Composite fiber containing Centella asiatica extract and preparation method thereof

Abstract

The present invention discloses a composite fiber containing a Centella asiatica extract. The present invention discloses a method for preparing the composite fiber containing the Centella asiatica extract, comprising the following steps: dissolving gum arabic and gelatin in water, adding the Centella asiatica extract, β-cyclodextrin, and Tween-20, stirring at 50-60°C for 20-40 minutes, cooling to room temperature, homogenizing, solidifying, standing for stratification, removing the supernatant, and freeze-drying to obtain a Centella asiatica microcapsule complex; adding nano-titanium dioxide and succinic anhydride to a 1-butyl-3-methylimidazole-chloroaluminate aqueous solution and stirring evenly, adding cellulose and the Centella asiatica microcapsule complex, stirring at 50-60°C for 1-2 hours, and evaporating to remove water to obtain a spinning solution; extruding the spinning solution from a spinneret, cooling by cold air intervals, coagulating in a coagulation bath, desulfurizing in a desulfurization bath, washing with water, and drying to obtain the composite fiber containing the Centella asiatica extract.

Description

Technical Field

[0001] The present invention relates to the technical field of regenerated fibers, and in particular to a composite fiber containing a Centella asiatica extract and a preparation method thereof. Background Art

[0002] Cellulose is the most abundant renewable biomass resource in nature, with a wide range of sources. Found in abundance in plants such as wood, cotton, linen, algae, and cereal straw, it is a key component of plant cell walls. Approximately one billion tons of cellulose are produced annually, making it an inexhaustible and sustainable resource. Its effective utilization holds immense value for both economic development and environmental protection. Cellulose products are inexpensive, abundant, diverse, water-resistant, and environmentally friendly, making them suitable for widespread use in textile engineering.

[0003] At present, regenerated cellulose fiber with better performance is produced by using natural cellulose as raw material, without changing its basic chemical structure but only changing its physical structure. Its moisture absorption and breathability are better than cotton fiber, and it also has some advantages of silk. It is more comfortable to wear and has a soft touch. Moreover, regenerated cellulose fiber can be naturally degraded, making it an environmentally friendly fiber with excellent performance.

[0004] As petroleum resources become increasingly depleted, the use of synthetic fibers is becoming increasingly restricted. Regenerated cellulose fibers, due to their excellent properties, have attracted the attention of industry professionals. However, with the development of regenerated cellulose fiber technology, functional regenerated cellulose fibers have become a new development direction. One of the preparation methods is to add functional additives to the spinning solution, followed by extrusion and coagulation.

[0005] Centella asiatica, used as a medicinal plant in its entirety, is cold in nature, bitter, and pungent in flavor. It has the effects of clearing heat and dampness, detoxifying, and reducing swelling. It is clinically used to treat damp-heat jaundice, carbuncles, swelling, traumatic injuries, arsenic poisoning, tansy poisoning, summer heat, infectious hepatitis, and epidemic cerebrospinal meningitis. Adding Centella asiatica extract to regenerated cellulose fiber imparts heat-clearing and dampness-clearing, antibacterial, anti-inflammatory, and skin-nourishing properties. However, mixing the Centella asiatica extract directly with the spinning solution is difficult due to the high viscosity of the cellulose solution, and the extract is easily lost and mixed unevenly during the spinning and post-processing processes, resulting in unstable antibacterial and mechanical properties of the fiber. This issue urgently needs to be addressed. Summary of the Invention

[0006] Based on the technical problems existing in the background technology, the present invention proposes a composite fiber containing Centella asiatica extract and a preparation method thereof.

[0007] A composite fiber containing a Centella asiatica extract. The raw materials thereof comprise, by weight, 40-60 parts of cellulose, 72-143 parts of 1-butyl-3-methylimidazole chloroaluminate, 5-12 parts of nano-titanium dioxide, 1-3 parts of succinic anhydride, 1-2 parts of gum arabic, 1-2 parts of gelatin, 2-5 parts of Centella asiatica extract, 1-3 parts of beta-cyclodextrin, and 0.1-1 part of Tween-20.

