Antibacterial fiber, method for preparing the same, and fabric

Abstract

The application discloses an antibacterial fiber and a preparation method and fabric thereof, relates to the technical field of functional fibers, and belongs to the patent publication D01F6 / 54. The preparation method of the antibacterial fiber comprises the following steps: uniformly mixing acrylonitrile monomers, vinyl acetate, methyl methacryloyloxyethyl trimethyl ammonium chloride and anhydrous ethanol to obtain a mixed solution; adding polyvinyl alcohol into the mixed solution and performing heating and stirring reaction to obtain polyacrylonitrile copolymer powder; adding polyvinylpyrrolidone and nano zinc oxide into dimethylacetamide to obtain nano antibacterial dispersion slurry; adding the polyacrylonitrile copolymer powder into the nano antibacterial dispersion slurry to obtain composite nano antibacterial spinning stock solution; and conveying the composite nano antibacterial spinning stock solution to a spinning machine for spinning to obtain the antibacterial fiber. The antibacterial fiber fabric prepared by the application has excellent antibacterial performance and antibacterial durability.

Description

Technical Field

[0001] This invention relates to the field of fiber fabric technology, specifically to an antibacterial fiber, its preparation method, and the fabric thereof. Background Technology

[0002] Polyacrylonitrile fiber (commonly known as acrylic fiber) is widely used in clothing, home textiles, and decoration due to its excellent weather resistance, elasticity, and warmth retention, making it one of the most widely used synthetic fibers. However, in practical applications, the inherently insufficient antibacterial properties of polyacrylonitrile fiber have become a key bottleneck in expanding its application scenarios. The polyacrylonitrile molecule lacks antibacterial groups, meaning the fiber itself does not possess the ability to inhibit or kill bacteria, fungi, or other microorganisms. Simultaneously, the fiber has a certain degree of hygroscopicity, easily absorbing human sweat, sebum, and other secretions on its surface. Under suitable temperature and humidity conditions, it easily becomes a breeding ground for common pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus. The proliferation of microorganisms not only leads to problems such as odor and mildew in the fiber fabric, reducing product lifespan, but can also cause health hazards such as skin itching and inflammation. This deficiency is particularly prominent in areas with high hygiene requirements, such as intimate apparel and medical protective fabrics.

[0003] To improve the antibacterial properties of polyacrylonitrile fibers, existing technologies mostly employ post-treatment methods, such as padding, coating, and printing, to attach antibacterial agents to the surface of the fiber or fabric. However, these methods have significant limitations: the binding force between the antibacterial agent and the fiber is weak, making it prone to detachment and loss during subsequent washing and use, resulting in poor antibacterial durability and potential safety risks due to antibacterial agent migration. Therefore, developing an antibacterial polyacrylonitrile fiber with excellent antibacterial effects and strong durability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an antibacterial fiber, its preparation method, and the fabric thereof, to solve the technical problems mentioned in the background section. The antibacterial fiber prepared by this invention has excellent antibacterial properties and long-lasting antibacterial activity.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing antibacterial fibers includes the following steps:

[0007] S1. Mix acrylonitrile monomer, vinyl acetate, methacryloyloxyethyltrimethylammonium chloride and anhydrous ethanol evenly to obtain a mixed solution;

[0008] S2. Polyvinyl alcohol is added to deionized water, stirred and heated to dissolve it, the above mixed solution is added, then potassium persulfate initiator solution is added, the pH value is adjusted to 6-7, and the reaction is carried out under nitrogen atmosphere with heating and stirring. After filtration, washing and drying, polyacrylonitrile copolymer powder is obtained.

[0009] S3. Add polyvinylpyrrolidone and nano zinc oxide to dimethylacetamide, and disperse evenly by ultrasonic vibration to obtain nano antibacterial dispersion slurry;

[0010] S4. Add the polyacrylonitrile copolymer powder to the nano-antibacterial dispersion slurry and stir to dissolve it to obtain the composite nano-antibacterial spinning solution.

