A durable antibacterial fiber and a method for preparing the same

Abstract

The present application relates to a kind of persistent antibacterial fiber and its preparation method, it relates to high polymer material technical field.The persistent antibacterial fiber is prepared in the present application, copper atom monatomic catalyst is prepared by pyrolysis, copper atom monatomic catalyst is crosslinked and wrapped with chitosan and 2,4,6-trihydroxybenzene-1,3,5-triformaldehyde, then aldehyde group is reacted with ethylenediamine and silver ion is complexed to obtain composite particles.Polymerize terephthalic acid and ethylene glycol on the surface of composite particle to obtain fiber core master batch.9,10-dihydro-9-oxo-10-phenyl-10-oxa-phenanthrene alcohol, maleic anhydride grafted polyethylene and dicumyl peroxide are mixed to obtain fiber skin master batch.Fiber core master batch and fiber skin master batch are mixed with calcium carbonate to obtain a kind of persistent antibacterial fiber.The fiber forms dense structure after high temperature stretching, has excellent mechanical properties and long-acting antibacterial capacity, and is suitable for medical, clothing and home textile field.

Description

Technical Field

[0001] This invention relates to the field of fiber materials technology, specifically to a durable antibacterial fiber and its preparation method. Background Technology

[0002] With increasing public health awareness and the widespread application of antibacterial materials in medical, textile, and packaging fields, the development of novel, long-lasting antibacterial fiber materials has become a hot research topic. Traditional antibacterial fibers are often modified by blending with metal ions (such as silver and copper ions) or inorganic antibacterial agents (such as zinc oxide and titanium dioxide). However, these methods suffer from unstable antibacterial effects, rapid migration and release, and easy inactivation, making it difficult to meet long-term antibacterial requirements. Especially in actual wear environments such as humid heat or friction, antibacterial components easily detach from the fiber surface, leading to a rapid decline in antibacterial performance and affecting the actual service life.

[0003] In recent years, single-atom catalysts have been increasingly introduced into the field of antibacterial materials due to their atomic-level dispersibility, high reactivity, and stability. Copper-based single-atom catalysts not only efficiently induce bacterial membrane structure disruption and oxidative stress but also possess strong binding stability, promising to achieve "non-release" and long-lasting antibacterial effects. Meanwhile, surface modification or coating of copper-based single-atom catalysts is a key step in improving their stability and processing performance in polymer systems, in order to enhance their hydrophilicity, biocompatibility, and dispersibility.

[0004] Chitosan, as a natural polysaccharide, possesses excellent biodegradability, biocompatibility, and intrinsic antibacterial activity. Cross-linking chitosan with multifunctional aldehydes can form a stable three-dimensional network structure, effectively encapsulating metal or catalyst nanoparticles and further enhancing their stability and synergistic antibacterial effect. Furthermore, the chitosan composite layer constructed using covalent cross-linking can further complex silver ions or other bactericidal components, thereby broadening the antibacterial spectrum.

[0005] In polymer processing, polyethylene terephthalate (PET) is an ideal fiber matrix due to its excellent mechanical properties, fiber-forming properties, and chemical stability. By blending chitosan / copper single-atom catalyst composite particles into the PET core layer and using phosphorus-modified flame-retardant polyethylene as the sheath, a core-sheath composite spinning structure is achieved. This not only endows the fiber with excellent antibacterial and flame-retardant properties but also improves its breathability and comfort by adding calcium carbonate pore-forming agents, thus meeting the application requirements of more high-performance fibers.

[0006] Therefore, constructing a high-performance fiber with a copper-based single-atom catalyst as the core, stable chitosan network coating, further blended with polyethylene terephthalate to form fibers, and improving antibacterial durability and functional diversity through a core-skin composite structure has become a key direction for current antibacterial fiber research and industrial transformation. Summary of the Invention

[0007] The purpose of this invention is to provide a durable antibacterial fiber and its preparation method to solve the problems existing in the prior art.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A durable antibacterial fiber, wherein the durable antibacterial fiber is obtained by composite spinning of fiber core masterbatch and fiber sheath masterbatch mixed with calcium carbonate.

