Antistatic modified polyamide fiber and preparation method thereof

Abstract

The invention discloses an antistatic modified polyamide fiber and a preparation method thereof, and relates to the field of fibers. When the antistatic modified polyamide fiber is prepared, nano-silver is loaded on halloysite powder nanotubes in situ to prepare pre-modified halloysite powder nanotubes; grafting 9H-carbazole-9-formaldehyde to chitosan, and uniformly mixing the chitosan with the pre-modified halloysite powder nanotube and silver nitrate to obtain a modified halloysite powder nanotube; the preparation method comprises the following steps: reacting diethyl (hydroxymethyl) phosphate with carbazole-N-formyl chloride to obtain a functional monomer; reacting hexamethylenediamine, adipic acid, pyromellitic dianhydride and a functional monomer to prepare a modified polyamide slice; uniformly mixing the modified polyamide slices, the modified halloysite powder nanotubes, carbazole and ferric trichloride, spinning, and grafting 4-aminomethyl-2, 2, 6, 6-tetramethylpiperidine to obtain the antistatic modified polyamide fiber. The antistatic modified polyamide fiber prepared by the invention has excellent antistatic property, antibacterial property, flame retardance and aging resistance.

Description

Technical Field

[0001] The present invention relates to the field of fibers, and particularly to an antistatic modified polyamide fiber and a preparation method thereof. Background Art

[0002] As one of the main fibers for textile fabrics, polyamide fibers have advantages such as wear resistance, light weight, and good elasticity. In daily life, polyamide fabrics are everywhere, such as socks, stockings, underwear, mountaineering clothes, and down jacket fabrics. With the improvement of living standards, the requirements for the comfort of textile fabrics are also constantly increasing, and the problems highlighted by polyamide fabrics have attracted more attention. Since there are few hydrophilic groups in the polyamide fiber molecules, the water absorption of polyamide fiber fabrics is poor, and a stuffy feeling is easily generated when worn; at the same time, the surface resistance of polyamide is extremely large, and the static electricity phenomenon is serious, affecting the wearing comfort. At present, solving the disadvantages and problems existing in polyamide fabrics and making polyamide fiber fabrics better meet the requirements of people for clothing comfort have become a research hotspot in the textile printing and dyeing industry. Therefore, the present invention prepares a modified polyamide fiber with excellent antistatic properties. Summary of the Invention

[0003] The purpose of the present invention is to provide an antistatic modified polyamide fiber and a preparation method thereof to solve the problems existing in the prior art.

[0004] To solve the above technical problems, the present invention provides the following technical solution: an antistatic modified polyamide fiber, which is prepared by uniformly mixing modified polyamide chips, modified halloysite nanotubes, carbazole, and ferric chloride, spinning, and then grafting 4-aminomethyl-2,2,6,6-tetramethylpiperidine.

[0005] Preferably, the modified polyamide chips are prepared by reacting hexamethylenediamine, adipic acid, pyromellitic dianhydride, and a functional monomer.

[0006] Preferably, the functional monomer is obtained by reacting diethyl (hydroxymethyl) phosphate and carbazole-N-formyl chloride.

[0007] Preferably, the modified halloysite nanotubes are prepared by grafting chitosan with 9H-carbazole-9-carbaldehyde, mixing with pre-modified halloysite nanotubes and silver nitrate.

[0008] Preferably, the pre-modified halloysite nanotubes are prepared by in-situ loading of silver nanoparticles on halloysite nanotubes.

[0009] Preferably, the halloysite nanotubes are from Lingshou County Nanyu Mineral Products Processing Factory.

[0010] Preferably, the chitosan is of industrial grade and is from Wuhan Zero Plus One Chemical Co., Ltd.

