Preparation method of organic acid-modified antibacterial and antioxidant cotton fiber

Abstract

The invention discloses a preparation method of an organic acid-modified antibacterial and antioxidant cotton fiber, comprising the following steps: (1) taking a certain amount of cotton fiber for standby use; (2) soaking the cotton fiber in a sodium hydroxide aqueous solution for alkalization, reacting the cotton fiber at 30-40° C. for 10-20 min, so that the alcoholic hydroxyl groups form alcohol anions, thereby increasing the reactive centers in the cellulose structure; (3) adjusting the temperature to 50-70° C., adding 5-chlorosalicylic acid, and carrying out an etherification reaction for 1-6 h, so that the halogen is removed and an ether bond is formed between the cellulose and the alkali cellulose; (4) after the reaction is completed, taking out the cotton fiber for washing and drying; and (5) obtaining the organic acid-modified antibacterial and antioxidant cotton fiber. The salicylic acid-modified antibacterial cotton fiber provided by the present invention can exhibit long-lasting excellent antibacterial properties while maintaining the inherent morphology and structure, and has good anti-inflammatory and antioxidant effects and biosafety.

Description

Technical Field

[0001] The invention belongs to the technical field of functional fibers, and in particular relates to a method for preparing organic acid-modified antibacterial and antioxidant cotton fibers. Background Art

[0002] As people's living standards gradually improve, personal hygiene and health issues are receiving increasing attention. As essential products for human life, fiber textiles are also increasingly valued for their safety and hygienic properties. Driven by this societal trend, research on various antimicrobial fabrics has experienced rapid development over the past two decades. The antimicrobial properties of fiber textiles have also garnered increasing attention, making antimicrobial research on textiles extremely important.

[0003] Cotton fiber is one of the world's most important natural textile materials. Its excellent properties, such as comfort, warmth, and moisture wicking, have led to its widespread use in various fields. However, this high moisture absorption capacity also creates favorable conditions for microbial growth, posing numerous safety risks during use. Therefore, developing the antimicrobial properties of cotton fiber is crucial to expanding its application.

[0004] Currently, methods for preparing antibacterial fabrics can be broadly categorized into two types: physical modification and chemical modification. Physical methods involve adding an antibacterial agent to fabric fibers, physically bonding the fibers and the agent. Specific implementation methods include co-spinning and fiber surface modification. Chemical methods, on the other hand, involve chemically bonding the antibacterial agent to fabric fibers. Specific implementation methods include fiber surface grafting and surface finishing. However, the antibacterial agents used in these methods are all metals (silver, zinc, copper, etc.) or chemical agents (such as quaternary ammonium salts and bisquaterniums), all of which exhibit certain cytotoxicity and are therefore unsuitable for use in applications involving direct contact with human skin (such as underwear worn next to the skin). For example, CN117802771A utilizes a sol-gel spray growth method and plasma surface modification to prepare a cotton fabric with both unidirectional moisture absorption and perspiration-wicking properties. The treated cotton fabric exhibits antibacterial rates of 89.22% and 92.61% against Staphylococcus aureus and Escherichia coli, respectively. CN118373821A discloses a method for preparing a cationic perylene diimide antimicrobial agent and grafting it onto polydopamine-modified cotton fabric, resulting in excellent washability and antibacterial properties. CN114164655B pads a synthetic antimicrobial solution onto cotton fabric, ensuring that the fabric maintains its antibacterial properties even after 100 washes. Patent CN114575149B first prepares a phosphate-based antimicrobial sol and then uses ultraviolet light to graft phosphate inorganic particles onto cotton fibers, resulting in Ag-based phosphate-based inorganic antimicrobial coupled cotton fibers.

