A kind of milk protein modified acrylic fiber and preparation method thereof

Abstract

The present invention provides a milk protein modified acrylic fiber and a preparation method thereof, wherein the milk protein modified acrylic fiber has a dry strength of 3.7-3.92 cN / dtex, a wet strength of 3.05-3.2 cN / dtex, and a boiling water shrinkage of <3%, and the preparation method includes the preparation of a casein solution, casein-coated plant active ingredients, blending and spinning. The present invention improves the defects of poor structure and poor dimensional stability of milk protein modified acrylic fiber in the prior art; reduces the loss of plant active ingredients in the spinning process of acrylic fiber, and further improves the electrostatic properties of the fiber by introducing plant active ingredients, and enhances the wearability, comfort and skin-friendliness of the fabric. The milk protein modified acrylic fiber prepared by the present invention, the plant active ingredients and casein are not easily lost during the washing process, and the loss rate of the plant active ingredients after washing 50 times is 1.2-1.7%, and the loss rate of casein is 1.1-1.4%.

Description

Technical Field

[0001] The invention belongs to the technical field of fibers, and in particular relates to a milk protein modified acrylic fiber and a preparation method thereof. Background Art

[0002] Acrylic fiber is a synthetic fiber made of polyacrylonitrile or acrylonitrile copolymer with an acrylonitrile content greater than 85% (mass percentage). It has excellent moth resistance and good fluffiness and comfort. It has a wool-like feel, and its wearing comfort and breathability are more in line with people's needs. Therefore, it is widely used in clothing, decoration and other fields.

[0003] Adding casein extracted from milk to acrylic fiber can improve the defect of poor hygroscopicity of acrylic fiber. The main methods of using milk protein to modify acrylic fiber are blending, crosslinking and grafting. The blending method is to blend casein with polyacrylonitrile spinning solution and make fibers through conventional polyacrylonitrile spinning process. The method is simple, but the dispersion of casein is poor and uneven, which easily affects the fiber quality; the crosslinking method uses casein and polyacrylonitrile as raw materials, adds a crosslinking agent to carry out polyacrylonitrile crosslinking chemical reaction, and the dispersion of casein is relatively uniform, and the dispersed particles are less than 20nm; the grafting method is to make casein and polymer undergo grafting copolymerization to make spinning solution, and then wet spinning into fiber. The fiber structure of this method is more stable than that of the crosslinking method, but the actual operation is more complicated.

[0004] Patent No. "CN01131920.8" entitled "Method for producing silkworm pupa protein-acrylonitrile grafted copolymer fibers" uses azobisisobutyronitrile as an initiator, acrylonitrile as the first polymerization monomer, methyl acrylate or methyl methacrylate as the second polymerization monomer, and sodium propylene sulfonate or sodium methpropylene sulfonate as the third monomer to produce silkworm pupa protein and acrylonitrile grafted copolymer fibers. However, if plant extracts are added to the spinning solution during the graft copolymerization, the plant extracts will also destroy the stability of the fiber structure, causing a significant decrease in the mechanical properties of the fiber.

[0005] The patent number "CN202110027002.X" and the name "An acrylic fiber containing plant extracts and collagen powder and its preparation method" add heat setting, cross-linking bath and other treatments during the spinning process to improve the strength of the acrylic fiber containing plant extracts and protein powder and reduce the loss rate. However, casein is basically amorphous and not easy to crystallize. The structure of the fiber is relatively unstable, and the dimensional stability of water washing resistance is relatively poor. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a milk protein modified acrylic fiber and a preparation method thereof, so as to achieve the following invention objectives:

[0007] 1. Improve the defects of poor structure and poor dimensional stability of milk protein modified acrylic fiber in the prior art;

[0008] 2. Reduce the loss of plant active ingredients in the spinning process of acrylic fibers, and by introducing plant active ingredients, further improve the electrostatic properties of the fibers, thereby enhancing the wearability, comfort, and skin-friendliness of the fabric.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A milk protein modified acrylic fiber and a preparation method thereof, comprising the following steps:

[0011] S1. Preparation of casein solution

[0012] Add casein to sodium hydroxide solution and ultrasonically treat at 40-50°C for 10-20 minutes to make the protein structure relatively loose, providing a basis for subsequent casein modification. After cooling to room temperature, add PBS buffer to obtain a casein solution.