[0011] A preparation method of antistatic modified polyamide fiber, comprising the following preparation steps: (1) Mix halloysite nanotubes and a silver nitrate solution with a concentration of 0.04 - 0.06 mol / mL according to a mass ratio of 1:(4 - 6), ultrasonicate for 10 - 20 min, add a sodium borohydride solution with a concentration of 0.1 - 0.3 mol / L and a mass 0.01 - 0.03 times that of the halloysite nanotubes, stir at 20 - 30 °C and 200 - 400 rpm for 55 - 65 min, then filter, wash with deionized water 3 - 5 times, and dry at 55 - 65 °C for 8 - 10 h to obtain pre-modified halloysite nanotubes; (2) Mix chitosan, 9H-carbazole-9-carbaldehyde and an acetic acid solution with a mass fraction of 4% - 6% according to a mass ratio of 1:(0.5 - 1.5):(45 - 55), stir at 65 - 75 °C and 800 - 900 r / min for 6 - 8 h to obtain a modified chitosan solution; Mix halloysite nanotubes, a silver nitrate solution with a concentration of 0.04 - 0.06 mol / mL and the modified chitosan solution according to a mass ratio of 1:(0.05 - 0.07):(5 - 15), ultrasonicate for 10 - 20 min, stir at 20 - 30 °C and 700 - 900 r / min for 1 - 3 h, then filter, wash with deionized water 3 - 5 times, and dry at 55 - 65 °C for 8 - 10 h to obtain modified halloysite nanotubes; (3) Mix diethyl( hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine and dichloromethane according to a mass ratio of 1:(1.3 - 1.4):(0.6 - 0.7):(2 - 4), stir at 1 - 5 °C and 100 - 200 rpm for 55 - 65 min, raise the temperature to 20 - 30 °C and continue stirring for 4 - 6 h, wash with water to remove insoluble substances, separate the organic phase, dry with anhydrous sodium sulfate and then filter, and carry out rotary evaporation under reduced pressure to obtain a functional monomer; (4) Mix hexamethylenediamine, adipic acid, pyromellitic dianhydride and the functional monomer according to a mass ratio of 1:(0.2 - 0.3):(0.7 - 0.8):(1.2 - 1.3), stir in a nitrogen atmosphere at 115 - 125 °C and 200 - 400 rpm for 20 - 30 min, add sodium hypophosphite with a mass 0.005 - 0.015 times that of hexamethylenediamine, raise the temperature to 235 - 245 °C and carry out polycondensation at 0.09 - 0.10 MPa for 2 - 3 h, cool and slice to obtain modified polyamide slices; (5) Mix the modified polyamide chips, modified halloysite nanotubes, carbazole, ferric trichloride, and dichloroethane at a mass ratio of 1:(0.04 - 0.06):(0.003 - 0.004):(0.01 - 0.03):(0.3 - 0.5). Use a twin-screw extruder to carry out spinning under the conditions of 240 - 250 °C in zone 1, 245 - 255 °C in zone 2, 245 - 255 °C in zone 3, 250 - 260 °C in zone 4, 250 - 260 °C in zone 5, a side blowing temperature of 16 - 17 °C, a wind speed of 0.3 - 0.5 m / s, a drawing temperature of 140 - 150 °C, and a draw ratio of 1.1 - 1.3. Let it stand at 75 - 85 °C for 9 - 11 h, wash it 3 - 5 times with a hydrochloric acid solution with a mass fraction of 5% - 15% and deionized water respectively, and dry it at 55 - 65 °C for 11 - 13 h to obtain pre-modified fibers; (6) Immerse the pre-modified fibers in a 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution with a mass fraction of 1% - 3%. After ultrasonic treatment for 20 - 30 min, take them out, let them stand at 20 - 30 °C for 11 - 13 h, wash them 3 - 5 times with deionized water, and dry them at 55 - 65 °C for 8 - 10 h to obtain antistatic modified polyamide fibers.

[0012] As an optimization, the reaction equation of the modified halloysite nanotubes described in step (2) is: .

[0013] As an optimization, the reaction equation of the functional monomer described in step (3) is: .

[0014] As an optimization, the reaction equation of the modified polyamide chips described in step (4) is: ; where R1 is , R2 is or or .

