Ailanthus leaf lyocell fiber, preparation method and application

Abstract

The application discloses aile lyocell fiber, a preparation method and application, wherein the preparation method comprises the following steps: obtaining ailao powder from fresh ail leaves; under fermentation conditions, the ailao powder is fermented by microorganisms to selectively degrade lignin and hemicellulose in the ail leaves, and an ail leaf cellulose pulp rich in active ingredients is obtained; the ail leaf cellulose pulp is subjected to auxiliary hydrolysis by sodium chlorite and sodium hydroxide to obtain purified ail leaf cellulose; the purified ail leaf cellulose is dissolved in N-methyl morpholine-N-oxide aqueous solution, an antioxidant and an alkaline adjusting agent are added, and a spinning dope is obtained; and the spinning dope is subjected to post-treatment to obtain the ail lyocell fiber. The application provides the ail lyocell fiber, the preparation method and the application, adopts a microbial fermentation technology as a core, and realizes efficient extraction of cellulose and in-situ reservation of natural active ingredients under mild conditions by screening of efficient composite microbial flora for directional degradation of lignin and hemicellulose in the ail leaves.

Description

Technical Field

[0001] This invention relates to the field of fiber materials technology, and in particular to an artemisia argyi lyocell fiber, its preparation method, and its application. Background Technology

[0002] Lyocell fiber, as an environmentally friendly regenerated cellulose fiber, is widely used in textiles, apparel, home textiles, and medical dressings due to its excellent mechanical properties, good moisture absorption, and biodegradability. Combining natural plant components with multiple bioactive properties with lyocell fiber is an important way to enhance product added value and expand the application of functional textiles.

[0003] Artemisia argyi, a traditional Chinese herbal medicine, is rich in various active ingredients such as flavonoids, polyphenols, and polysaccharides, possessing antibacterial, antioxidant, and anti-allergic properties. Currently, the main technologies for introducing the functional components of Artemisia argyi into fibers include finishing methods and blending spinning. Finishing methods suffer from poor bonding strength between functional components and fibers, and poor wash resistance; blending spinning faces stability issues with Artemisia argyi extracts in highly polar solvents, as well as the damage to active ingredients caused by traditional chemical extraction processes. Furthermore, traditional Artemisia argyi cellulose extraction often employs high-temperature, strong-alkali processes, resulting in high energy consumption, significant pollution, and severe damage to the natural active ingredients in Artemisia argyi. To obtain soft fibers, the industry habitually uses expensive "three-year aged Artemisia argyi," increasing raw material storage costs.

[0004] In recent years, the application of bio-fermentation technology in plant fiber extraction has attracted attention. Studies have shown that enzymatic hydrolysis and fermentation processes can effectively break down plant cell walls, releasing cellulose and active ingredients. However, research on optimizing the extraction of cellulose from Artemisia argyi using fermentation technology and preparing lyocell fiber spinning solutions while retaining active ingredients remains lacking. Summary of the Invention

[0005] In view of the aforementioned deficiencies in the prior art, the technical problem to be solved by this invention is that there is currently a lack of research on the application of fermentation technology to optimize the extraction of Artemisia argyi cellulose and the preparation of lyocell fiber spinning dope while retaining active ingredients; and the problems of high pollution, high energy consumption, easy destruction of active ingredients, and high storage costs of three-year-aged Artemisia argyi in traditional Artemisia argyi fiber extraction processes. This invention provides Artemisia argyi lyocell fiber, its preparation method, and its application. It utilizes microbial fermentation technology as the core, and through the screening of highly efficient complex bacterial communities to directionally degrade lignin and hemicellulose in Artemisia argyi, it achieves efficient extraction of cellulose and in-situ retention of natural active ingredients under mild conditions.

