Preparation method of polyamide fiber

Abstract

The invention discloses a preparation method of polyamide fiber, and belongs to the technical field of synthetic fiber modification treatment. The preparation method comprises the following steps: adding polyamino organosiloxane (at) CuS-PDA, nylon 66 salt and a nylon antioxidant into an extruder according to a weight part ratio of 1: (10-20): (0.01-0.02), and carrying out blending granulation to obtain the high-strength antibacterial polyamide fiber. Nano copper sulphide with a photo-thermal antibacterial effect and polydopamine with good mechanical properties are introduced into a polyamide fiber structure, and the high-strength antibacterial polyamide fiber is obtained.

Description

[0001] This application is a divisional application with application number 2024117765451, application date December 5, 2024, and invention name “A high-strength antibacterial nylon fiber and its preparation method”. Technical Field

[0002] The invention belongs to the technical field of synthetic fiber modification and treatment, and specifically discloses a method for preparing nylon fiber. Background Art

[0003] Nylon fiber (PA), also known as polyamide fiber, is one of the earliest synthetic fibers to be put into use, with the widest range of uses and excellent performance. Currently, nylon 6 and nylon 66 are the most widely used. The macromolecular chain of nylon is connected by amide bonds (-CONH-), and its molecules are composed of hydrophilic polar group amide bonds, methylene segments, terminal amino groups and carboxyl groups. Among them, amide bonds can form stable hydrogen bonds, so that molecules interact with each other to form crystal regions. Nylon has good wear resistance, elasticity, strength, toughness and easy dyeing, so it has been widely used in textile industries such as clothing, ropes and other industries, automotive interior industries and household products industries such as curtains. However, due to the easy generation of static electricity in nylon fibers, dust absorption on the fabric surface, and the discharge of human sweat, bacteria can easily multiply on the fabric surface, thus affecting human health. Since laundry cannot effectively protect the surface of nylon fabrics from microbial contamination, there is a great market demand for antibacterial nylon fabrics.

[0004] Antimicrobial textiles can be divided into natural antimicrobial textiles and artificial antimicrobial textiles according to the sources of effective antimicrobial components in textiles. Natural antimicrobial textiles refer to textiles processed from raw materials with inherent antimicrobial properties that grow in nature, such as bamboo pulp fiber, ramie fiber, etc. Artificial antimicrobial textiles are textiles that are artificially endowed with antimicrobial properties such as fibers or fabrics. At present, artificial antimicrobial textiles are usually obtained by the following methods: (1) The co-spinning method is to mix antimicrobial agents with fiber raw materials and then produce antimicrobial fibers through melt spinning; (2) The chemical grafting modification method is to graft antimicrobial groups onto the fiber surface through chemical bonds; (3) The composite spinning method is to spin antimicrobial fibers and ordinary fibers together through a special spinneret; (4) The antimicrobial agent is attached to the fiber through post-finishing methods.

[0005] Patent CN114672894A discloses an antibacterial nylon yarn and its preparation process, wherein the antibacterial nylon yarn is made of antibacterial masterbatch and ordinary masterbatch, wherein the antibacterial masterbatch is made of graphene oxide / nanosilver antibacterial agent, antioxidant, dispersant and PA6 carrier resin, and the ordinary masterbatch is made of PA6 carrier resin. After graphene oxide is combined with nanosilver particles as a carrier, the nanosilver is mainly loaded on the graphene oxide sheet, which plays a stabilizing and protective role on the nanosilver, and improves the problem of easy oxidation and discoloration of nanosilver to a certain extent. At the same time, the graphene oxide / nanosilver composite material can reduce the release rate of nanosilver, play a sustained release role, and prolong the action time of the antibacterial nylon yarn, so that the antibacterial nylon yarn maintains good antibacterial properties for a long time.

[0006] Patent CN113417026A discloses a graphene high thermal insulation fiber and its preparation method. The graphene aerogel high thermal insulation composite nylon fiber prepared by the invention has more pores, which reduces heat loss by reducing the flow of surrounding air. At the same time, the infrared function of graphene enables the fiber to absorb and release far infrared rays, thereby improving the high thermal insulation of the fiber. In addition, the antibacterial function of graphene itself is used to make the nylon fiber have antibacterial function to protect human health.