[0013] Preferably, the concentration of the sodium hydroxide solution is 0.05-0.1 mol / L, the pH of the PBS buffer is 7.2-7.5, and the concentration is 0.1-0.15 mol / L; the volume ratio of the sodium hydroxide solution to the PBS buffer is 1:10-15; and the frequency of the ultrasonic treatment is 25-75 kHz.

[0014] Preferably, the casein content in the casein solution is 6-10wt%.

[0015] S2, casein-encapsulated plant active ingredients

[0016] Add hydrogen peroxide solution to the casein solution, then slowly add the alcohol solution of the plant active ingredients, stir and react for 60-70 minutes, generate disulfide cross-linking on the casein surface to coat the plant active ingredients, then put it in the freezer for 6-8 hours, and then place it at room temperature for 2-3 hours to obtain an emulsion, centrifuge and freeze-dry to obtain modified protein composite microspheres.

[0017] Preferably, the content of the plant active ingredient in the alcohol solution of the plant active ingredient is 10-20wt%; the plant active ingredient is one or more hydrophobic compounds such as curcumin, veratric acid, menthol, eugenol, etc.

[0018] Preferably, the concentration of the hydrogen peroxide solution is 20-30 wt %, and the amount of the hydrogen peroxide solution added is 10-18 wt % of the casein solution.

[0019] Preferably, the mass ratio of the casein solution to the alcohol solution of the plant active ingredient is 3-4:1.

[0020] S3. Blending

[0021] The modified protein composite microspheres are added into the acrylic spinning solution and mixed, and the mixture is stirred at 50-65° C. for 40-60 minutes, filtered and degassed to obtain the composite spinning solution.

[0022] Preferably, the added amount of the modified protein composite microspheres is 6-8wt% of the polyacrylonitrile content in the acrylic spinning solution.

[0023] Preferably, the solvent in the acrylic spinning solution is dimethyl sulfoxide, and the solvent accounts for 70-85% of the mass of the acrylic spinning solution; the viscosity of the acrylic spinning solution at room temperature is 10-30 Pa·S, and the stirring rate is 600-800 r / min.

[0024] S4. Spinning

[0025] The composite spinning solution is metered by a metering pump and extruded through a spinneret into a coagulation bath. The filament bundles from the coagulation bath enter a preheating bath and are stretched to 1-2.5 times, and then enter a high-temperature washing tank at 80-90°C for water washing. After washing, the filament bundles are stretched for a second time by 2-5 times, and then subjected to heat setting, a cross-linking bath, oiling, and cutting to obtain milk protein modified acrylic fibers.

[0026] Preferably, the extrusion rate is 10-20 m / s and the extrusion temperature is 30-40°C.

[0027] Preferably, the coagulation bath comprises the following components, by mass: 6-10 parts of dimethyl sulfoxide, 1-2 parts of n-butanol, 80-90 parts of water, and the temperature is 15-30°C.

[0028] Preferably, the preheating bath comprises the following components, by weight: 5-8 parts of dimethyl sulfoxide, 0.5-1 parts of n-butanol, 10-15 parts of water, and the temperature is 55-65°C.

[0029] Preferably, the secondary stretching temperature is 90-95°C.

[0030] Preferably, the heat setting temperature is 100-105° C., and the time is 30-40 seconds.

[0031] Preferably, the crosslinking agent in the crosslinking bath is one or more of glyoxal, glutaraldehyde, ethylenediamine, and epichlorohydrin, the content of the crosslinking agent in the crosslinking bath is 5-15wt%, the crosslinking time is 5-20min, and the temperature is 35-40°C.

[0032] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are:

[0033] 1. The milk protein modified acrylic fiber prepared by the present invention has excellent mechanical properties, dry strength of 3.7-3.92 cN / dtex, wet strength of 3.05-3.2 cN / dtex, good dimensional stability, boiling water shrinkage <3%; fiber surface resistivity of 2-8 Ω·cm.

[0034] 2. Casein includes α-S1 casein, α-S2 casein, β-casein, and κ-casein. Due to the intermolecular forces in the solution, α-S casein and β-casein aggregate to form a "core" structure, and the "core" is hydrophobic; while κ-casein aggregates on the surface of the "core", where the hydrophobic end of κ-casein faces the "core" and generates hydrophobic forces with α-S casein and β-casein, while the hydrophilic end forms a "shell" structure outward. Ultrasonic treatment is conducive to loosening the structure of casein and is conducive to the hydrophobic plant active ingredients to move closer to the hydrophobic interlayer area of ​​casein.

