Antistatic modified polyester staple fiber and method for preparing the same

Abstract

The application relates to the polyester fiber field and discloses an antistatic modified polyester staple fiber and a preparation method thereof, the preparation method of which comprises the following steps: mixing and melting polyester chips and modified graphene oxide, extruding through a spinneret hole, winding, heat stretching, curling and cutting to prepare; the polyester chips are prepared by taking terephthalic acid and ethylene glycol as reaction raw materials, adding carboxylated copolymer microspheres and a catalyst, and performing esterification reaction, pre-polycondensation and final polycondensation reaction; the modified graphene oxide is prepared by modifying phytic acid doped polypyrrole on the surface of graphene oxide and loading layered double hydroxides of nickel and cobalt through a hydrothermal reaction; the carboxylated copolymer microspheres are prepared by using divinylbenzene, carbazole monomers prepared by reacting carbazole and bromo-undecylen and maleic anhydride, and hydrolyzing the anhydride groups in the copolymer microspheres into carboxyl groups; and the polyester staple fiber prepared by the application has good mechanical properties, thermal stability, antistatic property, moisture absorption and flame retardancy.

Description

Technical Field

[0001] This invention belongs to the field of polyester fiber technology, specifically relating to an antistatic modified polyester staple fiber and its preparation method. Background Technology

[0002] Polyester staple fiber is a synthetic fiber obtained by spinning polyester, which is formed by the condensation polymerization of organic diacids and diols. Polyester staple fiber has good abrasion resistance, light resistance, and corrosion resistance, as well as high strength and low deformation. It is increasingly replacing cotton in textiles, clothing, nonwovens, and medical industries. However, the molecular structure of polyester determines its low molecular polarity, making the fiber surface prone to static electricity. The volume resistivity of conventional polyester staple fiber is around 10⁻⁶. 13 With an Ω·cm or higher limit, polyester staple fiber has poor antistatic properties, which limits the wide application of its products. In addition, polyester staple fiber has a low limiting oxygen index, making it flammable. When burning, it produces a large amount of molten drips that can quickly spread the flame to other combustible materials, posing a significant safety hazard during use. Furthermore, the thermal stability of existing polyester staple fibers is insufficient, and their mechanical properties need to be further improved to better expand the application range of polyester staple fiber products. Summary of the Invention

[0003] To address the shortcomings mentioned in the background art, the present invention aims to provide an antistatic modified polyester staple fiber and its preparation method. Using terephthalic acid and ethylene glycol as reactants, carboxylated copolymer microspheres are introduced to prepare polyester chips. Modified graphene oxide is then combined with the polyester chips. The resulting polyester staple fiber possesses excellent mechanical properties, thermal stability, antistatic properties, moisture absorption properties, and flame retardant properties.

[0004] The objective of this invention can be achieved through the following technical solutions: A method for preparing antistatic modified polyester staple fiber includes the following steps: pre-dried polyester chips and modified graphene oxide are thoroughly mixed, melted by a screw extruder, extruded through a spinneret and wound by a winding machine to obtain nascent fibers, and then the nascent fibers are thermally stretched, crimped and cut on a stretching device to obtain antistatic modified polyester staple fiber. The polyester chips are made from terephthalic acid and ethylene glycol as reactants, with the addition of carboxylated copolymer microspheres and catalysts. After esterification, pre-condensation and final condensation, the chips are cooled with cold water and then cut into polyester chips by a pelletizer. The modified graphene oxide is prepared by modifying polypyrrole on the surface of graphene oxide by in-situ precipitation and doping with phytic acid to obtain modified graphene oxide, and then loading layered bimetallic hydroxides of nickel and cobalt on the surface of modified graphene oxide in situ through hydrothermal reaction. The carboxylated copolymer microspheres are prepared in situ by self-stabilizing precipitation polymerization using carbazole monomer (prepared by N-alkylation reaction of carbazole and undecene bromide) as crosslinking agent and maleic anhydride as reactant monomers, and then the anhydride groups in the copolymer microspheres are hydrolyzed to carboxyl groups.