[0005] Generally speaking, most current antibacterial cotton fiber products are produced by adding antimicrobial agents or by subjecting cellulose to antimicrobial modification. The former's antimicrobial durability and the basic properties of cotton fiber products are significantly affected by the antimicrobial agents, while the latter typically involves complex processes and demanding production conditions. Salicylic acid, as an organic acid, possesses excellent antimicrobial, anti-inflammatory, and antioxidant properties and has been widely used in various fields, including medicine. In daily chemical products, it typically acts on the surface of human skin through dissolution, exhibiting temporary efficacy. Therefore, how to utilize the antimicrobial, anti-inflammatory, and antioxidant properties of salicylic acid and incorporate it into cotton fibers to impart them with long-lasting, excellent antimicrobial properties while also maintaining good anti-inflammatory, antioxidant, and biosafety, while also maintaining the mechanical properties and wearability of the cotton fibers, has become a pressing challenge for those skilled in the field of functional fibers. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a method for preparing organic acid-modified antibacterial and antioxidant cotton fibers with long-lasting excellent antibacterial properties, good anti-inflammatory and antioxidant effects and biosafety.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing organic acid-modified antibacterial and antioxidant cotton fibers, comprising the following steps:

[0008] (1) Take a certain amount of cotton fiber and set aside;

[0009] (2) Soak the cotton fiber in a sodium hydroxide aqueous solution for alkalization and react it at 30-40°C for 10-20 minutes to form alcohol anions on the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure;

[0010] (3) Adjust the temperature to 50-70°C, add 5-chlorosalicylic acid, and allow the etherification reaction to proceed for 1-6 hours to remove the halogen and form an ether bond with the alkali cellulose;

[0011] (4) After the reaction is completed, the cotton fibers are taken out for washing and drying;

[0012] (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

[0013] In the above-mentioned method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber, in the step (2), the concentration of the sodium hydroxide aqueous solution is 5%-30%, and the reaction is carried out at 35° C. for 15 minutes.

[0014] In the above-mentioned method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber, in the step (3), the etherification reaction temperature is 60° C. and the reaction time is 3 hours.

[0015] In the above-mentioned method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber, in the step (3), the mass ratio of the cotton fiber to 5-chlorosalicylic acid is 1:0.5-4.

[0016] In the above-mentioned method for preparing organic acid-modified antibacterial and antioxidant cotton fibers, in step (3), the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.5.

[0017] In the preparation method of the above-mentioned organic acid-modified antibacterial and antioxidant cotton fiber, in the step (4), the residual solution on the surface of the cotton fiber is washed clean with ethanol and deionized water in sequence, and then placed in a cool and ventilated place to dry or dried at 40°C.

[0018] The preparation method of the above-mentioned organic acid-modified antibacterial and antioxidant cotton fibers, the cotton fibers include cotton bulk fibers or products containing cotton bulk fibers, specifically including cotton yarn or cotton blended yarn prepared from cotton bulk fibers as raw materials through processes such as blowing and carding, pre-drawing, strip winding, drawing, roving, spun yarn, and bobbin winding.

[0019] The advantages of the method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber of the present invention are as follows: the cotton fiber is alkalized in a sodium hydroxide aqueous solution, the alcoholic hydroxyl groups form alcohol anions, and the reactive centers in the cellulose structure are increased; then chlorosalicylic acid is added to remove the halogen and form an ether bond with the alkali cellulose to obtain salicylic acid-modified antibacterial cotton fiber. The antibacterial cotton fiber of the present invention is obtained by grafting salicylic acid onto the modified fiber surface through an etherification reaction under alkaline conditions. The present invention uses a simple and convenient method, low production cost, and a rapid process flow to graft salicylic acid onto the cellulose molecules of the cotton fiber through an etherification reaction, so that the cotton fiber exhibits excellent long-lasting antibacterial effect. While having anti-inflammatory properties, antioxidant properties, and biosafety, the fiber still has a smooth and continuous twisted structure after modification, which is similar to the structure of natural cotton fiber, ensuring that the cotton fiber still has ideal mechanical properties and wearability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the reaction mechanism of salicylic acid-modified antibacterial cotton fiber of the present invention;

[0021] Figure 2 The DPPH free radical scavenging rate curve of the modified antibacterial cotton fiber obtained at different salicylic acid dosages;

[0022] Figure 3 This is a comparison chart of the survival rates of L929 cells after one day and three days of culture on the modified antibacterial cotton fiber surface obtained under different salicylic acid dosages;

[0023] Figure 4This is a comparison chart of ELISA test results after culturing macrophages with modified antibacterial cotton fibers obtained under different salicylic acid dosages;

[0024] Figure 5 This is an electron microscope photograph of cotton fiber when the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:1.5;

[0025] Figure 6 This is an electron microscope photograph of cotton fiber when the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2;

[0026] Figure 7 This is an electron microscope photograph of cotton fiber when the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.5;

[0027] Figure 8 This is an electron microscope photograph of cotton fiber when the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:3. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] In this disclosure, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower parts of a device in actual use or operation, specifically in the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "including" means "including but not limited to." Terms such as first, second, and third are used merely as designations and do not impose numerical requirements or establish a sequence. The term "plurality" means "two or more."

