Aerogel-based polyester fiber and preparation method thereof

Abstract

The invention discloses an aerogel-based polyester fiber and a preparation method thereof, and relates to the technical field of fiber materials, the aerogel-based polyester fiber comprises the following raw materials by weight: 900-1200 parts of polyester chips, 80-160 parts of functional master batch, 3-8 parts of a hydrophobing agent, 2-6 parts of a heat stabilizer, 1-5 parts of an antioxidant, and 0.5-3 parts of an antistatic synergist; the preparation is performed based on the raw materials. According to the aerogel-based polyester fiber and the preparation method thereof, the functional master batch is introduced into a polyester system, and the functional master batch contains the polyester carrier and the modified silicon dioxide aerogel, so that the problems of poor dispersity and weak interface bonding force when the aerogel is directly added are solved, and the fiber can be used for preparing the aerogel-based polyester fiber while maintaining the mechanical properties of conventional polyester. The multifunctional effects of keeping warm, insulating heat, being light, hydrophobic, antistatic and the like are achieved, so that the application range of the polyester fiber in the fields of clothing, outdoor and functional materials is expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber materials, in particular to a kind of polyester fiber based on aerogel and preparation method thereof. BACKGROUND

[0002] Polyester fiber has been widely used in clothing, home textile and industrial material fields due to its excellent mechanical properties, low cost and good processability. However, conventional polyester fiber has certain limitations. On the one hand, the dense molecular chain structure of polyester results in high thermal conductivity, which leads to poor performance in warmth retention and thermal insulation, making it difficult to meet the needs of winter clothing or high-performance protective materials. On the other hand, the low surface energy of polyester fiber makes it difficult to achieve stable interfacial bonding with functional inorganic fillers, resulting in uneven dispersion of fillers and easy aggregation, which affects the spinnability and performance of the fiber. In addition, the introduction of functional components by traditional methods often leads to a decrease in fiber strength or instability in the spinning process, making it difficult to balance lightness, hydrophobicity and antistatic properties. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a polyester fiber based on aerogel and a preparation method thereof to solve the problems raised in the background art.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The present application provides a polyester fiber based on aerogel, comprising the following raw materials by weight: Polyester chips, 900-1200 parts; Functional masterbatch, 80-160 parts; Hydrophobic agent, 3-8 parts; Thermal stabilizer, 2-6 parts; Antioxidant, 1-5 parts; Antistatic synergist, 0.5-3 parts.

[0005] Further optimization of the present technical solution, the functional masterbatch specifically comprises the following raw materials by weight: Polyester carrier resin, 50-120 parts; Modified silica aerogel, 10-35 parts; Dispersion aid, 1-5 parts.

[0006] Further optimization of the present technical solution, the functional masterbatch is specifically prepared by the following steps: A1, in-situ preparation of polyaniline modified aerogel; A2, surface secondary modification reaction to obtain multifunctional silica aerogel; A3, melt blending and granulation of masterbatch to obtain functional masterbatch.

[0007] Further optimize the technical solution, the step A1, the preparation process of polyaniline modified aerogel includes: The silica is prepared into aerogel with three-dimensional network structure by sol-gel method, which is uniformly dispersed in deionized water, the solid content is controlled at 1.0-2.0wt%, and ultrasonic dispersion is used for 3-5 minutes to make it fully dispersed; Then aniline monomer is added to the system, and a dopant is added to keep the pH value of the reaction system in the range of 1.5-2.0; The catalyst is added dropwise to the system, and the reaction is carried out at 10-35℃ for 3-4 hours. In this process, aniline is in-situ polymerized on the pore wall and surface of the silica aerogel to form a polyaniline doped layer, and a polyaniline modified aerogel is formed; After the reaction is completed, it is separated by suction filtration and washed with deionized water until it is neutral, and then dried at 40-60℃ in a vacuum environment for 12-24 hours to obtain polyaniline modified aerogel powder.

[0008] Further optimize the technical solution, the dopant is phosphoric acid; and the oxidation catalyst is ammonium persulfate or sodium periodate.