[0011] S5. The composite nano antibacterial spinning solution is defoamed and then fed to a spinning machine for spinning. It passes through a coagulation bath for initial forming, stretching and relaxation heat setting in sequence to obtain antibacterial fibers.

[0012] In this invention, the antibacterial properties of polyacrylonitrile fibers are enhanced through a two-pronged synergistic effect. Firstly, through free radical copolymerization, the methacryloyloxyethyltrimethylammonium chloride quaternary ammonium salt antibacterial monomer is permanently covalently bonded to the polyacrylonitrile macromolecular chain, giving the prepared fiber matrix inherent antibacterial properties. The antibacterial mechanism primarily involves contact sterilization. The quaternary ammonium salt cations on the fiber surface strongly adsorb negatively charged microbial cell membranes such as bacteria and fungi through electrostatic interactions. This tight adsorption disrupts the original lipid bilayer structure of the cell membrane, increasing its permeability and leading to irreversible leakage of cell contents. It also interferes with normal cellular metabolic activities, ultimately causing microbial death. Because the antibacterial groups are firmly covalently linked, they are not easily detached by washing or friction; therefore, this mechanism endows the fiber with a long-lasting and stable antibacterial effect.

[0013] On the other hand, by dispersing nano-zinc oxide inside the fiber, another highly efficient antibacterial pathway with a different mechanism of action is introduced into the fiber. Its antibacterial performance mainly stems from two mechanisms: First, photocatalytic oxidative stress. As a semiconductor photocatalyst, nano-zinc oxide, under light irradiation, can generate highly reactive electron-hole pairs, which then react with water or oxygen molecules on the surface to generate reactive oxygen species such as superoxide anions and hydroxyl radicals. These reactive oxygen species can indiscriminately attack the cell membranes, proteins, and DNA of microorganisms, leading to their oxidative decomposition and death. Second, the metal ion effect. Nano-zinc oxide can slowly release trace amounts of zinc ions in a humid environment. These zinc ions can penetrate into the interior of microorganisms, interfering with the normal function of their enzyme systems and disrupting their metabolic processes. The introduction of nano-zinc oxide not only broadens the antibacterial spectrum but also achieves self-enhanced antibacterial effects under light irradiation, forming a multi-target, multi-mode synergistic antibacterial network with quaternary ammonium salt antibacterial monomers. Figure 1The image shows an SEM image of the surface of the antibacterial fiber prepared in Example 1 of this invention. The image shows that the fiber surface exhibits a groove-like structure.

[0014] Preferably, in step S1, the mass ratio of acrylonitrile monomer, vinyl acetate, and methacryloyloxyethyltrimethylammonium chloride is 180:15-20:5-10.

[0015] Preferably, in step S2, the heating and stirring reaction temperature is 60-70°C, and the reaction time is 4-6 hours.

[0016] Preferably, in step S3, the nano-zinc oxide undergoes a modification treatment, including the following steps:

[0017] 3-(trimethoxysilyl)propyl succinic anhydride was added to a mixed solution of ethanol and water, and nano-zinc oxide was added under stirring. The mixture was heated and stirred, and after centrifugation, washing and drying, modified nano-zinc oxide was obtained.

[0018] In the technical solution of this invention, in order to further improve the synergistic antibacterial effect of the above two aspects, the team of this invention modified the nano zinc oxide and performed surface carboxylation modification on the nano zinc oxide. The modified nano zinc oxide surface is rich in negatively charged carboxyl groups, which can generate strong electrostatic attraction with positively charged quaternary ammonium salt groups, actively pulling and firmly fixing the nano zinc oxide particles around the polymer chain segments richest in quaternary ammonium salts. This greatly improves the initial efficiency of antibacterial treatment, because the bacteria adsorbed by the positively charged quaternary ammonium salts will be directly surrounded by a high concentration of nano zinc oxide and encounter immediate physicochemical attack, realizing a highly efficient linkage of adsorption and killing, thereby further improving the synergistic antibacterial effect of the fiber.