[0007] Patent CN115074857A discloses a cooling iodine antibacterial fiber and a preparation method thereof. The invention first reacts silicon carbide nanowires and 3-chloropropyltrimethoxysilane and then reacts with sodium azide to obtain modified silicon carbide nanowires, reacts graphene oxide and 2-(4-ethynylphenyl)ethylene oxide to obtain modified graphene oxide, extrude and melt the modified silicon carbide nanowires, modified graphene oxide, and polyamide to obtain silicon carbide nylon masterbatch, reacts iodine solution prepared from potassium iodide and iodine element with soluble starch and polyvinyl alcohol to obtain composite gel, extrude and melt the composite gel and polyamide to obtain PAT masterbatch, and composite spins the silicon carbide nylon masterbatch and the PAT masterbatch to obtain the cooling iodine antibacterial fiber.

[0008] The above patents use graphene, nanosilver or graphene oxide as the core antibacterial raw materials. Although these materials have good antibacterial properties, due to the dark color of graphene and graphene oxide, it is difficult to change the color of the fiber through subsequent dyeing. In addition, due to the particularity of the nanostructure, graphene, graphene oxide and nanosilver have high surface energy and are easy to agglomerate. When they are prepared with nylon fiber materials only by melt blending, if the core process parameters such as the addition ratio are not controlled, uneven dispersion may occur due to agglomeration, which will reduce the antibacterial and toughness properties of the antibacterial nylon fiber.

[0009] Therefore, it is of great significance to design a high-strength antibacterial nylon fiber that avoids the agglomeration phenomenon caused by the direct use of nano-antibacterial materials, which in turn has a negative impact on the nylon fiber. Summary of the invention

[0010] In view of the deficiencies of the prior art, the present invention introduces nano copper sulfide with photothermal antibacterial effect and polydopamine with good mechanical properties into the nylon fiber structure through the synergistic cooperation of constructed metal coordination and chemical covalent crosslinking, thereby obtaining high-strength antibacterial nylon fiber, which solves the technical problems raised in the background technology. Specifically, the technical solution of the present invention includes the following contents: One of the purposes of the present invention is to provide a method for preparing nylon fiber, the preparation method comprising the following steps: Polyaminoorganosiloxane @CuS-PDA, nylon 66 salt and nylon antioxidant are added into an extruder in a weight ratio of 1:10-20:0.01-0.02, and blended and granulated to obtain the high-strength antibacterial nylon fiber.

[0011] Furthermore, the preparation method of the polyaminoorganosiloxane @CuS-PDA comprises the following steps: The monoamino-terminated organic siloxane and the alcohol amine compound are mixed in a mass ratio of 1:0.05-0.1 in a temperature environment of 30°C-40°C and heated for reaction for 1h-2h to obtain the polyamino-terminated organic siloxane; The polyamino-terminated organosiloxane, dopamine hydrochloride, carboxylic acid activator and carboxylic acid cross-linking agent are mixed and stirred in a mass ratio of 1:1-2:1.5-2.5:2-3 to form a reaction solution, and the temperature of the reaction solution is controlled at a temperature environment of 20°C-25°C to react for 20h-24h to obtain dopamine-modified polyamino organosiloxane; The dopamine-modified polyaminoorganosiloxane, copper salt and vulcanizing agent are mixed in a mass ratio of 1:0.1-0.2:0.01-0.05 and heated to 80°C-90°C for vulcanization reaction for 2h-3h. After the vulcanization reaction is completed, the polyaminoorganosiloxane@CuS-PDA is obtained by base-catalyzed cross-linking.

[0012] Furthermore, the monoamino-terminated organosiloxane includes 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

[0013] Furthermore, the alcoholamine compound includes ethanolamine or propanolamine.

[0014] Furthermore, the carboxylic acid activating agent is composed of an EDC reagent and a DMAP reagent in a mass ratio of 1:1.

[0015] Furthermore, the carboxylic acid crosslinking agent includes oxalic acid, and the structure of the carboxylic acid crosslinking agent needs to contain two carboxylic acid structures, which are used for amidation with dopamine hydrochloride and the amino group on the polyamino-terminated organosiloxane, respectively, to further connect dopamine to the polyamino-terminated organosiloxane.

[0016] Furthermore, the copper salt includes copper sulfate, copper chloride or copper nitrate.

[0017] Furthermore, the sulfiding agent includes sodium sulfide nonahydrate, and the sulfiding agent can also be sulfur-containing hydrogen sulfide or sodium thiosulfate.

[0018] Furthermore, the conditions for the base-catalyzed cross-linking include a pH value of 8-9, a cross-linking temperature of 25° C.-35° C., and a cross-linking time of 1 h-3 h.