[0009] Further optimize the technical solution, the preparation process of multifunctional silica aerogel in step A2 includes: The polyaniline modified aerogel powder obtained in step A1 is dispersed in an organic solvent, and the dispersion concentration is controlled at 1.0-1.5wt%; Under the conditions of nitrogen protection and stirring, phosphorus oxychloride, p-hydroxyphenethyl alcohol and methanol are added to the system, and the whole reaction is carried out at 10-35℃ for 3-4 hours; After the reaction is completed, it is separated by suction filtration, washed with anhydrous methanol and solvent in sequence, and then dried at 40-60℃ in a vacuum environment to obtain multifunctional silica aerogel with polyaniline doped layer and phosphate esterified arylethyl layer on the surface.

[0010] Further optimize the technical solution, the organic solvent is selected from one or more of trichloromethane, dichloromethane or tetrahydrofuran; and the molar ratio of phosphorus oxychloride, p-hydroxyphenethyl alcohol and methanol is 3-3.5:1:2-2.2:0.5-1.

[0011] Further optimize the technical solution, in step A3, the melt blending and granulation of the master batch, the specific preparation process includes: The multifunctional silica aerogel obtained in step A2 and the polyester carrier resin are dried respectively at a temperature of 120℃ for 4-6 hours to control the moisture content below 200ppm, and then premixed, and a dispersing aid is added to improve the melt flowability; The mixture is sent into a double screw extruder for melt blending, the material is drawn after water cooling and then is cut into particles to obtain functional master batch with particle size of 2-3mm.

[0012] Further optimization of the technical solution, the barrel temperature is set to 240-280 DEG C in turn, the screw rotation speed is controlled at 150-300 rpm; supplementary feeding of aerogel powder at the middle section side feeding port ensures uniform dispersion, a vacuum exhaust port is arranged at the rear section, the vacuum degree is less than or equal to-0.08 MPa, for removing residual solvent and low molecular byproducts.

[0013] A preparation method of polyester fiber based on aerogel, which is prepared based on the polyester fiber described above, and comprises the following specific steps: S1, raw material pretreatment and mixing, polyester chips, functional master batch and hydrophobic agent, thermal stabilizer, antioxidant, antistatic synergist are mixed in proportion, and a mixture is formed; S2, melt spinning and forming, the mixture is melted at 260-285 DEG C, filtered and metered, then extruded from the spinneret hole, rapidly cooled and solidified to form filaments, the functional master batch is uniformly embedded in the polyester matrix to form the primary filaments; S3, drawing and winding, the primary filaments are drawn 2.5-3.5 times and heat set at 80-120 DEG C, so that the molecular chains are oriented and the strength is improved, and finally the fibers are collected by winding; S4, product finishing, the fiber is subjected to relaxation heat treatment or opening process to obtain polyester fiber based on aerogel.

[0014] Compared with the prior art, the polyester fiber based on aerogel and the preparation method thereof have the following beneficial effects: The polyester fiber based on aerogel and the preparation method thereof introduce functional master batch into the polyester system, the functional master batch contains polyester carrier and modified silica aerogel, which not only solves the problems of poor dispersion and weak interfacial bonding force when aerogel is directly added, but also enables the fiber to maintain the mechanical properties of conventional polyester while obtaining multiple functional effects such as warmth, heat insulation, lightness, hydrophobicity and antistatic property, thereby expanding the application range of polyester fiber in the fields of clothing, outdoor and functional materials. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0016] Figure 1A flowchart of a preparation method of a polyester fiber based on aerogel according to the present application is shown. DETAILED DESCRIPTION

[0017] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0018] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details presented, that in some instances, well-known methodologies have not been described in detail in order to avoid obscuring aspects of the present application. Thus, the present application is not intended to be limited by the embodiments set forth and will include all changes coming within the scope of the claims.

[0019] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor does it mean an embodiment that is separate or selectively excluded from other embodiments.

[0020] A polyester fiber based on aerogel, characterized in that it comprises the following raw materials by weight: Polyester chips, 900-1200 parts.