[0019] Preferably, the mass ratio of the nano zinc oxide to 3-(trimethoxysilyl)propylsuccinic anhydride is 10:0.2-0.6.

[0020] Preferably, the heating and stirring reaction temperature is 60-70°C, and the reaction time is 2-4 hours.

[0021] Preferably, the mass ratio of the modified nano zinc oxide to polyvinylpyrrolidone is 10:0.5-1.

[0022] An antibacterial fiber is prepared by the method described above.

[0023] An antibacterial fiber fabric is prepared from the aforementioned antibacterial fiber.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. Quaternary ammonium salt antibacterial monomers are permanently bonded to the polyacrylonitrile molecular chain in the form of covalent bonds through free radical copolymerization, giving the fiber intrinsic antibacterial properties. Since the antibacterial components are fixed by covalent bonds, they are not easily detached by washing or friction, thus giving the fiber stable and long-lasting antibacterial properties.

[0026] 2. By introducing nano-zinc oxide and combining it with quaternary ammonium salt-modified fibers, a synergistic effect of multiple antibacterial mechanisms is achieved. Simultaneously, the nano-zinc oxide undergoes carboxylation surface modification, causing it to be directionally enriched around the quaternary ammonium salt segments through electrostatic attraction. When bacteria are adsorbed by the quaternary ammonium salt, they are simultaneously exposed to the photocatalytic reactive oxygen species and zinc ion attack of high-concentration nano-zinc oxide, achieving a highly efficient linkage between adsorption and killing, significantly improving antibacterial efficiency and enhancing the durability of the antibacterial effect. Attached Figure Description

[0027] Figure 1 This is a SEM image of the surface of the antibacterial fiber prepared in Example 1 of the present invention. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] A method for preparing antibacterial fibers includes the following steps:

[0031] Step 1: Add 180g acrylonitrile monomer, 18g vinyl acetate and 9g methacryloyloxyethyltrimethylammonium chloride to a beaker, then add 300mL anhydrous ethanol. Stir with a magnetic stirrer at 400 rpm for 30 minutes at room temperature until all components are mixed evenly to obtain a clear and transparent mixed monomer solution for later use.

[0032] Step 2: In a four-necked flask, add 500 mL of deionized water and 5 g of polyvinyl alcohol (PVA-1788). Start mechanical stirring and heat to 90 °C to completely dissolve the PVA. After the solution cools to 60 °C, add the mixed monomer solution and 1.0 g of potassium persulfate initiator dissolved in 20 mL of deionized water. Adjust the pH of the reaction system to 6.5 by adding dilute sodium hydroxide solution dropwise. Under a nitrogen atmosphere, raise the temperature of the reaction system to 65 °C and stir at a constant speed of 300 rpm for 5.5 h. After the reaction is complete, filter the resulting white polymer slurry and wash it repeatedly with deionized water 5 times. Finally, dry the filter cake in a vacuum drying oven at 70 °C for 12 h to obtain a white polyacrylonitrile copolymer powder.

[0033] Step 3: Add a mixed solution consisting of 90 mL anhydrous ethanol and 10 mL deionized water to a three-necked flask. Add 0.5 g of 3-(trimethoxysilyl)propylsuccinic anhydride to the solution under mechanical stirring and stir for 10 min. Then, slowly add 10.0 g of nano-zinc oxide powder. Heat the reaction system to 65 °C and stir continuously at 400 rpm under reflux for 3.5 h. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 min to separate the solid, and wash it three times with anhydrous ethanol. Finally, dry the product in a vacuum drying oven at 80 °C for 6 h to obtain surface carboxylated modified nano-zinc oxide powder.

[0034] Add 200 mL of dimethylacetamide solvent to a beaker, then add 0.9 g of polyvinylpyrrolidone (PVPK30) and 10.0 g of modified nano zinc oxide powder in sequence. Place the beaker in an ultrasonic cell disruptor and, under ice-water bath cooling conditions, ultrasonically disperse at 400 W for 45 min to obtain a uniform and stable nano antibacterial dispersion slurry.

