A corrosion-resistant nylon 66 industrial yarn and its preparation method

Abstract

The present invention provides a corrosion-resistant polyamide 66 industrial yarn and its preparation method, belonging to the technical field of industrial yarns, and comprising the following steps: After grinding copper sulfate pentahydrate, zinc acetate, and acetanilide, acetone is added and mixed evenly, and then polyamide 66 powder and acetone are added for melting and mixing, followed by hot pressing and granulation to obtain modified polyamide 66; After mixing the modified polyamide 66 and calcium stearate evenly, it is heated and melted by a screw extruder, and then through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, and winding, the modified polyamide 66 industrial yarn is obtained; Under magnetic stirring, phosphated chitosan is dissolved in an aqueous acetic acid solution, 2-hydroxy-2-methylpropiophenone is added and stirred evenly, heated, the modified polyamide 66 industrial yarn is added for impregnation, after drying, it is exposed to an ultraviolet light source, then washed and dried to obtain the corrosion-resistant polyamide 66 industrial yarn. The present invention can improve the corrosion resistance of polyamide 66 industrial yarn while improving the overall strength and antibacterial property.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial yarns, and particularly relates to a corrosion-resistant polyamide 66 industrial yarn and a preparation method thereof. Background Art

[0002] At present, the development speed of industrial fibers and products is getting faster and faster. Polyamide (nylon) fiber is the first fiber to be industrially produced in the world and is the main raw material for outdoor products second only to polyester fiber. Nylon 66, also known as polyamide 66, is a commonly used synthetic polymer material and is applied in the fields of textiles, industry, automobiles, electronics, etc., especially in the production of industrial yarns. Nylon 66 industrial yarn has become an important material for making various industrial products due to its excellent mechanical properties, good wear resistance and chemical stability. However, although nylon 66 industrial yarn has good comprehensive properties, in some specific application environments, especially in environments where it comes into contact with corrosive substances, its corrosion resistance still has relatively large problems.

[0003] The corrosion resistance of nylon 66 industrial yarn is mainly restricted by its molecular structure and production process. Nylon 66 is a polyamide material obtained by the polymerization reaction of adipic acid and 1,6-hexanediamine, and has good physical and chemical properties, especially heat resistance and strength. However, the amino and acyl groups in the nylon 66 molecule are prone to hydrolysis or oxidation reactions when contacting certain chemical substances. Especially in a humid or high-temperature environment, the molecular chains of the nylon 66 material may break or undergo chemical degradation, resulting in a decrease in its strength and wear resistance. In addition, when nylon 66 industrial yarn is in long-term contact with corrosive substances, the surface is prone to corrosive damage. Especially in the special environments of the fertilizer, petroleum, chemical and other industries, corrosion spots, cracks or peeling phenomena may appear on the surface of the industrial yarn, affecting the appearance and service performance of the product.

[0004] Therefore, it is necessary to provide a corrosion-resistant nylon 66 industrial yarn and a preparation method thereof to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] In view of this, the present invention provides a corrosion-resistant nylon 66 industrial yarn and a preparation method thereof, which can improve the corrosion resistance of nylon 66 industrial yarn while improving the overall strength and antibacterial property.

[0006] To achieve the above object, the present invention provides a preparation method of a corrosion-resistant nylon 66 industrial yarn, comprising the following steps:

[0007] S1. Grind copper sulfate pentahydrate, zinc acetate, and acetanilide, then add acetone and mix evenly. Add nylon 66 powder and acetone for melt mixing, and then perform hot pressing and granulation to obtain modified nylon 66;

[0008] S2. After mixing the modified polyamide 66 and calcium stearate, heat and melt them at 300 - 350 °C through a screw extruder, and obtain modified polyamide 66 industrial yarn through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, winding, etc.

[0009] S3. Under magnetic stirring, dissolve phosphated chitosan in an aqueous solution of glacial acetic acid, add 2 - hydroxy - 2 - methylpropiophenone and stir evenly, heat, add the modified polyamide 66 industrial yarn for impregnation, after drying, expose it to an ultraviolet light source, then wash and dry to obtain corrosion - resistant polyamide 66 industrial yarn.

