Environment-friendly polyamide fiber and preparation method thereof

Abstract

The application belongs to the technical field of textiles, and particularly relates to a green and environment-friendly nylon fiber and a preparation method thereof. The preparation method of the green and environment-friendly nylon fiber comprises the following steps: step one, melt blending and spinning of polyamide 6 and a spinning aid in a spinning machine to obtain modified nylon fiber; step two, mixing of fluorosilicon resin and dimethylbenzene, stirring until uniform, then adding modified kaolin, ultrasonic treatment, cooling to room temperature, then adding a curing agent, and stirring to obtain a modified liquid; and step three, complete immersion of the modified nylon fiber in the modified liquid, ultrasonic treatment, draining of water, and drying to obtain the green and environment-friendly nylon fiber. The nylon fiber prepared by the application has excellent breaking strength and elongation at break, and the fabric made therefrom has high hydrophobicity and wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to a green and environmentally friendly nylon fiber and its preparation method. Background Technology

[0002] Nylon (polyamide fiber) is widely used in clothing, industrial textiles, and engineering plastics due to its excellent mechanical properties, good abrasion resistance, and ease of processing. Although nylon itself has good overall performance, in certain specific applications, such as outdoor sportswear, functional protective fabrics, or high-abrasion industrial parts, higher requirements are placed on the fiber's mechanical properties, hydrophobic and sweat-wicking properties, and abrasion resistance.

[0003] Currently, conventional methods for improving the performance of nylon include copolymerization modification, blending and addition, and surface treatment. However, some methods have problems such as uneven dispersion of additives, poor durability of modification effect, complex process or introduction of harmful substances, making it difficult to balance performance improvement and environmental friendliness.

[0004] Therefore, developing a new type of nylon fiber with excellent mechanical properties, good hydrophobicity, and high abrasion resistance has become an important research direction in the field of textile materials. Summary of the Invention

[0005] The purpose of this invention is to provide a green and environmentally friendly nylon fiber and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing green and environmentally friendly nylon fiber includes the following steps:

[0008] Step 1: Polyamide 6 and spinning aids are melt-blended and spun in a spinning machine to obtain modified nylon fiber;

[0009] Step 2: Mix fluorosilicone resin and xylene, stir evenly, then add modified kaolin, sonicate, cool to room temperature, then add curing agent, stir, and obtain modified liquid;

[0010] Step 3: Completely immerse the modified nylon fiber in the modification solution, ultrasonically treat it, drain the water, and dry it to obtain green and environmentally friendly nylon fiber.

[0011] Preferably, the spinning conditions are: melt blending temperature of 230-240℃, spinning temperature of 250-260℃, draw ratio of 3 times, and heat setting temperature of 90-100℃.

[0012] Preferably, the preparation method of modified kaolin is as follows: palmitic acid, kaolin and anhydrous ethanol are mixed evenly in a mass ratio of 1:(5-10):(15-20), heated under reflux, cooled and dried, and ground to obtain modified kaolin.

[0013] Preferably, the mass ratio of modified kaolin to fluorosilicone resin is (0.5-0.6):1.

[0014] Preferably, the preparation method of the spinning aid includes the following steps:

[0015] (1) Crush wheat straw to obtain wheat straw powder, add glucose and water to wheat straw powder to obtain a mixture, add fermentation agent; perform aerobic fermentation, sterilize, and then dry naturally to obtain fermentation product;

[0016] (2) Add catalyst solution to fermentation product, stir, and then dry at high temperature to obtain precursor;

[0017] (3) The precursor is carbonized under a nitrogen atmosphere to obtain carbonized products;

[0018] (4) The carbonization product is acid-treated, washed with water until neutral, and dried to obtain the spinning aid.

[0019] Preferably, the fermentation agent includes Bacillus subtilis, Bacillus lateralis, and Gluconobacterium xylose in a live bacteria ratio of 1:(1.2-1.5):(0.4-0.7).

[0020] The preferred conditions for aerobic fermentation are: 30-35℃ aerobic fermentation for 5-7 days.

[0021] Preferably, the dosage of fermentation agent is 10. 6 -10 7 CFU / g mixture.