[0030] like Figure 1 As shown, a method for preparing an organic acid-modified antibacterial and antioxidant cotton fiber comprises the following steps:

[0031] (1) Take a certain amount of cotton fiber and set aside;

[0032] (2) Soak the cotton fiber in a sodium hydroxide aqueous solution for alkalization and react it at 30-40°C for 10-20 minutes to form alcohol anions on the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure;

[0033] (3) Adjust the temperature to 50-70°C, add 5-chlorosalicylic acid, and allow the etherification reaction to proceed for 1-6 hours to remove the halogen and form an ether bond with the alkali cellulose;

[0034] (4) After the reaction is completed, the cotton fibers are taken out for washing and drying;

[0035] (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

[0036] Among them, cotton fiber includes cotton bulk fiber or products containing cotton bulk fiber, specifically including cotton yarn or cotton blended yarn prepared with cotton bulk fiber as raw material through processes such as carding, pre-drawing, strip winding, drawing, coarse yarn, spun yarn, and bobbin winding.

[0037] The present invention uses a one-step grafting modification process to fix salicylic acid in the cellulose macromolecular chain, which can enable the cotton fiber to obtain long-term and stable antibacterial, anti-inflammatory and antioxidant functions. At the same time, it simplifies the process flow, reduces production costs, and ensures the basic performance of the cotton fiber, laying the foundation for the development of subsequent series of products.

[0038] The present application will be described in detail below through specific examples. The following examples are only some examples of the present application and are not limitations of the present application.

[0039] Example 1

[0040] A method for preparing organic acid-modified antibacterial and antioxidant cotton fibers comprises the following steps:

[0041] (1) taking a certain amount of cotton fiber for standby use, wherein the cotton fiber includes cotton bulk fiber or products containing cotton bulk fiber, specifically including cotton yarn or cotton blended yarn prepared from cotton bulk fiber through processes such as blowing and carding, pre-drawing, strip and winding, drawing, roving, spun yarn, and bobbin winding;

[0042] (2) Soak the cotton fiber in a 5% sodium hydroxide aqueous solution for alkalization and react at 30°C for 20 minutes to form alcohol anions from the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure;

[0043] (3) Adjust the temperature to 50°C, add 5-chlorosalicylic acid, and conduct etherification reaction for 6 hours to remove the halogen and form an ether bond with alkali cellulose; the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:0.5;

[0044] (4) After the reaction is completed, the cotton fibers are taken out for washing and drying; the residual solution on the surface of the cotton fibers is washed clean with ethanol and deionized water in sequence, and the fibers are wrung out and placed in a cool and ventilated place to dry or dried at 40°C;

[0045] (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

[0046] Example 2

[0047] A method for preparing organic acid-modified antibacterial and antioxidant cotton fibers comprises the following steps:

[0048] (1) taking a certain amount of cotton fiber for standby use, wherein the cotton fiber includes cotton bulk fiber or products containing cotton bulk fiber, specifically including cotton yarn or cotton blended yarn prepared from cotton bulk fiber through processes such as blowing and carding, pre-drawing, strip and winding, drawing, roving, spun yarn, and bobbin winding;

[0049] (2) Soak the cotton fiber in a 15% sodium hydroxide aqueous solution for alkalization and react at 35°C for 15 minutes to form alcohol anions from the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure;

[0050] (3) Adjust the temperature to 60°C, add 5-chlorosalicylic acid, and conduct etherification reaction for 3 hours to remove the halogen and form an ether bond with alkali cellulose; the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.5;

[0051] (4) After the reaction is completed, the cotton fibers are taken out for washing and drying; the residual solution on the surface of the cotton fibers is washed clean with ethanol and deionized water in sequence, and the fibers are wrung out and placed in a cool and ventilated place to dry or dried at 40°C.