[0010] In the present invention, after first preparing modified polyamide 66 using copper sulfate pentahydrate, zinc acetate, and acetanilide, it is applied to the preparation of polyamide 66 industrial yarn. Different from the phenomenon that directly adding metal particles during the preparation of polyamide 66 industrial yarn will cause uneven distribution and easy agglomeration, in the process of manufacturing industrial yarn with acetanilide - modified polyamide 66, the reduction effect of its aniline group can promote the reduction of copper ions in copper sulfate to copper microparticles. Additionally, at a heating and melting state of 300 - 350 °C, zinc oxide generated by the high - temperature decomposition of zinc acetate, and acetanilide directly sublimes above 300 °C, thus leaving voids where it sublimes, promoting the penetration and diffusion of the molten liquid, enabling the copper microparticles and the zinc oxide generated by decomposition in the heating state to migrate to the surface of the polyamide 66 industrial yarn while being more evenly dispersed. The copper microparticles provide antibacterial effects, and zinc oxide provides stronger corrosion - resistant protection. When the two are combined, while ensuring the antibacterial and corrosion - resistant properties of the material, the long - term use performance of the material can be optimized.

[0011] In the present invention, phosphated chitosan is induced by ultraviolet irradiation and applied to the surface of the modified polyamide 66 industrial yarn. The introduction of phosphate groups also increases the overall thermal degradation temperature, further improving the durability in high - temperature environments; and the phosphate groups increase the polarity of chitosan, making it more easily and evenly dispersed in glacial acetic acid. Under the action of a photoinitiator (2 - hydroxy - 2 - methylpropiophenone), phosphated chitosan forms a covalent cross - linked network with the surface of the modified polyamide 66 industrial yarn through a free - radical reaction. This three - dimensional structure significantly improves the mechanical strength and adhesion of the coating, reduces the failure of the protective layer caused by physical wear, and improves the overall durability; in addition, the film - forming property of phosphated chitosan is also better than that of ordinary chitosan, the porosity of the coating is reduced, effectively blocking the erosion of acidic or alkaline media, and improving the overall corrosion resistance. [[ID=II]]

[0012] Optionally, modified basalt fibers are also added while adding polyamide 66 powder in step S1.

[0013] The present invention also adds modified basalt fibers to improve the overall corrosion resistance and durability. Basalt fibers themselves have good corrosion resistance, high strength, and good toughness. Here, by modifying them, while improving the bonding strength with the matrix, the durability is further enhanced.

[0014] Optionally, the modified basalt fibers are prepared by soaking basalt fibers in acetone at room temperature for 48 h, drying at 100 °C for 1 h, soaking in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, washing 3 - 4 times with distilled water, drying in a drying oven at 100 °C for 1 h, soaking in a lanthanum chloride solution for 2 h, and then drying in a drying box at 100 °C for 1 h.

[0015] When preparing the modified basalt fibers in the present invention, the surface roughness of the basalt fibers is increased by treatment with concentrated nitric acid, thereby improving the interfacial bonding strength between the fibers and the matrix. And lanthanum ions can be embedded in the gaps on the surface of the basalt fibers, further improving the corrosion resistance of the fiber surface. Lanthanum ions form a dense oxide or hydroxide protective layer on the fiber surface, blocking the intrusion of water, oxygen, and corrosive ions, delaying the dissolution and corrosion of the fibers in an acidic environment, and further improving the overall corrosion resistance.

[0016] Optionally, the lanthanum chloride solution is prepared by mixing deionized water and lanthanum chloride and stirring for 10 min.

[0017] Optionally, in step S1, copper sulfate pentahydrate and zinc acetate are ball - milled for 15 min, acetanilide is added and grinding is continued for 10 min, acetone is added and mixed evenly, then added to a two - roll mill, and nylon 66 powder, modified basalt fibers, and acetone are melt - mixed for 15 - 20 min, and then hot - pressed at 230 °C and 10 MPa for 10 min, and then pelletized to obtain modified nylon 66.