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: When preparing the antistatic modified polyamide fibers, the present invention in-situ loads nano-silver on the halloysite powder nanotubes to obtain pre-modified halloysite powder nanotubes; grafts chitosan with 9H-carbazole-9-carbaldehyde and then mixes it with the pre-modified halloysite powder nanotubes and silver nitrate to obtain modified halloysite powder nanotubes; reacts diethyl(hydroxymethyl)phosphate with carbazole-N-carbonyl chloride to obtain a functional monomer; then reacts hexamethylenediamine, adipic acid, pyromellitic dianhydride, and the functional monomer to obtain modified polyamide chips; mixes the modified polyamide chips, modified halloysite powder nanotubes, carbazole, and ferric trichloride, spins them, and then grafts 4-aminomethyl-2,2,6,6-tetramethylpiperidine to obtain antistatic modified polyamide fibers.

[0016] First, halloysite nanotubes are in-situ loaded with nano silver to obtain pre-modified halloysite nanotubes; chitosan grafted with 9H-carbazole-9-carboxaldehyde is mixed with the pre-modified halloysite nanotubes and silver nitrate to obtain modified halloysite nanotubes; nano silver is in-situ immobilized through the pore structure of the halloysite nanotubes, and then silver ions are complexed and coated by the hydroxyl groups in the chitosan molecule to continuously release silver ions, inhibit the growth of bacteria, and improve the persistent antibacterial property of the antistatic modified polyamide fiber; a large number of hydroxyl groups in the chitosan molecule can also form hydrogen bonds and attract water molecules, and the conductivity of water molecules is used to dissipate static electricity. At the same time, the carbazole rings grafted by the Schiff base reaction polymerize with the carbazole rings on the polyamide main chain to form a conductive network, further reducing the accumulation of static electricity and improving the antistatic property of the antistatic modified polyamide fiber.

[0017] Second, diethyl (hydroxymethyl) phosphate and carbazole-N-carbonyl chloride are reacted to obtain a functional monomer; then hexamethylenediamine, adipic acid, pyromellitic dianhydride and the functional monomer are reacted to obtain a modified polyamide chip; the modified polyamide chip, the modified halloysite nanotubes, carbazole and ferric chloride are mixed and spun, and then 4-aminomethyl-2,2,6,6-tetramethylpiperidine is grafted to obtain an antistatic modified polyamide fiber; a functional monomer is obtained by the reaction of a hydroxyl group and an acyl chloride, and a phosphorus element and a carbazole ring are introduced into the polyamide main chain. The phosphorus element can promote the formation of a carbon layer at high temperature and improve the flame retardancy of the antistatic modified polyamide fiber; carbazole can polymerize to form a conductive network and improve the antistatic property of the antistatic modified polyamide fiber; pyromellitic dianhydride is used to form active carboxyl groups on the polyamide main chain, and 4-aminomethyl-2,2,6,6-tetramethylpiperidine is grafted after spinning to avoid affecting the free radicals generated during the polymerization of carbazole and improve the anti-aging property of the antistatic modified polyamide fiber. Specific embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] The raw materials used in the following examples and comparative examples are all commercially available: the halloysite nanotubes come from Lingshou County Nanyu Mineral Products Processing Factory; the chitosan model is industrial grade and comes from Wuhan Zero Plus One Chemical Co., Ltd.