[0052] (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

[0053] Example 3

[0054] A method for preparing organic acid-modified antibacterial and antioxidant cotton fibers comprises the following steps:

[0055] (1) taking a certain amount of cotton fiber for standby use; wherein the cotton fiber includes cotton bulk fiber or products containing cotton bulk fiber, specifically including cotton yarn or cotton blended yarn prepared from cotton bulk fiber through processes such as blowing and carding, pre-drawing, strip and winding, drawing, roving, spun yarn, and bobbin winding;

[0056] (2) Soak the cotton fiber in a 30% sodium hydroxide aqueous solution for alkalization and react at 40°C for 10 minutes to form alcohol anions from the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure;

[0057] (3) Adjust the temperature to 70°C, add 5-chlorosalicylic acid, and conduct etherification reaction for 1 hour to remove the halogen and form an ether bond with alkali cellulose; the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:4;

[0058] (4) After the reaction is completed, the cotton fibers are taken out for washing and drying; the residual solution on the surface of the cotton fibers is washed clean with ethanol and deionized water in sequence, and the fibers are wrung out and placed in a cool and ventilated place to dry or dried at 40°C;

[0059] (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

[0060] The performance test results of various antibacterial and antioxidant cotton fibers obtained by using different amounts of 5-chlorosalicylic acid under the process conditions of Example 2 are as follows:

[0061] 1. Long-lasting antibacterial and washable performance:

[0062] 1. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:0.5.

[0063] Soak 10g of cotton fiber in 100mL of 15% sodium hydroxide solution and react at 35°C for 15 minutes. Then, heat to 60°C, add 5g of 5-chlorosalicylic acid, and continue the reaction for 3 hours to obtain 5% salicylic acid-modified antibacterial cotton fiber. After the reaction, wash the residual solution on the cotton fiber surface with ethanol and deionized water, wring it out, and place it in a cool, ventilated place to dry or dry it in an oven at 40°C.

[0064] Antibacterial Performance Testing: The antibacterial and washability properties of salicylic acid-grafted antibacterial cotton fibers were tested in accordance with FZ / T 73023-2006. The same batch of antibacterial cotton fibers was stored in a cool, ventilated place and tested for antibacterial performance after 6 and 12 months. The inhibition rates are shown in Table 1. All samples demonstrated washability and long-lasting antibacterial properties, but the overall antibacterial efficacy was poor.

[0065] Table 1 Antibacterial effect of 5% salicylic acid modified antibacterial cotton fiber

[0066] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 5% salicylic acid 71.4 63.9 61.8 5% salicylic acid - after 6 months 70.9 63.0 60.5 5% salicylic acid - after 12 months 69.5 61.7 59.4 5% salicylic acid - 50 washes 69.8 59.3 60.2 5% salicylic acid - 100 washes 68.3 58.6 60.0

[0067] 2. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:1.

[0068] 5g of 5-chlorosalicylic acid was replaced with 10g of 5-chlorosalicylic acid to obtain 10% salicylic acid-modified antibacterial cotton fiber, which was tested for antibacterial properties, and the inhibition rates were shown in Table 2. All samples showed washability and long-lasting antibacterial effects, but the overall antibacterial effect was poor.

[0069] Table 2 Antibacterial effect of 10% salicylic acid modified antibacterial cotton fiber

[0070] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 10% salicylic acid 84.0 75.8 73.8 10% salicylic acid - after 6 months 81.2 74.6 70.3 10% salicylic acid - after 12 months 80.7 73.1 69.1 10% salicylic acid - 50 washes 82.8 75.7 71.5 10% Salicylic Acid - 100 washes 81.3 75.6 71.0

[0071] 3. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:1.5.

[0072] 5g of 5-chlorosalicylic acid was replaced by 15g of 5-chlorosalicylic acid to obtain 15% salicylic acid modified antibacterial cotton fiber, which was tested for its antibacterial properties. The antibacterial rate was shown in Table 3, and the antibacterial level reached AAA level of the FZ / T73023-2006 standard.

[0073] Table 3 Antibacterial effect of 15% salicylic acid modified antibacterial cotton fiber

[0074]

[0075]

[0076] 4. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.