[0018] Optionally, the phosphorylated chitosan is prepared by mixing chitosan powder with methanesulfonic acid, adding phosphorus pentoxide, mechanically stirring, pouring into ether for precipitation, filtering the precipitate, washing, and then vacuum - drying.

[0019] In the present invention, when preparing phosphorylated chitosan, chitosan is treated with phosphorus pentoxide in a strong acid environment, and the hydroxyl groups are phosphorylated to form a phosphate ester structure, enhancing its chelating ability, which can effectively bind metal ions, reduce the corrosion damage of the nylon 66 industrial yarn caused by metal - catalyzed oxidation reactions, and improve the overall corrosion resistance.

[0020] Optionally, the mechanical stirring is carried out at 0 - 5 °C, and the mechanical stirring time is 2 - 3 h; the vacuum - drying temperature is 60 °C and the time is 24 h.

[0021] Optionally, the washing is carried out successively with acetone, methanol, and ether.

[0022] The present invention uses different methods for multiple washings to completely remove the residual acid.

[0023] Optionally, in step S3, the heating temperature is 80 °C, the impregnation time is 1 - 1.5 h, the drying temperature is 80 °C for 10 min, and the baking temperature is 80 °C for 1 h; the volume concentration of the glacial acetic acid aqueous solution is 2%.

[0024] Optionally, the corrosion - resistant nylon 66 industrial yarn comprises the following raw materials in parts by weight: 10 - 16 parts of phosphated chitosan, 1.6 - 3.2 parts of 2 - hydroxy - 2 - methylpropiophenone, and 20 - 25 parts of modified nylon 66 industrial yarn.

[0025] The present invention can obtain the best comprehensive performance by using the raw materials in such parts by weight, meeting the requirements of corrosion resistance, antibacterial property and physical strength.

[0026] The above - mentioned technical solution of the present invention has at least the following beneficial effects:

[0027] 1. The present invention modifies nylon 66 with copper sulfate pentahydrate, zinc acetate and acetanilide, overcoming the problems of uneven distribution and agglomeration of metal particles in the traditional method. After acetanilide modification, the aniline group reduces copper ions to copper microparticles, zinc oxide is generated at high temperature and forms voids through sublimation, promoting liquid penetration and diffusion. Finally, the copper microparticles provide antibacterial effect, and zinc oxide provides corrosion - resistant protection, and the combination of the two optimizes the antibacterial property, corrosion resistance and long - term use performance of nylon 66 industrial yarn.

[0028] 2. The present invention applies phosphated chitosan to modified nylon 66 industrial yarn through ultraviolet - induced graft polymerization. The phosphate group improves the thermal degradation temperature and high - temperature durability. The phosphate group increases the polarity of chitosan, promotes its dispersion in glacial acetic acid, and forms a covalent cross - linked network with the surface of nylon 66 through a photoinitiator, enhancing the mechanical strength and adhesion of the coating, reducing wear failure and improving durability. At the same time, the film - forming property of phosphated chitosan is better than that of ordinary chitosan, reducing the coating porosity and enhancing the corrosion resistance. Detailed implementation mode

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are some embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention belong to the scope of protection of the present invention.

[0030] Embodiment 1

[0031] 100 mL of deionized water and 0.1 g of lanthanum chloride were mixed and stirred for 10 min to prepare a lanthanum chloride solution; at room temperature, basalt fibers were immersed in acetone for 48 h, dried at 100 °C for 1 h, immersed in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, washed 3 times with distilled water, then the fibers were dried in a drying oven at 100 °C for 1 h, immersed in the lanthanum chloride solution for 2 h, and dried in a drying box at 100 °C for 1 h to obtain modified basalt fibers.

[0032] 0.2 g of copper sulfate pentahydrate and 3 g of zinc acetate were ball-milled for 15 min, then 10 g of acetanilide was added and grinding continued for 10 min. After that, 10 g of acetone was added and mixed evenly, then the mixture was added to a two-roll mill, and 88.5 g of nylon 66 powder, modified basalt fibers and 5 g of acetone were added and mixed. The temperature of the machine rolls was set at 230 °C, the rotational speed of the front roll was 40 rpm, the rotational speed of the rear roll was 25 rpm, the distance between the front roll and the rear roll was 0.25 mm, and they were melt-mixed for 15 min. Then, they were hot-pressed at 230 °C and 10 MPa for 10 min, and then granulated to obtain modified nylon 66; 100 g of modified nylon 66 and 5 g of calcium stearate were evenly mixed, heated and melted at 350 °C through a screw extruder, and then passed through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, and winding to obtain modified nylon 66 industrial yarn.