[0006] To achieve the above objectives, the present invention provides a method for preparing Artemisia argyi Lyocell fiber, comprising the following steps:

[0007] (1) Fresh mugwort leaves are dried, crushed, and sieved to obtain mugwort powder;

[0008] (2) The mugwort powder is subjected to targeted fermentation under optimized fermentation conditions by using the endogenous microorganisms carried on its surface or by inoculating a complex microbial community with the ability to degrade lignin and hemicellulose, in order to selectively degrade lignin and hemicellulose in mugwort leaves.

[0009] (3) After fermentation, the fermentation product is separated into solid and liquid components. The precipitate is collected, washed, ultrasonically separated, and dried to obtain Artemisia argyi cellulose pulp rich in active ingredients.

[0010] (4) The Artemisia argyi cellulose pulp was subjected to hydrolysis with sodium chlorite and sodium hydroxide to obtain purified Artemisia argyi cellulose;

[0011] (5) Dissolve the purified Artemisia argyi cellulose in an aqueous solution of N-methylmorpholine-N-oxide, add an antioxidant and an alkaline regulator, heat and stir to dissolve, and obtain a spinning solution;

[0012] (6) The spinning solution is defoamed and filtered, and then shaped by wet spinning or dry-jet wet spinning process, and then post-treated to obtain Artemisia argyi Lyocell fiber.

[0013] Furthermore, the particle size of the mugwort powder is set to be 80 mesh or larger, and the purity is ≥98.7%; the moisture content of the fresh mugwort leaves is controlled to be below 10%.

[0014] Furthermore, the composite microbial community includes at least two of the following: *Phanerochaete chrysosporium*, *Aspergillus niger*, and *Bacillus subtilis*; the directional fermentation temperature is 25–35°C, the initial pH is 6.0–7.5, and the fermentation time is 5–10 days.

[0015] Furthermore, the inoculation of the complex microbial community adopts a segmented fermentation strategy, first inoculating fungi for lignin degradation, and then inoculating bacteria for hemicellulose degradation.

[0016] Furthermore, the fermentation process should be kept in an aerobic or microaerobic state.

[0017] Furthermore, the ultrasonic power for the ultrasonic-assisted separation is 200–400 W, the ultrasonic time is 20–40 minutes, and the solid-liquid ratio is 1:10–1:20 g / mL.

[0018] Further, in step (4), the mass fraction of sodium chlorite is 1.0% to 1.5%, the treatment temperature is 60 to 80°C, and the treatment time is 4 to 8 hours; the mass fraction of sodium hydroxide is 0.3% to 0.8%, and the treatment time is 20 to 40 minutes.

[0019] Further, the N-methylmorpholine-N-oxide aqueous solution in step (5) has a mass fraction of 80% to 85%, a dissolution temperature of 80 to 100°C, and a dissolution time of 1 to 4 hours.

[0020] Further, the antioxidant mentioned in step (5) is propyl gallate, the alkali is hydroxylamine, and the amount added is 0.03% to 0.05% of the mass of cellulose pulp.

[0021] Further, the coagulation bath in step (6) is an aqueous solution of N-methylmorpholine-N-oxide with a mass fraction of 10% to 20%.

[0022] In a preferred embodiment of the present invention, an Artemisia argyi Lyocell fiber prepared by the above method is provided, characterized in that the cellulose content is ≥95% and the antibacterial rate against Staphylococcus aureus, Escherichia coli and Candida albicans is ≥99%.

[0023] Furthermore, the DPPH free radical scavenging rate was ≥80%, the hyaluronidase inhibition rate was ≥70%, and the erythrocyte hemolysis test result was negative.

[0024] In a preferred embodiment of the invention, the use of Artemisia argyi Lyocell fiber in functional clothing, home textiles, medical dressings, hygiene products, thermotherapy materials, or filter materials is provided.

[0025] Technical effect

[0026] (1) This invention introduces microbial fermentation technology into the extraction process of Artemisia argyi cellulose for the first time. It adopts compound microbial group directional fermentation to achieve efficient degradation of lignin and hemicellulose under mild conditions, avoiding the degradation of cellulose and the destruction of active ingredients by strong acids and alkalis. The resulting cellulose pulp has high purity (≥95%), good degree of polymerization, and completely retains the natural functional components such as flavonoids and polyphenols in Artemisia argyi.