[0005] Preferably, the method for preparing the modified graphene oxide includes the following steps: I. Graphene oxide was ultrasonically dispersed in deionized water to obtain a dispersion. Pyrrole and 70% phytic acid solution were dispersed in a mixed solution of ethanol and deionized water. The dispersion was then added and stirred at 0–5°C for 25–40 min. Subsequently, ammonium persulfate aqueous solution was slowly added dropwise and stirred at 0–5°C for 4–6 h. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying. II. Modified graphene oxide was ultrasonically dispersed in deionized water, and then nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and hexamethylenetetramine were added. The mixture was magnetically stirred for 20-30 minutes, and then transferred to a polytetrafluoroethylene liner in a stainless steel reactor. The reactor was placed at 85-95°C and reacted for 10-14 hours. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying.

[0006] Preferably, the concentration of the ammonium persulfate aqueous solution in step I is 0.013-0.015 mol / L; the addition ratio of graphene oxide, pyrrole, phytic acid solution with a mass fraction of 70% and ammonium persulfate aqueous solution is 1-2 g: 0.8 g: 2 g: 200 mL.

[0007] Preferably, in step II, the mass ratio of modified graphene oxide, nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and hexamethylenetetramine is 1.5–2.2: 7.2–7.3: 7.2–7.3: 8.3–8.5.

[0008] Preferably, the preparation method of the carboxylated copolymer microspheres includes the following steps: A. Carbazole, sodium hydride and anhydrous N,N-dimethylformamide were added to the reactor and stirred at room temperature for 1 hour. Then, undecene bromide was added dropwise after vacuum distillation. The mixture was heated to 75-80°C and refluxed for 2-3 hours. The reaction solution was then added to a saturated ammonium chloride solution to quench the reaction. The mixture was extracted and separated. The organic phases were combined and the solvent was removed by rotary evaporation. The mixture was dried with anhydrous magnesium sulfate and purified by column chromatography to prepare the carbazole monomer. B. Add maleic anhydride, carbazole monomer, crosslinking agent divinylbenzene, initiator azobisisobutyronitrile and isoamyl acetate solvent to the reactor, sonicate to dissolve for 5 min, evacuate and circulate nitrogen to remove air from the system, and then place it at 70-75℃ for polymerization reaction for 5-7 h. After the reaction is completed, cool to room temperature, wash with ethanol to remove unreacted material and dry to prepare copolymer microspheres. C. Add copolymer microspheres, sodium hydroxide and deionized water to the reactor, stir and mix, and heat under reflux at 100-110℃ for 10-12h. After the reaction is completed, cool to room temperature, precipitate in 0.5mol / L hydrochloric acid solution, wash with deionized water until neutral and dry to prepare carboxylated copolymer microspheres.

[0009] Preferably, in step B, the molar ratio of maleic anhydride, carbazole monomer, and divinylbenzene is 1–1.2:1–1.2:0.1.

[0010] Preferably, the mass ratio of the polyester chips to the modified graphene oxide is 100:1 to 4; the molar ratio of the total amount of terephthalic acid and ethylene glycol is 1:1.3 to 1.6; and the mass of the carboxylated copolymer microspheres is 1.5 to 3% of the mass of terephthalic acid.

[0011] Preferably, the process parameters for obtaining the nascent fiber are: zone 1 250°C, zone 2 260°C, zone 3 265°C, and head 260°C; spinneret diameter 1 mm; winding speed 450 r / min; and the temperature for hot stretching is 60–75°C, with a draw ratio of 3–4.

[0012] Preferably, the method for preparing the polyester chips includes the following steps: S1. Mix 70-75% of the total amount of ethylene glycol with terephthalic acid to obtain a mixed slurry; S2. Mix 15-20% of the total amount of ethylene glycol with the catalyst to obtain a catalyst solution. The catalyst is one or more of the following: antimony acetate, zinc acetate, cobalt acetate, antimony trioxide, and manganese acetate. S3. Take the carboxylated copolymer microspheres and the remaining ethylene glycol and mix them evenly to obtain the additive solution; S4. After mixing the mixed slurry and catalyst solution, carry out the first esterification reaction at a temperature of 230-260℃ for 1-3 hours. When the polyester polymerization esterification rate reaches 85-90%, add the additive solution and carry out the second esterification reaction at a temperature of 230-260℃ for 0.5-1 hours to obtain the esterified product. S5. Press the esterification product into the prepolymerization reactor. Raise the temperature of the reactor jacket to 250-270°C and use a vacuum pump to draw a vacuum. Slowly draw the vacuum down to -100Pa through the reactor's fine-tuning valve to reach the high vacuum stage. Then set the jacket temperature to 270-280°C. When the vacuum level inside the reactor is below 50Pa, carry out the final polymerization reaction. When the viscosity reaches the required level, start discharging. After the reaction is completed, cool with cold water and then cut into polyester chips using a pelletizer.