[0010] As an optimization, the fiber core masterbatch is composed of composite particles polymerized and encapsulated by terephthalic acid and ethylene glycol.

[0011] As an optimization, the composite particles are prepared by cross-linking 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde with chitosan to encapsulate copper-based single-atom catalyst powder, and then reacting excess aldehyde groups with ethylenediamine to complex silver ions.

[0012] As an optimization, the copper-based single-atom catalyst is prepared by high-temperature pyrolysis using zeolite imidazole framework-8 as a support, copper chloride hexahydrate as a core, and n-hexane as an auxiliary agent.

[0013] As an optimization, the fiber skin masterbatch is produced by reacting and polymerizing 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol and maleic anhydride-grafted polyethylene under the initiation of dicumyl peroxide, and then producing the fiber skin masterbatch in a twin-screw extruder.

[0014] A method for preparing a durable antibacterial fiber includes the following preparation steps:

[0015] (1) A mixture of zeolite imidazole framework-8 with n-hexane at a mass ratio of 1:(80-90) was ultrasonically dispersed for 10 min to obtain a mixed solution; a mixture of copper chloride hexahydrate with a mass ratio of 1:(1000-1200) was mixed with the mixed solution and ultrasonically dispersed for 10 min, and then stirred at 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution; after centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70 °C for 12 h, and then heated to 900 °C at a heating rate of 5 °C / s in an argon environment. After pyrolysis for two hours, copper-based single-atom catalyst powder can be obtained.

[0016] (2) Prepare a chitosan solution by mixing chitosan, dilute acetic acid, and deionized water in a mass ratio of 1:(2~4):(95~97); mix copper-based single-atom catalyst powder and chitosan solution in a mass ratio of 1:(10~50), and sonicate for 10 min to obtain a dispersion; at (40~50)℃, take 0.5~0.8 times the mass of the dispersion of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde. 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde was added dropwise to the dispersion over 3 hours and allowed to stand for 2–3 hours. The mixture was then heated to 50°C in a water bath, and 0.6–1.0 times the mass of the dispersion was added to ethylenediamine. The mixture was allowed to stand for 2 hours to obtain the solution to be complexed. A silver nitrate aqueous solution at a mass ratio of 1:(0.05–0.2) was mixed with the solution to be complexed and stirred in the dark for 12–18 hours. The mixture was then centrifuged for 15 minutes to obtain the composite particles.

[0017] (3) The composite particles with a mass ratio of 1:(20-30) were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of (1.8-2.2):1:0.001 and added to a polymerization reactor equipped with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for (2-4) hours. The temperature was then increased to 280°C and the reactor pressure was controlled at (40-50) Pa. The reaction was continued for (2-3) hours to obtain fiber core masterbatch.

[0018] (4) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:(6~10):(0.1~0.3) and place them in a high-temperature reactor. Heat to (170~190)℃ and react for (6~8)h. Then take it out and put it into a twin-screw extruder. Set the speed to (40~80)rpm and react for (6~8)h. Increase the temperature to (250~260)℃, melt and extrude and cool to obtain fiber skin masterbatch.

[0019] (5) A fiber sheath masterbatch with a mass ratio of 1:(1~1.5) is mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch is used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture is used as the core layer. The mixture is placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature is set to (250~260)℃, the core spinning temperature is set to (290~300)℃, the winding speed is set to 1500m / s, and the stretch ratio is set to (3.8~4.0) to obtain durable antibacterial fiber.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] In preparing durable antibacterial fibers, this invention involves obtaining a copper atom single-atom catalyst through pyrolysis, cross-linking the copper atom single-atom catalyst with chitosan and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, and then reacting the excess aldehyde groups with ethylenediamine to complex silver ions to obtain composite particles. Terephthalic acid and ethylene glycol are polymerized on the surface of the composite particles to obtain a fiber core masterbatch. A mixture of 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene, and dicumyl peroxide is added to a twin-screw extruder to obtain a fiber sheath masterbatch. The fiber core masterbatch and fiber sheath masterbatch are then mixed with calcium carbonate and spun to obtain a durable antibacterial fiber.