[0022] Preferably, the carbonization conditions are as follows: heating to 400-500℃ at a heating rate of 5-10℃ / min and holding for 2-3 hours; then heating to 900-1000℃ at a rate of 10-20℃ / min and holding for 8-10 hours.

[0023] Using biomass as a raw material to prepare graphene is an environmentally friendly and sustainable method that not only helps reduce environmental impact but also effectively lowers the production cost of graphene. Currently, the main method for preparing graphene from biomass is to coordinate biomass with catalyst ions, perform high-temperature deoxidation to obtain a precursor, and then prepare the graphene through heat treatment (e.g., patent CN 104724699 B). However, the nylon fibers prepared by spinning nylon fibers with graphene mixed with polyamide 6 in existing technologies do not achieve ideal improvements in tensile strength and elongation at break due to graphene agglomeration problems. This invention pre-treats the biomass raw material through fermentation before preparing graphene, which serves as a spinning aid, thereby improving the tensile strength and elongation at break of nylon fibers. Analysis shows that fermentation pre-treatment allows microbial metabolism to partially decompose biomass macromolecules, producing smaller molecular weight intermediates, thus causing the carbon structure to become more ordered at the molecular level. Simultaneously, fermentation decomposes some of the biomass structure, forming more pores, which greatly increases the accessibility and coordination efficiency of subsequent catalyst ions. The graphene obtained by the above process has fewer defects, higher crystallinity, and better mechanical properties. High-quality graphene (with suitable surface chemistry) is more easily and uniformly dispersed in polyamide 6 melt, avoiding agglomeration.

[0024] However, the hydrophobicity of nylon fibers after adding graphene is not ideal. This invention further treats graphite-modified nylon fibers with a modifying solution prepared from palmitic acid-modified kaolin and fluorosilicone resin, which improves the hydrophobicity and abrasion resistance of the nylon fibers. Analysis shows that kaolin, through the assistance of fluorosilicone resin, adheres to the surface of the nylon fabric, resulting in better bonding with the modified nylon and increasing the surface roughness of the fabric. Simultaneously, the low surface energy of palmitic acid and fluorosilicone resin imparts superhydrophobic properties to the nylon fabric.

[0025] This invention provides a green and environmentally friendly nylon fiber prepared by the aforementioned method.

[0026] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0027] 1. The nylon fiber prepared by this invention possesses excellent breaking strength and elongation at break, significantly improving the fiber's mechanical properties and making it less prone to breakage under high tensile force and deformation. It is suitable for manufacturing high-strength industrial fabrics, safety protective clothing, and outdoor sports equipment. The fiber's good toughness ensures stability during subsequent textile processing, reduces breakage rates, and improves production efficiency and product quality.

[0028] 2. The fabric made of nylon fiber of the present invention not only has excellent abrasion resistance and can maintain structural integrity in frequent friction and harsh use environments, but also exhibits excellent hydrophobic properties, effectively blocking liquid water penetration and keeping the wearer dry and comfortable. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] All raw materials used in the following embodiments of the present invention are commercially available products:

[0031] Fluorosilicone resin LS-8722, Hubei Shuaiyan Ligao Biomedical Co., Ltd.

[0032] Bacillus subtilis, catalog number BNCC338006, Beinachuanglian Biotechnology Co., Ltd.

[0033] Bacillus lateralis, BNCC336966, Beinachuanglian Biotechnology Co., Ltd.

[0034] Acetobacter xylose, bio-03931, Beijing BioBio Biotechnology Co., Ltd.

[0035] Bacillus licheniformis, BNCC336463, Beina Chuanglian Biotechnology Co., Ltd.

[0036] Polyamide 6, Guangzhou Changse Trading Co., Ltd. Example 1

[0037] This embodiment provides a method for preparing green and environmentally friendly nylon fiber, including the following steps:

[0038] Step 1: Polyamide 6 and graphene in a mass ratio of 100:1 are melt-blended and spun in a spinning machine. The melt blending temperature is controlled at 235℃ and the spinning temperature is controlled at 255℃. Then, the fibers are stretched and heat-set in a hot roller stretcher. The stretching ratio is 3 times and the heat setting temperature is 95℃ to obtain modified nylon fibers.