[0027] (2) The antibacterial rate of the Artemisia argyi Lyocell fiber prepared by this invention is ≥90% against Staphylococcus aureus, Escherichia coli and Candida albicans, the DPPH free radical scavenging rate is ≥80%, the hyaluronidase inhibition rate is ≥70%, and the red blood cell hemolysis test is negative, indicating that the fiber has multiple functions such as antibacterial, antioxidant, anti-allergic and low irritation.

[0028] (3) This invention uses fresh mugwort leaves instead of traditional three-year aged mugwort leaves as raw materials, accelerates the aging process of mugwort leaves through microbial fermentation, significantly reduces the cost of raw material storage, and realizes the high-value utilization of the whole mugwort plant.

[0029] (4) The preparation method of the present invention is simple and highly controllable. The fineness of the obtained fiber can reach 1.0 to 1.5 dtex and the breaking strength is ≥3.5 cN / dtex. It is suitable for weaving high-end woven products such as functional clothing, home textiles, medical dressings, hygiene care products, thermotherapy materials, and filter materials.

[0030] (5) Significantly environmentally friendly and economically efficient: Compared with the traditional alkaline boiling method, the bio-fermentation process adopted in this invention reduces the COD load in wastewater by more than 60%. The waste liquid rich in organic acids and micronutrients generated during the fermentation process can be used as liquid fertilizer for farmland irrigation after simple neutralization treatment, realizing the recycling of water resources, reducing wastewater treatment costs, and meeting the requirements of green manufacturing.

[0031] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the extraction of Artemisia argyi fiber according to a preferred embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the antibacterial test results of Artemisia argyi fiber according to a preferred embodiment of the present invention. Detailed Implementation

[0034] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0035] In the following description, specific details, such as particular internal procedures and techniques, are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will appreciate that the invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of the invention with unnecessary detail.

[0036] Example 1: Extraction of Artemisia argyi cellulose and preparation of Lyocell fiber based on fermentation of a complex microbial community

[0037] This embodiment provides a method for preparing natural Artemisia argyi lyocell fiber based on fermentation-optimized Artemisia argyi cellulose extraction, including the following steps:

[0038] (1) Preparation of mugwort powder: Take freshly picked mugwort leaves, dry them naturally in a ventilated place until the moisture content is less than 10%, put them in a crusher and mixer to crush them, pass them through an 80-mesh sieve, and collect the mugwort powder that passes through the sieve.

[0039] (2) Activation and inoculation of the complex microbial community: Endogenous microorganisms in Artemisia argyi, such as *Phanerochaete chrysosporium*, *Aspergillus niger*, and *Bacillus subtilis*, exhibit significant lignin and hemicellulose degradation effects. Therefore, the corresponding microorganisms were first isolated from the Artemisia argyi fermentation material and purified for preservation. Then, the complex microbial community was exogenously inoculated by activating *Phanerochaete chrysosporium*, *Aspergillus niger*, and *Bacillus subtilis* to the logarithmic growth phase. They were mixed in a volume ratio of 2:1:1. *Phanerochaete chrysosporium* and *Aspergillus niger* were initially inoculated into the fermentation tank culture medium containing Artemisia argyi powder at an inoculation amount of 5% (v / w). The fermentation temperature was 30℃, and the initial pH was 6.8. After 5 days of fermentation, the mixture was turned over once, and *Bacillus subtilis* was added to continue fermentation for 3 days. The complex microbial community was then added for further fermentation. The Artemisia argyi exhibited significant softening and collapse, indicating a significant degradation effect on lignin.

[0040] (3) Post-fermentation treatment: After fermentation, the fermentation product was collected, and physiological saline was added to soak for 1 hour. Solid-liquid separation was performed, and the precipitate was separated by ultrasonic assistance. The ultrasonic power was 300 W, the time was 30 min, the solid-liquid ratio was 1:15, and after filtration, it was dried in an oven at 55℃ to constant weight to obtain Artemisia argyi cellulose pulp rich in active ingredients.