[0022] First, the fiber core contains a copper-based single-atom catalyst. When exposed to air, the copper-based single atoms can persistently generate active oxygen to participate in sterilization. During melt-spinning, nano-calcium carbonate is added to ensure the air permeability of the fiber skin and to ensure the generation of active oxygen. Chitosan crosslinks with 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde to form free aldehyde groups, which then react with excess ethylenediamine to generate free amino groups. The free amino groups complex with silver ions, thus binding the silver ions in the fiber. Silver ions can not only provide long-lasting antibacterial effects by destroying cell structure and inactivating intracellular enzymes, but also form a multi-pathway, highly controllable, and broad-spectrum sterilization effect with the copper-based single-atom catalyst.

[0023] Secondly, 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenhydrol and maleic anhydride grafted with polyethylene are reacted and combined in a mass ratio of 1:(6~10):(0.1~0.3) to form the fiber skin material. 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenhydrol will generate and release phosphoric acid during combustion, which promotes the formation of a char layer. The char layer can insulate heat and oxygen, thus achieving a flame-retardant effect. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] To more clearly illustrate the method provided by the present invention, the following embodiments will be described in detail.

[0026] Example 1

[0027] A method for preparing a durable antibacterial fiber includes the following preparation steps:

[0028] (1) A mixture of zeolite imidazole framework-8 (mass ratio 1:80) and n-hexane was ultrasonically dispersed for 10 min to obtain a mixed solution; a mixture of copper chloride hexahydrate (mass ratio 1:1000) and the mixed solution was ultrasonically dispersed for 10 min, and then stirred at 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution; after centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70 °C for 12 h, and then heated to 900 °C at a heating rate of 5 °C / s in an argon environment. After pyrolysis for two hours, copper-based single-atom catalyst powder could be obtained.

[0029] (2) A chitosan solution was prepared by mixing chitosan, dilute acetic acid and deionized water in a mass ratio of 1:2:95; a copper-based single-atom catalyst powder in a mass ratio of 1:10 was mixed with the chitosan solution and sonicated for 10 min to obtain a dispersion; at 40℃, 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde equivalent to 0.5 times the mass of the dispersion was added dropwise to the dispersion over 3 h, and the mixture was allowed to stand for 2 h; the mixture was heated to 50℃ in a water bath, and ethylenediamine in a mass ratio of 0.6 times the mass of the dispersion was added, and the mixture was allowed to stand for 2 h to obtain the solution to be complexed; a silver nitrate aqueous solution in a mass ratio of 1:0.05 was mixed with the solution to be complexed, and the mixture was stirred in the dark for 12 h; the mixture was centrifuged for 15 min to obtain composite particles;

[0030] (3) The composite particles with a mass ratio of 1:20 were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of 1.8:1:0.001 and added to a polymerization reactor with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for 2 hours. The temperature was then increased to 280°C and the reactor pressure was controlled at 40 Pa. The reaction was continued for 2 hours to obtain fiber core masterbatch.

[0031] (4) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:6:0.1 and put them into a high-temperature reactor. Heat to 170°C and react for 6 hours. Then take it out and put it into a twin-screw extruder. Set the speed to 40 rpm and react for 6 hours. Increase the temperature to 250°C. After melting, extrude and cool to obtain fiber skin masterbatch.

[0032] (5) A fiber sheath masterbatch with calcium carbonate in a mass ratio of 1:1 was mixed to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch was used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture was used as the core layer. The mixture was placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature was set to 250℃, the core spinning temperature was set to 290℃, the winding speed was set to 1500m / s, and the stretching ratio was set to 3.8 to obtain durable antibacterial fiber.

[0033] Example 2

[0034] A method for preparing a durable antibacterial fiber includes the following preparation steps:

[0035] (1) A mixture of zeolite imidazole framework-8 (mass ratio 1:85) and n-hexane was ultrasonically dispersed for 10 min to obtain a mixed solution; a mixture of copper chloride hexahydrate (mass ratio 1:1100) and the mixed solution was ultrasonically dispersed for 10 min, and then stirred at 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution; after centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70 °C for 12 h, and then heated to 900 °C at a heating rate of 5 °C / s in an argon environment. After pyrolysis for two hours, copper-based single-atom catalyst powder could be obtained.

