Preparation method of high-antibacterial hydrophobic polyamide fiber

Abstract

The invention relates to a preparation method of a high-antibacterial hydrophobic polyamide fiber. The preparation method comprises the following steps: carrying out melt extrusion grafting on polyamide, a quaternary ammonium salt monomer, an initiator and an auxiliary agent to prepare quaternary ammonium salt grafted polyamide; and carrying out melt blending on the prepared quaternary ammonium salt grafted polyamide, polyamide, cuprous oxide and polydimethylsiloxane to obtain the high-antibacterial hydrophobic nylon composite material. And spinning the high-antibacterial hydrophobic nylon composite material to obtain the high-antibacterial hydrophobic polyamide fiber. The high-antibacterial hydrophobic nylon composite material prepared by the method disclosed by the invention can realize efficient antibacterial performance, and the high antibacterial hydrophobic performance of the prepared polyamide fiber is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer molding and processing, and particularly relates to a method for preparing highly antibacterial and hydrophobic nylon fiber. Background Art

[0002] Nylon fiber (polyamide fiber) is one of the most widely used synthetic fiber materials in the world. It possesses excellent elasticity, superior strength, and outstanding chemical and abrasion resistance, making it widely used in clothing, home textiles, medical applications, and other fields. However, due to its hydrophilic nature and loose structure, nylon fiber is susceptible to bacterial growth in humid environments. To meet the growing demand for antimicrobial fibers and expand their applications, the development of antimicrobial nylon fibers and textiles has become a hot topic of research. Common methods for preparing antimicrobial fibers include fiber surface impregnation coating, chemical grafting and crosslinking, and melt blending and spinning. Of these methods, impregnation coating is simple but suffers from poor antimicrobial durability. Chemical grafting and crosslinking offers good durability but carries significant side effects and a complex process. Melt blending is a simple process but requires high stability, dispersibility, and compatibility of the antimicrobial agent with nylon, making it difficult to achieve effective antimicrobial properties. Therefore, the development of antimicrobial nylon fibers with simple processes, strong antimicrobial properties, and stability is of great significance.

[0003] Hydrophobic fibers are a type of fiber material with super-hydrophobic properties, exhibiting excellent repellency against liquids such as water and oil. They are widely used in waterproofing, antifouling, and oil-water separation. Due to the hydrophilic nature of nylon fibers, they are susceptible to bacterial growth in humid environments. Material modification can improve the hydrophobicity of nylon fibers and further enhance their antibacterial properties. Therefore, the development of novel preparation processes for antibacterial hydrophobic nylon fibers, which enhance the durability of their antibacterial properties, has enormous application value and market potential. Summary of the Invention

[0004] In light of this, the present invention provides a method for preparing highly antibacterial and hydrophobic nylon fibers. By utilizing the synergistic effect of a quaternary ammonium salt polymer and cuprous oxide, the method combines the advantages of both quaternary ammonium salt antimicrobial agents and copper-based antimicrobial agents to develop a novel, highly antimicrobial and hydrophobic nylon composite material. This overcomes the low antimicrobial efficiency of conventional fibers and achieves highly effective antimicrobial properties. Furthermore, by adding polydimethylsiloxane, the method addresses the issues of enhancing and regulating the hydrophobic properties of nylon fibers, achieving improved high antimicrobial and hydrophobic properties of nylon fibers.

[0005] To achieve the above object, the present invention provides a method for preparing highly antibacterial hydrophobic nylon fiber, the method comprising the following steps: The quaternary ammonium salt grafted polyamide is prepared by melt-extrusion grafting of polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent; The prepared quaternary ammonium salt grafted polyamide is melt-blended with polyamide, cuprous oxide, and polydimethylsiloxane to obtain a highly antibacterial and hydrophobic nylon composite material; The highly antibacterial and hydrophobic nylon composite material is spun to obtain highly antibacterial and hydrophobic nylon fibers.

