for 1 hour, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) The chitosan spinning solution was injected into a coagulation bath with a temperature of 30 ° C to form fibers. The coagulation bath used was H ₂ SO ₄ with a mass fraction of 2.0%, ethanol and NaCl with a mass fraction of 2.0% According to the mixed solution with a volume ratio of 3:6:1, the primary chitosan fiber is obtained;

4) Washing the primary chitosan fibers with water at 25°C and drying at 30°C to obtain white chitosan fibers.

Embodiment 6:

1) Take each component according to the weight percentage content: 12.0g chitosan, 15.0g lithium hydroxide, 5.0g sodium hydroxide, 24.0g urea, 7.5g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -50°C for 1.5h, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) The chitosan spinning solution is injected into a coagulation bath with a temperature of 30°C to coagulate into filaments to form fibers. The coagulation bath used is a mixture of H ₂ SO ₄ and ethanol with a mass fraction of 2.0% in a volume ratio of 8:1 solution to obtain chitosan fibrils;

4) After washing the primary chitosan fiber at 25°C, drying at 50°C to obtain white chitosan fiber.

Embodiment 7:

1) Take each component according to the weight percentage content: 10.5g chitosan, 18.0g lithium hydroxide, 1.5g sodium hydroxide, 24.0g urea, 3.0g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -40°C for 2 hours, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) The chitosan spinning solution was injected into a coagulation bath with a temperature of 30 ° C to form fibers. The coagulation bath used was H ₂ SO ₄ with a mass fraction of 14.0%, ethanol and NaCl with a mass fraction of 7.0% According to the mixed solution with a volume ratio of 3:6:1, the primary chitosan fiber is obtained;

4) Wash the primary chitosan fiber at 20°C and dry at 40°C to obtain white chitosan fiber.

Embodiment 8:

1) Take each component according to the weight percentage content: 10.5g chitosan, 15.0g lithium hydroxide, 1.5g sodium hydroxide, 24.0g urea, 4.5g glycerol, and the rest are water, a total of 300g; Swell for 3 hours after mixing, freeze the swelling solution at -30°C for 2 hours, and then thaw at room temperature to obtain a chitosan solution;

2) The chitosan solution is filtered and degassed by a centrifuge to obtain a chitosan spinning solution;

3) The chitosan spinning solution was injected into a coagulation bath with a temperature of 30 ° C to form fibers. The coagulation bath used was H ₂ SO ₄ with a mass fraction of 12.0%, ethanol and NaCl with a mass fraction of 5.0% According to the mixed solution with a volume ratio of 3:6:1, the primary chitosan fiber is obtained;

4) Wash the primary chitosan fibers at 10°C and dry at 50°C to obtain white chitosan fibers.

Claims (1)

1. the preparation method of a chitin fiber is characterized in that step is following:

1) contain by weight percentage and measure each component: shitosan 2.0～6.0%, lithium hydroxide 4.0～6.0%, NaOH 0.5～4.0%, urea 6.0～9.0%, glycerine 0.1～3.0%, all the other are water; Said components is mixed the back swelling 3 hours, swelling solution at-60 ℃～-20 ℃ freezing 1-4h, is at room temperature thawed then, get chitosan solution;

2) chitosan solution is through filtering, and uses the centrifuge deaeration, makes the shitosan spinning solution;

3) be to solidify precipitating in 30 ℃ the coagulating bath that is frozen into silk to generate protofilament with shitosan spinning solution implantation temperature, through 5～30 ℃ of following washing stretchings after, 20～50 ℃ of dryings must chitin fiber;

Above-mentioned coagulating bath is that mass fraction is 2.0～18.0% H ₂SO ₄, or mass fraction is 2.0～18.0% H ₂SO ₄With 1: 8 by volume～8: 1 mixed liquor of ethanol, or mass fraction is 2.0～18.0% H ₂SO ₄, ethanol and mass fraction be 2.0～8.0% 3: 6: 1 by volume mixed liquor of NaCl.