[0035] Step 4: Transfer the nano-antibacterial dispersion slurry to a three-necked flask. While continuously stirring, slowly add 50.0g of polyacrylonitrile copolymer powder to the slurry. After the addition is complete, place the mixture in a 55°C water bath and stir at 200 rpm for 6 hours until the polymer powder is completely dissolved, forming a homogeneous, viscous composite nano-antibacterial spinning solution.

[0036] Step 5: The composite nano-antibacterial spinning solution is degassed for 2 hours under vacuum conditions of 60℃ and -0.095MPa. The degassed spinning solution is then transported to a wet spinning machine using a precision metering pump. The solution is extruded from a spinneret with a 0.08mm orifice under a pressure of 0.35 MPa and enters a coagulation bath of a 55wt% dimethylacetamide aqueous solution at 45℃ to complete the formation of nascent fibers. The nascent fibers are then introduced into a 55℃ hot water bath for three-stage drawing, with the total draw ratio controlled at 5.5 times. Finally, the fibers are relaxed and heat-set in a saturated steam atmosphere at 128℃ for 15 minutes, followed by washing, oiling, drying, and winding to obtain antibacterial fibers.

[0037] Example 2

[0038] A method for preparing antibacterial fibers includes the following steps:

[0039] Step 1: Add 180g acrylonitrile monomer, 16g vinyl acetate and 6g methacryloyloxyethyltrimethylammonium chloride to a beaker, then add 300mL anhydrous ethanol. Stir with a magnetic stirrer at 400 rpm for 30 minutes at room temperature until all components are mixed evenly to obtain a clear and transparent mixed monomer solution for later use.

[0040] Step 2: In a four-necked flask, add 500 mL of deionized water and 5 g of polyvinyl alcohol (PVA-1788). Start mechanical stirring and heat to 90 °C to completely dissolve the PVA. After the solution cools to 60 °C, add the mixed monomer solution and 1.0 g of potassium persulfate initiator dissolved in 20 mL of deionized water. Adjust the pH of the reaction system to 6.5 by adding dilute sodium hydroxide solution dropwise. Under a nitrogen atmosphere, raise the temperature of the reaction system to 65 °C and stir at a constant speed of 300 rpm for 4.5 h. After the reaction is complete, filter the resulting white polymer slurry and wash it repeatedly with deionized water 5 times. Finally, dry the filter cake in a vacuum drying oven at 70 °C for 12 h to obtain a white polyacrylonitrile copolymer powder.

[0041] Step 3: Add a mixed solution consisting of 90 mL anhydrous ethanol and 10 mL deionized water to a three-necked flask. Add 0.3 g of 3-(trimethoxysilyl)propylsuccinic anhydride to the solution with mechanical stirring and stir for 10 min. Then, slowly add 10.0 g of nano-zinc oxide powder. Heat the reaction system to 65 °C and stir continuously at 400 rpm under reflux for 2.5 h. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 min to separate the solid, and wash it three times with anhydrous ethanol. Finally, dry the product in a vacuum drying oven at 80 °C for 6 h to obtain surface carboxylated modified nano-zinc oxide powder.

[0042] Add 200 mL of dimethylacetamide solvent to a beaker, then add 0.6 g of polyvinylpyrrolidone (PVPK30) and 10.0 g of modified nano zinc oxide powder in sequence. Place the beaker in an ultrasonic cell disruptor and, under ice-water bath cooling conditions, ultrasonically disperse at 400 W for 45 min to obtain a uniform and stable nano antibacterial dispersion slurry.

[0043] Step 4: Transfer the nano-antibacterial dispersion slurry to a three-necked flask. While continuously stirring, slowly add 50.0g of polyacrylonitrile copolymer powder to the slurry. After the addition is complete, place the mixture in a 55°C water bath and stir at 200 rpm for 6 hours until the polymer powder is completely dissolved, forming a homogeneous, viscous composite nano-antibacterial spinning solution.