[0006] In a preferred embodiment of the method of the present invention, the polyamide is polyamide 6 or polyamide 66.

[0007] In a preferred embodiment of the method of the present invention, the raw materials for preparing the quaternary ammonium salt grafted polyamide include, by mass: Quaternary ammonium salt monomer, 5-30 parts, preferably 5-25 parts, more preferably 5-20 parts; Initiator, 0.2-2 parts, preferably 0.2-1.5 parts, more preferably 0.2-1 part; and Auxiliary agent, 0.1-2 parts, preferably 0.2-2 parts, more preferably 0.2-1 parts, Based on 100 parts of polyamide.

[0008] In a preferred embodiment of the method of the present invention, the quaternary ammonium salt monomer is selected from one or a combination of methacryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyldodecyldimethylammonium chloride and methacryloyloxydodecylpyridinium bromide.

[0009] In a preferred embodiment of the method of the present invention, the initiator is selected from one or a combination of dicumyl peroxide, benzoyl peroxide, and azobisisobutyronitrile.

[0010] In a preferred embodiment of the method of the present invention, the auxiliary agent is selected from dilauryl thiodipropionate, antioxidant 1010, antioxidant 1076, or a combination of several of them.

[0011] In a preferred embodiment of the method of the present invention, the quaternary ammonium salt grafted polyamide is prepared by first mixing polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent in a high-speed mixer, and then adding the mixed raw material mixture into an extruder for melt extrusion grafting reaction, and then pelletizing the obtained product in a granulator. The extrusion temperature of the melt extrusion grafting reaction is 180-280° C., the screw speed is 30-200 rpm; and the pelletizing speed of the pelletizer is 10-200 rpm.

[0012] In a preferred embodiment of the method of the present invention, the raw materials for preparing the highly antibacterial hydrophobic nylon composite material include, by mass: The quaternary ammonium salt grafted polyamide, 10-50 parts, preferably 20-40 parts; Cuprous oxide, 1-10 parts, preferably 2-8 parts, more preferably 2-5 parts; Polydimethylsiloxane, 2-20 parts, preferably 2-10 parts, more preferably 2-5 parts, Based on 100 parts of polyamide.

[0013] In a preferred embodiment of the method of the present invention, the highly antibacterial hydrophobic nylon composite material is prepared by uniformly mixing quaternary ammonium salt grafted polyamide, polyamide, cuprous oxide, and polydimethylsiloxane in a high-speed mixer, adding the mixed raw material mixture to an extruder for melt blending and extrusion, and pelletizing in a granulator; The extrusion temperature of the melt blending extrusion is 180-280° C., the screw speed is 100-300 rpm; and the pelletizing speed of the pelletizer is 30-200 rpm.

[0014] In a preferred embodiment of the method of the present invention, spinning comprises melt spinning, solution spinning, and electrospinning.

[0015] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. The present invention uses melt grafting technology to melt-extrude the polyamide and quaternary ammonium salt monomer under the action of an initiator and an auxiliary agent to form a quaternary ammonium salt grafted polyamide. By utilizing the combined effect of the quaternary ammonium salt polymer and cuprous oxide, the polyamide has the advantages of both quaternary ammonium salt antimicrobial agents and copper-based antimicrobial agents, thereby solving the problem of low antimicrobial efficiency of traditional fibers and achieving efficient antimicrobial performance.

[0016] 2. By adding polydimethylsiloxane as a hydrophobic agent, a highly antibacterial hydrophobic nylon composite material was prepared. The dispersion problem of polyamide and cuprous oxide was improved by grafting polyamide with polydimethylsiloxane and quaternary ammonium salt. At the same time, the problem of improving and regulating the hydrophobicity of nylon fiber was solved by adjusting the content of polydimethylsiloxane, thereby achieving the dispersion of cuprous oxide in the highly antibacterial hydrophobic nylon composite material and the improvement of the hydrophobicity of nylon fiber.