[0036] (2) A chitosan solution was prepared by mixing chitosan, dilute acetic acid and deionized water in a mass ratio of 1:3:96; a copper-based single-atom catalyst powder in a mass ratio of 1:30 was mixed with the chitosan solution and sonicated for 10 min to obtain a dispersion; at 45℃, 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, equivalent to 0.65 times the mass of the dispersion, was added dropwise to the dispersion over 3 h and allowed to stand for 2.5 h; the dispersion was heated to 50℃ in a water bath and ethylenediamine, equivalent to 0.8 times the mass of the dispersion, was added and allowed to stand for 2 h to obtain the solution to be complexed; a silver nitrate aqueous solution in a mass ratio of 1:0.125 was mixed with the solution to be complexed and stirred in the dark for 15 h; the mixture was centrifuged for 15 min to obtain composite particles;

[0037] (3) The composite particles with a mass ratio of 1:25 were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of 2:1:0.001 and added to a polymerization reactor with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for 3 hours. The temperature was then increased to 280°C and the reactor pressure was controlled at 45 Pa. The reaction was continued for 2.5 hours to obtain fiber core masterbatch.

[0038] (4) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:8:0.2 and put them into a high-temperature reactor. Heat to 180°C and react for 7 hours. Then take it out and put it into a twin-screw extruder. Set the speed to 60 rpm and react for 7 hours. Increase the temperature to 255°C. After melting, extrude and cool to obtain fiber skin masterbatch.

[0039] (5) A fiber sheath masterbatch with a mass ratio of 1:1.25 was mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch was used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture was used as the core layer. The mixture was placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature was set to 255℃, the core spinning temperature was set to 295℃, the winding speed was set to 1500m / s, and the stretching ratio was set to 3.9 to obtain durable antibacterial fiber.

[0040] Example 3

[0041] A method for preparing a durable antibacterial fiber includes the following preparation steps:

[0042] (1) A mixture of zeolite imidazole framework-8 (mass ratio 1:90) and n-hexane was ultrasonically dispersed for 10 min to obtain a mixed solution. A mixture of copper chloride hexahydrate (mass ratio 1:1200) and the mixed solution was ultrasonically dispersed for 10 min and then stirred at 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution. After centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70 °C for 12 h. The precipitate was then heated to 900 °C at a heating rate of 5 °C / s in an argon environment and pyrolyzed for two hours to obtain copper-based single-atom catalyst powder.

[0043] (2) Chitosan, dilute acetic acid and deionized water were mixed in a mass ratio of 1:4:97 to prepare a chitosan solution; copper-based single-atom catalyst powder in a mass ratio of 1:50 was mixed with the chitosan solution and sonicated for 10 min to obtain a dispersion; at 50℃, 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde equivalent to 0.8 times the mass of the dispersion was added dropwise to the dispersion over 3 h, and the mixture was allowed to stand for 3 h; the mixture was heated to 50℃ in a water bath, and ethylenediamine in a mass ratio of 1 times the mass of the dispersion was added, and the mixture was allowed to stand for 2 h to obtain the solution to be complexed; silver nitrate aqueous solution in a mass ratio of 1:0.2 was mixed with the solution to be complexed and stirred in the dark for 18 h; the mixture was centrifuged for 15 min to obtain composite particles;

[0044] (3) The composite particles with a mass ratio of 1:30 were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of 2.2:1:0.001 and added to a polymerization reactor with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for 4 hours. The temperature was then increased to 280°C and the reactor pressure was controlled at 50 Pa. The reaction was continued for 3 hours to obtain fiber core masterbatch.

[0045] (4) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:10:0.3 and put them into a high-temperature reactor. Heat to 190°C and react for 8 hours. Then take it out and put it into a twin-screw extruder. Set the speed to 80 rpm and react for 8 hours. Increase the temperature to 260°C. After melting, extrude and cool to obtain fiber skin masterbatch.

[0046] (5) A fiber sheath masterbatch with a mass ratio of 1:1.5 was mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch was used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture was used as the core layer. The mixture was placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature was set to 260℃, the core spinning temperature was set to 300℃, the winding speed was set to 1500m / s, and the stretching ratio was set to 4.0 to obtain durable antibacterial fiber.