[0033] In a three-necked flask, 30 g of chitosan powder was mixed with 128 mL of methanesulfonic acid, and then 14.5 g of phosphorus pentoxide was slowly added. After mechanical stirring at 0 °C for 2 h, it was poured into ether for precipitation. The precipitate was filtered and washed with 50 mL of acetone, 50 mL of methanol and 50 mL of ether respectively, and then vacuum-dried at 60 °C for 24 h to obtain phosphorylated chitosan; under magnetic stirring, 10 g of the obtained phosphorylated chitosan was dissolved in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%, 1.6 mL of 2-hydroxy-2-methylpropiophenone was added and stirred evenly, then heated to 80 °C, 20 g of modified nylon 66 industrial yarn was added and impregnated for 1.5 h, dried at 80 °C for 10 min, then exposed to an ultraviolet light source, washed, and dried in an oven at 80 °C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0034] Example 2

[0035] 100 mL of deionized water and 0.4 g of lanthanum chloride were mixed and stirred for 10 min to prepare a lanthanum chloride solution; at room temperature, basalt fibers were immersed in acetone for 48 h, dried at 100 °C for 1 h, immersed in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, washed 4 times with distilled water, then the fibers were dried in a drying oven at 100 °C for 1 h, immersed in the lanthanum chloride solution for 2 h, and dried in a drying box at 100 °C for 1 h to obtain modified basalt fibers.

[0036] After ball-milling 0.2 g of copper sulfate pentahydrate and 3 g of zinc acetate for 15 min, add 10 g of acetanilide and continue to grind for 10 min. Then add 10 g of acetone and mix evenly. Add the mixture into a two-roll mill, and add 88.5 g of nylon 66 powder, modified basalt fiber and 5 g of acetone and mix. Set the temperature of the machine rolls at 230 °C, the rotational speed of the front roll at 40 rpm, the rotational speed of the rear roll at 25 rpm, and the distance between the front roll and the rear roll at 0.25 mm. After melt mixing for 20 min, hot press at 230 °C and 10 MPa for 10 min, and then granulate to obtain modified nylon 66. After uniformly mixing 100 g of modified nylon 66 and 15 g of calcium stearate, heat and melt them at 300 °C through a screw extruder, and obtain modified nylon 66 industrial yarn through processes such as melt filtration, side air blowing cooling, oiling, drawing and setting, winding, etc.

[0037] In a three-necked flask, mix 30 g of chitosan powder with 128 mL of methanesulfonic acid, slowly add 14.5 g of phosphorus pentoxide, mechanically stir at 5 °C for 3 h, pour it into ether for precipitation, filter the precipitate, wash it with 50 mL of acetone, 50 mL of methanol and 50 mL of ether respectively, and vacuum dry at 60 °C for 24 h to obtain phosphorylated chitosan. Under magnetic stirring, dissolve 16 g of the obtained phosphorylated chitosan in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%, add 3.2 mL of 2-hydroxy-2-methylpropiophenone and stir evenly, heat to 80 °C, add 25 g of modified nylon 66 industrial yarn and impregnate for 1.5 h, dry at 80 °C for 10 min, then expose it to a UV light source on one side in an air environment, wash it, and dry it in an oven at 80 °C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0038] Example 3

[0039] Mix 100 mL of deionized water and 0.4 g of lanthanum chloride and stir for 10 min to prepare a lanthanum chloride solution. Immerse basalt fiber in acetone at room temperature for 48 h, dry at 100 °C for 1 h, then immerse it in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h. After washing 3 times with distilled water, dry the fiber in a drying oven at 100 °C for 1 h, then immerse it in the lanthanum chloride solution for 2 h, and dry it in a drying box at 100 °C for 1 h to obtain modified basalt fiber.