[0039] Step 2: Mix palmitic acid, kaolin, and anhydrous ethanol in a mass ratio of 1:8:17 until homogeneous, heat to 100℃ and reflux for 2.5 hours, cool and dry, and grind to less than 50 mesh to obtain modified kaolin; mix fluorosilicone resin and xylene in a mass ratio of 1:10, stir until homogeneous, then add modified kaolin. The mass ratio of modified kaolin to fluorosilicone resin LS-8722 is 0.5:1. Ultrasonically treat for 25 minutes at 80W / L, cool to room temperature, then add 0.8wt% of curing agent (Shin-Etsu CAT-PL-56, Japan) based on the mass of fluorosilicone resin, and stir for 2.4 hours to obtain the modified solution;

[0040] Step 3: Completely immerse the modified nylon fiber in the modification solution, ultrasonically treat it at 80W / L for 2.5 hours, drain the water, and dry it to obtain green and environmentally friendly nylon fiber.

[0041] The preparation method of the spinning aid includes the following steps:

[0042] (1) Crush wheat straw to a length of less than 5 cm to obtain wheat straw powder. Add 2% glucose by mass to the wheat straw powder, add water to obtain a mixture, with water accounting for 65% of the mixture's mass. Add fermentation agent, which includes Bacillus subtilis, Bacillus laterosporus, and Acetobacter xylose in a live bacteria ratio of 1:1.4:0.6. The amount of fermentation agent used is 10 6 The mixture of CFU / g was fermented aerobically at 35℃ for 6 days with an aeration rate of 0.8 vvm. It was maintained at 121℃ and 0.1 MPa pressure for 15 minutes, and then naturally dried to a moisture content of 8% to obtain the fermentation product.

[0043] (2) Mix ferrous chloride and distilled water at a mass ratio of 1:15 and stir for 2.5 h to obtain a catalyst solution; add the catalyst solution to the fermentation product, with a mass ratio of fermentation product to catalyst solution of 3:10, stir for 3 h, and then dry at 140 °C for 12 h to obtain the precursor;

[0044] (3) Under a nitrogen atmosphere, the precursor was heated to 500°C at a heating rate of 10°C / min and held for 2.5 h; then heated to 1000°C at a heating rate of 20°C / min and held for 9 h to obtain the carbonized product.

[0045] (4) Add the carbonized product to 14% v / v nitric acid, immerse it for 5 hours, centrifuge it, wash it with distilled water until neutral, dry it, and obtain the spinning aid. Example 2

[0046] This embodiment provides a method for preparing green and environmentally friendly nylon fiber, including the following steps:

[0047] Step 1: Polyamide 6 and spinning aid in a mass ratio of 100:1 are melt-blended and spun in a spinning machine. The melt-blending temperature is controlled at 230℃ and the spinning temperature is controlled at 260℃. Then, the fiber is stretched and heat-set in a hot roller stretcher. The stretching ratio is 3 times and the heat-setting temperature is 90℃ to obtain modified nylon fiber.

[0048] Step 2: Mix palmitic acid, kaolin, and anhydrous ethanol in a mass ratio of 1:10:20 until homogeneous. Heat to 100℃ and reflux for 2 hours. Cool and dry. Grind to less than 50 mesh to obtain modified kaolin. Mix fluorosilicone resin and xylene in a mass ratio of 1:10 and stir until homogeneous. Add modified kaolin. The mass ratio of modified kaolin to fluorosilicone resin LS-8722 is 0.6:1. Ultrasonically treat for 20 minutes at 80W / L. Cool to room temperature. Add fluorosilicone resin and then add 1wt% curing agent (Shin-Etsu CAT-PL-56, Japan) based on the mass of the fluorosilicone resin. Stir for 2 hours to obtain the modified solution.

[0049] Step 3: Completely immerse the modified nylon fiber in the modification solution, ultrasonically treat it at 100W / L for 2 hours, drain the water, and dry it to obtain green and environmentally friendly nylon fiber.