[0008] Preferably, the cellulose is at least one of cotton cellulose, hemp cellulose, bamboo cellulose and wood pulp cellulose.

[0009] Preferably, the cellulose is wood pulp cellulose.

[0010] Preferably, the degree of polymerization of wood pulp cellulose is 800-820.

[0011] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0012] S1. Dissolve gum arabic and gelatin in water, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 50-60° C. for 20-40 minutes, cool to room temperature, homogenize for 1-3 minutes, solidify, stand for stratification, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0013] S2. Add nano-titanium dioxide and succinic anhydride to a 1-butyl-3-methylimidazole-chloroaluminate aqueous solution and stir evenly, add cellulose and Centella asiatica microcapsule complex, stir at 50-60° C. for 1-2 hours, and evaporate to remove water to obtain a spinning solution;

[0014] S3. The spinning solution is extruded from the spinneret, cooled through a cold air interval, wherein the cold air interval length is 10-18 cm, the cold air temperature is 5-15° C., coagulated in a coagulation bath, desulfurized in a desulfurization bath, washed with water, and dried to obtain a composite fiber containing the Centella asiatica extract.

[0015] Preferably, in S1, formaldehyde is used for curing after homogenization.

[0016] Preferably, in S2, the mass fraction of the 1-butyl-3-methylimidazolium-chloroaluminate aqueous solution is 90-95%.

[0017] Preferably, during the evaporation and dehydration process of S2, the vacuum degree is -40 to -80 kPa and the evaporation temperature is 90-100°C.

[0018] Preferably, the viscosity of the spinning solution obtained in S2 is 6000-6800 cP.

[0019] Preferably, in the coagulation bath used in S3, the concentration of sulfuric acid is 95-98 g / L, the concentration of zinc sulfate is 5-10 g / L, the concentration of sodium sulfate is 280-300 g / L, and the concentration of tetrabutylammonium sulfate is 120-140 g / L; and the temperature of the coagulation bath is 40-50°C.

[0020] Preferably, the desulfurization bath used in S3 is a Na2SO3 solution with a concentration of 2-4 g / L.

[0021] The technical effects of the present invention are as follows:

[0022] The present invention adopts a compound of gum arabic and gelatin, which has an excellent adsorption and coating effect on the Centella asiatica extract under the action of beta-cyclodextrin. After solidification, the Centella asiatica microcapsule complex is obtained, which can effectively prevent the loss of the Centella asiatica extract. Cellulose is dissolved in a 1-butyl-3-methylimidazole-chloroaluminate aqueous solution, and then succinic anhydride is added. Not only is the cellulose well dispersed in the system, but it also has excellent affinity with the dissolved cellulose and combines with the beta-cyclodextrin in the Centella asiatica microcapsule complex. The succinic anhydride plays a bridging role, bridging the Centella asiatica microcapsule complex to the fiber structure.

[0023] The composite fiber obtained by the present invention not only has good and lasting antibacterial function, but also greatly reduces the loss of Centella asiatica extract in the fiber during the spinning process or post-treatment process through the dual protection effect of chemical grafting and microcapsule coating, ensuring that the obtained fiber can achieve the expected effect.

[0024] The regenerated cellulose fiber obtained by the present invention not only does not require the addition of strong acids or strong bases during the adsorption process, but also does not use high temperatures, so the effective ingredients of the Centella asiatica extract will not be destroyed. The composite fiber has excellent effects of clearing away heat and dampness, resisting bacteria and inflammation, and nourishing the skin. At the same time, the amount of Centella asiatica extract added is not restricted, which greatly increases the added amount. On the basis of the increased amount, the fiber is resistant to washing, and the structure has good chemical stability, which ensures and effectively enhances the mechanical strength of the fiber. The regenerated cellulose fiber has good hygroscopicity and glossiness, and can meet the needs of most textiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1-2 is a comparison chart of the strength and elongation at break of the composite fibers obtained in Example 5 and Comparative Examples 1-2.

[0026] Figure 2 This is a comparison chart of the moisture regain and dry heat shrinkage of the composite fibers obtained in Example 5 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is described in detail below through specific embodiments.

