Preparation method of procyanidine anti-oxidation polyamide filament

Abstract

The invention belongs to the technical field of synthetic fibers, and particularly relates to a preparation method of a procyanidine anti-oxidation polyamide filament, which comprises the steps of preparation of organic-inorganic hybrid silicon dioxide aerogel, adsorption, preparation of procyanidine functional particles and melt spinning. According to the preparation method, the silicon dioxide aerogel is subjected to hybrid modification, a vinyl ether structure in 2-chloroethyl vinyl ether and silicon hydroxyl are subjected to electrophilic addition to form Si-O-C bonds, the Si-O-C bonds and a Si-O-Si network jointly form a semi-interpenetrating network structure, and the organic-inorganic hybrid silicon dioxide aerogel which is good in mechanical property, compact in structure and good in dispersity is obtained. And the procyanidine is subjected to adsorption protection, so that the high-temperature loss of the procyanidine in the chinlon preparation process is reduced. The procyanidine antioxidant polyamide filament prepared by the method has excellent antibacterial and antioxidant properties, the antibacterial rates on staphylococcus aureus, escherichia coli and candida albicans are all greater than 95% after the procyanidine antioxidant polyamide filament is washed with water for 50 times, and the free radical scavenging rate is greater than 92%.

Description

Technical Field

[0001] This invention belongs to the field of synthetic fiber technology, specifically, it is a method for preparing proanthocyanidin antioxidant nylon filament. Background Technology

[0002] Nylon (polyamide fiber) is widely used in textiles, medical textiles, and industrial textiles due to its high strength, high abrasion resistance, chemical corrosion resistance, and good resilience. However, the nylon molecular chain contains a large number of methylene (-CH2-) and amide bonds (-CONH-), which are prone to free radical chain reactions under light, high temperature, and oxidizing environments, leading to fiber aging (such as decreased strength, yellowing, and embrittlement), thus limiting its application in high-end functional textiles.

[0003] Proanthocyanidins are natural polyphenolic compounds widely found in plants such as grape seeds, pine bark, and black goji berries. They possess natural antioxidant, anti-inflammatory, and antibacterial biological activities. However, proanthocyanidins are easily oxidized and decomposed under high-temperature conditions. When directly added to nylon spinning melt, they will become ineffective due to thermal degradation during spinning. In addition, unmodified proanthocyanidins have weak interfacial bonding with the nylon matrix, making them prone to migration and loss, thus making it difficult to achieve long-lasting antioxidant and antibacterial effects.

[0004] Based on this, a method for preparing proanthocyanidin antioxidant nylon filament is proposed. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for preparing proanthocyanidin-based antioxidant nylon filaments, achieving the following objectives: 1. Improve the antioxidant properties and moisture absorption of nylon filament; 2. Reduce the high-temperature loss of proanthocyanidins during nylon preparation and improve the interfacial compatibility between proanthocyanidins and fibers.

[0006] A method for preparing proanthocyanidin antioxidant nylon filament includes the following steps: S1. Preparation of organic-inorganic hybrid silica aerogels A silicon source, deionized water, and anhydrous ethanol were mixed and stirred for 15–20 min. Then, hydrochloric acid solution was added to adjust the pH to 3–4, and hydrolysis was performed to form a sol. 2-chloroethyl vinyl ether was then added, and the mixture was heated to 50–55 °C and stirred for 60–80 min. After cooling, N,N-dimethylformamide was added and stirred for 10–15 min. Then, ammonia water was added to adjust the pH to 5.5–7 to catalyze the polycondensation reaction. Stirring was continued for 10–15 min, and the mixture was allowed to stand until gelation. After aging, solvent replacement, and supercritical CO2 drying, an organic-inorganic hybrid silica aerogel was obtained.

[0007] Preferably, the silicon source is one or more of tetraethyl orthosilicate, methyltrimethoxysilane, and methyl orthosilicate.

[0008] Preferably, the molar ratio of the silicon source, deionized water and anhydrous ethanol is 1:4 to 7:8 to 12.

[0009] Preferably, the concentration of the hydrochloric acid solution is 0.5 to 1 mol / L.