[0050] The preparation method of the spinning aid includes the following steps:

[0051] (1) Crush wheat straw to a length of less than 5 cm to obtain wheat straw powder. Add 2% glucose by mass to the wheat straw powder, add water to obtain a mixture, with water accounting for 70% of the mixture's mass. Add fermentation agent, which includes Bacillus subtilis, Bacillus laterosporus, and Acetobacter xylose in a live bacteria ratio of 1:1.5:0.4. The amount of fermentation agent used is 10 6 The mixture of CFU / g was fermented aerobically at 35℃ for 5 days with an aeration rate of 0.8 vvm. It was maintained at 121℃ and 0.1 MPa pressure for 15 minutes, and then naturally dried to a moisture content of 7% to obtain the fermentation product.

[0052] (2) Mix ferrous chloride and distilled water at a mass ratio of 1:10 and stir for 3 hours to obtain a catalyst solution; add the catalyst solution to the fermentation product at a mass ratio of 1:10 and stir for 4 hours, then dry at 120°C for 15 hours to obtain the precursor;

[0053] (3) Under a nitrogen atmosphere, the precursor was heated to 500°C at a heating rate of 5°C / min and held for 2 hours; then heated to 1000°C at a rate of 10°C / min and held for 8 hours to obtain the carbonized product.

[0054] (4) Add the carbonized product to 15% v / v nitric acid, immerse it for 4 hours, centrifuge it, wash it with distilled water until neutral, and dry it to obtain the spinning aid. Example 3

[0055] This embodiment provides a method for preparing green and environmentally friendly nylon fiber, including the following steps:

[0056] Step 1: Polyamide 6 and spinning aid in a mass ratio of 100:1 are melt-blended and spun in a spinning machine. The melt-blending temperature is controlled at 240℃ and the spinning temperature is controlled at 250℃. Then, the fiber is stretched and heat-set in a hot roller stretcher. The stretching ratio is 3 times and the heat-setting temperature is 100℃ to obtain modified nylon fiber.

[0057] Step 2: Mix palmitic acid, kaolin, and anhydrous ethanol in a mass ratio of 1:5:15 until homogeneous, heat to 100℃ and reflux for 3 hours, cool and dry, and grind to less than 50 mesh to obtain modified kaolin; mix fluorosilicone resin and xylene in a mass ratio of 1:10, stir until homogeneous, then add modified kaolin. The mass ratio of modified kaolin to fluorosilicone resin LS-8722 is 0.5:1. Ultrasonically treat for 30 minutes at 80W / L, cool to room temperature, then add fluorosilicone resin and 0.5wt% curing agent (Shin-Etsu CAT-PL-56, Japan) by mass of fluorosilicone resin, stir for 3 hours to obtain modified liquid;

[0058] Step 3: Completely immerse the modified nylon fiber in the modification solution, ultrasonically treat it at 50W / L for 3 hours, drain the water, and dry it to obtain green and environmentally friendly nylon fiber.

[0059] The preparation method of the spinning aid includes the following steps:

[0060] (1) Crush wheat straw to a length of less than 5 cm to obtain wheat straw powder. Add 2% glucose by mass to the wheat straw powder, add water to obtain a mixture, with water accounting for 60% of the mixture's mass. Add fermentation agent, which includes Bacillus subtilis, Bacillus laterosporus, and Acetobacter xylose in a live bacteria ratio of 1:1.2:0.7. The amount of fermentation agent used is 10 7 The mixture of CFU / g was fermented aerobically at 30℃ for 7 days with an aeration rate of 0.8 vvm and maintained at 121℃ and 0.1 MPa pressure for 15 minutes. Then it was naturally dried until the moisture content was less than 7% to obtain the fermentation product.

[0061] (2) Mix ferrous chloride and distilled water at a mass ratio of 1:20 and stir for 2 hours to obtain a catalyst solution; add the catalyst solution to the fermentation product, with a mass ratio of fermentation product to catalyst solution of 3:10, stir for 4 hours, and then dry at 150°C for 10 hours to obtain the precursor;

[0062] (3) Under a nitrogen atmosphere, the precursor was heated to 400°C at a heating rate of 10°C / min and held for 2 hours; then heated to 900°C at a rate of 10°C / min and held for 10 hours to obtain the carbonized product.

