Corrosion-resistant chinlon 66 industrial yarn and preparation method thereof

Abstract

The invention provides a corrosion-resistant chinlon 66 industrial yarn and a preparation method thereof, and belongs to the technical field of industrial yarns, and the preparation method comprises the following steps: grinding copper sulfate pentahydrate, zinc acetate and acetanilide, adding acetone, uniformly mixing, adding chinlon 66 powder and acetone, melting, mixing, hot-pressing and granulating to obtain modified chinlon 66; uniformly mixing the modified chinlon 66 and calcium stearate, heating and melting through a screw extruder, and carrying out melt filtering, side blowing cooling, oiling, drafting and shaping, winding and the like to obtain the modified chinlon 66 industrial yarn. Under magnetic stirring, dissolving phosphatized chitosan in a glacial acetic acid aqueous solution, adding 2-hydroxy-2-methyl propiophenone, uniformly stirring, heating, adding the modified chinlon 66 industrial yarn, dipping, drying, exposing to an ultraviolet light source, cleaning, and drying to obtain the corrosion-resistant chinlon 66 industrial yarn. The corrosion resistance of the chinlon 66 industrial yarn can be improved, and meanwhile the overall strength and the antibacterial property are improved.

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. Due to its excellent mechanical properties, good wear resistance and chemical stability, nylon 66 industrial yarn has become an important material for making various industrial products. 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 they come into contact with 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 industries such as fertilizers, petroleum, and chemicals, 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: 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; 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. 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.

[0007] In the present invention, after first preparing modified polyamide 66 by 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, during the manufacturing process of polyamide 66 industrial yarn modified by acetanilide, the reduction effect of its aniline group can promote the reduction of copper ions in copper sulfate to copper microparticles. Additionally, under the 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. As a result, while the copper microparticles and zinc oxide generated by decomposition under the heating state migrate to the surface of the polyamide 66 industrial yarn, they are 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.

[0008] 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 under 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 and the surface of the modified polyamide 66 industrial yarn form a covalent cross - linked network 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.

[0009] Optionally, in step S1, modified basalt fibers are also added while adding polyamide 66 powder.

[0010] 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 their bonding strength with the matrix, the durability is further improved.

[0011] Optionally, 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 lanthanum chloride solution for 2 h, and then drying in a drying box at 100 °C for 1 h.

[0012] When preparing the modified basalt fiber in the present invention, the surface roughness of the basalt fiber is increased by treatment with concentrated nitric acid, thereby improving the interfacial bonding strength between the fiber and the matrix. Moreover, lanthanum ions can be embedded in the gaps on the surface of the basalt fiber, 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 fiber in an acidic environment, and further improving the overall corrosion resistance.

[0013] Optionally, the lanthanum chloride solution is prepared by mixing deionized water and lanthanum chloride and stirring for 10 min.

[0014] 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 it is added to a two-roll mill, and nylon 66 powder, modified basalt fiber, 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.

[0015] Optionally, the phosphorylated chitosan is prepared by mixing chitosan powder and methanesulfonic acid, adding phosphorus pentoxide, mechanically stirring, pouring into ether for precipitation, filtering the precipitate, washing, and then drying under vacuum.

[0016] In the present invention, phosphorylated chitosan is prepared. 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. It 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.

[0017] 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.

[0018] Optionally, the washing is carried out successively with acetone, methanol, and ether.

[0019] In the present invention, different methods are used for washing multiple times to thoroughly remove the residual acid.

[0020] 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%.

[0021] Optionally, the corrosion-resistant polyamide 66 industrial yarn comprises raw materials in the following weight parts: 10 - 16 parts of phosphated chitosan, 1.6 - 3.2 parts of 2-hydroxy-2-methylpropiophenone, and 20 - 25 parts of modified polyamide 66 industrial yarn.

[0022] The present invention can obtain the best comprehensive performance by using the raw materials in such weight parts, meeting the requirements of corrosion resistance, antibacterial property and physical strength.