[0028] Example 1

[0029] A composite fiber containing Centella asiatica extract, wherein the raw materials include: 40 kg of cotton cellulose, 72 kg of 1-butyl-3-methylimidazole chloroaluminate, 5 kg of nano titanium dioxide, 1 kg of succinic anhydride, 1 kg of gum arabic, 1 kg of gelatin, 2 kg of Centella asiatica extract, 1 kg of beta-cyclodextrin, and 0.1 kg of Tween-20.

[0030] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0031] S1. Dissolve gum arabic and gelatin in 20 kg of water and stir evenly, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 50°C for 20 minutes, cool to room temperature, homogenize at a speed of 10,000 r / min for 1 minute, solidify with formaldehyde, let stand to separate, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0032] S2. Add nano-titanium dioxide and succinic anhydride to 80 kg of a 90% by mass aqueous solution of 1-butyl-3-methylimidazole-chloroaluminate and stir evenly. Add cotton cellulose and Centella asiatica microcapsule complex, stir at 50°C for 1 hour, and evaporate to remove water in a vacuum environment of -40 kPa at an evaporation temperature of 90°C to obtain a spinning solution with a viscosity of 6000 cP.

[0033] S3. The spinning solution is extruded from a spinneret with an aperture of 0.2 mm, cooled through a cold air interval with a length of 10 cm and a cold air temperature of 5°C, and sent into a coagulation bath at a temperature of 40°C for coagulation. The solution is added to a Na2SO3 solution with a concentration of 2 g / L for desulfurization, washed with water, and dried at 110°C to obtain a composite fiber containing Centella asiatica extract.

[0034] In the coagulation bath used, the concentration of sulfuric acid was 95 g / L, the concentration of zinc sulfate was 5 g / L, the concentration of sodium sulfate was 280 g / L, and the concentration of tetrabutylammonium sulfate was 120 g / L.

[0035] Example 2

[0036] A composite fiber containing Centella asiatica extract, wherein the raw materials include: 60 kg of bamboo cellulose, 142.5 kg of 1-butyl-3-methylimidazole chloroaluminate, 12 kg of nano titanium dioxide, 3 kg of succinic anhydride, 2 kg of gum arabic, 2 kg of gelatin, 5 kg of Centella asiatica extract, 3 kg of beta-cyclodextrin, and 1 kg of Tween-20.

[0037] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0038] S1. Dissolve gum arabic and gelatin in 50 kg of water and stir evenly, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 60°C for 40 min, cool to room temperature, homogenize at 20,000 rpm for 3 min, solidify with formaldehyde, let stand to separate, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0039] S2. Add nano-titanium dioxide and succinic anhydride to 150 kg of a 95% by mass 1-butyl-3-methylimidazolium-chloroaluminate aqueous solution and stir evenly. Add bamboo cellulose and Centella asiatica microcapsule complex, stir at 60°C for 2 h, and evaporate to remove water in a vacuum environment of -80 kPa at an evaporation temperature of 100°C to obtain a spinning solution with a viscosity of 6800 cP.

[0040] S3. The spinning solution is extruded from a spinneret with an aperture of 0.3 mm, cooled through a cold air interval with a length of 18 cm and a cold air temperature of 15°C, and sent into a coagulation bath at a temperature of 50°C for coagulation. The solution is added to a Na2SO3 solution with a concentration of 4 g / L for desulfurization, washed with water, and dried at 125°C to obtain a composite fiber containing Centella asiatica extract.

[0041] In the coagulation bath used, the concentration of sulfuric acid was 98 g / L, the concentration of zinc sulfate was 10 g / L, the concentration of sodium sulfate was 300 g / L, and the concentration of tetrabutylammonium sulfate was 140 g / L.

[0042] Example 3

[0043] A composite fiber containing Centella asiatica extract, wherein the raw materials include: 55 kg of wood pulp cellulose with a degree of polymerization of 803, 93 kg of 1-butyl-3-methylimidazole chloroaluminate, 8 kg of nano titanium dioxide, 2.5 kg of succinic anhydride, 1.3 kg of gum arabic, 1.8 kg of gelatin, 3 kg of Centella asiatica extract, 2.5 kg of beta-cyclodextrin, and 0.4 kg of Tween-20.