[0035] 3. Casein is basically amorphous and difficult to crystallize; polyacrylonitrile is only two-dimensionally ordered and it is difficult to generate three-dimensional ordered crystals. It is a quasi-crystalline structure. In the aggregated structure of acrylic fiber modified by casein alone, the crystalline region and the amorphous region coexist, and the crystalline region is largely composed of polyacrylonitrile. The structure is relatively unstable, so the dimensional stability is poor. κ-casein contains two hydrophobic groups, which react with hydrogen peroxide to form disulfide cross-links that stabilize on the surface, forming microspheres with dense surface coating of plant active ingredients. The spatial structure of the microcrystals is more stable, so the dimensional stability and mechanical properties are better.

[0036] 4. The plant active ingredients and casein of the milk protein modified acrylic fiber prepared by the present invention are not easily lost during the washing process. After washing 50 times, the loss rate of the plant active ingredients is 1.2-1.7%, and the loss rate of the casein is 1.1-1.4%. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] S1. Preparation of casein solution

[0040] Casein was added to a sodium hydroxide solution and ultrasonically treated at 45°C for 15 minutes to make the protein structure relatively loose, providing a basis for subsequent casein modification. After cooling to room temperature, PBS buffer was added to obtain a casein solution.

[0041] The concentration of the sodium hydroxide solution is 0.07 mol / L, the pH of the PBS buffer is 7.5, and the concentration is 0.1 mol / L; the volume ratio of the sodium hydroxide solution to the PBS buffer is 1:12; and the frequency of the ultrasonic treatment is 50 kHz.

[0042] The casein content in the casein solution is 8 wt %.

[0043] S2, casein-encapsulated plant active ingredients

[0044] Add hydrogen peroxide solution to the casein solution, then slowly add the alcohol solution of plant active ingredients, stir and react for 65 minutes, generate disulfide cross-linking on the casein surface to coat the plant active ingredients, then put it in the freezer for 7 hours, and then leave it at room temperature for 3 hours to obtain an emulsion, centrifuge and freeze-dry to obtain modified protein composite microspheres.

[0045] The content of the plant active ingredients in the alcohol solution of the plant active ingredients is 15wt%; the plant active ingredients are curcumin, veratric acid, menthol and eugenol in a mass ratio of 1:1:1:1.

[0046] The concentration of the hydrogen peroxide solution is 25 wt %, and the amount of the hydrogen peroxide solution added is 16 wt % of the casein solution.

[0047] The mass ratio of the casein solution to the alcohol solution of plant active ingredients is 3.4:1.

[0048] S3. Blending

[0049] The modified protein composite microspheres were added into the acrylic spinning solution and mixed, and the mixture was stirred at 60° C. for 50 min, and then filtered and degassed to obtain the composite spinning solution.

[0050] The added amount of the modified protein composite microspheres is 7wt% of the polyacrylonitrile content in the acrylic spinning solution.

[0051] The solvent in the acrylic spinning solution is dimethyl sulfoxide, and the solvent accounts for 80% of the mass of the acrylic spinning solution; the viscosity of the acrylic spinning solution at room temperature is 20 Pa·S, and the stirring rate is 700 r / min.

[0052] S6. Spinning

[0053] The composite spinning solution is metered by a metering pump and extruded through a spinneret into a coagulation bath. The filament bundles from the coagulation bath enter a preheating bath and are stretched to 2 times, and then enter a high-temperature washing tank at 85°C for water washing. After washing, the filament bundles are stretched 4 times for a second time, and then subjected to heat setting, a cross-linking bath, oiling, and cutting to obtain milk protein modified acrylic fibers.

[0054] The extrusion rate was 15 m / s and the extrusion temperature was 35°C.

[0055] The coagulation bath comprises the following components by weight: 8 parts of dimethyl sulfoxide, 2 parts of n-butanol, and 85 parts of water, and the temperature is 20°C.

[0056] The preheating bath comprises the following components, by mass: 7 parts of dimethyl sulfoxide, 1 part of n-butanol, and 13 parts of water, and the temperature is 60°C.

[0057] The secondary stretching temperature is 92°C.

[0058] The heat setting temperature is 102° C. and the time is 35 seconds.

[0059] The crosslinking agent in the crosslinking bath is glutaraldehyde, the content of the crosslinking agent in the crosslinking bath is 10wt%, the crosslinking time is 15min, and the temperature is 40°C.