[0047] Comparative Example 1

[0048] (1) The composite particles with a mass ratio of 1:25 were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of 2:1:0.001 and added to a polymerization reactor with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for 3 hours. The temperature was then increased to 280°C and the reactor pressure was controlled at 45 Pa. The reaction was continued for 2.5 hours to obtain fiber core masterbatch.

[0049] (2) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:8:0.2 and put them into a high-temperature reactor. Heat to 180°C and react for 7 hours. Then take it out and put it into a twin-screw extruder. Set the speed to 60 rpm and react for 7 hours. Increase the temperature to 255°C. After melting, extrude and cool to obtain fiber skin masterbatch.

[0050] (3) A fiber sheath masterbatch with a mass ratio of 1:1.25 was mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch was used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture was used as the core layer. The mixture was placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature was set to 255℃, the core spinning temperature was set to 295℃, the winding speed was set to 1500m / s, and the stretching ratio was set to 3.9 to obtain durable antibacterial fiber.

[0051] Comparative Example 2

[0052] The only difference from Example 2 is the step (2), which removes the step of "mixing the silver nitrate aqueous solution with a mass ratio of 1:0.2 and the solution to be complexed, and stirring in the dark for 18 hours".

[0053] Comparative Example 3

[0054] The only difference from Example 2 is step (4). The original text is incorrect. Instead of mixing 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:8:0.2 and placing them in a high-temperature reactor, heating to 180°C, reacting for 7 hours, then removing them and placing them in a twin-screw extruder, setting the speed to 60 rpm, reacting for 7 hours, increasing the temperature to 255°C, melting, extruding and cooling to obtain fiber skin masterbatch, the original text is incorrect. Instead of mixing 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene in a mass ratio of 1:8:0.2 and placing them in a high-temperature reactor, heating to 180°C, reacting for 7 hours, then extruding and cooling to obtain fiber skin masterbatch, the original text is incorrect.

[0055] Comparative Example 4

[0056] (1) A mixture of zeolite imidazole framework-8 (mass ratio 1:85) and n-hexane was ultrasonically dispersed for 10 min to obtain a mixed solution; a mixture of copper chloride hexahydrate (mass ratio 1:1100) and the mixed solution was ultrasonically dispersed for 10 min, and then stirred at 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution; after centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70 °C for 12 h, and then heated to 900 °C at a heating rate of 5 °C / s in an argon environment. After pyrolysis for two hours, copper-based single-atom catalyst powder could be obtained.

[0057] (2) A chitosan solution was prepared by mixing chitosan, dilute acetic acid and deionized water in a mass ratio of 1:3:96; a copper-based single-atom catalyst powder in a mass ratio of 1:30 was mixed with the chitosan solution and sonicated for 10 min to obtain a dispersion; at 45℃, 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, equivalent to 0.65 times the mass of the dispersion, was added dropwise to the dispersion over 3 h and allowed to stand for 2.5 h; the dispersion was heated to 50℃ in a water bath and ethylenediamine, equivalent to 0.8 times the mass of the dispersion, was added and allowed to stand for 2 h to obtain the solution to be complexed; a silver nitrate aqueous solution in a mass ratio of 1:0.125 was mixed with the solution to be complexed and stirred in the dark for 15 h; the mixture was centrifuged for 15 min to obtain composite particles;

[0058] (3) The composite particles with a mass ratio of 1:25 were mixed with ethylene glycol and stirred for 2 hours. The mixture was then ultrasonically treated at 0°C for 2 hours to obtain a composite particle suspension. Terephthalic acid, the composite particle suspension and antimony glycol were mixed with a mass ratio of 2:1:0.001 and added to a polymerization reactor with a mechanical stirrer. The mixture was heated to 180°C under flowing air and reacted for 3 hours. The temperature was then increased to 280°C and the reactor pressure was controlled at 45 Pa. The reaction was continued for 2.5 hours to obtain fiber core masterbatch.

[0059] (4) Place the fiber core masterbatch into the spinning box, set the temperature to 295℃, the winding speed to 1500m / s, and the stretch ratio to 3.9, and perform melt spinning to obtain a fiber.