[0077] 5g of 5-chlorosalicylic acid was replaced with 20g of 5-chlorosalicylic acid to obtain 20% salicylic acid modified antibacterial cotton fiber, which was tested for antibacterial properties. The inhibition rate was shown in Table 4, and the antibacterial level reached AAA level of the FZ / T73023-2006 standard.

[0078] Table 4 Antibacterial effect of 20% salicylic acid modified antibacterial cotton fiber

[0079] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 20% salicylic acid 98.5 98.0 98.6 20% salicylic acid - after 6 months 97.5 97.4 96.8 20% salicylic acid - after 12 months 96.2 95.9 95.2 20% salicylic acid - 50 washes 98.4 97.2 98.4 20% Salicylic Acid - 100 washes 97.5 97.1 97.4

[0080] 5. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.5.

[0081] 5g of 5-chlorosalicylic acid was replaced with 25g of 5-chlorosalicylic acid to obtain 25% salicylic acid modified antibacterial cotton fiber, which was tested for antibacterial properties. The inhibition rates were shown in Table 5, and the antibacterial level reached AAA level according to the FZ / T73023-2006 standard.

[0082] Table 5 Antibacterial effect of 25% salicylic acid modified antibacterial cotton fiber

[0083] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 25% salicylic acid ≥99.9 ≥99.9 ≥99.9 25% salicylic acid - after 6 months ≥99.9 ≥99.9 ≥99.9 25% salicylic acid - after 12 months ≥99.9 ≥99.9 ≥99.9 25% salicylic acid - 50 washes ≥99.9 ≥99.9 ≥99.9 25% Salicylic Acid - 100 washes ≥99.9 ≥99.9 ≥99.9

[0084] 6. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:3.

[0085] 5g of 5-chlorosalicylic acid was replaced with 30g of 5-chlorosalicylic acid to obtain 30% salicylic acid modified antibacterial cotton fiber, which was tested for antibacterial properties. The inhibition rate was shown in Table 6, and the antibacterial level reached AAA level of the FZ / T73023-2006 standard.

[0086] Table 6 Antibacterial effect of 30% salicylic acid modified antibacterial cotton fiber

[0087] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 30% salicylic acid ≥99.9 ≥99.9 ≥99.9 30% salicylic acid - after 6 months ≥99.9 ≥99.9 ≥99.9 30% Salicylic Acid - After 12 months ≥99.9 ≥99.9 ≥99.9 30% Salicylic Acid - 50 washes ≥99.9 ≥99.9 ≥99.9 30% Salicylic Acid - 100 washes ≥99.9 ≥99.9 ≥99.9

[0088] 7. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:3.5.

[0089] 5g of 5-chlorosalicylic acid was replaced with 35g of 5-chlorosalicylic acid to obtain 35% salicylic acid modified antibacterial cotton fiber, which was tested for its antibacterial properties. The antibacterial rate was shown in Table 7, and the antibacterial level reached AAA level of the FZ / T73023-2006 standard.

[0090] Table 7 Antibacterial effect of 35% salicylic acid modified antibacterial cotton fiber

[0091] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 35% salicylic acid ≥99.9 ≥99.9 ≥99.9 35% salicylic acid - after 6 months ≥99.9 ≥99.9 ≥99.9 35% Salicylic Acid - After 12 months ≥99.9 ≥99.9 ≥99.9 35% Salicylic Acid - 50 washes ≥99.9 ≥99.9 ≥99.9 35% Salicylic Acid - 100 washes ≥99.9 ≥99.9 ≥99.9

[0092] 8. The mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:4.

[0093] 5g of 5-chlorosalicylic acid was replaced with 40g of 5-chlorosalicylic acid to obtain 40% salicylic acid modified antibacterial cotton fiber, which was subjected to antibacterial performance testing. The antibacterial rate was shown in Table 8, and the antibacterial level reached AAA level of the FZ / T73023-2006 standard.