[0021] Functional masterbatch, 80-160 parts.

[0022] Hydrophobic agent, 3-8 parts, using silane type hydrophobic agent KH-550 (γ-aminopropyl triethoxysilane), The hydrophobicity and moisture resistance of the fiber surface are improved by silanization, and a stable organic-inorganic interface layer can be formed in the polyester matrix.

[0023] Thermal stabilizer, 2-6 parts, using Irganox 1010 (tetra[β-(3,5-di-tert-butyl-4-hydroxyphenylpropionic acid)]pentaerythritol ester), effectively inhibiting thermal oxidative degradation at high temperature, maintaining the molecular weight stability during polyester spinning process.

[0024] Antioxidant, 1-5 parts, using Irgafos 168 (tris(2,4-di-tert-butylphenyl) phosphite), which is used in conjunction with Irganox 1010, can effectively capture peroxide, and enhance the long-term stability of polyester.

[0025] Antistatic synergist, 0.5-3 parts, using polyethylene glycol monostearate (PEG-400MS), forming a conductive channel on the surface of the fiber, reducing the surface resistance, and preventing static accumulation.

[0026] Further, the functional masterbatch specifically comprises the following raw materials by weight: Polyester carrier resin, 50-120 parts, about 70%-80% of the total amount of masterbatch, used to carry modified aerogel, ensure compatibility and spinnability with the base PET.

[0027] Modified silica aerogel, 10-35 parts, about 15%-25% of the total amount of masterbatch, containing polyaniline doped layer and phosphate esterified arylethyl activated layer on the surface, giving warmth, thermal insulation, lightweight and antistatic properties.

[0028] Dispersion aid, 1-5 parts, about 2%-5% of the total amount of masterbatch, improving melt mixing fluidity and uniform dispersion of aerogel.

[0029] Further, the functional masterbatch, the specific preparation steps are as follows: A1, in-situ preparation of polyaniline modified aerogel.

[0030] First, silica is prepared into aerogel with three-dimensional network structure by sol-gel method, which appears cloudy and has large specific surface area and high porosity. Disperse it uniformly in deionized water, control the solid content at 1.0-2.0wt%, and use ultrasonic dispersion for 3-5 minutes to make it fully dispersed. Then add aniline monomer and phosphoric acid as a dopant to the system, keeping the pH value of the reaction system in the range of 1.5-2.0. Add ammonium persulfate and sodium periodate as oxidation catalysts, slowly drop into the system, and react at 10-35℃ for 3-4 hours. In this process, aniline is in-situ polymerized on the pore wall and surface of the silica aerogel to form a polyaniline doped layer, forming a polyaniline modified aerogel. The introduction of polyaniline effectively increases the number of active amino groups on the surface of the aerogel, making it have good chemical reaction performance and giving it stable conductivity and antistatic properties. After the reaction is completed, separate by suction filtration and wash with deionized water until neutral, then dry at 40-60℃ in a vacuum environment for 12-24 hours to obtain polyaniline modified aerogel powder. By introducing conductive polyaniline into the aerogel porous framework in-situ, the lightweight and thermal insulation properties of the aerogel are maintained, and the problem of lack of electrical function in fiber application is solved.

[0031] A2, surface secondary modification reaction is carried out to obtain multifunctional silica aerogel.