[0063] (4) Add the carbonized product to 13% v / v nitric acid, immerse it for 6 hours, centrifuge it, wash it with distilled water until neutral, dry it, and obtain the spinning aid.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that fermentation is not performed in the preparation method of the spinning aid.

[0066] The preparation method of the spinning aid includes the following steps:

[0067] (1) Crush wheat straw to a length of less than 5cm to obtain fermentation products;

[0068] (2) Mix ferrous chloride and distilled water at a mass ratio of 1:15 and stir for 2.5 h to obtain a catalyst solution; add the catalyst solution to the fermentation product, with a mass ratio of fermentation product to catalyst solution of 3:10, stir for 3 h, and then dry at 140 °C for 12 h to obtain the precursor;

[0069] (3) Under a nitrogen atmosphere, the precursor was heated to 500°C at a heating rate of 10°C / min and held for 2.5 h; then heated to 1000°C at a heating rate of 20°C / min and held for 9 h to obtain the carbonized product.

[0070] (4) Add the carbonized product to 14% v / v nitric acid, immerse it for 5 hours, centrifuge it, wash it with distilled water until neutral, dry it, and obtain the spinning aid.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that the fermentation agent contains Bacillus subtilis, Bacillus lateralis, and Bacillus licheniformis in a live bacteria ratio of 1:1.5:0.4.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 1 is that the fermentation agent includes Bacillus subtilis and Bacillus lateralis in a live bacteria ratio of 1:1.5.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 1 is that the fermentation agent contains Bacillus subtilis, Bacillus lateralis, and Gluconobacterium xylose in a live bacteria ratio of 1:1.1:0.8.

[0077] Comparative Example 5

[0078] The difference between this comparative example and Example 1 is that the fermentation agent contains Bacillus subtilis, Bacillus lateralis, and Gluconobacterium xylose in a live bacteria ratio of 1:1.6:0.3.

[0079] Comparative Example 6

[0080] The difference between this comparative example and Example 1 is that palmitic acid is replaced with stearic acid in the preparation method of the modified liquid.

[0081] Comparative Example 7

[0082] The difference between this comparative example and Example 1 is that the fluorosilicone resin is replaced with polydimethylsiloxane in the preparation method of the modified liquid.

[0083] Performance testing

[0084] The performance of the nylon fibers prepared in Examples 1-3 and Comparative Examples 1-7 was tested.

[0085] 1. The mechanical properties of nylon fiber were tested according to the FZ / T54007-2009 standard, and the results are shown in Table 1.

[0086] Table 1 Test Results

[0087]

[0088] 2. The nylon fiber is made into a plain weave fabric with a warp and weft yarn density of 20D and a warp and weft density of 75×75 yarns / cm.

[0089] The contact angle of plain weave fabric was tested using a contact angle meter. Six points were measured for each sample, and the average value was taken.

[0090] A plain weave fabric with a load of 100g is placed on 1000-grit sandpaper and rubbed on the sandpaper for 50cm at a speed of 2cm / s. The contact angle is then measured.

[0091] The results are shown in Table 2.

[0092] Table 2 Performance Test Results

[0093]

[0094] As shown in Table 1, the nylon fibers of Examples 1-3 have excellent breaking strength and breaking elongation, and the fabrics made from them have high hydrophobicity and abrasion resistance.

[0095] In Comparative Example 1, the preparation of graphene without fermentation pretreatment resulted in a decrease in the breaking strength and elongation at break of nylon fibers.

[0096] In Comparative Examples 2-5, fermentation using different strains and ratios resulted in a decrease in the breaking strength and elongation at break of nylon fibers, indicating that the type and ratio of strains have a significant impact on the processing of biomass raw materials. The strains and ratios selected in this invention can reduce defects in graphene, increase its crystallinity, and improve its dispersibility in the system. Furthermore, the combined effect of the three strains in Comparative Example 2 was worse than that of the two strains in Comparative Example 3, indicating that not all strains have synergistic effects, while the strains selected in this invention exhibit excellent synergistic effects.