[0044] Step 5: The composite nano-antibacterial spinning solution is degassed for 2 hours under vacuum conditions of 60℃ and -0.095MPa. The degassed spinning solution is then transported to a wet spinning machine using a precision metering pump. The solution is extruded from a spinneret with a 0.08mm orifice under a pressure of 0.35 MPa and enters a coagulation bath of a 55wt% dimethylacetamide aqueous solution at 45℃ to complete the formation of nascent fibers. The nascent fibers are then introduced into a 55℃ hot water bath for three-stage drawing, with the total draw ratio controlled at 5.5 times. Finally, the fibers are relaxed and heat-set in a saturated steam atmosphere at 128℃ for 15 minutes, followed by washing, oiling, drying, and winding to obtain antibacterial fibers.

[0045] Example 3

[0046] A method for preparing antibacterial fibers includes the following steps:

[0047] Step 1: Add 180g acrylonitrile monomer, 17g vinyl acetate and 7g methacryloyloxyethyltrimethylammonium chloride to a beaker, then add 300mL anhydrous ethanol. Stir with a magnetic stirrer at 400 rpm for 30 minutes at room temperature until all components are mixed evenly to obtain a clear and transparent mixed monomer solution for later use.

[0048] Step 2: In a four-necked flask, add 500 mL of deionized water and 5 g of polyvinyl alcohol (PVA-1788). Start mechanical stirring and heat to 90 °C to completely dissolve the PVA. After the solution cools to 60 °C, add the mixed monomer solution and 1.0 g of potassium persulfate initiator dissolved in 20 mL of deionized water. Adjust the pH of the reaction system to 6.5 by adding dilute sodium hydroxide solution dropwise. Under a nitrogen atmosphere, raise the temperature of the reaction system to 65 °C and stir at a constant speed of 300 rpm for 5 hours. After the reaction is complete, filter the resulting white polymer slurry and wash it repeatedly with deionized water 5 times. Finally, dry the filter cake in a vacuum drying oven at 70 °C for 12 hours to obtain a white polyacrylonitrile copolymer powder.

[0049] Step 3: Add a mixed solution consisting of 90 mL anhydrous ethanol and 10 mL deionized water to a three-necked flask. Add 0.4 g of 3-(trimethoxysilyl)propylsuccinic anhydride to the solution with mechanical stirring and stir for 10 min. Then, slowly add 10.0 g of nano-zinc oxide powder. Heat the reaction system to 65 °C and stir continuously at 400 rpm under reflux for 3 h. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 min to separate the solid, and wash it three times with anhydrous ethanol. Finally, dry the product in a vacuum drying oven at 80 °C for 6 h to obtain surface carboxylated modified nano-zinc oxide powder.

[0050] Add 200 mL of dimethylacetamide solvent to a beaker, then add 0.7 g of polyvinylpyrrolidone (PVPK30) and 10.0 g of modified nano zinc oxide powder in sequence. Place the beaker in an ultrasonic cell disruptor and, under ice-water bath cooling conditions, ultrasonically disperse at 400 W for 45 min to obtain a uniform and stable nano antibacterial dispersion slurry.

[0051] Step 4: Transfer the nano-antibacterial dispersion slurry to a three-necked flask. While continuously stirring, slowly add 50.0g of polyacrylonitrile copolymer powder to the slurry. After the addition is complete, place the mixture in a 55°C water bath and stir at 200 rpm for 6 hours until the polymer powder is completely dissolved, forming a homogeneous, viscous composite nano-antibacterial spinning solution.

[0052] Step 5: The composite nano-antibacterial spinning solution is degassed for 2 hours under vacuum conditions of 60℃ and -0.095MPa. The degassed spinning solution is then transported to a wet spinning machine using a precision metering pump. The solution is extruded from a spinneret with a 0.08mm orifice under a pressure of 0.35 MPa and enters a coagulation bath of a 55wt% dimethylacetamide aqueous solution at 45℃ to complete the formation of nascent fibers. The nascent fibers are then introduced into a 55℃ hot water bath for three-stage drawing, with the total draw ratio controlled at 5.5 times. Finally, the fibers are relaxed and heat-set in a saturated steam atmosphere at 128℃ for 15 minutes, followed by washing, oiling, drying, and winding to obtain antibacterial fibers.