[0010] Preferably, the molar ratio of the 2-chloroethyl vinyl ether to the silicon source is 1:5 to 8; the N,N-dimethylformamide is a pore regulator, and its molar ratio to the silicon source is 0.05 to 0.1:1.

[0011] Preferably, the mass fraction of the ammonia water is 1-3%.

[0012] Preferably, the aging temperature is 30-40°C and the time is 6-10 hours.

[0013] Preferably, the aging temperature is 40-50°C and the time is 12-24 hours.

[0014] Preferably, the solvent replacement uses anhydrous ethanol, with an amount of 5 to 7 times the gel volume, and the solvent is replaced every 24 hours for a total of two replacements.

[0015] The silicon source hydrolyzes under acidic conditions to form silanol groups. Upon addition of 2-chloroethyl vinyl ether and heating, the vinyl groups in the 2-chloroethyl vinyl ether are protonated under acidic conditions, undergoing electrophilic addition with the silanol groups to form Si-OC bonds. This process introduces ether bonds and carbon chains into the silica sol network in a grafting manner, forming a semi-interpenetrating network structure together with the Si-O-Si network. This improves the material's mechanical properties and dispersibility, reduces brittleness, and also enhances the strength and stability of the aerogel's internal structure. Subsequently, ammonia is used to adjust the pH to promote the self-condensation of silanol groups, ultimately forming an organic-inorganic hybrid silica aerogel with a pore size range of 7–12 nm, a porosity of 90–92%, and a specific surface area of ​​614–657 m². 2 / g, density is 0.128~0.139g / cm³ 3 .

[0016] S2, adsorption Proanthocyanidins are dissolved in deionized water to obtain a proanthocyanidin solution. Then, organic-inorganic hybrid silica aerogel is added to the proanthocyanidin solution and stirred for 10-15 minutes. After standing and soaking for 50-60 minutes, the organic-inorganic hybrid silica aerogel fully adsorbs the proanthocyanidins. After adsorption, the proanthocyanidins are vacuum dried and pulverized to 1-3 μm to prepare a proanthocyanidin functional preparation.

[0017] Preferably, the mass fraction of the proanthocyanidin solution is 10-14%; the amount of the organic-inorganic hybrid silica aerogel added is 30-40% of the volume of the proanthocyanidin solution.

[0018] Preferably, the vacuum drying temperature is 60-70°C and the time is 5-6 hours.

[0019] S3. Preparation of proanthocyanidin functional particles PA6 chips are pulverized to 100-200 mesh, then mixed with proanthocyanidin functional agents and melt-extruded, granulated and dried using a twin-screw extruder to produce proanthocyanidin functional granules.

[0020] Preferably, the mass ratio of the PA6 slices to the proanthocyanidin functional preparation is 93-96:4-7.

[0021] Preferably, the twin-screw extruder has an extrusion temperature range of 230–250°C and a rotation speed of 100–200 r / min.

[0022] During the preparation of the proanthocyanidin functional formulation, the organic-inorganic hybrid silica aerogel was incorporating chloroethyl groups on its surface. During granulation, the terminal amino groups of PA6 chips and the chloroethyl groups on the surface of the organic-inorganic hybrid silica aerogel underwent nucleophilic substitution, thereby grafting and crosslinking the proanthocyanidin functional formulation with the PA6 chips, further enhancing their binding force.

[0023] S4, melt spinning Proanthocyanidin functional particles were blended with PA6 chips, then melt-spun and cooled to form filaments, thus obtaining proanthocyanidin antioxidant nylon filaments.

[0024] Preferably, the mass ratio of the proanthocyanidin functional particles to the PA6 slices is 8-11:89-92.

[0025] Preferably, the parameters for melt spinning are: screw temperature of 230-260°C, spinning box temperature of 250-270°C, and side blowing temperature of 20-25°C.