[0023] The above technical solutions of the present invention have at least the following beneficial effects: 1. The present invention modifies polyamide 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 voids are left through sublimation to promote liquid penetration and diffusion. Finally, the copper microparticles provide antibacterial effect, and zinc oxide provides corrosion protection, and the combination of the two optimizes the antibacterial property, corrosion resistance and long-term use performance of the polyamide 66 industrial yarn.

[0024] 2. The present invention applies phosphated chitosan to the modified polyamide 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 crosslinking network with the surface of polyamide 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. Specific Embodiments

[0025] 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 part of the 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.

[0026] Example 1 100 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.

[0027] 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 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 after melt mixing for 15 min, hot pressing was carried out at 230 °C and 10 MPa for 10 min, and then granulation was carried out to obtain modified nylon 66; 100 g of modified nylon 66 and 5 g of calcium stearate were uniformly mixed, heated and melted at 350 °C through a screw extruder, and passed through processes such as melt filtration, side blowing cooling, oiling, drawing and setting, and winding to obtain modified nylon 66 industrial yarn.

[0028] 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, 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.

[0029] Example 2 100 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.

[0030] After 0.2g of copper sulfate pentahydrate and 3g of zinc acetate were ball-milled for 15min, 10g of acetanilide was added and the grinding was continued for 10min, 10g of acetone was added and mixed evenly, and then 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, the distance between the front roller and the rear roller was 0.25mm, and after melt mixing for 20min, hot pressing was carried out at 230°C and 10MPa for 10min, and then granulation was performed to obtain modified nylon 66; 100g of modified nylon 66 and 15g of calcium stearate were evenly mixed, heated and melted at 300°C by a screw extruder, and modified nylon 66 industrial yarn was obtained through melt filtration, side blowing cooling, oiling, drawing and shaping, winding and other processes.

[0031] 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 5 ° C for 3 h, the mixture 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 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, and then heated to 80 ° C, 25 g of modified nylon 66 industrial yarn was added and immersed for 1.5 h, dried at 80 ° C for 10 min, and 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.

[0032] Example 3 100 mL of deionized water and 0.4 g of lanthanum chloride were mixed and stirred for 10 min to prepare a lanthanum chloride solution; the basalt fiber was immersed in acetone at room temperature 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 with distilled water 3 times, dried in a drying furnace at 100 ° C for 1 h, immersed in the lanthanum chloride solution for 2 h, and dried in a drying oven at 100 ° C for 1 h to obtain the modified basalt fiber.

[0033] 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 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 17 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 10 g of calcium stearate, heat and melt them at 310 °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.

[0034] 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 2 °C for 2.5 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 13 g of the obtained phosphorylated chitosan in 500 mL of an aqueous acetic acid solution with a volume concentration of 2%, add 2.2 mL of 2-hydroxy-2-methylpropiophenone and stir evenly, heat to 80 °C, add 24 g of modified nylon 66 industrial yarn and impregnate for 1.2 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.

[0035] Example 4 Mix 100 mL of deionized water and 0.7 g of lanthanum chloride and stir for 10 min to obtain 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, wash it 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 oven at 100 °C for 1 h to obtain modified basalt fiber.

[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 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 them 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.

[0037] After mixing 30 g of chitosan powder and 128 mL of methanesulfonic acid in a three-necked flask, 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 it 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%. After adding 2.5 mL of 2-hydroxy-2-methylpropiophenone and stirring evenly, heat it to 80 °C, add 22 g of modified nylon 66 industrial yarn and immerse it for 1 h. Dry it 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 5 After mixing 100 mL of deionized water and 0.2 g of lanthanum chloride and stirring for 10 min, a lanthanum chloride solution is prepared. Soak basalt fiber in acetone at room temperature for 48 h, then dry it 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.

