Preparation method and application of high-performance chitosan fiber

Abstract

The present invention discloses a method for preparing and applying high-performance chitosan fibers. The method involves dissolving chitosan and glycerol in a glutamic acid aqueous solution to prepare a spinning solution. Using a polyol and calcium chloride ethanol solution as a coagulation bath, the chitosan is slowly coagulated while undergoing ionic crosslinking, promoting orderly stacking of the chitosan molecules and facilitating subsequent stretching and orientation. Further coagulation and alcohol washing are then performed to remove the polyol, further compacting and ordering the chitosan molecules and enhancing the mechanical properties of the fiber. The resulting high-performance chitosan fibers can be used to manufacture fiber products such as filament yarn, spun yarn, batting, and non-woven fabrics, and have broad application prospects in the field of functional textiles.

Description

Technical Field

[0001] The invention belongs to the technical field of natural polymer material processing, and particularly relates to a preparation method and application of high-performance chitosan fiber. Background Art

[0002] Chitosan is a natural polymer product with high resource abundance. It has good antibacterial properties, biocompatibility, and biodegradability. It is widely used in the fields of biomaterials, biomedical materials, and health care products. However, the concentration of pure chitosan solution is low and the viscosity is high. The mechanical properties of chitosan fibers prepared by existing methods are not ideal. Therefore, chitosan is often blended with other polymer solutions to prepare composite fibers, composite films, hydrogels and other materials. Patent CN113862830A discloses a method for preparing chitosan / polyvinyl pyrrolidone composite fibers, using an aqueous solution of acetic acid and polyvinyl pyrrolidone as a solvent to dissolve chitosan, and the breaking strength of the obtained composite fibers is significantly improved. Patent CN111519280B discloses a method for preparing chitosan fiber materials, dissolving chitosan in an alkaline solution, and obtaining chitosan fibers after spinning and coagulation. This method avoids the degradation of chitosan by acid or strong base. Patent CN112323181A discloses a method for preparing high-performance chitosan fibers, using citric acid as a solvent and cross-linking agent for chitosan, and using NaOH and ethanol aqueous solution as a coagulation bath, and the prepared chitosan fibers have improved tensile properties. Patent CN110359101B discloses a gel spinning method for manufacturing chitosan fibers, adding organic sodium phosphate to a chitosan solution, raising the temperature at the spinning outlet to gel the spinning solution, and then entering the coagulation bath for molding. The existing methods ignore the problem of drastic changes in the molecular structure of dilute chitosan solutions during the coagulation process, resulting in many random coil structures and weak intermolecular forces, which makes the mechanical properties of chitosan fibers poor. Therefore, changing the coagulation and concentration process of the chitosan solution, reducing the curling and locking structure of the chitosan molecules, and improving the drafting of the chitosan fibers and the orderly arrangement of their molecules are the keys to improving the mechanical properties of chitosan fibers. Summary of the Invention

[0003] The present invention aims to provide a method for preparing high-performance chitosan fibers and its application, wherein chitosan is gently dehydrated in a polyol solution containing calcium ions, while simultaneously forming ionic crosslinks, thereby controlling the chitosan macromolecular structure and facilitating subsequent stretching and orientation. The chitosan fibers are then further coagulated and the polyol removed, thereby making the chitosan molecules more compact and orderly stacked, thereby enhancing the mechanical properties of the fibers. The technical solution for achieving this purpose comprises the following steps:

[0004] S1. Dissolving chitosan and glycerol in an aqueous glutamic acid solution, filtering and degassing to obtain a chitosan spinning solution;

[0005] S2. The polyol and calcium chloride ethanol solution are mixed to obtain a coagulation bath A, wherein the polyol is one or more of glycerol, polyethylene glycol 400, and triethanolamine;

[0006] S3. Dissolve calcium chloride in ethanol to obtain coagulation bath B;

[0007] S4. The chitosan spinning solution obtained in S1 is squeezed into the coagulation bath A obtained in S2 and coagulated for 10-30 min to obtain chitosan primary fibers;

[0008] S5. After the chitosan nascent fibers obtained in S4 are drawn, they are introduced into the coagulation bath B obtained in S3 and coagulated again for 30-300 min;

[0009] S6. The coagulated chitosan fibers obtained in S5 are dried, washed with alcohol, stretched, and dried again to obtain high-performance chitosan fibers.

[0010] Preferably, the concentrations of chitosan and glutamic acid in S1 are both 3 wt%, and the concentration of glycerol is 0.5 wt%-5 wt%.

[0011] Preferably, the volume ratio of the polyol to the calcium chloride ethanol solution in S2 is 1-4:1, and the concentration of calcium chloride in the calcium chloride ethanol solution is 20wt%-30wt%.

[0012] Preferably, the concentration of calcium chloride in the coagulation bath B in S3 is 10 wt % to 30 wt %.

[0013] Preferably, the drafting ratio described in S5 is 1.0-1.2 times.

[0014] Preferably, the drying temperature in S6 is 25-60° C., and the drafting ratio is 1.2-2 times.

[0015] Furthermore, the present invention provides a high-performance chitosan fiber.

[0016] Furthermore, the present invention provides high-performance chitosan fibers for use in manufacturing filament yarns, staple yarns, waddings, and non-woven fabrics.