[0026] By adopting the above technical solution, the technical effect achieved by this invention is as follows: 1. The proanthocyanidin-based antioxidant nylon filament prepared by this invention exhibits excellent mechanical properties, with a breaking strength of 5.26–5.48 cN / dtex. It also possesses excellent antibacterial and antioxidant properties. After 50 washes, it shows an inhibition rate of over 97% against Staphylococcus aureus, over 95% against Escherichia coli, and over 95% against Candida albicans (determined according to GB / T20944.3-2008, Evaluation of Antibacterial Properties of Textiles Part 3: Vibration Method); and a free radical scavenging rate of over 92% (determined according to T / CCTA 20102-2023 ABTS method).

[0027] 2. The proanthocyanidin antioxidant nylon filament prepared by the present invention has a low density, ranging from 0.53 to 0.61 g / cm³, and is lightweight while having good moisture absorption, with a moisture regain of 6.6 to 7.8%, thus improving the defects of nylon fiber, such as being heavy and having poor moisture absorption.

[0028] 3. This invention utilizes aerogel to adsorb and protect proanthocyanidins, avoiding significant loss of proanthocyanidins due to high temperatures during nylon filament preparation. However, conventional silica aerogels have poor dispersibility, are brittle, and have poor interfacial compatibility with nylon, easily affecting the mechanical properties and washability durability of nylon filaments. Therefore, the silica aerogel is hybridized by utilizing the vinyl ether structure in 2-chloroethyl vinyl ether to form Si-OC bonds through electrophilic addition with silanol groups, increasing the network structure of the aerogel. This results in an organic-inorganic hybrid silica aerogel with good mechanical properties, a compact structure, and good dispersibility. The compressive strength is 7.73–8.04 MPa, the flexural strength is 1.5–1.63 MPa, and the elastic modulus is 12.26–13.41 MPa. In contrast, the compressive strength of conventional silica aerogel is less than 1 / 10 of that of the organic-inorganic hybrid silica aerogel, and its flexural strength is close to 0, indicating significantly inferior performance. Organic-inorganic hybrid silica aerogel has good mechanical properties and high temperature resistance. Furthermore, it has stronger binding force when grafted and crosslinked with PA6 slices, resulting in less loss of proanthocyanidins and strong functional durability after washing. Detailed Implementation

[0029] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0030] Example 1: A method for preparing proanthocyanidin antioxidant nylon filament, comprising the following steps: S1. Preparation of organic-inorganic hybrid silica aerogels Tetraethyl orthosilicate, deionized water, and anhydrous ethanol were mixed and stirred for 20 min. Then, hydrochloric acid solution was added to adjust the pH to 3.5, and hydrolysis was carried out to form a sol. 2-chloroethyl vinyl ether was then added, and the mixture was heated to 52°C and stirred for 70 min. After cooling, N,N-dimethylformamide was added and stirred for 15 min. Then, ammonia water was added to adjust the pH to 6.5 to catalyze the polycondensation reaction. After stirring for another 15 min, the mixture was allowed to stand and wait for gelation. After aging, solvent replacement, and supercritical CO2 drying, organic-inorganic hybrid silica aerogel was obtained.

[0031] The molar ratio of tetraethyl orthosilicate, deionized water, and anhydrous ethanol is 1:5:10.

[0032] The concentration of the hydrochloric acid solution is 0.75 mol / L.

[0033] The molar ratio of the 2-chloroethyl vinyl ether to the silicon source is 1:6; the N,N-dimethylformamide is a pore regulator with a molar ratio of 0.07:1 to the silicon source.

[0034] The ammonia solution has a mass fraction of 2%.

[0035] The aging process was carried out at a temperature of 35°C for 8 hours.

[0036] The aging temperature was 45℃ and the time was 20 hours.

[0037] The solvent replacement was performed using anhydrous ethanol, at a volume of 6 times the gel volume. The solvent was replaced every 24 hours, for a total of two replacements.

[0038] The organic-inorganic hybrid silica aerogel has an average pore size of 7 nm, a porosity of 92%, and a specific surface area of ​​657 m². 2 / g, density is 0.128g / cm³ 3 .