[0020] Example 1 A preparation method of an antistatic modified polyamide fiber, the preparation method of the antistatic modified polyamide fiber includes the following preparation steps: (1) Mix halloysite nanotubes and a 0.04 mol / mL silver nitrate solution at a mass ratio of 1:4, ultrasonicate for 10 min, add a 0.1 mol / L sodium borohydride solution that is 0.01 times the mass of the halloysite nanotubes, stir at 20 °C and 200 rpm for 65 min, then filter, wash 3 times with deionized water, and dry at 55 °C for 10 h to obtain pre-modified halloysite nanotubes; (2) Mix chitosan, 9H-carbazole-9-carbaldehyde, and a 4% acetic acid solution at a mass ratio of 1:0.5:45, stir at 65 °C and 800 r / min for 8 h to obtain a modified chitosan solution; Mix halloysite nanotubes, a 0.04 mol / mL silver nitrate solution, and the modified chitosan solution at a mass ratio of 1:0.05:5, ultrasonicate for 10 min, stir at 20 °C and 700 r / min for 3 h, then filter, wash 3 times with deionized water, and dry at 55 °C for 10 h to obtain modified halloysite nanotubes; (3) Mix diethyl (hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine, and dichloromethane at a mass ratio of 1:1.3:0.6:2, stir at 1 °C and 100 rpm for 65 min, raise the temperature to 20 °C and continue stirring for 6 h, wash with water to remove insoluble substances, separate the organic phase, dry with anhydrous sodium sulfate, filter, and perform rotary evaporation under reduced pressure to obtain a functional monomer; (4) Mix hexamethylenediamine, adipic acid, pyromellitic dianhydride, and the functional monomer at a mass ratio of 1:0.2:0.7:1.2, stir at 115 °C and 200 rpm for 30 min in a nitrogen atmosphere, add sodium hypophosphite that is 0.005 times the mass of hexamethylenediamine, raise the temperature to 235 °C and carry out polycondensation at 0.09 MPa for 3 h, cool and slice to obtain modified polyamide slices; (5) Mix the modified polyamide slices, modified halloysite nanotubes, carbazole, ferric chloride, and dichloroethane at a mass ratio of 1:0.04:0.003:0.01:0.3, and carry out spinning using a twin-screw extruder under the conditions of zone 1 at 240 °C, zone 2 at 245 °C, zone 3 at 245 °C, zone 4 at 250 °C, zone 5 at 250 °C, side blowing temperature of 16 °C, wind speed of 0.3 m / s, drawing temperature of 140 °C, and draw ratio of 1.1. Let it stand at 75 °C for 11 h, wash 3 times with a 5% hydrochloric acid solution and deionized water respectively, and dry at 55 °C for 13 h to obtain pre-modified fibers; (6) Immerse the pre-modified fibers in a 1% 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution, take them out after ultrasonication for 20 min, let them stand at 20 °C for 13 h, wash 3 times with deionized water, and dry at 55 °C for 10 h to obtain antistatic modified polyamide fibers.

[0021] Example 2 A preparation method of antistatic modified polyamide fiber, the preparation method of the antistatic modified polyamide fiber comprising the following preparation steps: (1) Mix halloysite nanotubes and 0.05 mol / mL silver nitrate solution at a mass ratio of 1:5, ultrasonicate for 15 min, add 0.2 mol / L sodium borohydride solution which is 0.02 times the mass of the halloysite nanotubes, stir at 25 °C and 300 rpm for 60 min, then filter, wash 4 times with deionized water, and dry at 60 °C for 9 h to obtain pre-modified halloysite nanotubes; (2) Mix chitosan, 9H-carbazole-9-carbaldehyde and 5% acetic acid solution at a mass ratio of 1:1:50, stir at 70 °C and 850 r / min for 7 h to obtain a modified chitosan solution; Mix halloysite nanotubes, 0.05 mol / mL silver nitrate solution and the modified chitosan solution at a mass ratio of 1:0.06:10, ultrasonicate for 15 min, stir at 25 °C and 800 r / min for 2 h, then filter, wash 4 times with deionized water, and dry at 60 °C for 9 h to obtain modified halloysite nanotubes; (3) Mix diethyl( hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine and dichloromethane at a mass ratio of 1:1.35:0.65:3, stir at 3 °C and 150 rpm for 60 min, raise the temperature to 25 °C and continue stirring for 5 h, wash with water to remove insoluble substances, separate the organic phase, dry with anhydrous sodium sulfate and then filter, and perform rotary evaporation under reduced pressure to obtain a functional monomer; (4) Mix hexamethylenediamine, adipic acid, pyromellitic dianhydride and the functional monomer at a mass ratio of 1:0.25:0.75:1.25, stir at 120 °C and 300 rpm for 25 min in a nitrogen atmosphere, add sodium hypophosphite which is 0.01 times the mass of hexamethylenediamine, raise the temperature to 240 °C and 0.095 MPa for polycondensation for 2.5 h, cool and slice to obtain modified polyamide slices; (5) Mix the modified polyamide slices, modified halloysite nanotubes, carbazole, ferric trichloride and dichloroethane at a mass ratio of 1:0.05:0.0035:0.02:0.4, and use a twin-screw extruder to spin at conditions of zone 1 at 245 °C, zone 2 at 250 °C, zone 3 at 250 °C, zone 4 at 255 °C, zone 5 at 255 °C, side blowing temperature of 16.5 °C, wind speed of 0.4 m / s, drawing temperature of 145 °C, and drawing ratio of 1.2, stand still at 80 °C for 10 h, wash 4 times with 10% hydrochloric acid solution and deionized water respectively, and dry at 60 °C for 12 h to obtain pre-modified fibers; (6) Immerse the pre-modified fibers in a 2% 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution, take them out after ultrasonication for 25 min, stand still at 25 °C for 12 h, wash 4 times with deionized water, and dry at 60 °C for 9 h to obtain antistatic modified polyamide fibers.