[0060] Comparative Example 5

[0061] (1) 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide were mixed in a mass ratio of 1:8:0.2 and placed in a high-temperature reactor. The mixture was heated to 180°C and reacted for 7 hours. The mixture was then removed and placed in a twin-screw extruder. The speed was set to 60 rpm and the mixture was reacted for 7 hours. The temperature was then increased to 255°C. After melting, the mixture was extruded and cooled to obtain fiber skin masterbatch.

[0062] (2) A fiber sheath masterbatch with a mass ratio of 1:1.25 was mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; a fiber core masterbatch with a mass ratio of 1:1.5 and the fiber sheath masterbatch / calcium carbonate mixture were added to a spinning box, the spinning temperature was set to 255℃, the winding speed was 1500m / s, the stretch ratio was 3.9, and the fiber was obtained by melt spinning.

[0063] Comparative Example 6

[0064] The only difference from Example 2 is step (5). The step of "mixing masterbatch with calcium carbonate at a mass ratio of 1:1.25 to obtain fiber sheath masterbatch / calcium carbonate mixture" is removed, and "using fiber core masterbatch as sheath layer and fiber sheath masterbatch / calcium carbonate mixture as core layer and placing it in a dual-temperature-controlled composite spinning box" is adjusted to "using fiber core masterbatch as sheath layer and fiber sheath masterbatch as core layer and placing it in a dual-temperature-controlled composite spinning box".

[0065] Test Example 1

[0066] The antibacterial properties of the fibers prepared in Example 2 and Comparative Examples 1, 2, and 6 were tested: 10% of the total bacterial count per milliliter were prepared. 6 Staphylococcus aureus was cultured using products from Examples 2 and 1-2, respectively, and a blank control group was prepared. After culturing in a shaker at 37°C for 24 hours, 0.1 ml of the bacterial suspension was spread onto a culture medium and incubated at 37°C for another 24 hours. The number of colonies on each plate was then counted.

[0067] Antibacterial rate = ((N0-N) T ) / N0)×100%;

[0068] Where N0 is the number of viable bacteria in the blank control group, N t The number of viable bacteria after adding Example 2 or Comparative Examples 1-2

[0069] Table 1

[0070] Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 6 Blank control group Antibacterial rate 99.97％ 8.33％ 99.71％ 90.3％ ——

[0071] Compared with Example 2, Comparative Example 1 did not add antibacterial components to the fiber; compared with Example 2, Comparative Example 2 did not continue to complex silver ions after completing the copper-based single-atom catalyst encapsulation; compared with Example 2, Comparative Example 6 did not add nano-calcium carbonate to control fiber skin porosity in the final spinning stage, thus affecting fiber air permeability.

[0072] As shown in Table 1, the antibacterial performance of Example 2 is superior to that of Comparative Example 1 and Comparative Example 2, indicating that the fiber prepared by this invention has good antibacterial ability. Comparative Example 1 did not show any antibacterial effect, and the antibacterial effect of Comparative Example 2 was not as good as that of Example 2. In Example 2, the fiber core contains a copper-based single-atom catalyst, which can release active oxygen in an oxygen-containing environment, oxidizing and destroying bacterial cell membranes, proteins, and DNA. At the same time, silver ions are complexed in the fiber core, which can also achieve sterilization by destroying the bacterial cell structure. The combination of the two can even achieve a synergistic effect of silver ions destroying bacterial membrane permeability and copper-based single-atom catalyst generating active oxygen to easily enter the bacterial cell. In addition, the copper-based single-atom catalyst can delay the inactivation of silver ions and increase the duration of silver ion sterilization. Comparative Example 1 does not contain sterilization components and has basically no sterilization ability. Comparative Example 2 only contains copper-based single-atom catalyst components, while Example 2 has the synergistic effect of silver ions and copper-based single-atom catalyst. Compared with Comparative Example 2, Example 2 shows a higher sterilization efficiency.