[0013] An antistatic modified polyester staple fiber is prepared by the method described above.

[0014] The beneficial effects of this invention are: This invention employs an in-situ precipitation method to modify the surface of graphene oxide with polypyrrole and dope it with phytic acid to impart phosphorus, thus preparing modified graphene oxide. Then, through a hydrothermal reaction, layered bimetallic hydroxides of nickel and cobalt are in-situ loaded onto the surface of the modified graphene oxide to prepare modified graphene oxide. The modification with polypyrrole and phytic acid increases the interlayer spacing of the graphene oxide, and the synergistic effect of the layered bimetallic hydroxides enhances the mechanical properties, antistatic properties, and moisture absorption capacity of the fiber material. Simultaneously, the nickel-cobalt layered bimetallic hydroxides can act as physical crosslinking points, limiting the polyester separation... The thermal motion of the sub-chain segments enhances the thermal stability of the fiber material. In addition, the barrier effect of graphene oxide, the synergistic effect of phosphorus and nitrogen in polypyrrole-doped phytic acid, and the catalytic effect of nickel-cobalt transition metal ions combine to promote the formation of a continuous and complete carbon layer containing a nano-barrier network. This significantly inhibits heat and mass exchange and the release of toxic fumes during combustion, giving the fiber material good flame retardant properties. Polyester fibers modified with graphene oxide composites show significant improvements in mechanical properties, thermal stability, antistatic properties, moisture absorption properties, and flame retardant properties.

[0015] This invention utilizes the N-alkylation reaction of carbazole and undecene bromide to prepare carbazole monomer. Then, using divinylbenzene as a crosslinking agent and maleic anhydride and carbazole monomer as reactants, maleic anhydride-carbazole monomer crosslinked copolymer microspheres are prepared in situ through self-stabilizing precipitation polymerization. Subsequently, the copolymer microspheres are reacted with sodium hydroxide to hydrolyze the anhydride groups of the copolymer microspheres into carboxyl groups, thus preparing carboxylated copolymer microspheres. Using terephthalic acid and ethylene glycol as reactants, the carboxylated copolymer microspheres are introduced to prepare polyester chips. The large number of carboxyl functional groups contained in the carboxylated copolymer microspheres can endow the fiber material with good antistatic properties and moisture absorption capacity. At the same time, the carbazole groups introduced into the carboxylated copolymer microspheres, as rigid groups with large conjugated structures, are beneficial to improving the thermal stability of the fiber material. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: A method for preparing modified graphene oxide includes the following steps: I. Take 1.6g of graphene oxide and ultrasonically disperse it in 200mL of deionized water to obtain a dispersion. Take 0.8g of pyrrole and 2g of 70% phytic acid solution and disperse them in a mixed solution of 200mL of ethanol and 200mL of deionized water. Then add the dispersion and stir at 0℃ for 30min. Then slowly add 200mL of 0.014mol / L ammonium persulfate aqueous solution and continue stirring at 0℃ for 5h. After the reaction is completed, centrifuge, wash and dry to prepare modified graphene oxide. II. Take 2g of modified graphene oxide and ultrasonically disperse it in 200mL of deionized water. Then add 7.27g of nickel nitrate hexahydrate, 7.28g of cobalt nitrate hexahydrate and 8.41g of hexamethylenetetramine. Stir magnetically for 30min. Then transfer it to a polytetrafluoroethylene liner in a stainless steel reactor and react at 90℃ for 12h. After the reaction is completed, centrifuge, wash and dry to prepare modified graphene oxide.