[0019] Furthermore, the nylon 66 salt is prepared by mixing adipic acid and hexamethylenediamine and heating them to react.

[0020] Furthermore, the nylon antioxidant includes antioxidant BHT or antioxidant BHA.

[0021] The second object of the present invention is to provide a high-strength antibacterial nylon fiber prepared by a method for preparing the high-strength antibacterial nylon fiber.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses an alcoholamine compound as an amino source, which can not only exert the alkaline catalytic effect of the alcoholamine compound, but also utilize the alcoholic hydroxyl group as a covalently bonded bridging effect, hydrolyze the monoamino-terminated organic siloxane in an alkaline environment, and introduce the amino group to the other side of the monoamino-terminated organic siloxane through a condensation reaction between the silanol hydroxyl group and the alcoholic hydroxyl group, thereby obtaining a polyamino-terminated organic siloxane having multiple amino structures. Then, with the help of a chemical crosslinking effect of a carboxyl crosslinking agent, the amino group on dopamine hydrochloride and the amino group of the polyamino-terminated organic siloxane are amidated and bridged to form a dopamine-modified polyamino organic siloxane. Then, the copper ions are fixed on the dopamine-modified polyaminoorganosiloxane by means of the coordination binding effect formed by the catechol hydroxyl group on the dopamine structure with the metal ions. The fixed copper ions are vulcanized and deposited by a vulcanizing agent to form nano copper sulfide with photothermal antibacterial effect. After the vulcanization treatment, the cross-linking polymerization is performed in the alkaline environment of dopamine to form a polyaminoorganosiloxane @CuS-PDA with a strong cross-linked network structure and antibacterial properties. Finally, the polyaminoorganosiloxane @CuS-PDA is fed to an extruder with nylon 66 salt and a nylon antioxidant for blending and granulation to obtain a high-strength antibacterial nylon fiber. The present invention creatively introduces nano copper sulfide with photothermal antibacterial effect into nylon fiber by load deposition, improves the antibacterial property of nylon, and reduces the possibility that the direct addition of nanomaterials with antibacterial properties and easy agglomeration will have a negative impact on nylon fiber. Then, with the help of dopamine polymerization, polydopamine (PDA) with good tensile strength and toughness is formed. Polydopamine is not only introduced into the nylon structure through covalent bonding, but also can form a cross-linked network structure with hydrogen bonding inside the nylon fiber, thereby improving the toughness of the nylon fiber. Through the synergistic combination of metal coordination, covalent cross-linking and hydrogen bonding, a nylon fiber material with high strength and antibacterial properties is prepared. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0024] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available or can be prepared by known methods.

[0025] Preparation method of nylon 66 salt: (can be purchased from the market or prepared on demand) Adipic acid is dispersed in purified water by an ultrasonic cleaning machine to form an adipic acid suspension with a mass concentration of 50%; then adipic acid is dissolved in purified water to form a hexamethylenediamine solution with a mass concentration of 50%. The adipic acid suspension is placed in a temperature environment of 50±1°C, and then the hexamethylenediamine solution is added dropwise thereto for mixed reaction. The reaction is stopped until the pH value reaches 8.0. Then the mixture is cooled to room temperature, filtered and dried to obtain nylon 66 salt.