[0017] The beneficial effects are:

[0018] 1) The chitosan spinning solution of the present invention has good stability and can be stored for a long time without affecting the processing performance;

[0019] 2) The preparation method of the present invention allows the chitosan molecules to be gently concentrated under the action of ionic cross-linking, which is beneficial to the orderly stacking and straight arrangement of the chitosan molecules, and greatly improves the mechanical properties of the chitosan fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1is an optical photograph of the high-performance chitosan fiber prepared in Example 1;

[0021] Figure 2 This is the tensile curve of the high-performance chitosan fiber prepared in Example 1. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but they are not intended to limit the present invention. Example

[0023] Dissolve 0.6g of glutamic acid in 17.8g of water, then dissolve 0.6g of chitosan and 1g of glycerol in the glutamic acid solution, filter and degas to obtain chitosan spinning solution. Mix 10ml of glycerol and 10ml of 30% calcium chloride ethanol solution evenly to obtain coagulation bath A. Squeeze the chitosan spinning solution into coagulation bath A and coagulate for 30min to obtain chitosan primary fiber. Stretch the chitosan primary fiber 1.0 times, introduce it into coagulation bath B of 30% calcium chloride ethanol solution, and coagulate it again for 100min. Dry the obtained chitosan fiber at 25℃ for 30min, wash it with ethanol, stretch it 1.5 times, and then dry it at 60℃ to obtain high-performance chitosan fiber. Figure 1 It can be seen that the obtained high-performance chitosan fiber has a fineness of about 26-28 μm, uniform thickness and smooth surface. Figure 2 It can be seen that the tensile breaking strength of chitosan fiber is 3.5-3.9 cN / dtex, and the elongation at break is 27%-33%. Example

[0024] Dissolve 0.6g of glutamic acid in 18.7g of water, then dissolve 0.6g of chitosan and 0.1g of glycerol in the glutamic acid solution. Filter and degas to obtain a chitosan spinning solution. Mix 15ml of glycerol, 5ml of polyethylene glycol 400, and 5ml of 20% calcium chloride in ethanol to obtain coagulation bath A. Extrude the chitosan spinning solution into coagulation bath A and coagulate for 10 minutes to obtain chitosan nascent fibers. The nascent chitosan fibers are drawn 1.2 times and introduced into coagulation bath B containing 20% ​​calcium chloride in ethanol, where they are coagulated again for 30 minutes. The resulting chitosan fibers are dried at 60°C for 30 minutes, washed with ethanol, drawn 1.2 times, and then dried at 40°C to obtain high-performance chitosan fibers. Example

[0025] Dissolve 0.6g of glutamic acid in 18.4g of water, then dissolve 0.6g of chitosan and 0.4g of glycerol in the glutamic acid solution. Filter and degas to obtain a chitosan spinning solution. Mix 10ml of glycerol, 5ml of polyethylene glycol 400, 5ml of triethanolamine, and 10ml of 30% calcium chloride in ethanol to obtain coagulation bath A. Extrude the chitosan spinning solution into coagulation bath A and coagulate for 20 minutes to obtain nascent chitosan fibers. The nascent chitosan fibers are drawn 1.1 times and introduced into coagulation bath B containing 10% calcium chloride in ethanol, where they are coagulated again for 300 minutes. The resulting chitosan fibers are dried at 40°C for 60 minutes, washed with ethanol, drawn 2 times, and dried again at 60°C to obtain high-performance chitosan fibers.

Claims

1. A method for preparing high-performance chitosan fiber, characterized in that: The steps include: S1. Dissolving chitosan and glycerol in an aqueous glutamic acid solution, filtering and degassing to obtain a chitosan spinning solution; S2. The polyol and calcium chloride ethanol solution are mixed to obtain a coagulation bath A, wherein the polyol is one or more of glycerol, polyethylene glycol 400, and triethanolamine; S3. Dissolve calcium chloride in ethanol to obtain coagulation bath B; S4. The chitosan spinning solution obtained in S1 is squeezed into the coagulation bath A obtained in S2 and coagulated for 10-30 min to obtain chitosan primary fibers; S5. After the chitosan nascent fibers obtained in S4 are drawn, they are introduced into the coagulation bath B obtained in S3 and coagulated again for 30-300 min; S6. The coagulated chitosan fibers obtained in S5 are dried, washed with alcohol, stretched, and dried again to obtain high-performance chitosan fibers.

2. The method for preparing high-performance chitosan fiber according to claim 1, characterized in that: The concentrations of chitosan and glutamic acid in S1 are both 3 wt %, and the concentration of glycerol is 0.5 wt %-5 wt %.

3. The method for preparing high-performance chitosan fiber according to claim 1, characterized in that: The volume ratio of the polyol to the calcium chloride ethanol solution in S2 is 1-4:1, and the concentration of calcium chloride in the calcium chloride ethanol solution is 20wt%-30wt%.

4. The method for preparing high-performance chitosan fiber according to claim 1, characterized in that: The concentration of calcium chloride in the coagulation bath B in S3 is 10 wt % to 30 wt %.

5. The method for preparing high-performance chitosan fiber according to claim 1, characterized in that: The draft ratio described in S5 is 1.0-1.2 times.

6. The method for preparing high-performance chitosan fiber according to claim 1, characterized in that: The drying temperature in S6 is 25-60° C., and the drafting ratio is 1.2-2 times.

7. High-performance chitosan fiber prepared according to the method according to any one of claims 1 to 6.

8. The high-performance chitosan fiber according to claim 7 is used to manufacture filament yarn, staple yarn, wadding, and non-woven fabric.

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