[0060] The milk protein modified acrylic fiber prepared in Example 1 has excellent mechanical properties, a dry strength of 3.92 cN / dtex, a wet strength of 3.2 cN / dtex, good dimensional stability, and a boiling water shrinkage of 2%; the fiber surface resistivity is 5Ω·cm; after washing 50 times, the loss rate of plant active ingredients is 1.2%, and the loss rate of casein is 1.1%.

[0061] Example 2

[0062] S1. Preparation of casein solution

[0063] Casein was added to a sodium hydroxide solution and ultrasonically treated at 40°C for 20 minutes to make the protein structure relatively loose, providing a basis for subsequent casein modification. After cooling to room temperature, PBS buffer was added to obtain a casein solution.

[0064] The concentration of the sodium hydroxide solution is 0.05 mol / L, the pH of the PBS buffer is 7.2, and the concentration is 0.1 mol / L; the volume ratio of the sodium hydroxide solution to the PBS buffer is 1:10; and the frequency of the ultrasonic treatment is 25 kHz.

[0065] The casein content in the casein solution is 6 wt %.

[0066] S2, casein-encapsulated plant active ingredients

[0067] Add hydrogen peroxide solution to the casein solution, then slowly add the alcohol solution of plant active ingredients, stir and react for 60 minutes, generate disulfide cross-linking on the casein surface to coat the plant active ingredients, then put it in the freezer for 6 hours, and then leave it at room temperature for 2 hours to obtain an emulsion, centrifuge and freeze-dry to obtain modified protein composite microspheres.

[0068] The content of the plant active ingredients in the alcohol solution of the plant active ingredients is 10wt%; the plant active ingredients are curcumin, veratric acid, menthol and eugenol in a mass ratio of 1:1:1:1.

[0069] The concentration of the hydrogen peroxide solution is 20 wt %, and the amount of the hydrogen peroxide solution added is 10 wt % of the casein solution.

[0070] The mass ratio of the casein solution to the alcohol solution of plant active ingredients is 3:1.

[0071] S3. Blending

[0072] The modified protein composite microspheres were added into the acrylic spinning solution and mixed, and the composite spinning solution was obtained after stirring at 50° C. for 40 min and filtering and degassing.

[0073] The added amount of the modified protein composite microspheres is 6wt% of the polyacrylonitrile content in the acrylic spinning solution.

[0074] The solvent in the acrylic spinning solution is dimethyl sulfoxide, and the solvent accounts for 70% of the mass of the acrylic spinning solution; the viscosity of the acrylic spinning solution at room temperature is 10 Pa·S, and the stirring rate is 600 r / min.

[0075] S6. Spinning

[0076] The composite spinning solution is metered by a metering pump and extruded through a spinneret into a coagulation bath. The filament bundles from the coagulation bath enter a preheating bath and are stretched to 1 times, and then enter a high-temperature washing tank at 80°C for water washing. After washing, the filament bundles are stretched 5 times for a second time, and then subjected to heat setting, a cross-linking bath, oiling, and cutting to obtain milk protein modified acrylic fibers.

[0077] The extrusion rate is 10 m / s and the extrusion temperature is 30°C.

[0078] The coagulation bath comprises the following components by weight: 6 parts of dimethyl sulfoxide, 1 part of n-butanol, and 80 parts of water, and the temperature is 15°C.

[0079] The preheating bath comprises the following components, by mass: 5 parts of dimethyl sulfoxide, 0.5 parts of n-butanol, and 10 parts of water, and the temperature is 55°C.

[0080] The secondary stretching temperature is 90°C.

[0081] The heat setting temperature is 100° C. and the time is 30 seconds.

[0082] The crosslinking agent in the crosslinking bath is glyoxal, the content of the crosslinking agent in the crosslinking bath is 5wt%, the crosslinking time is 20min, and the temperature is 35°C.

[0083] The milk protein modified acrylic fiber prepared in Example 2 has excellent mechanical properties, a dry strength of 3.7 cN / dtex, a wet strength of 3.05 cN / dtex, good dimensional stability, and a boiling water shrinkage of 2.8%; the fiber surface resistivity is 8Ω·cm; after washing 50 times, the loss rate of plant active ingredients is 1.7%, and the loss rate of casein is 1.4%.

[0084] Example 3

[0085] S1. Preparation of casein solution

[0086] Casein was added to a sodium hydroxide solution and ultrasonically treated at 50°C for 20 minutes to make the protein structure relatively loose, providing a basis for subsequent casein modification. After cooling to room temperature, PBS buffer was added to obtain a casein solution.