[0032] The polyaniline modified aerogel powder obtained in step A1 is dispersed in an organic solvent selected from one or more of trichloromethane, dichloromethane or tetrahydrofuran, and the dispersion concentration is controlled at 1.0-1.5 wt%. Under the conditions of nitrogen protection and stirring, phosphorus oxychloride, p-hydroxyphenethyl alcohol and methanol are sequentially added to the system in a molar ratio of 3-3.5:1:2-2.2:0.5-1. First, the phosphorus oxychloride reacts with the residual hydroxyl and amino groups on the surface of the aerogel to generate a highly active phosphoryl intermediate; then the p-hydroxyphenethyl alcohol condenses with the intermediate to build a phosphorylated arylethyl layer, so that a stable organic interface layer is formed on the surface of the aerogel; finally, methanol is added to close the unreacted sites and avoid side reactions. The entire reaction is carried out at a temperature of 10-35°C for a duration of 3-4 hours. After the reaction is completed, the product is separated by suction filtration, washed with anhydrous methanol and solvent in sequence, and then dried in a vacuum environment at a temperature of 40-60°C to obtain a multifunctional silica aerogel with a polyaniline doped layer and a phosphorylated arylethyl layer on the surface. Through the synergistic modification method of "phosphorylation + arylethyl introduction", the surface of the aerogel not only has a polar binding ability, but also can interact with polyester molecules through π-π interaction, greatly improving the dispersion stability and interfacial bonding strength of the aerogel in the polyester matrix.

[0033] A3, melt blending and granulation of the master batch are performed to obtain a functional master batch.

[0034] The multifunctional silica aerogel obtained in step A2 and the polyester carrier resin are dried separately at a temperature of 120°C for a time of 4-6 hours to control the moisture content to be below 200 ppm. Then, pre-mixing is performed in proportion, i.e. the polyester carrier accounts for 70%-80% of the total amount of the master batch, the multifunctional silica aerogel accounts for 15%-25%, and 2%-5% of a dispersing aid is additionally added to improve the melt flowability. The mixture is fed into a twin-screw extruder for melt blending, the barrel temperature is set to 240-280°C in sequence, and the screw rotation speed is controlled at 150-300 rpm. The aerogel powder is supplemented at the middle-stage side feeding port to ensure uniform dispersion, and a vacuum vent (vacuum degree ≤ -0.08 MPa) is provided at the rear stage to effectively remove residual solvents and low molecular by-products. After water cooling and strand drawing, the material is cut into granules to obtain a functional master batch with a particle size of 2-3 mm. By using the process path of "side feeding + vacuum venting + low shear section mixing", the collapse of the aerogel skeleton in a high shear environment is avoided, and at the same time, uniform dispersion of the aerogel in the polyester carrier is ensured, thereby providing a stable and controllable functional master batch for subsequent polyester fiber preparation.

[0035] Reference Figure 1 A method for preparing a polyester fiber based on aerogel, which is prepared based on the polyester fiber described above, comprising the following specific steps: S1, raw material pretreatment and mixing, the polyester chip, functional masterbatch and hydrophobic agent, thermal stabilizer, antioxidant, antistatic synergist are mixed according to the proportion to form a mixture.

[0036] Specifically, the polyester chip is dried at 120 DEG C for 4-6 hours to ensure that the moisture content is less than 200 ppm to avoid degradation in the melt spinning process. The functional masterbatch, hydrophobic agent, thermal stabilizer, antioxidant and antistatic synergist are vacuum dried respectively to meet the processing requirements. Then the raw materials are mixed uniformly according to the proportion, and are added to the spinning device through the metering feeding system to ensure the uniformity and stability of the raw materials in the subsequent melting process.

[0037] S2, melt spinning and forming, the mixture is melted at 260-285 DEG C, is extruded through the spinneret after filtration and metering, is rapidly cooled and solidified to form filaments, the functional masterbatch is uniformly embedded in the polyester matrix to form the primary filaments.

[0038] Specifically, the mixture is heated to 260-285 DEG C in the spinning grade double screw extruder, and is gradually heated in each subsection temperature zone to complete the melting and plasticization. After removing impurities through the precise melt filtration device, the mixture enters the metering pump to accurately control the flow, and is extruded through the spinning assembly. The melt is stretched and sprayed out through the spinneret, and is rapidly cooled and solidified in the cold air flow to obtain the primary filaments. The modified silica aerogel in the functional masterbatch can be stably embedded in the polyester matrix due to the uniform dispersion in the molten state, so that the fiber has the functional basis of heat insulation, warmth and lightness in the forming stage.

[0039] S3, drawing and winding, the primary filaments are drawn 2.5-3.5 times and heat set under the condition of 80-120 DEG C to orient the molecular chain and improve the strength, and finally are collected into fibers through winding.