[0017] 3. The preparation method of the present invention, which combines melt grafting, melt blending and spinning technology, effectively solves the problems that the fiber surface impregnation coating method is simple but has poor antibacterial durability, the chemical grafting cross-linking method has good durability but has a large impact of side reactions and a complex process, and the melt blending process is simple but has high requirements on the stability, dispersibility and compatibility of the antibacterial agent with nylon, making it difficult to achieve high-efficiency antibacterial properties.

[0018] 4. The method of the present invention is green and environmentally friendly, has a simple process, and a low preparation cost, and has great application value and market potential. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific embodiments, but the examples do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the examples of the present invention are conventionally purchased raw materials and reagents.

[0020] The present invention provides a method for preparing highly antibacterial hydrophobic nylon fiber, the method comprising the following steps: The quaternary ammonium salt grafted polyamide is prepared by melt-extrusion grafting of polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent; melt-blending the prepared quaternary ammonium salt grafted polyamide with polyamide, cuprous oxide, and polydimethylsiloxane to obtain a highly antibacterial and hydrophobic nylon composite material; and The highly antibacterial and hydrophobic nylon composite material is spun to obtain highly antibacterial and hydrophobic nylon fibers.

[0021] In a preferred embodiment of the method of the present invention, the polyamide is polyamide 6 or polyamide 66.

[0022] In a preferred embodiment of the method of the present invention, the raw materials for preparing the quaternary ammonium salt grafted polyamide include, by mass: Quaternary ammonium salt monomer, 5-30 parts.

[0023] Initiator, 0.2-2 parts; and Additives, 0.1-2 parts, Based on 100 parts of polyamide.

[0024] In the present method, the amount of the quaternary ammonium salt monomer is preferably 5-25 parts, more preferably 5-20 parts, based on 100 parts of polyamide. The amount of the initiator is preferably 0.2-1.5 parts, more preferably 0.2-1 parts. The amount of the auxiliary agent is preferably 0.2-2 parts, more preferably 0.2-1 parts, based on 100 parts of polyamide.

[0025] In a preferred embodiment of the method of the present invention, the quaternary ammonium salt monomer is selected from one or a combination of methacryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyldodecyldimethylammonium chloride and methacryloyloxydodecylpyridinium bromide.

[0026] In a preferred embodiment of the method of the present invention, the initiator is selected from one or a combination of dicumyl peroxide, benzoyl peroxide, and azobisisobutyronitrile.

[0027] In a preferred embodiment of the method of the present invention, the auxiliary agent is selected from dilauryl thiodipropionate, antioxidant 1010, antioxidant 1076, or a combination of several of them.

[0028] In a preferred embodiment of the method of the present invention, the quaternary ammonium salt grafted polyamide is prepared by firstly placing polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent into a high-speed mixer and mixing them uniformly, then adding the mixed raw material mixture into an extruder for melt extrusion grafting reaction, and then pelletizing it in a granulator.

[0029] The extrusion temperature of the melt extrusion grafting reaction is 180-280° C.; the screw speed is 30-200 rpm, preferably 50-150 rpm; and the pelletizing speed of the pelletizer is 10-200 rpm, preferably 10-100 rpm.

[0030] In a preferred embodiment of the method of the present invention, the raw materials for preparing the highly antibacterial hydrophobic nylon composite material include, by mass: 10-50 parts of the quaternary ammonium salt grafted polyamide; Cuprous oxide, 1-10 parts; Polydimethylsiloxane, 2-20 parts, Based on 100 parts of polyamide.

[0031] In the method of the present invention, the amount of the quaternary ammonium salt grafted polyamide is preferably 20-40 parts, based on 100 parts of polyamide. The amount of cuprous oxide is preferably 2-8 parts, more preferably 2-5 parts, based on 100 parts of polyamide. The amount of polydimethylsiloxane is preferably 2-10 parts, more preferably 2-5 parts, based on 100 parts of polyamide.