[0039] S2, adsorption Proanthocyanidins were dissolved in deionized water to obtain a proanthocyanidin solution. Then, organic-inorganic hybrid silica aerogel was added to the proanthocyanidin solution and stirred for 15 minutes. After standing and soaking for 60 minutes, the organic-inorganic hybrid silica aerogel was allowed to fully adsorb the proanthocyanidins. After adsorption, the proanthocyanidins were vacuum dried and pulverized to 1 μm to prepare a proanthocyanidin functional preparation.

[0040] The proanthocyanidin solution has a mass fraction of 12%; the amount of organic-inorganic hybrid silica aerogel added is 35% of the volume of the proanthocyanidin solution.

[0041] The vacuum drying temperature is 65°C and the time is 6 hours.

[0042] S3. Preparation of proanthocyanidin functional particles PA6 chips were pulverized to 150 mesh, then mixed with proanthocyanidin functional agents. The mixture was then melt-extruded, granulated, and dried using a twin-screw extruder to produce proanthocyanidin functional granules.

[0043] The mass ratio of the PA6 slices to the proanthocyanidin functional preparation is 95:5.

[0044] The temperatures of zones 1 to 5 of the twin-screw extruder are 240℃, 245℃, 250℃, 240℃, and 230℃, respectively, and the rotation speed is 150 r / min.

[0045] S4, melt spinning Proanthocyanidin functional particles were blended with PA6 chips, then melt-spun and cooled to form filaments, thus obtaining proanthocyanidin antioxidant nylon filaments.

[0046] The mass ratio of the proanthocyanidin functional particles to the PA6 slices is 9:91.

[0047] The parameters for melt spinning are: screw temperature 240℃, spinning box temperature 260℃, and side blowing temperature 22℃.

[0048] Example 2: A method for preparing proanthocyanidin antioxidant nylon filament, comprising the following steps: S1. Preparation of organic-inorganic hybrid silica aerogels Tetraethyl orthosilicate, deionized water, and anhydrous ethanol were mixed and stirred for 15 min. Hydrochloric acid solution was then added to adjust the pH to 3, and hydrolysis was performed to form a sol. 2-chloroethyl vinyl ether was then added, and the mixture was heated to 50°C and stirred for 60 min. After cooling, N,N-dimethylformamide was added and stirred for 10 min. Ammonia water was then added to adjust the pH to 5.5 to catalyze the polycondensation reaction. Stirring was continued for another 10 min, and the mixture was allowed to stand until gelation. After aging, solvent replacement, and supercritical CO2 drying, an organic-inorganic hybrid silica aerogel was obtained.

[0049] The molar ratio of tetraethyl orthosilicate, deionized water, and anhydrous ethanol is 1:4:8.

[0050] The concentration of the hydrochloric acid solution is 0.5 mol / L.

[0051] The molar ratio of 2-chloroethyl vinyl ether to the silicon source is 1:5; the N,N-dimethylformamide is a pore regulator with a molar ratio of 0.05:1 to the silicon source.

[0052] The ammonia solution has a mass fraction of 1%.

[0053] The aging temperature was 30°C and the time was 10 hours.

[0054] The aging temperature was 40°C and the time was 24 hours.

[0055] The solvent replacement was performed using anhydrous ethanol, at a volume of 5 times the gel volume. The solvent was replaced every 24 hours, for a total of two replacements.

[0056] The organic-inorganic hybrid silica aerogel has an average pore size of 12 nm, a porosity of 90%, and a specific surface area of ​​614 m². 2 / g, density is 0.139g / cm³ 3 .

[0057] S2, adsorption Proanthocyanidins were dissolved in deionized water to obtain a proanthocyanidin solution. Then, organic-inorganic hybrid silica aerogel was added to the proanthocyanidin solution and stirred for 10 minutes. After standing and soaking for 50 minutes, the organic-inorganic hybrid silica aerogel was allowed to fully adsorb the proanthocyanidins. After adsorption, the proanthocyanidins were vacuum dried and pulverized to 3 μm to prepare a proanthocyanidin functional preparation.

[0058] The proanthocyanidin solution has a mass fraction of 10%; the organic-inorganic hybrid silica aerogel is added at 30% of the volume of the proanthocyanidin solution.