[0026] Preparation Example 1: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: Take 500g of 3-aminopropyltrimethoxysilane and add it to a flask, add 200mL of purified water and stir to disperse it evenly (it can also be dispersed with an ultrasonic cleaner), then add 25g of ethanolamine and stir to form a reaction solution, and then place the reaction solution in a 30°C water bath environment to heat and react for 1h. After the reaction is completed, the mixed solution after the reaction is dialyzed with a dialysis bag with a molecular weight cutoff of 500kDa, and the dialysate outside the dialysis bag is retained. The dialysate is purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0027] Take 100g of polyamino-terminated organosiloxane and 100g of dopamine hydrochloride, mix them in 600mL of DMSO solvent and stir them evenly, then add 200g of oxalic acid, 75g of EDC reagent and 75g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 20°C water bath environment, the stirring speed is set to 200r / min, the stirring is turned on, and the reaction time is 20h. After the reaction is completed, the dialysis bag with a molecular weight cutoff of 500kDa is used for dialysis treatment to obtain a dialysis product in the dialysis bag, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0028] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.0), then add 20g copper nitrate and stir for 30min to form a reaction solution. Then add 2g sodium sulfide to the reaction solution and stir evenly, then heat to 80℃ and react for 2h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 1h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0029] Preparation Example 2: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500g of 3-aminopropyltrimethoxysilane was added to a flask and 210mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist dispersion), and then 30g of ethanolamine was added and mixed and stirred to form a reaction solution, and then the reaction solution was placed in a 32°C water bath environment and heated to react for 1h. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0030] Take 100g of polyamino-terminated organosiloxane and 120g of dopamine hydrochloride, mix them in 800mL of DMSO solvent and stir them evenly, then add 220g of oxalic acid, 85g of EDC reagent and 85g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 20°C water bath environment, the stirring speed is set to 200r / min, stirring is turned on, and the reaction time is 20h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0031] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.0), then add 25g copper nitrate and stir for 30min to form a reaction solution. Then add 4g sodium sulfide to the reaction solution and stir evenly, then heat to 80℃ and react for 2h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 1h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0032] Preparation Example 3: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500 g of 3-aminopropyltrimethoxysilane was added to a flask and 220 mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist dispersion), and then 35 g of ethanolamine was added and mixed and stirred to form a reaction solution, and then the reaction solution was placed in a 34°C water bath environment and heated to react for 1.5 hours. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500 kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0033] Take 100g of polyamino-terminated organosiloxane and 140g of dopamine hydrochloride, mix them in 800mL of DMSO solvent and stir them evenly, then add 240g of oxalic acid, 95g of EDC reagent and 95g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 20°C water bath environment, the stirring speed is set to 250r / min, stirring is turned on, and the reaction time is 22h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0034] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.0), then add 30g copper chloride and stir for 35min to form a reaction solution. Then add 6g sodium sulfide to the reaction solution and stir evenly, then heat to 85℃ and react for 2.5h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 2h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0035] Preparation Example 4: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500g of 3-aminopropyltriethoxysilane was added to a flask and 230mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist dispersion), and then 40g of propanolamine was added and stirred to form a reaction solution, and then the reaction solution was placed in a 36°C water bath environment and heated to react for 1.5h. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0036] Take 100g of polyamino-terminated organosiloxane and 160g of dopamine hydrochloride, mix them in 900mL of DMF solvent and stir them evenly, then add 260g of oxalic acid, 105g of EDC reagent and 105g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 25°C water bath environment, the stirring speed is set to 250r / min, stirring is turned on, and the reaction time is 22h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0037] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.5), then add 35g copper chloride and stir for 35min to form a reaction solution. Then add 8g sodium sulfide to the reaction solution and stir evenly, then heat to 85℃ and react for 2.5h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 2h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0038] Preparation Example 5: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500 g of 3-aminopropyltriethoxysilane was added to a flask and 240 mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist in dispersion), and then 45 g of propanolamine was added and stirred to form a reaction solution, and then the reaction solution was placed in a 38°C water bath environment and heated for reaction for 2 hours. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500 kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0039] Take 100g of polyamino-terminated organosiloxane and 180g of dopamine hydrochloride and mix them in 1L of DMF solvent and stir them evenly. Then add 280g of oxalic acid, 115g of EDC reagent and 115g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 25°C water bath environment, the stirring speed is set to 300r / min, the stirring is turned on, and the reaction time is 24h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa. The dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0040] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.5), then add 40g copper sulfate and stir for 40min to form a reaction solution. Then add 10g sodium sulfide to the reaction solution and stir evenly, then heat to 90℃ and react for 3h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 3h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0041] Preparation Example 6: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500 g of 3-aminopropyltriethoxysilane was added to a flask and 250 mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist dispersion), and then 50 g of propanolamine was added and stirred to form a reaction solution, and then the reaction solution was placed in a 40°C water bath environment and heated for reaction for 2 hours. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500 kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0042] Take 100g of polyamino-terminated organosiloxane and 200g of dopamine hydrochloride, mix them in 1L of DMF solvent and stir them evenly, then add 300g of oxalic acid, 125g of EDC reagent and 125g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 25°C water bath environment, the stirring speed is set to 300r / min, the stirring is turned on, and the reaction time is 24h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0043] Take 200g dopamine-modified polyaminoorganosiloxane and disperse it in 1L TE buffer (pH 7.5), then add 40g copper sulfate and stir for 40min to form a reaction solution. Then add 10g sodium sulfide to the reaction solution and stir evenly, then heat to 90℃ and react for 3h. After heating, add alkali to adjust the pH to 8.5±0.5, and continue to stir and crosslink at room temperature for 3h. After crosslinking, filter, wash and dry to obtain polyaminoorganosiloxane@CuS-PDA.