[0032] In a preferred embodiment of the method of the present invention, the highly antibacterial hydrophobic nylon composite material is prepared by uniformly mixing quaternary ammonium salt grafted polyamide, polyamide, cuprous oxide, and polydimethylsiloxane in a high-speed mixer, adding the mixed raw material mixture to an extruder for melt blending and extrusion, and pelletizing in a granulator; The extrusion temperature of the melt blending extrusion is 180-280° C., the screw speed is 100-300 rpm; and the pelletizing speed of the pelletizer is 30-200 rpm.

[0033] In a preferred embodiment of the method of the present invention, spinning comprises melt spinning, solution spinning, and electrospinning.

[0034] The method of the present invention utilizes the combined effects of a quaternary ammonium salt polymer and cuprous oxide, combining the advantages of both quaternary ammonium salt antimicrobial agents and copper-based antimicrobial agents to develop a novel antimicrobial and highly antimicrobial hydrophobic nylon composite material, thereby overcoming the low antimicrobial efficiency of conventional fibers and achieving highly effective antimicrobial properties. Furthermore, the addition of polydimethylsiloxane addresses the problem of enhancing and regulating the hydrophobic properties of nylon fibers, achieving improved high antimicrobial and hydrophobic properties of nylon fibers.

[0035] In this article, the nylon fiber prepared by the method of the present invention is woven into a fabric using a method known in the art, and the water contact angle and antibacterial properties of the nylon fiber are tested.

[0036] In this study, the hydrophobicity of nylon fiber fabrics was characterized by water contact angle. The static water contact angle measurement method described in GB / T 30693-2014, "Measurement of the Contact Angle of Water with Plastic Films," was used. The test steps are as follows: First, ultrasonically clean the nylon fiber fabric sample with anhydrous ethanol or deionized water and dry it. Then, a droplet (2–5 μL) was dripped vertically onto the surface of the nylon fiber fabric sample using a microsyringe (accuracy ±0.1 μL) on a contact angle meter (CA200, Guangdong Beidou Precision Instrument Co., Ltd.), with the needle tip 1–2 mm from the sample surface. After the droplet contacted the surface, a high-speed camera was used to capture the droplet's profile. The angle between the droplet and the nylon fiber surface was measured using the tangent method to obtain the water contact angle value. Measurements were taken at least five different locations on each sample, and the average value was calculated.

[0037] In this paper, the antibacterial properties of nylon fiber fabrics were tested for their antibacterial rates against Staphylococcus aureus and Escherichia coli according to the antibacterial performance measurement method in GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: Oscillation method”. The specific test steps are as follows: cut the nylon fiber fabric sample into pieces ≤5 mm², weigh 0.75 g ± 0.05 g, and prepare 1×10 5 ~5×10 5 The samples were then reacted with the bacterial solution in a 37°C constant temperature oscillator for 18 to 24 hours, and the antibacterial rate was calculated.

[0038] The method of the present invention can be implemented as follows: (1) preparing quaternary ammonium salt grafted polyamide by melt grafting polyamide and quaternary ammonium salt monomer by melt reaction extrusion under the action of initiator and auxiliary agent; (2) melt-blending the prepared quaternary ammonium salt grafted polyamide with polyamide, cuprous oxide, and polydimethylsiloxane to prepare a highly antibacterial hydrophobic nylon composite material; (3) The prepared highly antibacterial and hydrophobic nylon composite material is spun into highly antibacterial and hydrophobic nylon fibers through a spinning process.

[0039] In the method of the present invention, the extruder for the melt extrusion grafting reaction is a twin-screw extruder or a triple-screw extruder. Preferably, the extrusion temperature for the melt extrusion grafting reaction is 180-280°C, the screw speed is 30-200 rpm, and the pelletizing speed of the pelletizer is 10-200 rpm.