[0041] (4) Purification treatment: The above pulp was added to a 1.2% sodium chlorite solution and treated at 70°C for 6 hours. Then, a 0.5% sodium hydroxide solution was added and treated for 30 minutes. After filtration and washing until neutral, the purified Artemisia argyi cellulose was obtained after drying. The Artemisia argyi fiber obtained by gentle treatment is as follows: Figure 1 As shown.

[0042] (5) Preparation of spinning solution: The purified Artemisia argyi cellulose was added to an aqueous solution of N-methylmorpholine-N-oxide (NMMO) with a mass fraction of 85% to 87%, 0.04% of propyl gallate was added as an antioxidant, and 0.03% to 0.05% of hydroxylamine was added as an alkali regulator. The solution was stirred and dissolved at high temperature for 2 to 4 hours to obtain a uniform spinning solution.

[0043] (6) Spinning and forming: After vacuum degassing and filtration, the spinning solution is extruded through a spinneret into a coagulation bath and NMMO aqueous solution. The solution is then spun and formed by dry-spinning and wet-spinning, followed by washing, oiling, drying and stretching to obtain functional lyocell fiber.

[0044] This invention also provides a method for evaluating the performance of the obtained Artemisia argyi cellulose pulp and final fiber:

[0045] Lignin content determination: The Klason acid hydrolysis method or the acetyl bromide spectrophotometric method was used. For the Klason method, the sample was hydrolyzed with sulfuric acid, filtered, dried, and weighed to calculate the acid-insoluble lignin content. For the acetyl bromide method, quantitative analysis was performed using ultraviolet spectrophotometry after acetylation of the phenolic hydroxyl groups in lignin.

[0046] Cellulose and hemicellulose content determination: The colorimetric method was used. After appropriate dilution of the hydrolysate, the content of hemicellulose and cellulose was calculated using the xylose standard curve and the glucose standard curve, respectively.

[0047] Polysaccharide content determination: The anthrone-sulfuric acid method was used. After impurities were removed by reflux of ethanol, polysaccharides were extracted with water. The extract was then reacted with anthrone and concentrated sulfuric acid, and the absorbance was measured. The polysaccharide content was calculated using glucose as a standard.

[0048] Antibacterial performance was determined using the plate count method or the paper disc diffusion method. Staphylococcus aureus, Escherichia coli, and Candida albicans were used as test bacteria. After co-incubating the fiber sample with the bacterial solution, the sample was spread and cultured, the number of colonies was counted, and the inhibition rate was calculated. The experimental results showed that... Figure 2 As shown, the Artemisia argyi fiber group exhibits a significant antibacterial effect, and has a better antibacterial effect than ordinary Brazilian imported wood pulp fiber.

[0049] Antioxidant performance was determined using the DPPH and ABTS methods. After extraction with ethanol, the fiber samples were reacted with DPPH or ABTS working solutions. Changes in absorbance at characteristic wavelengths were measured, and the free radical scavenging rate was calculated.

[0050] Anti-allergic performance determination: An in vitro hyaluronidase inhibition assay was used. Based on the reaction between the product of hyaluronidase hydrolysis of hyaluronic acid and the chromogenic agent, the inhibition rate of the sample against hyaluronidase was calculated by measuring the absorbance.

[0051] Anti-irritant assay: The hemolysis test was used. The sample was co-incubated with a low concentration of red blood cell suspension, and the absorbance of hemoglobin at a specific wavelength was measured to calculate the hemolysis rate and evaluate the irritant properties of the sample. The protective effect of the sample against red blood cell rupture was measured in the presence of SDS to evaluate its anti-irritant properties.