[0040] After ball-milling 0.2 g of copper sulfate pentahydrate and 3 g of zinc acetate for 15 min, 10 g of acetanilide was added and grinding continued for 10 min. Then, 10 g of acetone was added and mixed evenly, and the mixture was added to a two-roll mill. 88.5 g of nylon 66 powder, modified basalt fiber, and 5 g of acetone were added and mixed. The temperature of the machine rolls was set at 230 °C, the speed of the front roll was 40 rpm, the speed of the rear roll was 25 rpm, and the distance between the front roll and the rear roll was 0.25 mm. After melt mixing for 17 min, hot pressing was carried out at 230 °C and 10 MPa for 10 min, and then pelletizing was carried out to obtain modified nylon 66. After evenly mixing 100 g of modified nylon 66 and 10 g of calcium stearate, it was heated and melted at 310 °C through a screw extruder, and passed through processes such as melt filtration, side blow cooling, oiling, drawing and setting, winding, etc. to obtain modified nylon 66 industrial yarn.

[0041] In a three-necked flask, 30 g of chitosan powder was mixed with 128 mL of methanesulfonic acid, and then 14.5 g of phosphorus pentoxide was slowly added. After mechanical stirring at 2 °C for 2.5 h, it was poured into ether for precipitation. The precipitate was filtered, washed with 50 mL of acetone, 50 mL of methanol, and 50 mL of ether respectively, and then vacuum dried at 60 °C for 24 h to obtain phosphorylated chitosan. Under magnetic stirring, 13 g of the obtained phosphorylated chitosan was dissolved in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%. After adding 2.2 mL of 2-hydroxy-2-methylpropiophenone and stirring evenly, it was heated to 80 °C, 24 g of modified nylon 66 industrial yarn was added and impregnated for 1.2 h, dried at 80 °C for 10 min, then exposed to a UV light source on one side in an air environment, washed, and dried in an oven at 80 °C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0042] Example 4

[0043] 100 mL of deionized water and 0.7 g of lanthanum chloride were mixed and stirred for 10 min to prepare a lanthanum chloride solution. At room temperature, basalt fiber was soaked in acetone for 48 h, then dried at 100 °C for 1 h, soaked in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, washed 4 times with distilled water, then the fiber was dried in a drying oven at 100 °C for 1 h, soaked in the lanthanum chloride solution for 2 h, and then dried in a drying oven at 100 °C for 1 h to obtain modified basalt fiber.

[0044] After ball-milling 0.2 g of copper sulfate pentahydrate and 3 g of zinc acetate for 15 min, add 10 g of acetanilide and continue ball-milling for 10 min. Then add 10 g of acetone and mix evenly. Add the mixture into a two-roll mill, and also add 88.5 g of nylon 66 powder, modified basalt fiber and 5 g of acetone and mix. Set the temperature of the machine rolls at 230 °C, the rotational speed of the front roll at 40 rpm, the rotational speed of the rear roll at 25 rpm, and the distance between the front roll and the rear roll at 0.25 mm. After melt-mixing for 20 min, hot-press at 230 °C and 10 MPa for 10 min, and then granulate to obtain modified nylon 66. After evenly mixing 100 g of modified nylon 66 and 11 g of calcium stearate, heat and melt it at 320 °C through a screw extruder, and obtain modified nylon 66 industrial yarn through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, winding, etc.

[0045] In a three-necked flask, mix 30 g of chitosan powder with 128 mL of methanesulfonic acid, then slowly add 14.5 g of phosphorus pentoxide. After mechanical stirring at 3 °C for 2.5 h, pour it into ether for precipitation. Filter the precipitate, wash it with 50 mL of acetone, 50 mL of methanol and 50 mL of ether respectively, and then vacuum-dry at 60 °C for 24 h to obtain phosphorylated chitosan. Under magnetic stirring, dissolve 14 g of the obtained phosphorylated chitosan in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%. Add 2.5 mL of 2-hydroxy-2-methylpropiophenone and stir evenly, then heat to 80 °C, add 22 g of modified nylon 66 industrial yarn and immerse for 1 h, dry at 80 °C for 10 min, then expose it to a UV light source on one side in an air environment, wash it, and dry it in an oven at 80 °C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0046] Example 5