[0022] Example 3 A preparation method of antistatic modified polyamide fiber, the preparation method of the antistatic modified polyamide fiber comprises the following preparation steps: (1) Mix halloysite nanotubes and 0.06 mol / mL silver nitrate solution according to a mass ratio of 1:6, ultrasonicate for 20 min, add 0.3 mol / L sodium borohydride solution which is 0.03 times the mass of the halloysite nanotubes, stir at 30 °C and 400 rpm for 55 min, then filter, wash with deionized water 5 times, and dry at 55 °C for 10 h to obtain pre-modified halloysite nanotubes; (2) Mix chitosan, 9H-carbazole-9-carboxaldehyde and 6% acetic acid solution according to a mass ratio of 1:1.5:55, stir at 75 °C and 900 r / min for 6 h to obtain a modified chitosan solution; Mix halloysite nanotubes, 0.06 mol / mL silver nitrate solution and the modified chitosan solution according to a mass ratio of 1:0.07:15, ultrasonicate for 20 min, stir at 30 °C and 900 r / min for 1 h, then filter, wash with deionized water 5 times, and dry at 65 °C for 8 h to obtain modified halloysite nanotubes; (3) Mix diethyl (hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine and dichloromethane according to a mass ratio of 1:1.4:0.7:4, stir at 5 °C and 200 rpm for 55 min, raise the temperature to 30 °C and continue to stir for 4 h, wash with water to remove insoluble substances, separate the organic phase, dry with anhydrous sodium sulfate and then filter, and perform rotary evaporation under reduced pressure to obtain a functional monomer; (4) Mix hexamethylenediamine, adipic acid, pyromellitic dianhydride and the functional monomer according to a mass ratio of 1:0.3:0.8:1.3, stir at 125 °C and 400 rpm for 20 min in a nitrogen atmosphere, add sodium hypophosphite which is 0.015 times the mass of hexamethylenediamine, raise the temperature to 245 °C and 0.10 MPa for polycondensation for 2 h, cool and slice to obtain modified polyamide slices; (5) Mix the modified polyamide slices, modified halloysite nanotubes, carbazole, ferric chloride and dichloroethane according to a mass ratio of 1:0.06:0.004:0.03:0.5, and perform spinning with a twin-screw extruder under the conditions of 250 °C in zone 1, 255 °C in zone 2, 255 °C in zone 3, 260 °C in zone 4, 260 °C in zone 5, side blowing temperature of 17 °C, wind speed of 0.5 m / s, drawing temperature of 150 °C, and drawing ratio of 1.3, stand still at 85 °C for 9 h, wash 5 times with 15% hydrochloric acid solution and deionized water respectively, and dry at 65 °C for 11 h to obtain pre-modified fibers; (6) Immerse the pre-modified fibers in a 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution with a mass fraction of 3%, take them out after ultrasonic treatment for 30 min, let them stand at 30 °C for 11 h, wash them 5 times with deionized water, and dry them at 65 °C for 8 h to obtain antistatic modified polyamide fibers.