[0018] Example 2: A method for preparing carboxylated copolymer microspheres includes the following steps: A. Add 9g of carbazole, 2.3g of sodium hydride (60% suspension in mineral oil) and 150mL of anhydrous N,N-dimethylformamide to a reactor, stir at room temperature for 1h, then add 24.5g of undecyl bromodimethylene dropwise, heat to 80℃ and reflux for 2h, then add the reaction solution to 500mL of saturated ammonium chloride solution to quench the reaction, extract with dichloromethane, combine the organic phases and remove the solvent by rotary evaporation, dry with anhydrous magnesium sulfate and purify by column chromatography to prepare carbazole monomer; B. Add 1.17g maleic anhydride, 3.19g carbazole monomer, 0.13g crosslinking agent divinylbenzene, 0.089g initiator azobisisobutyronitrile and 20mL isoamyl acetate solvent to the reactor, sonicate to dissolve for 5min, evacuate and circulate nitrogen to remove air from the system, and then place it at 72℃ for polymerization reaction for 6h. After the reaction is completed, cool to room temperature, wash with ethanol to remove unreacted material and dry to prepare copolymer microspheres; C. Add 2.01g of copolymer microspheres, 0.4g of sodium hydroxide and 20mL of deionized water to the reactor, stir and mix, and heat under reflux at 105℃ for 12h. After the reaction is completed, cool to room temperature and precipitate in 50mL of 0.5mol / L hydrochloric acid solution. Then wash with deionized water until neutral and dry to prepare carboxylated copolymer microspheres.

[0019] Example 3 A method for preparing polyester chips includes the following steps: S1. Take terephthalic acid and ethylene glycol at a molar ratio of 1:1.5. Mix 75% of the total amount of ethylene glycol with terephthalic acid to obtain a mixed slurry. S2. Ethylene glycol (15% of the total ethylene glycol) and antimony acetate are ultrasonically dispersed evenly. The amount of antimony acetate is 230 ppm of the total mass of terephthalic acid to obtain the catalyst solution. S3. Take 1.7% of the carboxylated copolymer microspheres prepared in Example 2 by mass of terephthalic acid and mix them evenly with the remaining ethylene glycol to obtain the additive solution; S4. After mixing the slurry and catalyst solution, a first esterification reaction is carried out at a temperature of 250℃ for 1.2 hours. When the polyester polymerization esterification rate reaches 85%, an additive solution is added to carry out a second esterification reaction at a temperature of 250℃ for 0.8 hours to obtain the esterified product. S5. Press the esterification product into the prepolymerization reactor. Raise the temperature of the reactor jacket to 270°C and use a vacuum pump to draw a vacuum. Slowly draw the vacuum down to -100Pa through the reactor's fine-tuning valve to reach the high vacuum stage. Then set the jacket temperature to 280°C. When the vacuum level inside the reactor is below 50Pa, carry out the final polymerization reaction. When the viscosity reaches the required level, start discharging. After the reaction is completed, cool with cold water and then cut into polyester chips using a pelletizer.

[0020] Example 4 A method for preparing polyester chips includes the following steps: Compared with Example 3, in step S3, 2.5% by mass of terephthalic acid of the carboxylated copolymer microspheres prepared in Example 2 and the remaining ethylene glycol are mixed evenly to obtain an additive solution. The remaining components and operating steps are the same as in Example 3.

[0021] Example 5 A method for preparing polyester chips includes the following steps: Compared with Example 3, in step S3, 3% by mass of terephthalic acid of the carboxylated copolymer microspheres prepared in Example 2 and the remaining ethylene glycol are mixed evenly to obtain an additive solution. The remaining components and operating steps are the same as in Example 3.

[0022] Example 6 A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Example 3 and the modified graphene oxide prepared in Example 1 were thoroughly mixed at a mass ratio of 100:1.3. The mixture was melted by a screw extruder, extruded through a spinneret, and wound by a winding machine to obtain nascent fibers (process parameters: zone 1 250°C, zone 2 260°C, zone 3 265°C, die head 260°C; spinneret diameter 1 mm; winding speed 450 r / min). The nascent fibers were then hot-stretched, crimped, and cut on a stretching device (hot stretching temperature 70°C, draw ratio 4) to prepare antistatic modified polyester staple fibers.

[0023] Example 7 A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Example 4 and the modified graphene oxide prepared in Example 1 were thoroughly mixed at a mass ratio of 100:2.7. The mixture was melted by a screw extruder, extruded through a spinneret, and wound by a winding machine to obtain nascent fibers (process parameters: zone 1 250°C, zone 2 260°C, zone 3 265°C, die head 260°C; spinneret diameter 1 mm; winding speed 450 r / min). The nascent fibers were then hot-stretched, crimped, and cut on a stretching device (hot stretching temperature 70°C, draw ratio 4) to prepare antistatic modified polyester staple fibers.