[0044] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0045] S1. Dissolve gum arabic and gelatin in 40 kg of water and stir evenly, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 52° C. for 35 min, cool to room temperature, homogenize at a speed of 12,000 rpm for 2.5 min, solidify with formaldehyde, let stand to separate, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0046] S2. Add nano-titanium dioxide and succinic anhydride to 100 kg of a 93% by mass 1-butyl-3-methylimidazolium-chloroaluminate aqueous solution and stir evenly. Add wood pulp cellulose and Centella asiatica microcapsule complex, stir at 53°C for 1.8 h, and evaporate to remove water in a vacuum environment of -50 kPa at an evaporation temperature of 96°C to obtain a spinning solution with a viscosity of 6217 cP.

[0047] S3. The spinning solution is extruded from a spinneret with an aperture of 0.25 mm, cooled through a cold air interval with a length of 16 cm and a cold air temperature of 8°C, and sent into a coagulation bath at a temperature of 47°C for coagulation. The solution is added to a Na2SO3 solution with a concentration of 2.5 g / L for desulfurization, washed with water, and dried at 120°C to obtain a composite fiber containing Centella asiatica extract.

[0048] In the coagulation bath used, the concentration of sulfuric acid was 96 g / L, the concentration of zinc sulfate was 8 g / L, the concentration of sodium sulfate was 285 g / L, and the concentration of tetrabutylammonium sulfate was 135 g / L.

[0049] Example 4

[0050] A composite fiber containing Centella asiatica extract, wherein the raw materials include: 45 kg of wood pulp cellulose with a degree of polymerization of 818, 118.3 kg of 1-butyl-3-methylimidazole chloroaluminate, 10 kg of nano titanium dioxide, 1.5 kg of succinic anhydride, 1.7 kg of gum arabic, 1.2 kg of gelatin, 4 kg of Centella asiatica extract, 1.5 kg of β-cyclodextrin, and 0.8 kg of Tween-20.

[0051] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0052] S1. Dissolve gum arabic and gelatin in 30 kg of water and stir evenly, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 58° C. for 25 min, cool to room temperature, homogenize at 17,000 rpm for 1.5 min, solidify with formaldehyde, let stand to separate, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0053] S2. Add nano-titanium dioxide and succinic anhydride to 130 kg of a 91% by mass 1-butyl-3-methylimidazolium-chloroaluminate aqueous solution and stir evenly. Add wood pulp cellulose and Centella asiatica microcapsule complex, stir at 57°C for 1.2 h, and evaporate to remove water in a vacuum environment of -70 kPa at an evaporation temperature of 92°C to obtain a spinning solution with a viscosity of 6581 cP.

[0054] S3. The spinning solution is extruded from a spinneret with an aperture of 0.25 mm, cooled through a cold air interval with a length of 12 cm and a cold air temperature of 12°C, and sent into a coagulation bath at a temperature of 43°C for coagulation. The solution is added to a Na2SO3 solution with a concentration of 3.5 g / L for desulfurization, washed with water, and dried at 115°C to obtain a composite fiber containing Centella asiatica extract.

[0055] In the coagulation bath used, the concentration of sulfuric acid was 97 g / L, the concentration of zinc sulfate was 6 g / L, the concentration of sodium sulfate was 295 g / L, and the concentration of tetrabutylammonium sulfate was 125 g / L.

[0056] Example 5

[0057] A composite fiber containing Centella asiatica extract, whose raw materials include: 50 kg of wood pulp cellulose with a degree of polymerization of 809, 105.8 kg of 1-butyl-3-methylimidazole chloroaluminate, 9 kg of nano titanium dioxide, 2 kg of succinic anhydride, 1.5 kg of gum arabic, 1.5 kg of gelatin, 3.5 kg of Centella asiatica extract, 2 kg of beta-cyclodextrin, and 0.6 kg of Tween-20.