[0044] Preparation Example 7: The preparation of polyaminoorganosiloxane @CuS-PDA specifically includes the following steps: 500 g of 3-aminopropyltriethoxysilane was added to a flask and 250 mL of purified water was added to stir and disperse evenly (an ultrasonic cleaner can also be used to assist dispersion), and then 50 g of propanolamine was added and stirred to form a reaction solution, and then the reaction solution was placed in a 40°C water bath environment and heated for reaction for 2 hours. After the reaction was completed, the mixed solution after the reaction was dialyzed with a dialysis bag with a molecular weight cutoff of 500 kDa, and the dialysate outside the dialysis bag was retained. The dialysate was purified by vacuum distillation to obtain a polyamino-terminated organosiloxane.

[0045] Take 100g of polyamino-terminated organosiloxane and 200g of dopamine hydrochloride, mix them in 1L of DMF solvent and stir them evenly, then add 300g of oxalic acid, 125g of EDC reagent and 125g of DMAP reagent, and continue to mix and stir to form a reaction solution. The reaction solution is placed in a 25°C water bath environment, the stirring speed is set to 300r / min, the stirring is turned on, and the reaction time is 24h. After the reaction is completed, the dialysis product in the dialysis bag is obtained by dialysis treatment with a molecular weight cutoff of 500kDa, and the dialysis product is filtered to remove insoluble impurities to obtain dopamine-modified polyamino organosiloxane.

[0046] 200 g of dopamine-modified polyaminoorganosiloxane was dispersed in 1 L of TE buffer (pH 7.5), and alkali was added to adjust the pH to 8.5±0.5, and the mixture was stirred and cross-linked for 3 h at room temperature. After the cross-linking was completed, the polyaminoorganosiloxane@CuS-PDA was obtained by filtration, washing and drying.

[0047] Embodiment 1: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 1, 50 parts by weight of nylon 66 salt, and 0.05 parts by weight of antioxidant BHT were mixed and added to the extruder, and then plasticized and blended at 210°C at a speed of 100 r / min for 70 minutes. The temperature was then raised to 260°C, melt blended at a speed of 150 r / min and a pressure of 0.5 MPa for 10 minutes, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0048] Embodiment 2: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 2, 60 parts by weight of nylon 66 salt, and 0.05 parts by weight of antioxidant BHT were mixed and added to the extruder, and then plasticized and blended at 210°C at a speed of 110 r / min for 80 minutes. The temperature was then raised to 260°C, melt blended at a speed of 150 r / min and a pressure of 0.6 MPa for 12 minutes, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0049] Embodiment 3: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 3, 70 parts by weight of nylon 66 salt, and 0.05 parts by weight of antioxidant BHT were mixed and added to the extruder, and then plasticized and blended at 220°C at a speed of 120 r / min for 90 minutes. The temperature was then raised to 270°C, melt blended at a speed of 200 r / min and a pressure of 0.7 MPa for 14 minutes, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0050] Embodiment 4: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 4, 80 parts by weight of nylon 66 salt, and 0.1 parts by weight of antioxidant BHA were mixed and added to the extruder, and then plasticized and blended at 220°C at a speed of 130 r / min for 100 min. The temperature was then raised to 270°C, melt blended at a speed of 200 r / min and a pressure of 0.8 MPa for 16 min, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0051] Embodiment 5: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 5, 90 parts by weight of nylon 66 salt, and 0.1 parts by weight of antioxidant BHA were mixed and added to the extruder, and then plasticized and blended at 230°C at a speed of 140 r / min for 110 min. The temperature was then raised to 280°C, melt blended at a speed of 250 r / min and a pressure of 0.9 MPa for 18 min, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0052] Embodiment 6: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 6, 100 parts by weight of nylon 66 salt, and 0.1 parts by weight of antioxidant BHA were mixed and added to the extruder, and then plasticized and blended at 230°C at a speed of 150 r / min for 110 minutes. The temperature was then raised to 280°C, melt blended at a speed of 250 r / min and a pressure of 1 MPa for 20 minutes, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0053] Comparative Example 1: A preparation method of high-strength antibacterial nylon fiber specifically includes the following processes: 5 parts by weight of the polyaminoorganosiloxane @CuS-PDA obtained in Preparation Example 7, 100 parts by weight of nylon 66 salt, 0.1 parts by weight of antioxidant BHA and 5 parts by weight of nano copper sulfide were mixed and added to an extruder, and then plasticized and blended at 230°C at a speed of 150 r / min for 110 minutes. The temperature was then raised to 280°C, melt blended at a speed of 250 r / min and a pressure of 1 MPa for 20 minutes, and then extruded and granulated to obtain high-strength antibacterial nylon fiber.