[0040] Specifically, the solidified primary filaments are drawn in multiple stages under the temperature condition of 80-120 DEG C, and the draw ratio is controlled to be 2.5-3.5 times to fully orient and crystallize the polyester molecular chain and improve the mechanical properties of the fiber. Then heat setting treatment is carried out at 150-180 DEG C, and the setting time is controlled to be 30-60 seconds to stabilize the internal structure of the fiber and prevent subsequent shrinkage. The drawn and set filaments are collected into shape through the winding device, the fiber surface is smooth, and the strength and toughness meet the use requirements. Because the functional masterbatch is uniformly distributed in the system, the fiber has good hydrophobicity and antistatic property, while maintaining the strength and spinnability comparable to conventional polyester fibers.

[0041] S4, finished product finishing, the fiber is subjected to relaxation heat treatment or opening process to obtain the aerogel-based polyester fiber.

[0042] Specifically, the wound aerogel-based polyester fiber is further subjected to a relaxation heat treatment or an opening process to improve the hand feeling and air permeability of the fiber. The fiber finally exhibits excellent comprehensive performance: warm-keeping, heat-insulating, lightweight, hydrophobic and anti-static properties. Due to the uniform dispersion of the modified silica aerogel in the polyester matrix ensured by the functional masterbatch during the preparation process, the final fiber has stable and reliable multifunctional performance and can be widely used in clothing, outdoor protection and thermal insulation materials and other fields. Examples

[0043] The preparation of the aerogel-based polyester fiber was carried out according to the following raw materials: Polyester chips 1000 parts; Functional masterbatch 100 parts; Hydrophobic agent 5 parts; Thermal stabilizer 4 parts; Antioxidant 3 parts; Antistatic synergist 1 part.

[0044] Example 2 (functional masterbatch enhancement type) The preparation of the aerogel-based polyester fiber was carried out according to the following raw materials: Polyester chips 950 parts; Functional masterbatch 140 parts; Hydrophobic agent 6 parts; Thermal stabilizer 4 parts; Antioxidant 3 parts; Antistatic synergist 1 part.

[0045] Example 3 (lightweight bias) The preparation of the aerogel-based polyester fiber was carried out according to the following raw materials: Polyester chips 1150 parts; Functional masterbatch 80 parts; Hydrophobic agent 4 parts; Thermal stabilizer 3 parts; Antioxidant 2 parts; Antistatic synergist 0.5 part.

[0046] Comparative Example 1 (without functional masterbatch) The preparation of the aerogel-based polyester fiber was carried out according to the following raw materials: Polyester chips 1100 parts; Functional masterbatch 0 parts; Hydrophobic agent 5 parts; Thermal stabilizer 4 parts; Antioxidant 3 parts; Antistatic synergist 1 part.

[0047] Comparative Example 2 (insufficient functional additives) Preparation of aerogel-based polyester fiber according to the following raw materials: Polyester chip 1000 parts; Functional masterbatch 80 parts; Hydrophobic agent 0 parts; Thermal stabilizer 4 parts; Antioxidant 3 parts; Antistatic synergist 0 parts.

[0048] Based on the above examples and comparative examples, a number of tests were carried out as shown in Table 1.

[0049] Test methods are as follows: Area density (g / m²); According to GB / T 24218.2-2010 (Textiles - Nonwoven fabrics - Test methods - Part 2: Mass per unit area), cut samples of specified size, weigh under constant temperature and humidity conditions, and divide by area to obtain.

[0050] Breaking strength (MPa); According to GB / T 1040.1-2018 (Plastics - Determination of tensile properties), using an electronic tensile testing machine, stretching at a specified speed until breaking, and recording the maximum stress.

[0051] Breaking elongation (%); The same as the breaking strength test method, the elongation is recorded simultaneously during the stretching process, and the elongation ratio at the time of breaking to the initial length is the breaking elongation.