[0087] The concentration of the sodium hydroxide solution is 0.1 mol / L, the pH of the PBS buffer is 7.5, and the concentration is 0.15 mol / L; the volume ratio of the sodium hydroxide solution to the PBS buffer is 1:15; and the frequency of the ultrasonic treatment is 75 kHz.

[0088] The casein content in the casein solution is 10 wt %.

[0089] S2, casein-encapsulated plant active ingredients

[0090] Add hydrogen peroxide solution to the casein solution, then slowly add the alcohol solution of plant active ingredients, stir and react for 70 minutes, generate disulfide cross-linking on the casein surface to coat the plant active ingredients, then put it in the freezer for 8 hours, and then leave it at room temperature for 3 hours to obtain an emulsion, centrifuge and freeze-dry to obtain modified protein composite microspheres.

[0091] The content of the plant active ingredients in the alcohol solution of the plant active ingredients is 20wt%; the plant active ingredients are curcumin, veratric acid, menthol and eugenol in a mass ratio of 1:1:1:1.

[0092] The concentration of the hydrogen peroxide solution is 30 wt %, and the amount of the hydrogen peroxide solution added is 18 wt % of the casein solution.

[0093] The mass ratio of the casein solution to the alcohol solution of plant active ingredients is 4:1.

[0094] S3. Blending

[0095] The modified protein composite microspheres were added into the acrylic spinning solution and mixed, and the mixture was stirred at 65° C. for 60 min, and then filtered and degassed to obtain the composite spinning solution.

[0096] The added amount of the modified protein composite microspheres is 8wt% of the polyacrylonitrile content in the acrylic spinning solution.

[0097] The solvent in the acrylic spinning solution is dimethyl sulfoxide, and the solvent accounts for 85% of the mass of the acrylic spinning solution; the viscosity of the acrylic spinning solution at room temperature is 30 Pa·S, and the stirring rate is 800 r / min.

[0098] S6. Spinning

[0099] The composite spinning solution is metered by a metering pump and extruded through a spinneret into a coagulation bath. The filament bundles from the coagulation bath enter a preheating bath and are stretched to 2.5 times, and then enter a high-temperature washing tank at 80-90°C for water washing. After washing, the filament bundles are stretched 2 times for a second time, and then subjected to heat setting, a cross-linking bath, oiling, and cutting to obtain milk protein modified acrylic fibers.

[0100] The extrusion rate is 20 m / s and the extrusion temperature is 40°C.

[0101] The coagulation bath comprises the following components by weight: 10 parts of dimethyl sulfoxide, 2 parts of n-butanol, and 90 parts of water, and the temperature is 30°C.

[0102] The preheating bath comprises the following components, by mass: 8 parts of dimethyl sulfoxide, 1 part of n-butanol, and 15 parts of water, and the temperature is 65°C.

[0103] The secondary stretching temperature is 95°C.

[0104] The heat setting temperature is 105° C. and the time is 40 seconds.

[0105] The crosslinking agent in the crosslinking bath is glutaraldehyde, the content of the crosslinking agent in the crosslinking bath is 15wt%, the crosslinking time is 5min, and the temperature is 40°C.

[0106] The milk protein modified acrylic fiber prepared in Example 3 has excellent mechanical properties, a dry strength of 3.83 cN / dtex, a wet strength of 3.12 cN / dtex, good dimensional stability, and a boiling water shrinkage of 2.5%; the fiber surface resistivity is 2Ω·cm; after washing 50 times, the loss rate of plant active ingredients is 1.6%, and the loss rate of casein is 1.2%.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that the ultrasonic treatment in S1 is removed, and the rest is consistent with Example 1, which is referred to as Comparative Example 1. The encapsulation efficiency of the modified protein composite microspheres prepared in Comparative Example 1 was measured to be 42%, and the fiber surface resistivity was 270Ω·cm, while the encapsulation efficiency of the modified protein composite microspheres prepared in Example 1 for plant active ingredients was 83%, indicating that the ultrasonic treatment made the protein structure relatively loose, which was conducive to more plant active ingredients to approach the hydrophobic interlayer structure of casein, thereby achieving the encapsulation of more plant active ingredients by the microspheres.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is that the modified protein composite microspheres are removed, and equal amounts of casein and plant active ingredients are directly made into a dispersion and added to the acrylic spinning solution for blending, and the rest is consistent with Example 1, as Comparative Example 2. The milk protein modified acrylic fiber prepared in Comparative Example 2 has excellent mechanical properties, dry strength of 3.1 cN / dtex, wet strength of 2.5 cN / dtex, good dimensional stability, boiling water shrinkage of 18%; fiber surface resistivity is 11Ω·cm; after 50 washings, the loss rate of plant active ingredients is 19%, and the loss rate of casein is 17.4%.