[0047] Mix 100 mL of deionized water and 0.2 g of lanthanum chloride and stir for 10 min to prepare a lanthanum chloride solution. Soak basalt fiber in acetone at room temperature for 48 h, then dry at 100 °C for 1 h, soak it in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, wash it 3 times with distilled water, then dry the fiber in a drying oven at 100 °C for 1 h, soak it in the lanthanum chloride solution for 2 h, and then dry it in a drying box at 100 °C for 1 h to obtain modified basalt fiber.

[0048] After ball-milling 0.2 g of copper sulfate pentahydrate and 3 g of zinc acetate for 15 min, add 10 g of acetanilide and continue ball-milling for 10 min. Then add 10 g of acetone and mix evenly. Add the mixture into a two-roll mill, and add 88.5 g of nylon 66 powder, modified basalt fiber and 5 g of acetone and mix. Set the temperature of the machine roll to 230 °C, the speed of the front roll to 40 rpm, the speed of the rear roll to 25 rpm, and the distance between the front roll and the rear roll to 0.25 mm. After melt-mixing for 18 min, hot-press at 230 °C and 10 MPa for 10 min, and then granulate to obtain modified nylon 66. After evenly mixing 100 g of modified nylon 66 and 7 g of calcium stearate, heat and melt them at 330 °C through a screw extruder, and obtain modified nylon 66 industrial yarn through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, and winding.

[0049] In a three-necked flask, mix 30 g of chitosan powder with 128 mL of methanesulfonic acid, slowly add 14.5 g of phosphorus pentoxide, mechanically stir at 4 °C for 3 h, then pour it into ether for precipitation. Filter the precipitate, wash it with 50 mL of acetone, 50 mL of methanol and 50 mL of ether respectively, and vacuum-dry at 60 °C for 24 h to obtain phosphorylated chitosan. Under magnetic stirring, dissolve 16 g of the obtained phosphorylated chitosan in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%, add 3.2 mL of 2-hydroxy-2-methylpropiophenone and stir evenly, heat to 80 °C, add 20 g of modified nylon 66 industrial yarn and impregnate for 1.5 h, dry at 80 °C for 10 min, then expose it to a UV light source on one side in an air environment, wash it, and dry it in an oven at 80 °C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0050] Example 6

[0051] Mix 100 mL of deionized water and 0.9 g of lanthanum chloride and stir for 10 min to prepare a lanthanum chloride solution. Soak basalt fiber in acetone at room temperature for 48 h, dry at 100 °C for 1 h, then soak it in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h. After washing 4 times with distilled water, dry the fiber in a drying oven at 100 °C for 1 h, then soak it in the lanthanum chloride solution for 2 h, and dry it in a drying box at 100 °C for 1 h to obtain modified basalt fiber.

[0052] After ball milling 0.2g of copper sulfate pentahydrate and 3g of zinc acetate for 15 minutes, 10g of acetanilide was added and the grinding was continued for 10 minutes. Then 10g of acetone was added and mixed evenly. The mixture was added to a double-roll mill, and 88.5g of nylon 66 powder, modified basalt fiber and 5g of acetone were added and mixed. The machine roller temperature was set to 230°C, the front roller speed was 40rpm, the rear roller speed was 25rpm, and the distance between the front roller and the rear roller was 0.25mm. After melt mixing for 20 minutes, the mixture was hot pressed at 230°C and 10MPa for 10 minutes, and then granulated to obtain modified nylon 66. After evenly mixing 100g of modified nylon 66 and 15g of calcium stearate, the mixture was heated and melted at 340°C through a screw extruder. The modified nylon 66 industrial yarn was obtained through melt filtration, side-blowing cooling, oiling, drawing and shaping, and winding.