[0059] The vacuum drying temperature is 60°C and the time is 6 hours.

[0060] S3. Preparation of proanthocyanidin functional particles PA6 chips were pulverized to 200 mesh, then mixed with proanthocyanidin functional agents. The mixture was then melt-extruded, granulated, and dried using a twin-screw extruder to produce proanthocyanidin functional granules.

[0061] The mass ratio of the PA6 slices to the proanthocyanidin functional preparation is 96:4.

[0062] The temperatures in zones 1 to 5 of the twin-screw extruder are 240℃, 245℃, 250℃, 240℃, and 230℃, respectively, and the rotation speed is 100 r / min.

[0063] S4, melt spinning Proanthocyanidin functional particles were blended with PA6 chips, then melt-spun and cooled to form filaments, thus obtaining proanthocyanidin antioxidant nylon filaments.

[0064] The mass ratio of the proanthocyanidin functional particles to the PA6 slices was 8:92.

[0065] The parameters for melt spinning are: screw temperature 230℃, spinning box temperature 250℃, and side blowing temperature 20℃.

[0066] Example 3: A method for preparing proanthocyanidin antioxidant nylon filament, comprising the following steps: S1. Preparation of organic-inorganic hybrid silica aerogels Tetraethyl orthosilicate, deionized water, and anhydrous ethanol were mixed and stirred for 20 min. Hydrochloric acid solution was then added to adjust the pH to 4, and hydrolysis was performed to form a sol. 2-chloroethyl vinyl ether was then added, and the mixture was heated to 55°C and stirred for 80 min. After cooling, N,N-dimethylformamide was added and stirred for 15 min. Ammonia water was then added to adjust the pH to 7 to catalyze the polycondensation reaction. Stirring was continued for another 15 min, and the mixture was allowed to stand until gelation. After aging, solvent replacement, and supercritical CO2 drying, an organic-inorganic hybrid silica aerogel was obtained.

[0067] The molar ratio of tetraethyl orthosilicate, deionized water, and anhydrous ethanol is 1:7:12.

[0068] The concentration of the hydrochloric acid solution is 1 mol / L.

[0069] The molar ratio of 2-chloroethyl vinyl ether to the silicon source is 1:5; the N,N-dimethylformamide is a pore regulator with a molar ratio of 0.1:1 to the silicon source.

[0070] The ammonia solution has a mass fraction of 3%.

[0071] The aging process was carried out at a temperature of 40°C for 6 hours.

[0072] The aging temperature was 50°C and the time was 12 hours.

[0073] The solvent replacement was performed using anhydrous ethanol, at a volume of 7 times the gel volume. The solvent was replaced every 24 hours, for a total of two replacements.

[0074] The organic-inorganic hybrid silica aerogel has an average pore size of 10 nm, a porosity of 91%, and a specific surface area of ​​633 m². 2 / g, density is 0.132g / cm³ 3 .

[0075] S2, adsorption Proanthocyanidins were dissolved in deionized water to obtain a proanthocyanidin solution. Then, an organic-inorganic hybrid silica aerogel was added to the proanthocyanidin solution and stirred for 15 minutes. After standing and soaking for 55 minutes, the organic-inorganic hybrid silica aerogel was allowed to fully adsorb the proanthocyanidins. After adsorption, the proanthocyanidins were vacuum dried and pulverized to 2 μm to prepare a proanthocyanidin functional preparation.

[0076] The proanthocyanidin solution has a mass fraction of 14%; the organic-inorganic hybrid silica aerogel is added at 40% of the volume of the proanthocyanidin solution.

[0077] The vacuum drying temperature is 70℃ and the time is 5 hours.

[0078] S3. Preparation of proanthocyanidin functional particles PA6 chips were pulverized to 200 mesh, then mixed with proanthocyanidin functional agents. The mixture was then melt-extruded, granulated, and dried using a twin-screw extruder to produce proanthocyanidin functional granules.

[0079] The mass ratio of the PA6 slices to the proanthocyanidin functional preparation is 93:7.