[0024] Example 8 A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Example 5 and the modified graphene oxide prepared in Example 1 were thoroughly mixed at a mass ratio of 100:3.7. The mixture was melted in a screw extruder, extruded through a spinneret, and wound in a winding machine to obtain nascent fibers (process parameters: zone 1 250°C, zone 2 260°C, zone 3 265°C, die head 260°C; spinneret diameter 1 mm; winding speed 450 r / min). The nascent fibers were then hot-stretched, crimped, and cut in a stretching device (hot stretching temperature 70°C, draw ratio 4) to obtain antistatic modified polyester staple fibers.

[0025] Comparative Example 1: A method for preparing polyester chips includes the following steps: S1. Take terephthalic acid and ethylene glycol at a molar ratio of 1:1.5. Mix 75% of the total amount of ethylene glycol with terephthalic acid to obtain a mixed slurry. S2. Ethylene glycol (25% of the total ethylene glycol) and antimony acetate are ultrasonically dispersed evenly. The amount of antimony acetate is 230 ppm of the total mass of terephthalic acid to obtain the catalyst solution. S3. After mixing the slurry and catalyst solution, carry out the esterification reaction at 250℃ for 2 hours to obtain the esterification product. S4. Press the esterification product into the prepolymerization reactor. Raise the reactor jacket temperature to 270°C and use a vacuum pump to evacuate to a vacuum. Slowly evacuate to -100Pa through the reactor's fine-tuning valve to reach the high vacuum stage. Then set the jacket temperature to 280°C. When the vacuum degree inside the reactor is lower than 50Pa, carry out the final polycondensation reaction. When the viscosity reaches the requirement, start discharging. After the reaction is completed, cool with cold water and then cut into polyester chips using a pelletizer.

[0026] Comparative Example 2: A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Example 5 and the modified graphene oxide prepared in Example 1 were thoroughly mixed at a mass ratio of 100:3.7. The mixture was melted in a screw extruder, extruded through a spinneret, and wound in a winding machine to obtain nascent fibers (process parameters: zone 1 250°C, zone 2 260°C, zone 3 265°C, die head 260°C; spinneret diameter 1 mm; winding speed 450 r / min). The nascent fibers were then hot-stretched, crimped, and cut on a stretching device (hot stretching temperature 70°C, draw ratio 4) to prepare antistatic modified polyester staple fibers.

[0027] Comparative Example 3: A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Example 5 and graphene oxide were thoroughly mixed at a mass ratio of 100:3.7, melted by a screw extruder, extruded through a spinneret, and wound by a winding machine to obtain nascent fibers (process parameters: zone 1 250°C, zone 2 260°C, zone 3 265°C, die head 260°C; spinneret diameter 1 mm; winding speed 450 r / min). Then, the nascent fibers were hot-stretched, crimped, and cut on a stretching device (hot stretching temperature 70°C, draw ratio 4) to prepare antistatic modified polyester staple fibers.

[0028] Comparative Example 4: A method for preparing antistatic modified polyester staple fiber, comprising the following steps: The pre-dried polyester chips prepared in Comparative Example 1 and the modified graphene oxide prepared in Example 1 were thoroughly mixed at a mass ratio of 100:3.7. The mixture was melted in a screw extruder, extruded through a spinneret, and wound in a winding machine to obtain nascent fibers (process parameters: zone 1 250℃, zone 2 260℃, zone 3 265℃, die head 260℃; spinneret diameter 1mm; winding speed 450r / min). The nascent fibers were then hot-stretched, crimped, and cut on a stretching device (hot stretching temperature 70℃, draw ratio 4) to prepare antistatic modified polyester staple fibers.

[0029] Performance testing The antistatic modified polyester staple fibers prepared in Examples 6-8 and Comparative Examples 2-4 were subjected to performance testing: (1) Mechanical property test: The breaking strength and breaking elongation of the sample were tested using a fiber tensile strength tester in accordance with GB / T 14337-2022. The data results are shown in Table 1.

[0030] (2) Thermal stability test: The fiber heat shrinkage rate tester was used to test the fiber length change of the sample before and after dry hot air treatment in an oven at 180℃ for 30 min in accordance with GB / T 43015-2023. The thermal stability of the sample was evaluated by the dry heat shrinkage rate at 180℃. The data results are shown in Table 1.