[0053] In a three-necked flask, 30 g of chitosan powder was mixed with 128 mL of methanesulfonic acid, and 14.5 g of phosphorus pentoxide was slowly added. After mechanical stirring at 0°C for 3 h, the mixture was poured into diethyl ether for precipitation. The precipitate was filtered, washed with 50 mL of acetone, 50 mL of methanol, and 50 mL of diethyl ether, and then vacuum-dried at 60°C for 24 h to obtain phosphated chitosan. Under magnetic stirring, 16 g of the obtained phosphated chitosan was dissolved in 500 mL of 2% glacial acetic acid aqueous solution. 3.2 mL of 2-hydroxy-2-methylpropiophenone was added and stirred evenly. The mixture was heated to 80°C, and 24 g of modified nylon 66 industrial yarn was added and impregnated for 1.5 h. The mixture was dried at 80°C for 10 min, and then exposed to ultraviolet light on one side in an air environment, washed, and dried in an oven at 80°C for 1 h to obtain corrosion-resistant nylon 66 industrial yarn.

[0054] The present invention also carried out comparative examples and related tests.

[0055] Comparative Example 1

[0056] Compared with Example 6, the difference is that modified nylon 66 is not prepared, copper particles and zinc oxide particles are directly added during the preparation of modified nylon 66 industrial yarn, and other preparation steps and components remain unchanged, and corrosion-resistant nylon 66 industrial yarn is finally prepared.

[0057] Comparative Example 2

[0058] Compared with Example 6, the difference is that acetanilide is not added during the preparation of modified nylon 66, and other preparation steps and components remain unchanged, and corrosion-resistant nylon 66 industrial yarn is finally obtained.

[0059] Comparative Example 3

[0060] Compared with Example 6, the difference is that phosphorylated chitosan is not added to the surface of the nylon 66 industrial yarn for grafting and modification, and the other preparation steps and components remain unchanged, and finally the corrosion-resistant nylon 66 industrial yarn is prepared.

[0061] Comparative Example 4

[0062] Compared with Example 6, the difference is that 2-hydroxy-2-methylpropiophenone was not added as a photoinitiator to graft phosphorylated chitosan. Instead, the impregnation method was directly used, that is: under magnetic stirring, 16 g of the obtained phosphated chitosan was dissolved in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%, 24 g of modified nylon 66 industrial yarn was added and impregnated for 1.5 h, and then dried in an oven at 80 °C for 1 h. Finally, corrosion-resistant nylon 66 industrial yarn was prepared.

[0063] Performance detection test

[0064] The corrosion-resistant nylon 66 industrial yarns prepared in the above Examples 1 to 6 and Comparative Examples 1 to 4 were tested for breaking strength and elongation at break according to the test method of the national standard GB / T 14344-2022 Test Method for Tensile Properties of Chemical Fiber Filaments, and the thermal shrinkage rate was tested according to the test method of GB / T 6505-2017 Test Method for Thermal Shrinkage Rate of Chemical Fiber Filaments. The test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] As can be seen from Table 1, the breaking strength of all examples was ≥8.30 cN / dtex, while that of Comparative Examples 1 to 4 was lower than 8.30 cN / dtex; the thermal shrinkage rate of Examples 1 to 6 was ≤1.9%, meeting the requirement of ≤2% for first-class products, and the thermal shrinkage rate of Comparative Examples 1 to 4 was ≥2.0%, which was unqualified.

[0068] Combined with the data in Table 1, it can be seen that the breaking strength of Example 6 was significantly higher than that of Comparative Example 1. It was analyzed that this was due to the uneven dispersion caused by the direct addition of metal particles, resulting in a decrease in mechanical properties. In addition, the use of acetanilide in Comparative Example 2 affected the reduction and dispersion of copper sulfate pentahydrate, also causing problems such as low breaking strength, breaking strength, and elongation at break; the surface thermal shrinkage rate of the nylon 66 industrial yarn grafted without adding phosphated chitosan in Comparative Example 3 increased significantly.

[0069] The salt spray test (ASTM B117) was carried out on Examples 1 to 6 and Comparative Examples 1 to 4 to analyze the corrosion resistance. The antibacterial rate was analyzed with reference to the method for determining the antibacterial properties of antibacterial finished textiles in ISO20743-2007. The adhesion of the phosphorylated chitosan coating was rated according to the ASTM D3359 cross-cut method. The specific test results are shown in Table 2.