[0053] Example 4

[0054] A method for preparing antibacterial fibers includes the following steps:

[0055] Step 1: Add 180g acrylonitrile monomer, 20g vinyl acetate and 10g methacryloyloxyethyltrimethylammonium chloride to a beaker, then add 300mL anhydrous ethanol. Stir with a magnetic stirrer at 400 rpm for 30 minutes at room temperature until all components are mixed evenly to obtain a clear and transparent mixed monomer solution for later use.

[0056] Step 2: In a four-necked flask, add 500 mL of deionized water and 5 g of polyvinyl alcohol (PVA-1788). Start mechanical stirring and heat to 90°C to completely dissolve the PVA. After the solution cools to 60°C, add the mixed monomer solution and 1.0 g of potassium persulfate initiator dissolved in 20 mL of deionized water. Adjust the pH of the reaction system to 7 by adding dilute sodium hydroxide solution dropwise. Under a nitrogen atmosphere, raise the temperature of the reaction system to 70°C and stir at a constant speed of 300 rpm for 6 hours. After the reaction is complete, filter the resulting white polymer slurry and wash it repeatedly with deionized water 5 times. Finally, dry the filter cake in a vacuum drying oven at 70°C for 12 hours to obtain a white polyacrylonitrile copolymer powder.

[0057] Step 3: Add a mixed solution consisting of 90 mL anhydrous ethanol and 10 mL deionized water to a three-necked flask. Add 0.6 g of 3-(trimethoxysilyl)propylsuccinic anhydride to the solution with mechanical stirring and stir for 10 min. Then, slowly add 10.0 g of nano-zinc oxide powder. Heat the reaction system to 70 °C and stir continuously at 400 rpm under reflux for 4 h. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 min to separate the solid, and wash it three times with anhydrous ethanol. Finally, dry the product in a vacuum drying oven at 80 °C for 6 h to obtain surface carboxylated modified nano-zinc oxide powder.

[0058] Add 200 mL of dimethylacetamide solvent to a beaker, then add 1.0 g of polyvinylpyrrolidone (PVPK30) and 10.0 g of modified nano zinc oxide powder in sequence. Place the beaker in an ultrasonic cell disruptor and, under ice-water bath cooling conditions, ultrasonically disperse at 400 W for 45 min to obtain a uniform and stable nano antibacterial dispersion slurry.

[0059] Step 4: Transfer the nano-antibacterial dispersion slurry to a three-necked flask. While continuously stirring, slowly add 50.0g of polyacrylonitrile copolymer powder to the slurry. After the addition is complete, place the mixture in a 55°C water bath and stir at 200 rpm for 6 hours until the polymer powder is completely dissolved, forming a homogeneous, viscous composite nano-antibacterial spinning solution.

[0060] Step 5: The composite nano-antibacterial spinning solution is degassed for 2 hours under vacuum conditions of 60℃ and -0.095MPa. The degassed spinning solution is then transported to a wet spinning machine using a precision metering pump. The solution is extruded from a spinneret with a 0.08mm orifice under a pressure of 0.35 MPa and enters a coagulation bath of a 55wt% dimethylacetamide aqueous solution at 45℃ to complete the formation of nascent fibers. The nascent fibers are then introduced into a 55℃ hot water bath for three-stage drawing, with the total draw ratio controlled at 5.5 times. Finally, the fibers are relaxed and heat-set in a saturated steam atmosphere at 128℃ for 15 minutes, followed by washing, oiling, drying, and winding to obtain antibacterial fibers.

[0061] Example 5

[0062] A method for preparing antibacterial fibers includes the following steps:

[0063] Step 1: Add 180g acrylonitrile monomer, 15g vinyl acetate and 5g methacryloyloxyethyltrimethylammonium chloride to a beaker, then add 300mL anhydrous ethanol. Stir with a magnetic stirrer at 400 rpm for 30 minutes at room temperature until all components are mixed evenly to obtain a clear and transparent mixed monomer solution for later use.