[0039] After 0.2g of copper sulfate pentahydrate and 3g of zinc acetate were ball-milled for 15min, 10g of acetanilide was added and the grinding was continued for 10min, 10g of acetone was added and mixed evenly, and then 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, the distance between the front roller and the rear roller was 0.25mm, and after melt mixing for 18min, hot pressing was carried out at 230°C and 10MPa for 10min, and then granulation was performed to obtain modified nylon 66; 100g of modified nylon 66 and 7g of calcium stearate were evenly mixed, heated and melted at 330°C by a screw extruder, and modified nylon 66 industrial yarn was obtained through melt filtration, side blowing cooling, oiling, drawing and shaping, winding and other processes.

[0040] 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 4 ° C for 3 h, the mixture 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 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, and then heated to 80 ° C, 20 g of modified nylon 66 industrial yarn was added and immersed for 1.5 h, dried at 80 ° C for 10 min, and 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.

[0041] Example 6 100 mL of deionized water and 0.9 g of lanthanum chloride were mixed and stirred for 10 min to prepare a lanthanum chloride solution; the basalt fiber was immersed in acetone at room temperature 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 with distilled water 4 times, dried in a drying furnace at 100 ° C for 1 h, immersed in the lanthanum chloride solution for 2 h, and dried in a drying oven at 100 ° C for 1 h to obtain the modified basalt fiber.

[0042] After 0.2g of copper sulfate pentahydrate and 3g of zinc acetate were ball-milled for 15min, 10g of acetanilide was added and the grinding was continued for 10min, 10g of acetone was added and mixed evenly, and then 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, the distance between the front roller and the rear roller was 0.25mm, and after melt mixing for 20min, hot pressing was carried out at 230°C and 10MPa for 10min, and then granulation was performed to obtain modified nylon 66; 100g of modified nylon 66 and 15g of calcium stearate were evenly mixed, heated and melted at 340°C by a screw extruder, and modified nylon 66 industrial yarn was obtained through melt filtration, side blowing cooling, oiling, drawing and shaping, winding and other processes.

[0043] 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 3 h, the mixture 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 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, and then heated to 80°C, 24 g of modified nylon 66 industrial yarn was added and immersed for 1.5 h, dried at 80°C for 10 min, and 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.

[0044] The present invention also carries out comparative examples and related tests.

[0045] Comparative Example 1 Compared with Example 6, the difference is that modified nylon 66 is not prepared, copper particles and zinc oxide particles are directly added in the process of preparing modified nylon 66 industrial yarn, and other preparation steps and components remain unchanged, and finally corrosion-resistant nylon 66 industrial yarn is obtained.

[0046] Comparative Example 2 Compared with Example 6, the difference is that acetanilide is not added in the process of preparing modified nylon 66, and other preparation steps and components remain unchanged, and finally corrosion-resistant nylon 66 industrial yarn is obtained.

[0047] Comparative Example 3 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 obtained.

[0048] Comparative Example 4 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 polyamide 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 polyamide 66 industrial yarn was prepared.

[0049] Performance detection test The breaking strength and breaking elongation of the corrosion-resistant polyamide 66 industrial yarns prepared in Examples 1 to 6 and Comparative Examples 1 to 4 above were tested according to the test method of the national standard GB / T 14344-2022 Test Method for Tensile Properties of Chemical Fiber Filaments. The heat shrinkage rate was tested according to the test method of GB / T 6505-2017 Test Method for Heat Shrinkage Rate of Chemical Fiber Filaments. The test results are shown in Table 1.

[0050] Table 1

[0051] 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 heat shrinkage rate of Examples 1 to 6 was ≤1.9%, meeting the requirement of ≤2% for first-class products, and the heat shrinkage rate of Comparative Examples 1 to 4 was ≥2.0%, which was unqualified.

[0052] 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. And in Comparative Example 2, the absence of acetanilide affected the reduction and dispersion of copper sulfate pentahydrate, also causing problems such as low breaking strength, breaking strength, and breaking elongation; in Comparative Example 3, the surface heat shrinkage rate of the polyamide 66 industrial yarn without the addition of phosphated chitosan graft modification increased significantly.