[0023] Comparative Example 1: The preparation method of the antistatic modified polyamide fibers in Comparative Example 1 is only different from that in Example 2 in steps (2) and (5). Omit step (2). Modify step (5) as follows: Mix the modified polyamide chips, pre-modified halloysite nanotubes, carbazole, ferric chloride, and dichloroethane in a mass ratio of 1:0.05:0.0035:0.02:0.4, and use a twin-screw extruder to carry out spinning under the conditions of zone 1 at 245 °C, zone 2 at 250 °C, zone 3 at 250 °C, zone 4 at 255 °C, zone 5 at 255 °C, side blowing temperature of 16.5 °C, wind speed of 0.4 m / s, drawing temperature of 145 °C, and drawing ratio of 1.2. Let it stand at 80 °C for 10 h, wash it 4 times with a 10% hydrochloric acid solution and deionized water respectively, and dry it at 60 °C for 12 h to obtain pre-modified fibers. The remaining steps are the same as those in Example 2.

[0024] Comparative Example 2: The preparation method of the antistatic modified polyamide fibers in Comparative Example 2 is only different from that in Example 2 in steps (3) and (4). Omit step (3). Modify step (4) as follows: Mix hexamethylenediamine, adipic acid, and pyromellitic dianhydride in a mass ratio of 1:0.25:1.5, stir at 120 °C and 300 rpm for 25 min in a nitrogen atmosphere, add sodium hypophosphite with a mass 0.01 times that of hexamethylenediamine, raise the temperature to 240 °C and carry out polycondensation at 0.095 MPa for 2.5 h, and cool and slice to obtain modified polyamide chips. The remaining steps are the same as those in Example 2.

[0025] Comparative Example 3: The preparation method of the antistatic modified polyamide fibers in Comparative Example 3 is only different from that in Example 2 in steps (5) and (6). Omit step (6). Modify step (5) as follows: Mix the modified polyamide chips, modified halloysite nanotubes, carbazole, ferric chloride, and dichloroethane in a mass ratio of 1:0.05:0.0035:0.02:0.4, and use a twin-screw extruder to carry out spinning under the conditions of zone 1 at 245 °C, zone 2 at 250 °C, zone 3 at 250 °C, zone 4 at 255 °C, zone 5 at 255 °C, side blowing temperature of 16.5 °C, wind speed of 0.4 m / s, drawing temperature of 145 °C, and drawing ratio of 1.2. Let it stand at 80 °C for 10 h, wash it 4 times with a 10% hydrochloric acid solution and deionized water respectively, and dry it at 60 °C for 12 h to obtain antistatic modified polyamide fibers. The remaining steps are the same as those in Example 2.

[0026] Test Example 1. Antistatic property Test method: Take 15 g of the antistatic modified polyamide fiber obtained from each example and comparative example, and test the volume resistivity according to GB / T14342 - 2015.

[0027] 2. Antibacterial property Test method: Wash the antistatic modified polyamide fiber obtained from each example and comparative example 4 times with deionized water and then dry at 60 °C for 10 h. Repeat the washing and drying 10 times to obtain the test sample. Take 0.4 g of the test sample and cut it into pieces as the test sample. According to GB / T20944 - 2007, select Gram - negative Escherichia coli and culture it at 37 °C for 18 h. Use an inoculation loop to transfer it to 20 mL of liquid medium and culture it at 37 °C and an oscillation speed of 120 r / min for 20 h to obtain the bacterial solution; Put the test sample into a flask (the control group without the sample), add 70 mL of PBS buffer and 5 mL of the diluted bacterial solution, shake it on a shaker at 37 °C and 120 rpm for 18 h, then dilute the bacterial suspension by the same multiple, take 100 μL of the diluted bacterial suspension, evenly coat it on the surface of the solid medium, and culture it in a sterile environment at a constant temperature of 37 °C for 24 h. Count the single colonies W1 on the solid medium (the viable bacteria concentration W0 of the control group), and calculate the antibacterial rate = (W0 - W1) / W0 * 100%.

[0028] 3. Flame retardancy Test method: Test the limiting oxygen index of the antistatic modified polyamide fiber obtained from each example and comparative example according to GB / T5454 - 1997.