[0052] The fiber obtained in Example 1 was subjected to performance tests: The dry breaking strength reached 3.6 cN / dtex, the wet strength retention rate was ≥85%, and the fiber linear density was controlled within the range of 1.0–1.5 dtex, exhibiting characteristics of fine denier and high toughness, making it suitable for weaving high-end woven products. Klason method analysis showed a cellulose content ≥98% and a polysaccharide retention rate ≥70%. Plate count analysis showed an inhibition rate of ≥95% against Staphylococcus aureus, ≥92% against Escherichia coli, and ≥90% against Candida albicans. DPPH assay showed a free radical scavenging rate ≥85%. Hyaluronidase in vitro inhibition test showed an inhibition rate ≥75%. Erythrocyte hemolysis test showed a hemolysis rate <5%, indicating no irritation.

[0053] Example 2

[0054] This implementation demonstrates the effect of different microbial community ratios on fermentation efficiency, and the method and steps are as follows:

[0055] This embodiment is basically the same as embodiment 1, except that the inoculation ratio of the compound microbial community in step (2) is adjusted to P. chrysophagus: Aspergillus niger: Bacillus subtilis = 2:1:2, and the total fermentation time is 7 days. P. chrysophagus and Aspergillus niger are fermented for 4 days first, and then Bacillus subtilis is added to continue fermentation for 3 days.

[0056] The resulting Artemisia argyi cellulose pulp had a cellulose content of about 95% and a polysaccharide retention rate of about 65%. Its antibacterial properties were slightly lower than those in Example 1, but it still had good antibacterial effects and free radical scavenging rate.

[0057] Example 3

[0058] This embodiment provides a method for measuring the three elements of Artemisia argyi fiber, and the method steps are as follows:

[0059] Take 0.3 g of fiber after the completion of 28-day, 30% moisture, wet-heat composting fermentation, add 3 ml of 72% concentrated sulfuric acid for hydrolysis, and hydrolyze at 30 ± 3℃ for 1 h;

[0060] Add 84 ml of water to a 250 ml blue-capped reagent bottle and autoclave at 121 ℃ for 1 h;

[0061] The above solution was removed, filtered, and dried in an oven at 105°C for 4 hours. The content of acid-insoluble lignin was calculated by weighing, which was 102 mg. The contents of cellulose and hemicellulose, determined by colorimetry, were 79 mg and 9 mg, respectively.

[0062] Example 4

[0063] This embodiment is basically the same as embodiment 1, except that in step (2), no exogenous compound microbial community is inoculated. Instead, the endogenous microorganisms carried on the surface of the mugwort leaves are used to ferment naturally for 8 days at 30°C and 80% humidity, with the material being turned over regularly during the period.

[0064] The resulting Artemisia argyi cellulose pulp had a cellulose content of about 90% and a polysaccharide retention rate of about 75%. Its antibacterial properties were comparable to those of Example 1, but the fermentation time was slightly longer and the lignin degradation efficiency was slightly lower than that of the compound microbial fermentation.

[0065] Comparative Example 1

[0066] This comparative example is basically the same as Example 1, except that the fermentation treatment in step (2) is omitted, and the Artemisia argyi powder is directly chemically extracted (treated with sodium chlorite and sodium hydroxide). The resulting cellulose pulp has a cellulose content of about 85%, but the polysaccharide retention rate is <20%, and the content of active ingredients is low, indicating that fermentation is crucial for the retention of active ingredients.

[0067] Comparative Example 2

[0068] This comparative example is basically the same as Example 1, except that only *Procambarus chrysospora* was used for fermentation, without the addition of *Aspergillus niger* and *Bacillus subtilis*. After fermentation, the cellulose extraction rate was low (approximately 70%), lignin residue was significant, and spinning performance was poor.

[0069] Comparative Example 3

[0070] Antibacterial experiments were conducted using imported Brazilian wood pulp fiber as a control. The results showed that the wood pulp fiber had no significant inhibitory effect on Escherichia coli, Staphylococcus aureus, and Candida albicans.