[0054] At room temperature, the viable bacterial count was 1×10 7 ~1×10 8 The bacterial liquid of Escherichia coli and Staphylococcus aureus with a concentration of CFU / mL was added dropwise to the surface of the high-strength antibacterial nylon fiber obtained in Examples 1 to 6 and Comparative Example 1, and then transferred to a NIR laser emitter with a wavelength of 1100 nm at a power of 0.7 W / cm 2 The irradiation power was irradiated for 10 minutes and the surface temperature was recorded with a temperature measuring instrument. After the treatment, the surface of the high-strength antibacterial nylon fiber was rinsed with PBS buffer solution. 100μL of the rinse solution was taken and spread on the LB solid culture medium. Finally, it was cultured in a 37℃ constant temperature incubator for 24 hours, and then the number of bacteria was recorded by the plate counting method and the sterilization rate was calculated. The results are shown in Table 1 below.

[0055] Table 1 The high-strength antibacterial nylon fibers obtained in Examples 1 to 6 and Comparative Example 1 were stretched at a stretching rate of 5 mm / min using an electronic universal material testing machine in accordance with ISO527-1-2012 Determination of tensile properties of plastics, and the tensile strength and elongation at break were calculated. The results are shown in Table 2 below.

[0056] Table 2 From Table 1 and Table 2 above, we can conclude that: (1) In Examples 1 to 6, the present invention introduces nano copper sulfide with photothermal antibacterial effect into nylon fiber by metal coordination and chemical deposition to improve the antibacterial property of nylon. Then, with the help of dopamine polymerization to form polydopamine (PDA) with good tensile strength and toughness, a cross-linked network structure with hydrogen bonding is formed inside the nylon fiber through covalent bonding and hydrogen bonding, thereby improving the mechanical properties of the nylon fiber.

[0057] (2) From Comparative Example 1, it can be seen that although the polyaminoorganosiloxane @CuS-PDA can enter the nylon fiber material through hydrogen bonding and covalent crosslinking, due to the agglomeration characteristics of nano-copper oxide, it can only rely on physical adsorption such as van der Waals force to bind to the nylon fiber, and the binding force is low. It is also easy to cause uneven dispersion on the nylon fiber, low tensile strength and elongation at break, decreased mechanical properties, and poor antibacterial properties.

[0058] The above-described embodiments provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected.

Claims

1. A method for preparing nylon fiber, characterized in that: The preparation method comprises the following steps: Polyaminoorganosiloxane @CuS-PDA, nylon 66 salt and nylon antioxidant are added into an extruder in a weight ratio of 1:10-20:0.01-0.02, and blended and granulated to obtain the high-strength antibacterial nylon fiber; The preparation method of the polyaminoorganosiloxane @CuS-PDA comprises the following steps: The monoamino-terminated organic siloxane and the alcohol amine compound are mixed in a mass ratio of 1:0.05-0.1 in a temperature environment of 30°C-40°C and heated for reaction for 1h-2h to obtain the polyamino-terminated organic siloxane; The polyamino-terminated organosiloxane, dopamine hydrochloride, carboxylic acid activator and carboxylic acid cross-linking agent are mixed and stirred in a mass ratio of 1:1-2:1.5-2.5:2-3 to form a reaction solution, and the temperature of the reaction solution is controlled at a temperature environment of 20°C-25°C to react for 20h-24h to obtain dopamine-modified polyamino organosiloxane; The dopamine-modified polyaminoorganosiloxane, copper salt and vulcanizing agent are mixed in a mass ratio of 1:0.1-0.2:0.01-0.05 and heated to 80°C-90°C for vulcanization reaction for 2h-3h. After the vulcanization reaction, the polyaminoorganosiloxane@CuS-PDA is obtained by base-catalyzed cross-linking. The monoamino-terminated organosiloxane is 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane; The alcoholamine compound includes ethanolamine or propanolamine, the carboxylic acid cross-linking agent includes oxalic acid, and the copper salt includes copper sulfate, copper chloride or copper nitrate.

2. The method for preparing nylon fiber according to claim 1, characterized in that: The vulcanizing agent includes sodium sulfide nonahydrate, and the conditions for the base-catalyzed cross-linking include a pH value of 8-9, a cross-linking temperature of 25° C.-35° C., and a cross-linking time of 1 h-3 h.

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