[0029] 4. Anti - aging property Test method: Test the breaking strength P0 of the antistatic modified polyamide fiber obtained from each example and comparative example according to GB / T14344 - 2008 under the conditions of a tensile gauge length of 500 mm, a tensile speed of 500 mm / min, and a pre - tension of 39 cN; Use a solar - aging test chamber to age it for 40 h under the conditions of a 300 W ultraviolet irradiation lamp, a vertical distance of 20 cm, 25 °C, and a relative humidity of 65%, and then test the breaking strength P1 according to GB / T14344 - 2008. Calculate the aging rate = (P0 - P1) / P0 * 100%.

[0030] Table 1 below gives the analysis results of the antistatic property, antibacterial property, flame retardancy, and anti - aging property of the antistatic modified polyamide fibers of Examples 1 - 3 and Comparative Examples 1 - 3 of the present invention.

[0031]

[0032] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the antistatic modified polyamide fiber prepared by the present invention has good antistatic property, antibacterial property, flame retardancy and anti-aging property.

[0033] In Comparative Example 1, halloysite nanotubes were not encapsulated; by comparison, Examples 1, 2, and 3 had lower volume resistivity and higher antibacterial property than Comparative Example 1, indicating that the hydroxyl groups in chitosan molecules complexed silver ions to coat halloysite nanotubes, continuously released silver ions, inhibited bacterial growth, and improved the persistent antibacterial property of the antistatic modified polyamide fiber; a large number of hydroxyl groups in chitosan molecules could also form hydrogen bonds and attract water molecules, dissipating static electricity by using the conductivity of water molecules. At the same time, the carbazole rings grafted by the Schiff base reaction polymerized with the carbazole rings on the polyamide main chain, forming a conductive network, further reducing the accumulation of static electricity and improving the antistatic property of the antistatic modified polyamide fiber.

[0034] In Comparative Example 2, functional monomers were not grafted onto the polyamide main chain; by comparison, Examples 1, 2, and 3 had lower volume resistivity and higher limiting oxygen index than Comparative Example 2, indicating that functional monomers were prepared by the reaction of hydroxyl groups and acyl chloride, introducing phosphorus elements and carbazole rings onto the polyamide main chain. Phosphorus elements could promote the formation of a carbon layer at high temperatures, improving the flame retardancy of the antistatic modified polyamide fiber; carbazole could polymerize to form a conductive network, reducing the accumulation of static electricity and improving the antistatic property of the antistatic modified polyamide fiber.

[0035] In Comparative Example 3, 4-aminomethyl-2,2,6,6-tetramethylpiperidine was not grafted; by comparison, Examples 1, 2, and 3 had a lower aging rate than Comparative Example 3, indicating that pyromellitic dianhydride was used to form active carboxyl groups on the polyamide main chain, and 4-aminomethyl-2,2,6,6-tetramethylpiperidine was grafted after spinning to avoid affecting the free radicals generated during carbazole polymerization, improving the anti-aging property of the antistatic modified polyamide fiber.

[0036] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An antistatic modified nylon fiber, characterized in that: The antistatic modified nylon fiber is prepared by mixing and spinning modified polyamide slices, modified halloysite powder nanotubes, carbazole and ferric chloride, and then grafting 4-aminomethyl-2,2,6,6-tetramethylpiperidine; the modified polyamide slices are prepared by reacting hexamethylenediamine, adipic acid, pyromellitic anhydride and functional monomers; the functional monomers are obtained by reacting diethyl (hydroxymethyl) phosphate and carbazole-N-carbonyl chloride; the modified halloysite powder nanotubes are prepared by grafting chitosan with 9H-carbazole-9-formaldehyde and then mixing with pre-modified halloysite powder nanotubes and silver nitrate; the pre-modified halloysite powder nanotubes are prepared by in-situ loading of nanosilver on halloysite powder nanotubes.