[0040] Preferably, the melt blending extrusion comprises placing the prepared quaternary ammonium salt grafted polyamide, polyamide, cuprous oxide, and polydimethylsiloxane in a high-speed mixer and mixing them uniformly, then adding the mixed raw materials to an extruder for melt blending and extrusion, and then pelletizing them in a granulator. The extruder for the melt blending extrusion is one of a twin-screw extruder and a triple-screw extruder. The extrusion temperature for the melt blending extrusion is 200-280°C, the screw speed is 100-300 rpm, and the pelletizing speed of the granulator is 30-200 rpm.

[0041] Preferably, the spinning technology uses one of melt spinning, solution spinning, electrospinning and the like. Example

[0042] The technical solution of the present invention is further described below with reference to implementation cases.

[0043] Unless otherwise specified, the raw materials listed in the following examples are commercially available products, and the amounts of the raw materials are in parts by mass. Methods and steps not otherwise specified are determined according to common techniques in the art.

[0044] Example 1 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, the preparation comprising the following steps: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 5 parts of methacryloyloxyethyltrimethylammonium chloride, 0.2 parts of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated by a pelletizer at a pelletizing speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 10 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 2 parts of cuprous oxide, and 2 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly, and the mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 220° C., 210° C., and 200° C., the die head temperature was 200° C., and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0045] Example 2 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, the preparation comprising the following steps: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 10 parts of methacryloyloxyethyltrimethylammonium chloride, 0.5 parts of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated by a pelletizer at a pelletizing speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 10 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 2 parts of cuprous oxide, and 2 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly, and the mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 220° C., 210° C., and 200° C., the die head temperature was 200° C., and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0046] Example 3 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, and the preparation steps are as follows: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 15 parts of methacryloyloxyethyltrimethylammonium chloride, 1 part of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210, 220, 230, 220, 210, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated at a pelletizer speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 10 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 2 parts of cuprous oxide, and 2 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die head temperature was 200°C, and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0047] Example 4 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, and the preparation steps are as follows: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 15 parts of methacryloyloxyethyltrimethylammonium chloride, 1 part of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated by a pelletizer at a pelletizing speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 20 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 2 parts of cuprous oxide, and 2 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 220° C., 210° C., and 200° C., the die head temperature was 200° C., and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0048] Example 5 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, and the preparation steps are as follows: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 15 parts of methacryloyloxyethyltrimethylammonium chloride, 1 part of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated by a pelletizer at a pelletizing speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 30 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 2 parts of cuprous oxide, and 2 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 220° C., 210° C., and 200° C., the die head temperature was 200° C., and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0049] Example 6 This embodiment provides a method for preparing highly antibacterial hydrophobic nylon fiber, and the preparation steps are as follows: Step S1, preparing quaternary ammonium salt grafted polyamide material by melt grafting technology: First, 100 parts of polyamide 6, 15 parts of methacryloyloxyethyltrimethylammonium chloride, 1 part of dicumyl peroxide, and 0.2 parts of dilauryl thiodipropionate were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion grafting reaction. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die temperature was 200°C, and the screw speed was 50 rpm. A quaternary ammonium salt grafted polyamide composite material was obtained through free radical grafting reaction, and granulated by a pelletizer at a pelletizing speed of 10 rpm to obtain quaternary ammonium salt grafted polyamide pellets. Step S2, melt extrusion to prepare a high-quality antibacterial and hydrophobic nylon composite material: 30 parts of the obtained quaternary ammonium salt grafted polyamide, 100 parts of polyamide 6, 5 parts of cuprous oxide, and 5 parts of polydimethylsiloxane were added to a high-speed mixer and mixed uniformly. The mixed raw materials were then added to a twin-screw extruder (MEDI-22 / 44, Guangzhou Putong Experimental Analytical Instrument Co., Ltd.) for melt extrusion. The temperatures of the extruder barrel sections were 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 220°C, 210°C, and 200°C, the die head temperature was 200°C, and the screw speed was 100 rpm. A highly antibacterial and hydrophobic nylon composite material was obtained by melt blending and extrusion, and nylon chips were obtained by granulation at a pelletizer speed of 20 rpm. Step S3, melt spinning to prepare nylon fiber, the melt spinning temperature is 210-230°C.