[0058] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0059] S1. Dissolve gum arabic and gelatin in 35 kg of water and stir evenly, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 55°C for 30 min, cool to room temperature, homogenize at a speed of 15,000 rpm for 2 min, solidify with formaldehyde, let stand to separate, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex;

[0060] S2. Add nano-titanium dioxide and succinic anhydride to 115 kg of a 92% by mass 1-butyl-3-methylimidazolium-chloroaluminate aqueous solution and stir evenly. Add wood pulp cellulose and Centella asiatica microcapsule complex, stir at 55°C for 1.5 h, and evaporate to remove water in a vacuum environment of -60 kPa at an evaporation temperature of 95°C to obtain a spinning solution with a viscosity of 6396 cP.

[0061] S3. The spinning solution is extruded from a spinneret with an aperture of 0.25 mm, cooled through a cold air interval with a length of 14 cm and a cold air temperature of 10°C, and sent into a coagulation bath at a temperature of 45°C for coagulation. The solution is added to a Na2SO3 solution with a concentration of 3 g / L for desulfurization, washed with water, and dried at 118°C to obtain a composite fiber containing Centella asiatica extract.

[0062] In the coagulation bath used, the concentration of sulfuric acid was 96.5 g / L, the concentration of zinc sulfate was 7 g / L, the concentration of sodium sulfate was 290 g / L, and the concentration of tetrabutylammonium sulfate was 130 g / L.

[0063] Comparative Example 1

[0064] A composite fiber containing Centella asiatica extract, whose raw materials include: 50 kg of wood pulp cellulose with a degree of polymerization of 809, 105.8 kg of 1-butyl-3-methylimidazole chloroaluminate, 9 kg of nano titanium dioxide, 2 kg of succinic anhydride, and 3.5 kg of Centella asiatica extract.

[0065] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0066] i. Add nano-titanium dioxide and succinic anhydride to 115 kg of a 92% by mass aqueous solution of 1-butyl-3-methylimidazolium-chloroaluminate and stir evenly. Add wood pulp cellulose and Centella asiatica extract, stir at 55°C for 1.5 hours, and evaporate to remove water in a vacuum environment of -60 kPa at an evaporation temperature of 95°C to obtain a spinning solution with a viscosity of 6396 cP.

[0067] ii. The spinning solution was extruded from a spinneret with an aperture of 0.25 mm, cooled through a cold air interval with a length of 14 cm and a temperature of 10°C, and sent into a coagulation bath at a temperature of 45°C for coagulation. The solution was added to a Na2SO3 solution with a concentration of 3 g / L for desulfurization, washed with water, and dried at 118°C to obtain a composite fiber containing Centella asiatica extract.

[0068] In the coagulation bath used, the concentration of sulfuric acid was 96.5 g / L, the concentration of zinc sulfate was 7 g / L, the concentration of sodium sulfate was 290 g / L, and the concentration of tetrabutylammonium sulfate was 130 g / L.

[0069] Comparative Example 2

[0070] A composite fiber containing Centella asiatica extract, wherein the raw materials include: 50 kg of wood pulp cellulose with a degree of polymerization of 809, 105.8 kg of 1-butyl-3-methylimidazole chloroaluminate, 9 kg of nano titanium dioxide, 1.5 kg of gum arabic, 1.5 kg of gelatin, 3.5 kg of Centella asiatica extract, 2 kg of beta-cyclodextrin, and 0.6 kg of Tween-20.

[0071] The method for preparing the composite fiber containing Centella asiatica extract comprises the following steps:

[0072] i. Gum arabic and gelatin were dissolved in 35 kg of water and stirred evenly. Centella asiatica extract, β-cyclodextrin, and Tween-20 were added and stirred at 55° C. for 30 min. The mixture was cooled to room temperature and homogenized at 15,000 rpm for 2 min. The mixture was solidified with formaldehyde, allowed to stand for stratification, the supernatant was removed, and the mixture was freeze-dried to obtain a Centella asiatica microcapsule complex.