[0073] As shown in Table 1, Example 2 exhibits superior antibacterial ability, indicating that the fiber prepared by this invention possesses excellent antibacterial properties. In Comparative Example 6, calcium carbonate was not added during the final melt spinning process to control the air permeability of the fiber sheath, resulting in the inability of the oxygen-requiring antibacterial components to fully exert their effects, leading to a decrease in antibacterial efficacy. In Example 2, calcium carbonate ensured the contact degree between the copper-based single-atom catalyst and oxygen, guaranteeing the generation of active oxygen and thus ensuring the strong antibacterial properties of the fiber.

[0074] The durability of the antibacterial properties of the fibers obtained in Example 2 was verified: Fibers produced in Example 2 were washed 0, 10, 30, and 50 times according to the ISO 6330 standard washing procedure, and recorded as S0, S10, S30, and S50, respectively; fibers produced in Comparative Example 2 were also washed 0, 10, 30, and 50 times according to the ISO 6330 standard washing procedure, and recorded as D0, D10, D30, and D50, respectively. Antibacterial rate tests were then conducted on the eight samples.

[0075] Table 2

[0076] S0 S10 S30 S50 D0 D10 D30 D50 Antibacterial rate 99.97％ 99.80％ 99.40％ 98.50％ 99.71％ 97.20％ 92.50％ 85.30％

[0077] Compared to Example 2, Comparative Example 2 did not continue to complex silver ions after completing the copper-based single-atom catalyst encapsulation. This not only reduced the antibacterial efficiency but also made the structure in the fiber core loose.

[0078] As can be seen from the data in Table 2, the antibacterial activity of Example 2 is more persistent than that of Comparative Example 2. This shows that the antibacterial activity of the present invention is persistent. Comparative Example 2 abandons the complexation of silver ions, which not only reduces the broad spectrum of antibacterial activity, but also makes the fiber core structure loose, making it more susceptible to damage due to hydrolysis and other reasons, resulting in the loss of antibacterial components.

[0079] Test Example 2

[0080] The fibers produced in Example 2 and Comparative Example 3 were ignited, and the extinguishing time was recorded.

[0081] Table 3

[0082] Example 2 Comparative Example 3 Extinguishing time 5.2s >10s (burned out)

[0083] Comparative Example 3 used only maleic anhydride-grafted polyethylene as the spinning material and ungrafted 9,10-dihydro-9-oxopyro-10-benzo-10-oxaphenanthrol as the flame retardant component.

[0084] As shown in Table 3, the flame retardant performance of Example 2 is superior to that of Comparative Example 3, indicating that the fiber designed in this invention has flame retardant properties. This is because 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol is grafted into the fiber cortex. 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol can form a char layer during combustion, isolating the combustible material from oxygen, thereby achieving the purpose of flame retardancy.

[0085] Test Example 3

[0086] Using a universal testing machine, 30 fibers each from Example 2, Comparative Example 4, and Comparative Example 5 were tested. The clamping distance was set to 20 mm and the tensile rate to 10 mm / min. The strength was calculated by dividing the maximum tensile force by the cross-sectional area, and the toughness was calculated by integrating the strain function.

[0087] Table 4

[0088] Example 2 Comparative Example 4 Comparative Example 5 Strength (MPA) 583.5 621.7 23 <![CDATA[Toughness (J / m 3 )]]> 87 25 42

[0089] Example 2 involves spinning a mixture of fiber core and fiber sheath masterbatch; Comparative Example 4 involves spinning the fiber core masterbatch separately; and Comparative Example 5 involves spinning the fiber sheath masterbatch separately.

[0090] As shown in Table 4, the strength of Example 2 is 93.86% of that of Comparative Example 4, and its toughness is 348% of that of Comparative Example 4. Meanwhile, the strength of Example 2 is 2537% of that of Comparative Example 5, and its toughness is 207% of that of Comparative Example 5. Compared to single-fiber spinning, composite spinning combines the strength advantage of polyethylene terephthalate with the toughness advantage of polyethylene, improving toughness while retaining strength. Therefore, this invention exhibits higher strength and toughness than ordinary fibers.