[0094] Table 8 Antibacterial effect of 40% salicylic acid modified antibacterial cotton fiber

[0095] Antibacterial rate (%) Escherichia coli Staphylococcus aureus Candida albicans 40% salicylic acid ≥99.9 ≥99.9 ≥99.9 40% salicylic acid - after 6 months ≥99.9 ≥99.9 ≥99.9 40% Salicylic Acid - After 12 months ≥99.9 ≥99.9 ≥99.9 40% Salicylic Acid - 50 washes ≥99.9 ≥99.9 ≥99.9 40% Salicylic Acid - 100 washes ≥99.9 ≥99.9 ≥99.9

[0096] 2. Antioxidant properties:

[0097] Prepare 0.1mM DPPH methanol solution, weigh 1.875mg, 3.75mg, 7.5mg, 15mg and 30mg of 5% salicylic acid modified antibacterial cotton fiber, 10% salicylic acid modified antibacterial cotton fiber, 15% salicylic acid modified antibacterial cotton fiber, 20% salicylic acid modified antibacterial cotton fiber, 25% salicylic acid modified antibacterial cotton fiber, 30% salicylic acid modified antibacterial cotton fiber, 35% salicylic acid modified antibacterial cotton fiber, and 40% salicylic acid modified antibacterial cotton fiber, respectively, add them to 3mL DPPH solution, and set 3mL DPPH solution as a blank control. After soaking in the dark for 30min at room temperature, read the absorbance at 517nm, and use the following formula to calculate the scavenging rate of the sample for DPPH free radicals.

[0098]

[0099] A0 is the average absorbance of the control group, A e The average absorbance of the experimental group was calculated and the DPPH removal rate of each gradient leaching solution was obtained as follows: Figure 2 As shown in the figure, cotton fibers grafted with low concentrations of salicylic acid have almost no antioxidant effect. However, as the salicylic acid grafting concentration increases, the DPPH scavenging effect is significantly improved. Furthermore, the DPPH scavenging rate gradually increases with increasing fiber soaking concentration. For antibacterial cotton fibers modified with 40% salicylic acid, the DPPH scavenging rate reaches a maximum of 84.7±6.8% at 30 mg / mL. This demonstrates that the cotton fibers prepared by the present invention possess ideal antioxidant properties.

[0100] 3. Cytotoxicity test:

[0101] Referring to the cytotoxicity test method of GBT 16886.5-2017, various antibacterial cotton fibers were made into a 20g / m2 The spunlace fabric was cut into 1 cm diameter discs and sterilized by autoclaving. Cells were evenly seeded on the sample surface and cultured for three consecutive days for in vitro cytotoxicity testing. Cell survival rate was calculated according to the following formula.

[0102]

[0103] Among them A e is the average absorbance measured in the experimental group, A0 is the average absorbance measured in the control group on the first day, and the cell survival rate is calculated as Figure 3 As shown. Figure 3 It can be seen that cotton fibers modified with salicylic acid at all concentrations have good cell compatibility. When co-cultured with fibroblasts for one day, the cell survival rate was higher than 98%. After co-culture for three days, the cell survival rate decreased slightly, but was still higher than 92%. This shows that the cotton fibers of the present invention have excellent biosafety.

[0104] 4. Anti-inflammatory performance test

[0105] Various antibacterial cotton fibers are made into a gram weight of 20g / m 2 The spunlace fabric was cut into 1 cm diameter discs and sterilized by high pressure. 5 The cells were uniformly seeded on the cotton fibers at a density of 100 cells / cell. After culturing for 72 hours, the culture medium was taken for ELISA test to characterize the secretion levels of pro-inflammatory factors interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and anti-inflammatory factors interleukin-10 (IL-10) and interleukin-13 (IL-13). The blank control group was set as a sample of ordinary cotton fiber spunlace fabric with the same gram weight, and the concentrations of various inflammatory factors were obtained as follows. Figure 4 As shown in the figure, the secretion levels of various inflammatory factors were similar in the ordinary cotton fiber, 5% salicylic acid modified cotton fiber, 10% salicylic acid modified cotton fiber, and 15% salicylic acid modified cotton fiber groups. However, when the salicylic acid concentration reached 20% or above, the concentrations of pro-inflammatory factors TNF-α and IL-6 decreased rapidly, while the concentrations of anti-inflammatory factors IL-10 and IL-13 increased rapidly, and the anti-inflammatory properties were significantly enhanced. This shows that when the salicylic acid grafting concentration reached the critical value of 20%, the modified cotton fiber began to show good anti-inflammatory efficacy, and as the salicylic acid concentration continued to increase, the anti-inflammatory ability also increased slightly.