[0073] ii. Add nano-titanium dioxide to 115 kg of a 92% by mass aqueous solution of 1-butyl-3-methylimidazolium-chloroaluminate and stir evenly. Add wood pulp cellulose and Centella asiatica microcapsule complex, stir at 55°C for 1.5 hours, and evaporate to remove water in a vacuum environment of -60 kPa at an evaporation temperature of 95°C to obtain a spinning solution with a viscosity of 6396 cP.

[0074] iii. The spinning solution is extruded from a spinneret with an aperture of 0.25 mm, cooled through a cold air interval with a length of 14 cm and a temperature of 10°C, and sent into a coagulation bath at a temperature of 45°C for coagulation. The solution is then added to a Na2SO3 solution with a concentration of 3 g / L for desulfurization, washed with water, and dried at 118°C to obtain a composite fiber containing Centella asiatica extract.

[0075] In the coagulation bath used, the concentration of sulfuric acid was 96.5 g / L, the concentration of zinc sulfate was 7 g / L, the concentration of sodium sulfate was 290 g / L, and the concentration of tetrabutylammonium sulfate was 130 g / L.

[0076] The mechanical properties of the composite fibers obtained in Example 5 and Comparative Examples 1-2 were tested with reference to GB / T 14463-2008 Viscose Staple Fiber. Figure 1 shown.

[0077] The hygroscopicity, dry heat shrinkage and strength unevenness of the composite fibers obtained in Example 5 and Comparative Examples 1-2 were measured. Figure 2 As shown, the strength unevenness of each group of composite fibers is 0.

[0078] Depend on Figure 1 and Figure 2 It can be seen that the strength and elongation at break of the composite fiber obtained in Example 5 are significantly better than those in the control example (P < 0.05). This is because the present invention uses β-cyclodextrin to adsorb and coat the Centella asiatica extract, and then uses succinic anhydride as a bridge to bridge the β-cyclodextrin to the fiber structure, thereby enhancing the mechanical properties of the fiber.

[0079] At the same time, the composite fiber obtained in Example 5 contains a large number of hydrophilic groups on its surface, resulting in a slightly better moisture regain than the comparative example. This allows for a faster moisture absorption rate, a strong capillary effect, and excellent breathability, keeping the fiber surface dry and ensuring comfortable wearing. The composite fiber obtained in Comparative Example 1 exhibits the lowest dry heat shrinkage, while the composite fiber obtained in Comparative Example 2 exhibits the highest dry heat shrinkage. This is because the composite fiber obtained in Comparative Example 2 fails to bridge the Centella asiatica microcapsule complex to the fiber structure via succinic anhydride, resulting in continuous dehydration in a dry heat environment, causing fiber shrinkage. The composite fiber obtained in Comparative Example 1, however, directly utilizes Centella asiatica extract mixed with the fiber, without the presence of substances containing hydrophilic groups such as gum arabic or gelatin. This results in a lower moisture content in the final fiber, making it less susceptible to dehydration in a dry heat environment.

[0080] Since it is difficult to directly test the Centella asiatica extract after combining it with the fiber, the applicant tested the antibacterial properties of the composite fiber to verify its washing resistance from an indirect perspective.

[0081] The antibacterial test was carried out using the GB / T 20944.3-2008 oscillation method, washing procedure 7B, 50 washes, and tumble drying.

[0082]

[0083]

[0084] The table above shows that the composite fiber obtained in Example 5 still has strong antibacterial properties after 50 washes, indicating that the composite fiber obtained in Example 5 still contains a large amount of Centella asiatica extract after washing. However, the antibacterial properties of the composite fibers obtained in Comparative Examples 1 and 2 significantly decline after washing. This is because Comparative Example 1 uses Centella asiatica extract mixed with the fiber, which only adheres to the fiber surface with poor adhesion and is easily destroyed by washing. In Comparative Example 2, the Centella asiatica microcapsule complex is not bridged to the fiber structure using succinic anhydride, failing to establish a strong fixed relationship between the Centella asiatica microcapsule complex and the fiber, resulting in loss of the Centella asiatica microcapsule complex during washing.