[0050] Comparative Example 1 This comparative example provides a method for preparing nylon fiber. The preparation steps thereof refer to step S3 of Example 1. The difference between this comparative example and Example 1 is that the polyamide 6 raw material used in this comparative example is melt-spinning.

[0051] Performance Testing The highly antibacterial, hydrophobic nylon fibers prepared in Examples 1-6 and the conventional nylon fiber prepared in Comparative Example 1 were tested for their water contact angle, E. coli antibacterial rate, and Staphylococcus aureus antibacterial rate. The highly antibacterial, hydrophobic nylon fibers prepared in Examples 1-6 and the conventional nylon fiber prepared in Comparative Example 1 were woven into fabrics using methods known in the art, and their water contact angle and antibacterial properties were measured.

[0052] 1. Water contact angle Hydrophobicity is characterized by water contact angle. This is measured using the static water contact angle measurement method specified in GB / T 30693-2014, "Measurement of the Contact Angle of Water with Plastic Films." The specific testing steps are as follows: First, ultrasonically clean the nylon fiber fabric sample with anhydrous ethanol or deionized water and dry it. Then, a droplet (3 μL) is dripped vertically onto the surface of the nylon fiber fabric sample using a microsyringe (accuracy ±0.1 μL) on a contact angle meter (CA200, Guangdong Beidou Precision Instrument Co., Ltd.), with the needle tip 2 mm from the sample surface. After the droplet contacts the surface, a high-speed camera is used to capture the droplet's profile. The angle between the droplet and the nylon fiber surface is measured using the tangent method to obtain the water contact angle value. Measurements are taken at least five different locations on each sample, and the average value is calculated.

[0053] 2. Antibacterial rate According to the antibacterial performance measurement method in GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method", the antibacterial rate of bacteria such as Staphylococcus aureus and Escherichia coli was tested. The specific test steps are as follows: cut the sample into 5 mm² pieces, weigh 0.75 g ± 0.05 g, and prepare the solution with a concentration of 4×10 5 The samples were then reacted with the bacterial solution in a 37°C constant temperature oscillator for 20 hours, and the antibacterial rate was calculated.

[0054] The specific test results are shown in Table 1: Table 1 is the test data of Examples 1-6 and Comparative Example 1 The test results in Table 1 show that the water contact angle, antibacterial rate against Escherichia coli, and antibacterial rate against Staphylococcus aureus of the nylon fibers prepared in Examples 1-6 of the present invention were significantly improved compared to those in Comparative Example 1, demonstrating the excellent effectiveness of the present invention. Regarding hydrophobicity, the addition of polydimethylsiloxane in Examples 1-6 effectively improved the hydrophobicity of the nylon fibers. However, at the same polydimethylsiloxane content (Examples 3-5), the addition of quaternary ammonium salt-grafted polyamide reduced the hydrophobicity of the nylon fibers to a certain extent. This is because the quaternary ammonium salt-grafted polyamide improves the interfacial interaction between the polyamide and the inorganic cuprous oxide, reducing its hydrophobicity. As for the antibacterial performance, compared with Example 1, in Examples 2-3, when the mass content of quaternary ammonium salt grafted polyamide, polyamide 6, cuprous oxide and polydimethylsiloxane remained unchanged, as the grafting rate of quaternary ammonium salt grafted polyamide increased, the antibacterial rate of the prepared nylon fiber against Escherichia coli and Staphylococcus aureus gradually increased; compared with Example 3, in Examples 4-5, when the grafting rate of quaternary ammonium salt grafted polyamide was the same, as the content of quaternary ammonium salt grafted polyamide increased, the antibacterial rate of the prepared nylon fiber against Escherichia coli The antibacterial rate of the prepared nylon fiber against Escherichia coli and Staphylococcus aureus also gradually increased; compared with Example 5, in Example 6, with the increase of the mass content of cuprous oxide and polydimethylsiloxane, the antibacterial rate of the prepared nylon fiber against Escherichia coli and Staphylococcus aureus further increased, wherein the water contact angle value of the nylon fiber prepared in Example 6 was 137.1°, and the antibacterial rate against Escherichia coli and the antibacterial rate against Staphylococcus aureus both reached 99%, indicating that the nylon fiber prepared by the present invention has excellent hydrophobicity and antibacterial properties.