[0053] 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 according to the method of ISO20743-2007 Determination of Antibacterial Properties of Antibacterial Finished Textiles. The adhesion of the phosphorylated chitosan coating was rated by the ASTM D3359 cross-cut method. The specific test results are shown in Table 2.

[0054] Table 2

[0055] 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 was formed by ultraviolet grafting of phosphorylated chitosan, and the corrosion resistance strength retention rate reached 98%, which was 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 were directly added, and in Comparative Example 2, the lack of acetanilide to assist the metal salt led 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 was 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 led to a significant decrease in the coating adhesion.

[0056] 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, which should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing corrosion-resistant nylon 66 industrial yarn, characterized in that: The steps include: S1. Grind copper sulfate pentahydrate, zinc acetate and acetanilide, add acetone and mix well, add nylon 66 powder and acetone to melt and mix, hot press and granulate to obtain modified nylon 66; S2, after the modified nylon 66 and calcium stearate are mixed, they are heated and melted at 300-350°C by a screw extruder, and the modified nylon 66 industrial yarn is obtained through melt filtration, side blowing cooling, oiling, drawing and shaping, winding and other processes; S3. Under magnetic stirring, dissolve the phosphated chitosan in an aqueous solution of glacial acetic acid, add 2-hydroxy-2-methylpropiophenone and stir evenly, heat, add modified nylon 66 industrial yarn to impregnate, dry, expose to an ultraviolet light source, wash, and dry to obtain corrosion-resistant nylon 66 industrial yarn.

2. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that: In the step S1, modified basalt fiber is added at the same time as nylon 66 powder.

3. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 2, characterized in that: The modified basalt fiber is prepared by soaking the basalt fiber in acetone at room temperature for 48 hours, drying at 100°C for 1 hour, soaking in a nitric acid solution with a volume concentration of 60% in a constant temperature water bath at 60°C for 2 hours, washing with distilled water for 3 to 4 times, drying in a drying furnace at 100°C for 1 hour, soaking in a lanthanum chloride solution for 2 hours, and drying in a drying oven at 100°C for 1 hour.

4. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 3, characterized in that: The lanthanum chloride solution is prepared by mixing deionized water and lanthanum chloride and stirring for 10 minutes.

5. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that: In the step S1, copper sulfate pentahydrate and zinc acetate are ball-milled for 15 minutes, acetanilide is added and ground for 10 minutes, acetone is added and mixed, and then the mixture is added to a double-roll mill, and nylon 66 powder, modified basalt fiber and acetone are added and melt-mixed for 15 to 20 minutes, and then hot-pressed at 230° C. and 10 MPa for 10 minutes, followed by granulation to obtain modified nylon 66.

6. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that: The phosphated chitosan is prepared by mixing chitosan powder and methanesulfonic acid, adding phosphorus pentoxide, mechanically stirring, pouring into ether for precipitation, filtering the precipitate, washing, and vacuum drying.

7. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 6, characterized in that: The mechanical stirring is carried out at 0-5°C for 2-3 hours; the vacuum drying temperature is 60°C for 24 hours.

8. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 6, characterized in that: The washing is carried out using acetone, methanol and ether in sequence.

9. The method for preparing corrosion-resistant nylon 66 industrial yarn according to claim 1, characterized in that: In step S3, the heating temperature is 80° C., the immersion time is 1-1.5 h, the drying temperature is 80° C., the time is 10 min, the drying temperature is 80° C., and the time is 1 h; the volume concentration of the glacial acetic acid aqueous solution is 2%.

10. A corrosion-resistant nylon 66 industrial yarn, characterized in that: The corrosion-resistant nylon 66 industrial yarn is prepared by the preparation method of any one of claims 1 to 9, comprising the following raw materials in parts by weight: 10 to 16 parts of phosphated chitosan, 1.6 to 3.2 parts of 2-hydroxy-2-methylpropiophenone, and 20 to 25 parts of modified nylon 66 industrial yarn.

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