[0080] The temperatures of zones 1 to 5 of the twin-screw extruder are 240℃, 245℃, 250℃, 240℃, and 230℃, respectively, and the rotation speed is 200 r / min.

[0081] S4, melt spinning Proanthocyanidin functional particles were blended with PA6 chips, then melt-spun and cooled to form filaments, thus obtaining proanthocyanidin antioxidant nylon filaments.

[0082] The mass ratio of the proanthocyanidin functional particles to the PA6 slices was 11:89.

[0083] The parameters for melt spinning are: screw temperature 260℃, spinning box temperature 270℃, and side blowing temperature 25℃.

[0084] Comparative Example 1: A representative example, Example 1, was selected. 2-chloroethyl vinyl ether in S1 was removed. After hydrolysis to form a sol, N,N-dimethylformamide was added directly. All other steps were the same as in Example 1. The resulting aerogel was a conventional silica aerogel, which served as Comparative Example 1.

[0085] Comparative Example 2: A representative example, Example 1, was selected. The 2-chloroethyl vinyl ether in S1 was replaced with ethyl vinyl ether, and the rest was the same as in Example 1. The resulting aerogel was a conventional silica aerogel, which was used as Comparative Example 1.

[0086] Comparative Example 3: The representative Example 1 was selected, the organic-inorganic hybrid silica aerogel was removed, and proanthocyanidins were directly added to PA6 slices for co-granulation. All other aspects were the same as in Example 1, and this was used as Comparative Example 3.

[0087] The aerogels and nylon filaments prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, as detailed in Tables 1 and 2.

[0088] Table 1 Table 2 Note: High-temperature loss rate refers to the total loss of proanthocyanidin active ingredients during granulation and melt spinning; water washing loss rate refers to the loss rate of proanthocyanidins after 50 water washes of nylon filament.

[0089] As can be seen from Table 1, the nylon fibers prepared using Examples 1-3 have excellent antibacterial and antioxidant effects, and their functionality is long-lasting and washable.

[0090] As shown in Table 2, the nylon filaments prepared in Comparative Example 1 not only exhibited a significant decrease in strength but also a greatly reduced protective effect against proanthocyanidins. This is because the addition of 2-chloroethyl vinyl ether in Example 1 increased the overall cross-linking structure of the aerogel, resulting in a denser and more stable internal structure, thus providing better high-temperature protection for proanthocyanidins. The aerogel's brittleness was also improved, leading to better washability of the fibers. After multiple washes, the aerogel was less prone to breakage, thus reducing loss. Furthermore, compared to the unhybridized silica aerogel in Comparative Example 1, the organic-inorganic hybrid silica aerogel of Example 1 exhibited better dispersibility and was less prone to agglomeration, demonstrating better interfacial compatibility with the nylon matrix. Therefore, the performance of Example 1 was significantly superior to that of Comparative Example 1.

[0091] In Comparative Example 2, replacing 2-chloroethyl vinyl ether with ethyl vinyl ether resulted in a significant decrease in fiber strength and water wash loss. This is because, compared to Comparative Example 2, the organic-inorganic hybrid silica aerogel prepared in Example 1 exhibits multiple chloroethyl groups on its surface, which undergo nucleophilic substitution reaction with the amino group of PA6, thereby grafting and crosslinking. This enhances the bonding force between the organic-inorganic hybrid silica aerogel and the fiber, achieving the goal of reducing water wash loss and further improving fiber strength.

[0092] Comparative Example 3 shows that proanthocyanidins have poor high-temperature resistance, resulting in extremely high high-temperature loss rate; furthermore, their poor dispersibility in nylon and poor compatibility with the matrix lead to a decrease in fiber strength.