[0085] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A composite fiber comprising a Centella asiatica extract, characterized in that: The raw materials include, by weight: 40-60 parts of cellulose, 72-143 parts of 1-butyl-3-methylimidazole chloroaluminate, 5-12 parts of nano titanium dioxide, 1-3 parts of succinic anhydride, 1-2 parts of gum arabic, 1-2 parts of gelatin, 2-5 parts of Centella asiatica extract, 1-3 parts of beta-cyclodextrin, and 0.1-1 part of Tween-20; Prepared by the following steps: S1. Dissolve gum arabic and gelatin in water, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 50-60° C. for 20-40 minutes, cool to room temperature, homogenize for 1-3 minutes, solidify, stand for stratification, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex; S2. Add nano-titanium dioxide and succinic anhydride to a 1-butyl-3-methylimidazole-chloroaluminate aqueous solution and stir evenly, add cellulose and Centella asiatica microcapsule complex, stir at 50-60° C. for 1-2 hours, and evaporate to remove water to obtain a spinning solution; S3. The spinning solution is extruded from the spinneret, cooled through a cold air interval, wherein the cold air interval length is 10-18 cm, the cold air temperature is 5-15° C., coagulated in a coagulation bath, desulfurized in a desulfurization bath, washed with water, and dried to obtain a composite fiber containing the Centella asiatica extract.

2. The composite fiber comprising the Centella asiatica extract according to claim 1, wherein The cellulose is at least one of cotton cellulose, hemp cellulose, bamboo cellulose and wood pulp cellulose.

3. The composite fiber comprising the Centella asiatica extract according to claim 2, wherein: The cellulose is wood pulp cellulose.

4. The composite fiber comprising a Centella asiatica extract according to claim 2 or 3, characterized in that The degree of polymerization of wood pulp cellulose is 800-820.

5. A method for preparing a composite fiber comprising a Centella asiatica extract according to any one of claims 1 to 3, characterized in that: The steps include: S1. Dissolve gum arabic and gelatin in water, add Centella asiatica extract, β-cyclodextrin, and Tween-20, stir at 50-60° C. for 20-40 minutes, cool to room temperature, homogenize for 1-3 minutes, solidify, stand for stratification, remove the supernatant, and freeze-dry to obtain a Centella asiatica microcapsule complex; S2. Add nano-titanium dioxide and succinic anhydride to a 1-butyl-3-methylimidazole-chloroaluminate aqueous solution and stir evenly, add cellulose and Centella asiatica microcapsule complex, stir at 50-60° C. for 1-2 hours, and evaporate to remove water to obtain a spinning solution; S3. The spinning solution is extruded from the spinneret, cooled through a cold air interval, wherein the cold air interval length is 10-18 cm, the cold air temperature is 5-15° C., coagulated in a coagulation bath, desulfurized in a desulfurization bath, washed with water, and dried to obtain a composite fiber containing the Centella asiatica extract.

6. The method for preparing a composite fiber containing a Centella asiatica extract according to claim 5, characterized in that: In S1, formaldehyde is used for curing after homogenization.

7. The method for preparing a composite fiber containing a Centella asiatica extract according to claim 5, characterized in that: During the evaporation and dehydration process of S2, the vacuum degree is -40 to -80 kPa and the evaporation temperature is 90-100°C.

8. The method for preparing a composite fiber containing a Centella asiatica extract according to claim 5, characterized in that: The viscosity of the spinning solution obtained in S2 is 6000-6800 cP.

9. The method for preparing a composite fiber containing a Centella asiatica extract according to claim 5, wherein: In the coagulation bath used in S3, the concentration of sulfuric acid is 95-98 g / L, the concentration of zinc sulfate is 5-10 g / L, the concentration of sodium sulfate is 280-300 g / L, and the concentration of tetrabutylammonium sulfate is 120-140 g / L; the coagulation bath temperature is 40-50°C.

10. The method for preparing a composite fiber containing a Centella asiatica extract according to claim 5, characterized in that: The desulfurization bath used for S3 is a Na2SO3 solution with a concentration of 2-4g / L.

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