[0052] Thermal conductivity (W / m·K); According to GB / T 10294-2008 (Determination of steady-state thermal resistance and related properties of thermal insulations - Heat flow meter method), the thermal conductivity of the material under steady-state conditions is measured by a heat flow meter device.

[0053] Thermal resistance R_ct (m²·K / W); According to ISO 11092-2014 (Textiles - Determination of physiological effects - Thermal resistance and vapour resistance), the thermal resistance of the fiber layer is measured on a skin model tester.

[0054] Air permeability (L / m²·s); According to GB / T 5453-1997 (Textiles - Determination of air permeability of fabrics), the air volume flow rate through the sample under a specified pressure difference is measured for a certain period of time.

[0055] Hydrophobic contact angle (°); Referring to ISO 15989-2004 (Plastics - Determination of contact angle - Drop method), deionized water is added to the surface of the fiber, and a contact angle measuring instrument is used to measure the static contact angle.

[0056] Surface resistance (Ω); Surface resistance was measured under standard humidity conditions using a high resistance meter according to GB / T 22042.2-2008 (Textiles - Determination of the static property - Surface resistance method).

[0057] Moisture regain (%); Moisture regain was calculated according to GB / T 9995-1997 (Test method for moisture regain and water content of textile materials) by drying the sample under constant temperature and humidity conditions and calculating the percentage of the mass difference before and after drying relative to the dry mass.

[0058] Table 1

[0059] The results from Table 1 show that: Compared with Comparative Example 1 (without functional masterbatch), the thermal conductivity of Examples 1-3 is reduced (0.034-0.037 W / m·K, compared with 0.046 W / m·K), and the thermal resistance R_ct is significantly improved (0.118-0.132 m²·K / W, compared with 0.087 m²·K / W), confirming that the functional masterbatch containing polyester carrier + modified silica aerogel effectively constructs a low-heat channel and a microporous thermal insulation structure; at the same time, the air permeability is maintained at 510-535 L / m²·s, balancing air permeability and warmth. The hydrophobic contact angle is increased from 98° in Comparative Example 1 to 130°-136°, indicating that the combined effect of the hydrophobic agent and the modified silica aerogel enhances the surface hydrophobicity; the surface resistance is reduced to 6.9×10^8-9.1×10^8 Ω, which is better than 3.2×10^11 Ω in Comparative Example 1, reflecting the synergy of the antistatic synergist and the polyaniline modified layer. The breaking strength of the three groups of examples is maintained at 415-425 MPa, and the elongation at break is 27%-29%, which is comparable to conventional polyester, proving that the introduction of the function does not significantly weaken the mechanical properties. After removing the hydrophobic agent and the antistatic synergist in Comparative Example 2, the contact angle is only 102°, and the surface resistance is 1.1×10^10 Ω, verifying the necessity of the corresponding additives for hydrophobic and antistatic properties. In summary, the addition of the functional masterbatch is the key to achieving the multi-objective balance of "warmth, thermal insulation, lightness, hydrophobicity, and antistaticity", and through different amounts (Example 2 is high, and Example 3 is low), the thermal resistance and mechanics can be flexibly traded off.

[0060] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. An aerogel-based polyester fiber, characterized in that It includes the following raw materials in parts by weight: Polyester chips, 900-1200 parts; Functional masterbatch, 80-160 parts; the functional masterbatch specifically comprises the following raw materials in parts by weight: polyester carrier resin, 50-120 parts; modified silica aerogel, 10-35 parts; dispersing aid, 1-5 parts; Hydrophobic agent, 3 to 8 parts; Heat stabilizer, 2 to 6 parts; Antioxidant, 1-5 parts; Antistatic synergist, 0.5 to 3 parts.

2. The aerogel-based polyester fiber according to claim 1, characterized in that: The functional masterbatch is specifically prepared in the following steps: A1. In-situ preparation of polyaniline modified aerogel; A2. Performing secondary surface modification reaction to obtain multifunctional silica aerogel; A3. Melt blending and granulation of the masterbatch are performed to obtain the functional masterbatch.