[0064] Step 2: In a four-necked flask, add 500 mL of deionized water and 5 g of polyvinyl alcohol (PVA-1788). Start mechanical stirring and heat to 90 °C to completely dissolve the PVA. After the solution cools to 60 °C, add the mixed monomer solution and 1.0 g of potassium persulfate initiator dissolved in 20 mL of deionized water. Adjust the pH of the reaction system to 6 by adding dilute sodium hydroxide solution dropwise. Under a nitrogen atmosphere, raise the temperature of the reaction system to 60 °C and stir at a constant speed of 300 rpm for 4 hours. After the reaction is complete, filter the resulting white polymer slurry and wash it repeatedly with deionized water 5 times. Finally, dry the filter cake in a vacuum drying oven at 70 °C for 12 hours to obtain a white polyacrylonitrile copolymer powder.

[0065] Step 3: Add a mixed solution consisting of 90 mL anhydrous ethanol and 10 mL deionized water to a three-necked flask. Add 0.2 g of 3-(trimethoxysilyl)propylsuccinic anhydride to the solution with mechanical stirring and stir for 10 min. Then, slowly add 10.0 g of nano-zinc oxide powder. Heat the reaction system to 60 °C and stir continuously at 400 rpm under reflux for 2 h. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 min to separate the solid, and wash it three times with anhydrous ethanol. Finally, dry the product in a vacuum drying oven at 80 °C for 6 h to obtain surface carboxylated modified nano-zinc oxide powder.

[0066] Add 200 mL of dimethylacetamide solvent to a beaker, then add 0.5 g of polyvinylpyrrolidone (PVPK30) and 10.0 g of modified nano zinc oxide powder in sequence. Place the beaker in an ultrasonic cell disruptor and, under ice-water bath cooling conditions, ultrasonically disperse at 400 W for 45 min to obtain a uniform and stable nano antibacterial dispersion slurry.

[0067] Step 4: Transfer the nano-antibacterial dispersion slurry to a three-necked flask. While continuously stirring, slowly add 50.0g of polyacrylonitrile copolymer powder to the slurry. After the addition is complete, place the mixture in a 55°C water bath and stir at 200 rpm for 6 hours until the polymer powder is completely dissolved, forming a homogeneous, viscous composite nano-antibacterial spinning solution.

[0068] Step 5: The composite nano-antibacterial spinning solution is degassed for 2 hours under vacuum conditions of 60℃ and -0.095MPa. The degassed spinning solution is then transported to a wet spinning machine using a precision metering pump. The solution is extruded from a spinneret with a 0.08mm orifice under a pressure of 0.35 MPa and enters a coagulation bath of a 55wt% dimethylacetamide aqueous solution at 45℃ to complete the formation of nascent fibers. The nascent fibers are then introduced into a 55℃ hot water bath for three-stage drawing, with the total draw ratio controlled at 5.5 times. Finally, the fibers are relaxed and heat-set in a saturated steam atmosphere at 128℃ for 15 minutes, followed by washing, oiling, drying, and winding to obtain antibacterial fibers.

[0069] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that methacryloyloxyethyltrimethylammonium chloride is not added in step 1.

[0070] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that modified nano zinc oxide powder is not added to the nano antibacterial dispersion slurry in step 3.

[0071] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that in step 3, the modified nano zinc oxide powder in the nano antibacterial dispersion slurry is replaced with ordinary nano zinc oxide powder.

[0072] Performance testing:

[0073] The antibacterial fibers from Examples 1-5 and Comparative Examples 1-3 were spun into yarn using the same spinning process (ring spinning, yarn count 21S), and then woven into plain weave fabric (warp and weft density both 28 threads / cm, fabric weight 120g / m²) using a rapier loom. 2 After weaving, the fabric undergoes routine desizing and setting treatment (setting temperature 130℃, time 30s) to obtain test fabrics of uniform specifications.