[0097] In Comparative Example 6, replacing palmitic acid with stearic acid resulted in a decrease in the hydrophobicity and abrasion resistance of the nylon. Analysis shows that kaolin is a layered silicate with numerous hydroxyl groups on its surface. Fatty acids are grafted onto the kaolin surface through esterification, forming an organic modified layer. Palmitic acid, due to its shorter carbon chain and weaker intermolecular forces, more easily forms a loose, porous grafted layer on the kaolin surface during heating and reflux. Stearic acid, on the other hand, has a longer carbon chain and stronger van der Waals forces, easily forming a dense, packed modified layer. This structural difference directly affects the subsequent composite effect of fluorosilicone resins. The loose palmitic acid modified layer acts like a "sponge," allowing the fluorosilicone resin to better penetrate and anchor, forming a stable micro-nano rough structure. The dense layer formed by stearic acid, however, acts as a "barrier," hindering resin penetration and leading to an uneven composite structure. When forming a film on the fiber surface, the palmitic acid system can form a more uniform and robust superhydrophobic coating, while the stearic acid system is prone to defects.

[0098] In Comparative Example 7, replacing fluorosilicone resin with polydimethylsiloxane resulted in a decrease in the hydrophobicity and abrasion resistance of the nylon. Analysis suggests that fluorosilicone resin, due to its strongly polar CF bonds, can form a stronger bond with kaolin and a stronger interfacial interaction with the fiber matrix. Simultaneously, the fluorinated groups in the fluorosilicone resin may form a stronger interaction with the functional groups on the graphene surface.

[0099] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing green and environmentally friendly nylon fiber, characterized in that, Includes the following steps: Step 1: Polyamide 6 and spinning aids are melt-blended and spun in a spinning machine to obtain modified nylon fiber; Step 2: Mix fluorosilicone resin and xylene, stir evenly, then add modified kaolin, sonicate, cool to room temperature, then add curing agent, stir, and obtain modified liquid; Step 3: Completely immerse the modified nylon fiber in the modification solution, ultrasonically treat it, drain the water, and dry it to obtain green and environmentally friendly nylon fiber. The preparation method of spinning aids includes the following steps: (1) Crush wheat straw to obtain wheat straw powder, add glucose and water to wheat straw powder to obtain a mixture, add fermentation agent; perform aerobic fermentation, sterilize, and then dry naturally to obtain fermentation product; (2) Add catalyst solution to fermentation product, stir, and then dry at high temperature to obtain precursor; (3) The precursor is carbonized under a nitrogen atmosphere to obtain carbonized products; (4) Treat the carbonization product with acid, wash it with water until neutral, and dry it to obtain the spinning aid; The fermentation agent contains Bacillus subtilis, Bacillus lateralis, and Acetobacter xylose in a live bacteria ratio of 1:(1.2-1.5):(0.4-0.7). The preparation method of modified kaolin is as follows: palmitic acid, kaolin and anhydrous ethanol are mixed evenly, heated under reflux, cooled and dried, and ground to obtain modified kaolin.

2. The method for preparing green and environmentally friendly nylon fiber according to claim 1, characterized in that, The spinning conditions are as follows: melt blending temperature is 230-240℃, spinning temperature is 250-260℃, and heat setting temperature is 90-100℃.

3. The method for preparing green and environmentally friendly nylon fiber according to claim 1, characterized in that, The mass ratio of modified kaolin to fluorosilicone resin is (0.5-0.6):

1.

4. The method for preparing green and environmentally friendly nylon fiber according to claim 1, characterized in that, The conditions for aerobic fermentation are: 30-35℃ for 5-7 days.

5. The method for preparing green and environmentally friendly nylon fiber according to claim 1, characterized in that, The dosage of fermentation inoculant is 10. 6 -10 7 CFU / g mixture.

6. The method for preparing green and environmentally friendly nylon fiber according to claim 1, characterized in that, The carbonization conditions are as follows: heat to 400-500℃ at a heating rate of 5-10℃ / min and hold for 2-3 hours; then heat to 900-1000℃ at a rate of 10-20℃ / min and hold for 8-10 hours.

7. A green and environmentally friendly nylon fiber prepared by the preparation method according to any one of claims 1-6.

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