3. The aerogel-based polyester fiber according to claim 2, characterized in that: The preparation process of the polyaniline-modified aerogel in step A1 includes: Silica is prepared into aerogel with a three-dimensional network structure by a sol-gel method, which is uniformly dispersed in deionized water with a solid content of 1.0-2.0 wt%, and ultrasonically dispersed for 3-5 minutes to ensure full dispersion. Then, aniline monomer is added to the system, and a dopant is added to keep the pH value of the reaction system within the range of 1.5 to 2.0; The catalyst is added dropwise to the system and reacted at 10-35°C for 3-4 hours. During this process, aniline undergoes in-situ polymerization on the pore walls and surface of the silica aerogel to form a polyaniline doped layer, thereby forming a polyaniline-modified aerogel. After the reaction is completed, the mixture is separated by suction filtration and washed with deionized water until neutral, and then dried under a vacuum environment of 40 to 60° C. for 12 to 24 hours to obtain polyaniline modified aerogel powder.

4. The aerogel-based polyester fiber according to claim 3, characterized in that: The dopant is phosphoric acid; the catalyst is ammonium persulfate or sodium periodate.

5. The aerogel-based polyester fiber according to claim 2, characterized in that: In step A2, the preparation process of the multifunctional silica aerogel includes: The polyaniline modified aerogel powder obtained in step A1 is dispersed in an organic solvent, and the dispersion concentration is controlled to be 1.0-1.5 wt%; Under nitrogen protection and stirring conditions, phosphorus oxychloride, p-hydroxyphenylethanol and methanol are added to the system, and the entire reaction is carried out at a temperature of 10 to 35° C. for 3 to 4 hours. After the reaction is completed, the mixture is separated by suction filtration, washed with anhydrous methanol and solvent in sequence, and then dried under a vacuum environment of 40-60° C. to obtain a multifunctional silica aerogel having a polyaniline doping layer and a phosphated aromatic ethyl layer on the surface.

6. The aerogel-based polyester fiber according to claim 5, characterized in that: The organic solvent is selected from one or more of chloroform, dichloromethane or tetrahydrofuran; the molar ratio of phosphorus oxychloride, p-hydroxyphenylethanol and methanol is 3-3.5:1:2-2.2:0.5-1.

7. The aerogel-based polyester fiber according to claim 2, characterized in that: In step A3, the melt blending and granulation of the masterbatch, the specific preparation process includes: The multifunctional silica aerogel and polyester carrier resin obtained in step A2 are dried separately at 120° C. for 4 to 6 hours to control the moisture content below 200 ppm, and then premixed, and a dispersing aid is added to improve melt fluidity; The mixture is fed into a twin-screw extruder for melt blending, and the material is water-cooled and drawn into strands before pelletizing to obtain functional masterbatch with a particle size of 2 to 3 mm.

8. The aerogel-based polyester fiber according to claim 7, characterized in that: During the melt blending, the barrel temperature is set to 240-280°C, and the screw speed is controlled at 150-300 rpm; the aerogel powder is fed at the middle side feed port to ensure its uniform dispersion, and a vacuum exhaust port is set at the rear section with a vacuum degree of ≤-0.08 MPa to remove residual solvent and low molecular weight by-products.

9. A method for preparing aerogel-based polyester fiber, comprising preparing the polyester fiber according to any one of claims 1 to 8, characterized in that: The specific steps include: S1, raw material pretreatment and mixing, polyester chips, functional masterbatch and hydrophobic agent, heat stabilizer, antioxidant, antistatic synergist are dry mixed in proportion to form a mixture; S2, melt spinning and forming, the mixture is melted at 260-285℃, filtered and measured, and then extruded from the spinneret. It is quickly cooled and solidified to form filaments. The functional masterbatch is evenly embedded in the polyester matrix to form primary filaments. S3, drawing and winding, the nascent filaments are drawn 2.5 to 3.5 times at 80 to 120°C and heat-set to orient the molecular chains and increase the strength, and finally collected into fibers by winding; S4, finishing the finished product, the fiber undergoes a relaxation heat treatment or an opening process to obtain aerogel-based polyester fiber.

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