[0091] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A durable antibacterial fiber, characterized in that, The durable antibacterial fiber is obtained by composite spinning of fiber core masterbatch and fiber sheath masterbatch mixed with calcium carbonate. The fiber core masterbatch is composed of composite particles polymerized and encapsulated by terephthalic acid and ethylene glycol. The composite particles are prepared by cross-linking 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde with chitosan to encapsulate copper-based single-atom catalyst powder, and then reacting excess aldehyde groups with ethylenediamine to complex silver ions. The copper-based single-atom catalyst is prepared by high-temperature pyrolysis of zeolite imidazole framework-8 as a support, copper chloride hexahydrate as a core, and n-hexane as an auxiliary agent. The fiber skin masterbatch is produced by reacting and polymerizing 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol and maleic anhydride-grafted polyethylene under the initiation of dicumyl peroxide, and then producing the fiber skin masterbatch in a twin-screw extruder.

2. A method for preparing the durable antibacterial fiber according to claim 1, characterized in that, The preparation steps include the following: (1) A mixture of zeolite imidazole framework-8 with hexane at a mass ratio of 1:(80~90) was ultrasonically dispersed for 10 min to obtain a mixed solution; a mixture of copper chloride hexahydrate with a mass ratio of 1:(1000~1200) was mixed with the mixed solution and ultrasonically dispersed for 10 min, and then stirred at a speed of 60 r / min for 2 h to obtain a copper-based single-atom catalyst stock solution; after centrifuging the copper-based single-atom catalyst stock solution, the precipitate was removed and dried in a vacuum environment at 70℃ for 12 h, and then heated to 900℃ at a heating rate of 5℃ / s in an argon environment. After pyrolysis for two hours, copper-based single-atom catalyst powder can be obtained. (2) Prepare a chitosan solution by mixing chitosan, dilute acetic acid, and deionized water in a mass ratio of 1:(2~4):(95~97); mix copper-based single-atom catalyst powder and chitosan solution in a mass ratio of 1:(10~50), and sonicate for 10 min to obtain a dispersion; at (40~50)℃, take 0.5~0.8 times the mass of the dispersion of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde. 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde was added dropwise to the dispersion over 3 hours and allowed to stand for 2-3 hours. The mixture was then heated to 50°C in a water bath, and 0.6-1.0 times the mass of the dispersion was added to ethylenediamine. The mixture was allowed to stand for 2 hours to obtain the solution to be complexed. A silver nitrate aqueous solution at a mass ratio of 1:(0.05-0.2) was mixed with the solution to be complexed and stirred in the dark for 12-18 hours. The mixture was then centrifuged for 15 minutes to obtain the composite particles. (3) Mix composite particles with ethylene glycol at a mass ratio of 1:(20~30), stir for 2 hours, and sonicate at 0°C for 2 hours to obtain a composite particle suspension; mix terephthalic acid, composite particle suspension and antimony glycol at a mass ratio of (1.8~2.2):1:0.001, add to a polymerization reactor with a mechanical stirrer, heat to 180°C under flowing air, react for (2~4) hours, raise the temperature to 280°C, control the reactor pressure to (40~50) Pa, and continue to react for (2~3) hours to obtain fiber core masterbatch; (4) Mix 9,10-dihydro-9-oxophospha-10-benzo-10-oxaphenanthrol, maleic anhydride-grafted polyethylene and dicumyl peroxide in a mass ratio of 1:(6~10):(0.1~0.3) and put them into a high-temperature reactor. Heat to (170~190)℃ and react for (6~8)h. Then take it out and put it into a twin-screw extruder. Set the speed to (40~80)rpm and react for (6~8)h. Increase the temperature to (250~260)℃, melt and extrude and cool to obtain fiber skin masterbatch. (5) A fiber sheath masterbatch with a mass ratio of 1:(1~1.5) is mixed with calcium carbonate to obtain a fiber sheath masterbatch / calcium carbonate mixture; the fiber core masterbatch is used as the sheath layer and the fiber sheath masterbatch / calcium carbonate mixture is used as the core layer. The mixture is placed in a dual-temperature-controlled composite spinning box, and the sheath spinning temperature is set to (250~260)℃, the core spinning temperature is set to (290~300)℃, the winding speed is set to 1500m / s, and the stretching ratio is set to (3.8~4.0) to obtain durable antibacterial fiber.

3. The method for preparing a durable antibacterial fiber according to claim 2, characterized in that, The calcium carbonate mentioned in step (5) is nano-calcium carbonate powder.