[0106] The performance test results show that:

[0107] The salicylic acid-modified antibacterial cotton fiber provided by the present invention can exhibit long-lasting excellent antibacterial properties while maintaining its inherent morphology and structure, while also having good anti-inflammatory and antioxidant efficacy and biosafety. Comparative analysis shows that the amount of 5-chlorosalicylic acid added significantly affects the antibacterial, anti-inflammatory, and antioxidant properties of the modified cotton fiber. As the proportion of 5-chlorosalicylic acid added increases, the antibacterial, anti-inflammatory, and antioxidant effects of the modified cotton fiber are enhanced. The mass ratio of cotton fiber to 5-chlorosalicylic acid is at least 1:2.5.

[0108] The surface morphology of the modified antibacterial cotton fiber obtained when the ratio of cotton fiber to salicylic acid addition is 1:1.5-3 is as follows: Figure 5-8 As shown in the figure, it can be clearly seen that the fiber still has a smooth and continuous twisted structure after modification, which is similar to the structure of untreated natural cotton fibers. It can be concluded that the modified cotton fibers ensure basic mechanical properties, machinability and wearability. The salicylic acid-modified antibacterial cotton fibers provided by the present invention can exhibit long-lasting excellent antibacterial properties while maintaining their inherent morphology and structure, while also having good anti-inflammatory and antioxidant effects and biosafety.

[0109] The present invention is based on the fact that after the cotton fiber is alkalized, the alcoholic hydroxyl groups form alcohol anions, which makes the cellulose have more reactive active groups for subsequent etherification reaction, thereby increasing the degree of substitution. 5-chlorosalicylic acid forms an ether bond with the alkali cellulose in an alkaline environment, thereby obtaining salicylic acid-modified antibacterial cotton fiber. The cellulose and salicylic acid in the cotton fiber are connected by the ether bond to establish a stable molecular structure. The modified cotton fiber has excellent antibacterial effect, is washable, and can achieve long-term antibacterial effect; the surface morphology does not change significantly; it has certain antioxidant properties; it has excellent biocompatibility; and it exhibits certain anti-inflammatory effects. By establishing an ether bond between cellulose and salicylic acid, a functional cotton fiber with a stable and firm structure is obtained, so that its antibacterial, antimicrobial and antioxidant properties remain long-lasting and effective. The production process is short, the process is convenient, and mass production can be achieved.

[0110] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for preparing organic acid-modified antibacterial and antioxidant cotton fibers, characterized in that: The steps include: (1) Take a certain amount of cotton fiber and set aside; (2) Soak the cotton fiber in a sodium hydroxide aqueous solution for alkalization and react at 30-40°C for 10-20 minutes to form alcohol anions at the alcohol hydroxyl groups, thereby increasing the reactive centers in the cellulose structure. (3) Adjust the temperature to 50-70°C, add 5-chlorosalicylic acid, and carry out etherification reaction for 1-6 hours to remove the halogen and form an ether bond with alkali cellulose; the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:1.5-4; (4) After the reaction is completed, the cotton fibers are taken out for washing and drying; (5) Prepare organic acid modified antibacterial and antioxidant cotton fibers.

2. The method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber according to claim 1, wherein: In the step (2), the concentration of the sodium hydroxide aqueous solution is 5%-30%, and the reaction is carried out at 35°C for 15 minutes.

3. The method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber according to claim 1, wherein: In the step (3), the etherification reaction temperature is 60° C. and the reaction time is 3 h.

4. The method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber according to claim 1, wherein: In the step (3), the mass ratio of cotton fiber to 5-chlorosalicylic acid is 1:2.

5.

5. The method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber according to claim 1, wherein: In the step (4), the residual solution on the surface of the cotton fiber is washed clean with ethanol and deionized water in sequence, and then placed in a cool and ventilated place to dry or dried at 40°C.

6. The method for preparing the organic acid-modified antibacterial and antioxidant cotton fiber according to claim 1, wherein: The cotton fibers include bulk cotton fibers or products containing bulk cotton fibers, specifically cotton yarn or cotton blended yarn prepared from bulk cotton fibers through blowing and carding, pre-drawing, strip and winding, drawing, roving, spun yarn, and bobbining processes.

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