[0031] (3) Antistatic performance test: The volume resistivity of the sample was measured using a fiber resistivity meter, and the data results are shown in Table 1.

[0032] (4) Moisture absorption performance test: The moisture regain of the sample was determined according to GB / T 6503-2017, and the data results are shown in Table 1.

[0033] (5) Flame retardant performance test: The limiting oxygen index was used to evaluate the flame retardant performance, and the data results are shown in Table 1.

[0034] Table 1 Sample performance test results

[0035] As can be seen from the data results in Table 1, the samples prepared in Examples 6-8 of this invention have good mechanical properties, thermal stability, antistatic properties, moisture absorption properties and flame retardant properties. In Comparative Example 2, modified graphene oxide was replaced with an equal amount of modified graphene oxide. In Comparative Example 3, no modification treatment was performed on the graphene oxide. The measured dry heat shrinkage rate and volume resistivity at 180℃ in Comparative Examples 2-3 were increased compared to Examples 6-8, while the breaking strength, elongation at break, moisture regain, and limiting oxygen index were decreased compared to Examples 6-8. This indicates that the loading of nickel-cobalt layered bimetallic hydroxide is beneficial to improving the mechanical properties, thermal stability, antistatic properties, moisture absorption properties, and flame retardant properties of the fiber material. Moreover, the measured reduction in Comparative Example 3 was more significant than that in Comparative Example 2, indicating that the modification of polypyrrole with phytic acid is beneficial to further improve the comprehensive performance of the fiber material. In Comparative Example 4, the added polyester chips did not introduce carboxylated copolymer microspheres. The measured dry heat shrinkage rate and volume resistivity at 180℃ were increased compared to Examples 6-8, while the moisture regain was decreased compared to Examples 6-8. This indicates that the introduction of carboxylated copolymer microspheres is beneficial to improving the thermal stability, antistatic properties, and moisture absorption properties of the fiber material.

[0036] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing antistatic modified polyester staple fiber, characterized in that, The process includes the following steps: pre-dried polyester chips and modified graphene oxide are thoroughly mixed, melted by a screw extruder, extruded through a spinneret, and wound by a winding machine to obtain nascent fibers. Then, the nascent fibers are thermally stretched, crimped, and cut on a stretching device to prepare antistatic modified polyester staple fibers. The polyester chips are made from terephthalic acid and ethylene glycol as reactants, with the addition of carboxylated copolymer microspheres and catalysts. After esterification, pre-condensation and final condensation, the chips are cooled with cold water and then cut into polyester chips by a pelletizer. The modified graphene oxide is prepared by modifying polypyrrole on the surface of graphene oxide by in-situ precipitation and doping with phytic acid to obtain modified graphene oxide, and then loading layered bimetallic hydroxides of nickel and cobalt on the surface of modified graphene oxide in situ through hydrothermal reaction. The carboxylated copolymer microspheres are prepared in situ by self-stabilizing precipitation polymerization using carbazole monomer (prepared by N-alkylation reaction of carbazole and undecene bromide) as crosslinking agent and maleic anhydride as reactant monomers, and then the anhydride groups in the copolymer microspheres are hydrolyzed to carboxyl groups.

2. The method for preparing antistatic modified polyester staple fiber according to claim 1, characterized in that, The preparation method of the modified graphene oxide includes the following steps: I. Graphene oxide was ultrasonically dispersed in deionized water to obtain a dispersion. Pyrrole and 70% phytic acid solution were dispersed in a mixed solution of ethanol and deionized water. The dispersion was then added and stirred at 0–5°C for 25–40 min. Subsequently, ammonium persulfate aqueous solution was slowly added dropwise and stirred at 0–5°C for 4–6 h. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying. II. Modified graphene oxide was ultrasonically dispersed in deionized water, and then nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and hexamethylenetetramine were added. The mixture was magnetically stirred for 20-30 minutes, and then transferred to a polytetrafluoroethylene liner in a stainless steel reactor. The reactor was placed at 85-95°C and reacted for 10-14 hours. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying.

3. The method for preparing antistatic modified polyester staple fiber according to claim 2, characterized in that, In step I, the concentration of the ammonium persulfate aqueous solution is 0.013–0.015 mol / L; the addition ratio of graphene oxide, pyrrole, phytic acid solution with a mass fraction of 70%, and ammonium persulfate aqueous solution is 1–2 g: 0.8 g: 2 g: 200 mL.