[0074] 1. Initial antibacterial performance test: The fabric was cut into 50mm×50mm samples and tested using the shaking flask method. *Escherichia coli* (ATCC 25922) and *Staphylococcus aureus* (ATCC 6538) were selected as test strains, and a 1×10⁻⁶ sample was prepared. 6 A bacterial suspension of CFU / mL was prepared. One fabric sample and 50 mL of the bacterial suspension were placed in an Erlenmeyer flask and shaken at 37℃ and 150 rpm for 24 hours. Then, 1 mL of the bacterial suspension was serially diluted, and the number of remaining viable bacteria was determined using the plate count method to calculate the antibacterial rate. Antibacterial rate = (number of viable bacteria in the blank group - number of viable bacteria in the sample group) / number of viable bacteria in the blank group × 100%. Three parallel samples were tested for each group, and the average value was taken. The test results are shown in Table 1.

[0075] 2. Antibacterial Durability Test: A 50mm × 50mm fabric sample was washed 50 times according to GB / T 8629-2017 "Household Washing Procedure" (40℃±2℃, standard detergent, liquor ratio 1:50, washing for 15 minutes, followed by dehydration and air drying). After washing, the antibacterial rate of the fabric against two bacterial species was determined according to the "Initial Antibacterial Performance Test" method to evaluate the durability of the antibacterial effect after washing. Three parallel samples were tested, and the average value was taken. The test results are shown in Table 1.

[0076] Table 1:

[0077]

[0078] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing antibacterial fibers, characterized in that, Includes the following steps: S1. Acrylonitrile monomer, vinyl acetate, methacryloyloxyethyltrimethylammonium chloride and anhydrous ethanol are mixed evenly, and the mass ratio of acrylonitrile monomer, vinyl acetate and methacryloyloxyethyltrimethylammonium chloride is 180:15~20:5~10 to obtain a mixed solution. S2. Polyvinyl alcohol is added to deionized water, stirred and heated to dissolve it, the above mixed solution is added, then potassium persulfate initiator solution is added, the pH value is adjusted to 6-7, and the reaction is carried out under nitrogen atmosphere with heating and stirring. After filtration, washing and drying, polyacrylonitrile copolymer powder is obtained. S3. Add 3-(trimethoxysilyl)propyl succinic anhydride to a mixed solution of ethanol and water, add nano zinc oxide under stirring, heat and stir to react, and obtain modified nano zinc oxide after centrifugation, washing and drying. Polyvinylpyrrolidone and modified nano zinc oxide were added to dimethylacetamide and dispersed evenly by ultrasonic vibration to obtain a nano antibacterial dispersion slurry. S4. Add the polyacrylonitrile copolymer powder to the nano-antibacterial dispersion slurry and stir to dissolve it to obtain the composite nano-antibacterial spinning solution. S5. The composite nano antibacterial spinning solution is defoamed and then fed to a spinning machine for spinning. It passes through a coagulation bath for initial forming, stretching and relaxation heat setting in sequence to obtain antibacterial fibers.

2. The method for preparing an antibacterial fiber according to claim 1, characterized in that, In step S2, the heating and stirring reaction temperature is 60-70℃, and the reaction time is 4-6 hours.

3. The method for preparing an antibacterial fiber according to claim 1, characterized in that, The mass ratio of the nano zinc oxide to 3-(trimethoxysilyl)propylsuccinic anhydride is 10:0.2-0.

6.

4. The method for preparing an antibacterial fiber according to claim 1, characterized in that, In step S3, the reaction temperature of 3-(trimethoxysilyl)propylsuccinic anhydride and nano zinc oxide is 60-70°C, and the reaction time is 2-4 hours.

5. The method for preparing an antibacterial fiber according to claim 1, characterized in that, The mass ratio of the modified nano zinc oxide to polyvinylpyrrolidone is 10:0.5-1.

6. An antibacterial fiber, characterized in that, It is prepared by the method described in any one of claims 1-5 above.

7. An antibacterial fiber fabric, characterized in that, It is prepared from the antibacterial fiber described in claim 6.

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