[0070] Table 2

[0071]

[0072] As can be seen from Table 2, the corrosion resistance strength retention rates of Examples 1 to 6 are all ≥90%, while those of Comparative Examples 1 to 4 are all <90%. In Example 6, a dense cross-linked coating is formed by ultraviolet grafting of phosphorylated chitosan, and the corrosion resistance strength retention rate reaches 98%, which is significantly better than that of Comparative Example 3 (without adding phosphorylated chitosan) and Comparative Example 4 (without adding photoinitiator). In Comparative Example 1, metal particles are directly added, and in Comparative Example 2, the lack of acetanilide to assist the metal salt leads to uneven dispersion, resulting in a significant decrease in the corrosion resistance strength retention rate and antibacterial rate. In Comparative Example 3, the surface of the graft-modified polyamide 66 industrial yarn is not added, resulting in the worst corrosion resistance and antibacterial properties. In Comparative Example 4, without a photoinitiator, the lower grafting rate of phosphated chitosan leads to a significant decrease in the coating adhesion.

[0073] The above are the preferred embodiments of the present invention. Without departing from the principle of the present invention, those of ordinary skill in the art can also make several improvements and refinements, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of corrosion-resistant nylon 66 industrial yarn, characterized in that, It includes the following steps: S1. Ball-mill copper sulfate pentahydrate and zinc acetate, add acetanilide and continue grinding, add acetone and mix evenly, add the mixture into a double-roll machine, and add nylon 66 powder, modified basalt fiber and acetone to melt and mix, then hot-press, and then granulate to obtain modified nylon 66; S2. Mix the modified nylon 66 and calcium stearate evenly, heat and melt them at 300-350 °C through a screw extruder, and obtain modified nylon 66 industrial yarn through the processes of melt filtration, side blowing cooling, oiling, drawing and setting, and winding; S3. Under magnetic stirring, dissolve phosphated chitosan in an aqueous acetic acid solution, add 2-hydroxy-2-methylpropiophenone and stir evenly, heat, add the modified nylon 66 industrial yarn for impregnation, dry, expose it to an ultraviolet light source, then wash and dry to obtain corrosion-resistant nylon 66 industrial yarn; The phosphated chitosan is prepared by mixing chitosan powder and methanesulfonic acid, adding phosphorus pentoxide, mechanically stirring, pouring it into ether for precipitation, filtering the precipitate, washing, and then vacuum drying; 2. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that, The modified basalt fiber is prepared by soaking basalt fiber in acetone at room temperature for 48 h, drying at 100 °C for 1 h, soaking in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60 °C for 2 h, washing 3-4 times with distilled water, drying in a drying oven at 100 °C for 1 h, soaking in a lanthanum chloride solution for 2 h, and then drying in a drying box at 100 °C for 1 h; 3. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 2, wherein The lanthanum chloride solution is prepared by mixing deionized water and lanthanum chloride and stirring for 10 min; 4. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that, In the step S1, the ball-milling time is 15 min, the grinding time is 10 min; the melting and mixing time is 15-20 min; the hot-pressing conditions are: hot-press at 230 °C and 10 MPa for 10 min; 5. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that, The mechanical stirring is carried out at 0-5 °C, and the mechanical stirring time is 2-3 h; the vacuum drying temperature is 60 °C and the time is 24 h; 6. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that, The washing is carried out in turn with acetone, methanol and ether; 7. The preparation method of a corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that, In the step S3, the heating temperature is 80 °C, the impregnation time is 1-1.5 h, the drying temperature is 80 °C and the time is 10 min, the drying temperature is 80 °C and the time is 1 h; the volume concentration of the aqueous acetic acid solution is 2%; 8. A corrosion-resistant nylon 66 industrial yarn, characterized in that, Prepared by using the preparation method of a corrosion-resistant nylon 66 industrial yarn according to any one of claims 1-7, and including the following raw materials in parts by weight: 10-16 parts of phosphated chitosan, 1.6-3.2 parts of 2-hydroxy-2-methylpropiophenone, and 20-25 parts of modified nylon 66 industrial yarn.

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