[0055] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A method for preparing highly antibacterial hydrophobic nylon fiber, characterized in that: The method comprises the following steps: The quaternary ammonium salt grafted polyamide is prepared by melt-extrusion grafting of polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent; The prepared quaternary ammonium salt grafted polyamide is melt-blended with polyamide, cuprous oxide, and polydimethylsiloxane to obtain a highly antibacterial and hydrophobic nylon composite material; The highly antibacterial and hydrophobic nylon composite material is spun to obtain highly antibacterial and hydrophobic nylon fibers.

2. The method for preparing highly antibacterial hydrophobic nylon fiber according to claim 1, characterized in that: The polyamide is polyamide 6 or polyamide 66.

3. The method for preparing highly antibacterial hydrophobic nylon fiber according to claim 1 or 2, characterized in that: The raw materials for preparing quaternary ammonium salt grafted polyamide include, by mass: Quaternary ammonium salt monomer, 5-30 parts, preferably 5-25 parts, more preferably 5-20 parts; Initiator, 0.2-2 parts, preferably 0.2-1.5 parts, more preferably 0.2-1 parts; Auxiliary agent, 0.1-2 parts, preferably 0.2-2 parts, more preferably 0.2-1 parts; Based on 100 parts of polyamide.

4. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 3, characterized in that: The quaternary ammonium salt monomer is selected from one or a combination of methacryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl dodecyl dimethyl ammonium chloride and methacryloyloxy dodecyl pyridinium bromide.

5. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 4, characterized in that: The initiator is selected from one or a combination of dicumyl peroxide, benzoyl peroxide, and azobisisobutyronitrile.

6. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 5, wherein: The auxiliary agent is selected from dilauryl thiodipropionate, antioxidant 1010, antioxidant 1076, or a combination of several of them.

7. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 6, characterized in that: The quaternary ammonium salt grafted polyamide is prepared by firstly placing polyamide, quaternary ammonium salt monomer, initiator and auxiliary agent into a high-speed mixer and mixing them uniformly, then adding the mixed raw material mixture into an extruder for melt extrusion grafting reaction, and then pelletizing the obtained product through a granulator. The extrusion temperature of the melt extrusion grafting reaction is 180-280° C., the screw speed is 30-200 rpm; and the pelletizing speed of the pelletizer is 10-200 rpm.

8. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 7, characterized in that: The raw materials for preparing the highly antibacterial hydrophobic nylon composite material include, by mass: The quaternary ammonium salt grafted polyamide, 10-50 parts, preferably 20-40 parts; Cuprous oxide, 1-10 parts, preferably 2-8 parts, more preferably 2-5 parts; Polydimethylsiloxane, 2-20 parts, preferably 2-10 parts, more preferably 2-5 parts, Based on 100 parts of polyamide.

9. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 8, characterized in that: The highly antibacterial hydrophobic nylon composite material is prepared by mixing quaternary ammonium salt grafted polyamide, polyamide, cuprous oxide, and polydimethylsiloxane in a high-speed mixer, adding the mixed raw material mixture into an extruder for melt blending and extrusion, and pelletizing in a granulator. The extrusion temperature of the melt blending extrusion is 180-280° C., the screw speed is 100-300 rpm; and the pelletizing speed of the pelletizer is 30-200 rpm.

10. The method for preparing highly antibacterial hydrophobic nylon fiber according to any one of claims 1 to 9, characterized in that: Spinning includes melt spinning, solution spinning, and electrospinning.

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