[0093] Unless otherwise specified, all proportions and percentages mentioned in this invention are mass proportions and mass percentages; all raw materials are commercially available.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing proanthocyanidin-based antioxidant nylon filament, characterized in that, The preparation method includes the preparation, adsorption, preparation of proanthocyanidin functional particles, and melt spinning of organic-inorganic hybrid silica aerogel; The organic-inorganic hybrid silica aerogel is prepared by mixing a silicon source, deionized water, and anhydrous ethanol, then adding hydrochloric acid solution to adjust the pH to acidic hydrolysis to form a sol, then adding 2-chloroethyl vinyl ether, heating and stirring, cooling, adding N,N-dimethylformamide, stirring, and adding ammonia water to adjust the pH to alkaline catalytic polycondensation reaction, continuing stirring and standing to wait for gelation, and obtaining the organic-inorganic hybrid silica aerogel after aging, solvent replacement, and supercritical CO2 drying.

2. The method for preparing proanthocyanidin antioxidant nylon filament according to claim 1, characterized in that, The preparation of the organic-inorganic hybrid silica aerogel is specifically as follows: a silicon source, deionized water, and anhydrous ethanol are mixed and stirred for 15-20 min. Then, hydrochloric acid solution is added to adjust the pH to 3-4, and hydrolysis is performed to form a sol. 2-chloroethyl vinyl ether is then added, and the mixture is heated to 50-55℃ and stirred for 60-80 min. After cooling, N,N-dimethylformamide is added and stirred for 10-15 min. Then, ammonia water is added to adjust the pH to 5.5-7 to catalyze the condensation reaction. Stirring is continued for 10-15 min, and the mixture is allowed to stand until gelation occurs. After aging, solvent replacement, and supercritical CO2 drying, the organic-inorganic hybrid silica aerogel is obtained.

3. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 2, characterized in that, The silicon source is one or more of tetraethyl orthosilicate, methyltrimethoxysilane, and methyl orthosilicate; The molar ratio of the silicon source, deionized water, and anhydrous ethanol is 1:4 to 7:8 to 12.

4. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 2, characterized in that, The molar ratio of the 2-chloroethyl vinyl ether to the silicon source is 1:5 to 8; the N,N-dimethylformamide is a pore regulator, and its molar ratio to the silicon source is 0.05 to 0.1:

1.

5. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 2, characterized in that, The concentration of the hydrochloric acid solution is 0.5–1 mol / L; The mass fraction of the ammonia solution is 1-3%; The aging temperature is 30–40°C, and the time is 6–10 hours; The aging temperature is 40–50°C, and the time is 12–24 hours; The solvent replacement uses anhydrous ethanol, with an amount of 5 to 7 times the gel volume. The solvent is replaced every 24 hours, for a total of two replacements.

6. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 1, characterized in that, The adsorption process involves dissolving proanthocyanidins in deionized water to obtain a proanthocyanidin solution, then adding an organic-inorganic hybrid silica aerogel to the proanthocyanidin solution and stirring for 10-15 minutes, followed by standing and soaking for 50-60 minutes. After adsorption is complete, the solution is vacuum dried and pulverized to 1-3 μm to prepare a proanthocyanidin functional preparation.

7. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 6, characterized in that, The proanthocyanidin solution has a mass fraction of 10-14%; the organic-inorganic hybrid silica aerogel is added at 30-40% of the volume of the proanthocyanidin solution. The vacuum drying temperature is 60–70°C, and the time is 5–6 hours.

8. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 1, characterized in that, The preparation of proanthocyanidin functional particles involves pulverizing PA6 slices to 100-200 mesh, adding proanthocyanidin functional agents and mixing them evenly, then melting and extruding them through a twin-screw extruder, granulating them, and drying them to produce proanthocyanidin functional particles. The mass ratio of the PA6 slices to the proanthocyanidin functional preparation is 93-96:4-7; The extrusion temperature range of the twin-screw extruder is 230–250℃, and the rotation speed is 100–200 r / min.

9. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 1, characterized in that, The melt spinning process involves blending proanthocyanidin functional particles with PA6 chips, then melt spinning and cooling them into filaments to obtain proanthocyanidin antioxidant nylon filaments.

10. The method for preparing a proanthocyanidin antioxidant nylon filament according to claim 9, characterized in that, The mass ratio of the proanthocyanidin functional particles to PA6 slices is 8-11:89-92; The parameters for melt spinning are: screw temperature 230-260℃, spinning box temperature 250-270℃, and side blowing temperature 20-25℃.

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