[0111] κ-casein contains two hydrophobic groups, which react with hydrogen peroxide to form disulfide bonds that are cross-linked and stabilized on the surface, forming microspheres with densely coated plant active ingredients. This changes the original amorphous structure of casein, making the spatial structure of the microcrystals more stable, and thus having better dimensional stability and mechanical properties.

[0112] At the same time, the use of κ-casein to cross-link and encapsulate plant active ingredients to form microspheres further improves the stability of casein and plant active ingredients, and reduces loss after multiple washings.

[0113] Unless otherwise specified, the ratios and percentages described in the present invention are all weight ratios and weight percentages; and the raw materials are all commercially available.

[0114] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A milk protein modified acrylic fiber, characterized in that: The milk protein modified acrylic fiber has a dry strength of 3.7-3.92 cN / dtex, a wet strength of 3.05-3.2 cN / dtex, and a boiling water shrinkage of <3%; The method for preparing the milk protein modified acrylic fiber comprises preparing a casein solution, coating the plant active ingredient with casein, blending and spinning; The casein solution is prepared by adding casein to a sodium hydroxide solution, ultrasonically treating the solution at 40-50° C. for 10-20 minutes, cooling the solution to room temperature, and then adding a PBS buffer solution to obtain a casein solution. The casein is coated with the plant active ingredient, a hydrogen peroxide solution is added to the casein solution, and then the alcohol solution of the plant active ingredient is slowly added, stirred for reaction for 60-70 minutes, then placed in a freezer for 6-8 hours, and then placed at room temperature for 2-3 hours to obtain an emulsion, and then centrifuged and freeze-dried to obtain modified protein composite microspheres; The content of the plant active ingredient in the alcohol solution of the plant active ingredient is 10-20wt%; the plant active ingredient is one or more of curcumin, veratric acid, menthol, and eugenol; The blending comprises adding the modified protein composite microspheres into the acrylic fiber spinning solution, stirring at 50-65° C. for 40-60 min, filtering, and degassing to obtain the composite spinning solution; The modified protein composite microspheres are added in an amount of 6-8wt% of the polyacrylonitrile content in the acrylic spinning solution; The spinning comprises: measuring the composite spinning solution by a metering pump, extruding the composite spinning solution through a spinneret into a coagulation bath, and the filament bundle after exiting the coagulation bath enters a preheating bath for primary stretching to 1-2.5 times, and enters a high-temperature water washing tank at 80-90° C. for water washing, and the filament bundle after water washing is secondary stretched 2-5 times, and then heat-set, cross-linked, oiled, and cut to obtain milk protein modified acrylic fiber; The coagulation bath comprises the following components, by weight: 6-10 parts of dimethyl sulfoxide, 1-2 parts of n-butanol, 80-90 parts of water, and the temperature is 15-30°C; The preheating bath comprises the following components by weight: 5-8 parts of dimethyl sulfoxide, 0.5-1 parts of n-butanol, 10-15 parts of water, and the temperature is 55-65°C; the temperature of the secondary stretching is 90-95°C; The heat setting temperature is 100-105°C and the time is 30-40s; The crosslinking agent in the crosslinking bath is one or more of glyoxal, glutaraldehyde, ethylenediamine, and epichlorohydrin. The content of the crosslinking agent in the crosslinking bath is 5-15wt%, the crosslinking time is 5-20min, and the temperature is 35-40°C.

2. The milk protein modified acrylic fiber according to claim 1, characterized in that: The concentration of the sodium hydroxide solution is 0.05-0.1 mol / L, the pH of the PBS buffer solution is 7.2-7.5, and the concentration is 0.1-0.15 mol / L; the volume ratio of the sodium hydroxide solution to the PBS buffer solution is 1:10-15; and the frequency of the ultrasonic treatment is 25-75 kHz.

3. The milk protein modified acrylic fiber according to claim 1, characterized in that: The casein content in the casein solution is 6-10wt%.

4. The milk protein modified acrylic fiber according to claim 1, characterized in that: The concentration of the hydrogen peroxide solution is 20-30wt%, and the amount of the hydrogen peroxide solution added is 10-18wt% of the casein solution; The mass ratio of the casein solution to the alcohol solution of plant active ingredients is 3-4:1.