[0071] The method for preparing Artemisia argyi Lyocell fiber provided by this invention has stable process and strong controllability. The resulting fiber has both excellent physical properties and multiple bioactivities, and can be widely used in functional clothing, medical dressings, hygiene care products, thermotherapy materials and other fields. It has good industrialization prospects and market value.

[0072] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for preparing Artemisia argyi Lyocell fiber, characterized in that, Includes the following steps: (1) Fresh mugwort leaves are dried, crushed, and sieved to obtain mugwort powder; (2) The mugwort powder is subjected to targeted fermentation under optimized fermentation conditions by using the endogenous microorganisms carried on its surface or by inoculating a complex microbial community with the ability to degrade lignin and hemicellulose, in order to selectively degrade lignin and hemicellulose in mugwort leaves. (3) After fermentation, the fermentation product is separated into solid and liquid components. The precipitate is collected, washed, ultrasonically separated, and dried to obtain Artemisia argyi cellulose pulp rich in active ingredients. (4) The Artemisia argyi cellulose pulp was subjected to hydrolysis with sodium chlorite and sodium hydroxide to obtain purified Artemisia argyi cellulose; (5) Dissolve the purified Artemisia argyi cellulose in an aqueous solution of N-methylmorpholine-N-oxide, add an antioxidant and an alkaline regulator, heat and stir to dissolve, and obtain a spinning solution; (6) The spinning solution is defoamed and filtered, and then shaped by wet spinning or dry-jet wet spinning process, and then post-treated to obtain Artemisia argyi Lyocell fiber.

2. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The particle size of the mugwort powder is set to be 80 mesh or larger, and the purity is ≥98.7%; the moisture content of the fresh mugwort leaves is controlled to be below 10%.

3. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The complex microbial community includes at least two of the following: *Phanerochaete chrysosporium*, *Aspergillus niger*, and *Bacillus subtilis*; the directional fermentation temperature is 25–35°C, the initial pH is 6.0–7.5, and the fermentation time is 5–10 days.

4. The method for preparing Artemisia argyi Lyocell fiber as described in claim 3, characterized in that, The inoculation of the complex microbial community adopts a staged fermentation strategy, first inoculating fungi to degrade lignin, and then inoculating bacteria to degrade hemicellulose.

5. The method for preparing Artemisia argyi Lyocell fiber as described in claim 3, characterized in that, Maintain an aerobic or microaerobic state during fermentation.

6. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The ultrasonic power for the ultrasonic-assisted separation is 200–400 W, the ultrasonic time is 20–40 minutes, and the solid-liquid ratio is 1:10–1:20 g / mL.

7. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, In step (4), the sodium chlorite has a mass fraction of 1.0% to 1.5%, the treatment temperature is 60 to 80°C, and the treatment time is 4 to 8 hours; the sodium hydroxide has a mass fraction of 0.3% to 0.8%, and the treatment time is 20 to 40 minutes.

8. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The N-methylmorpholine-N-oxide aqueous solution in step (5) has a mass fraction of 80% to 85%, a dissolution temperature of 80 to 100°C, and a dissolution time of 1 to 4 hours.

9. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The antioxidant mentioned in step (5) is propyl gallate, the alkali is hydroxylamine, and the amount added is 0.03% to 0.05% of the mass of cellulose pulp.

10. The method for preparing Artemisia argyi Lyocell fiber as described in claim 1, characterized in that, The coagulation bath in step (6) is an aqueous solution of N-methylmorpholine-N-oxide with a mass fraction of 10% to 20%.

11. A type of Lyocell fiber prepared by the method according to any one of claims 1-10, characterized in that, The cellulose content is ≥95%, and the inhibition rate against Staphylococcus aureus, Escherichia coli and Candida albicans is ≥99%.

12. The Lyocell fiber of claim 11, characterized in that, DPPH free radical scavenging rate ≥80%, hyaluronidase inhibition rate ≥70%, and red blood cell hemolysis test result negative.

13. Applications of Artemisia argyi Lyocell fiber in functional clothing, home textiles, medical dressings, hygiene care products, thermotherapy materials, or filter materials.

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