2. A method for preparing antistatic modified nylon fiber, characterized in that: The method comprises the following preparation steps: (1) mixing halloysite nanotubes and silver nitrate solution, ultrasonicating, adding sodium borohydride solution, stirring, filtering, washing and drying to obtain pre-modified halloysite nanotubes; (2) mixing chitosan, 9H-carbazole-9-carboxaldehyde and acetic acid solution, stirring to obtain a modified chitosan solution; mixing halloysite nanotubes, silver nitrate solution and modified chitosan solution, ultrasonically dispersing, stirring, filtering, washing and drying to obtain modified halloysite nanotubes; (3) Diethyl (hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine and dichloromethane are mixed and stirred, and the mixture is heated and stirred continuously. The insoluble matter is removed by washing with water, and the organic phase is separated, dried over anhydrous sodium sulfate, and evaporated under reduced pressure to obtain a functional monomer; (4) mixing hexamethylenediamine, adipic acid, pyromellitic anhydride and functional monomers, stirring in a nitrogen atmosphere, adding sodium hypophosphite, heating for polycondensation, cooling and slicing to obtain modified polyamide slices; (5) mixing the modified polyamide chips, the modified halloysite nanotubes, carbazole, ferric chloride and ethylene dichloride, extruding and spinning the fibers by a twin-screw extruder, standing, washing and drying to obtain pre-modified fibers; (6) The pre-modified fiber is immersed in 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution, taken out after ultrasonic treatment, allowed to stand, washed and dried to obtain antistatic modified nylon fiber.

3. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the pre-modified halloysite nanotubes in step (1) is as follows: the halloysite nanotubes and the silver nitrate solution are mixed in a mass ratio of 1:(4-6), ultrasonicated, and a sodium borohydride solution of 0.01-0.03 times the mass of the halloysite nanotubes is added, stirred at 20-30° C. for 55-65 min, filtered, washed with deionized water, and dried to obtain the pre-modified halloysite nanotubes.

4. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the modified halloysite nanotubes in step (2) is as follows: the halloysite nanotubes, silver nitrate solution and modified chitosan solution are mixed in a mass ratio of 1: (0.05-0.07): (5-15), ultrasonically dispersed, stirred at 20-30° C. for 1-3 hours, filtered, washed with deionized water, and dried to obtain the modified halloysite nanotubes; The preparation process of the modified chitosan solution is as follows: chitosan, 9H-carbazole-9-carboxaldehyde and acetic acid solution are mixed in a mass ratio of 1: (0.5-1.5): (45-55), and stirred at 65-75° C. for 6-8 hours to obtain the modified chitosan solution.

5. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the functional monomer in step (3) is as follows: diethyl (hydroxymethyl) phosphate, carbazole-N-carbonyl chloride, triethylamine and dichloromethane are mixed in a mass ratio of 1: (1.3~1.4): (0.6~0.7): (2~4), stirred at 1~5°C for 55~65min, heated to 20~30°C and continued to stir for 4~6h, washed with water to remove insoluble matter, separated the organic phase, dried with anhydrous sodium sulfate, filtered, and evaporated under reduced pressure to obtain the functional monomer.

6. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the modified polyamide slice in step (4) is as follows: hexamethylenediamine, adipic acid, pyromellitic anhydride and functional monomer are mixed in a mass ratio of 1: (0.2-0.3): (0.7-0.8): (1.2-1.3), stirred at 115-125° C. for 20-30 min in a nitrogen atmosphere, sodium hypophosphite in an amount of 0.005-0.015 times the mass of hexamethylenediamine is added, the temperature is raised to 235-245° C. for condensation for 2-3 h, and the slices are cooled and sliced ​​to obtain modified polyamide slices.

7. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the pre-modified fiber in step (5) is as follows: modified polyamide slices, modified halloysite nanotubes, carbazole, ferric chloride and ethylene dichloride are mixed in a mass ratio of 1: (0.04-0.06): (0.003-0.004): (0.01-0.03): (0.3-0.5), extruded and spun by a twin-screw extruder, allowed to stand at 75-85° C. for 9-11 hours, washed with hydrochloric acid solution and deionized water, and dried to obtain the pre-modified fiber.

8. The method for preparing an antistatic modified nylon fiber according to claim 2, characterized in that: The preparation process of the antistatic modified nylon fiber in step (6) is as follows: immersing the pre-modified fiber in a 1% to 3% mass fraction of 4-aminomethyl-2,2,6,6-tetramethylpiperidine ethanol solution, taking it out after ultrasonic treatment, standing it at 20 to 30° C. for 11 to 13 hours, washing it with deionized water, and drying it to obtain the antistatic modified nylon fiber.

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