4. The method for preparing antistatic modified polyester staple fiber according to claim 2, characterized in that, In step II, the mass ratio of modified graphene oxide, nickel nitrate hexahydrate, cobalt nitrate hexahydrate, and hexamethylenetetramine is 1.5–2.2: 7.2–7.3: 7.2–7.3: 8.3–8.

5.

5. The method for preparing antistatic modified polyester staple fiber according to claim 1, characterized in that, The preparation method of the carboxylated copolymer microspheres includes the following steps: A. Carbazole, sodium hydride and anhydrous N,N-dimethylformamide were added to the reactor and stirred at room temperature for 1 hour. Then, undecene bromide was added dropwise after vacuum distillation. The mixture was heated to 75-80°C and refluxed for 2-3 hours. The reaction solution was then added to a saturated ammonium chloride solution to quench the reaction. The mixture was extracted and separated. The organic phases were combined and the solvent was removed by rotary evaporation. The mixture was dried with anhydrous magnesium sulfate and purified by column chromatography to prepare the carbazole monomer. B. Add maleic anhydride, carbazole monomer, crosslinking agent divinylbenzene, initiator azobisisobutyronitrile and isoamyl acetate solvent to the reactor, sonicate to dissolve for 5 min, evacuate and circulate nitrogen to remove air from the system, and then place it at 70-75℃ for polymerization reaction for 5-7 h. After the reaction is completed, cool to room temperature, wash with ethanol to remove unreacted material and dry to prepare copolymer microspheres. C. Add copolymer microspheres, sodium hydroxide and deionized water to the reactor, stir and mix, and heat under reflux at 100-110℃ for 10-12h. After the reaction is completed, cool to room temperature, precipitate in 0.5mol / L hydrochloric acid solution, wash with deionized water until neutral and dry to prepare carboxylated copolymer microspheres.

6. The method for preparing antistatic modified polyester staple fiber according to claim 5, characterized in that, In step B, the molar ratio of maleic anhydride, carbazole monomer, and divinylbenzene is 1–1.2:1–1.2:0.

1.

7. The method for preparing antistatic modified polyester staple fiber according to claim 1, characterized in that, The mass ratio of the polyester chips to the modified graphene oxide is 100:1 to 4; the molar ratio of the total amount of terephthalic acid and ethylene glycol is 1:1.3 to 1.6; and the mass of the carboxylated copolymer microspheres is 1.5 to 3% of the mass of terephthalic acid.

8. The method for preparing antistatic modified polyester staple fiber according to claim 1, characterized in that, The process parameters for obtaining the nascent fiber are: zone 1 250℃, zone 2 260℃, zone 3 265℃, and head 260℃; spinneret diameter 1mm; winding speed 450r / min; the temperature for hot stretching is 60~75℃, and the draw ratio is 3~4.

9. The method for preparing antistatic modified polyester staple fiber according to claim 1, characterized in that, The method for preparing the polyester chips includes the following steps: S1. Mix 70-75% of the total amount of ethylene glycol with terephthalic acid to obtain a mixed slurry; S2. Mix 15-20% of the total amount of ethylene glycol with the catalyst to obtain a catalyst solution. The catalyst is one or more of the following: antimony acetate, zinc acetate, cobalt acetate, antimony trioxide, and manganese acetate. S3. Take the carboxylated copolymer microspheres and the remaining ethylene glycol and mix them evenly to obtain the additive solution; S4. After mixing the mixed slurry and catalyst solution, carry out the first esterification reaction at a temperature of 230-260℃ for 1-3 hours. When the polyester polymerization esterification rate reaches 85-90%, add the additive solution and carry out the second esterification reaction at a temperature of 230-260℃ for 0.5-1 hours to obtain the esterified product. S5. Press the esterification product into the prepolymerization reactor. Raise the temperature of the reactor jacket to 250-270°C and use a vacuum pump to draw a vacuum. Slowly draw the vacuum down to -100Pa through the reactor's fine-tuning valve to reach the high vacuum stage. Then set the jacket temperature to 270-280°C. When the vacuum level inside the reactor is below 50Pa, carry out the final polymerization reaction. When the viscosity reaches the required level, start discharging. After the reaction is completed, cool with cold water and then cut into polyester chips using a pelletizer.

10. An antistatic modified polyester staple fiber, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.

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