Conductive polyester fiber and preparation method thereof

Abstract

The invention relates to the technical field of fibers, in particular to a conductive polyester fiber and a preparation method thereof. The conductive polyester fiber comprises a modified carbon nano tube, polyester and a polyaniline / MXene composite nano material, wherein based on the total mass of the conductive polyester fiber, the mass percentage content of the modified carbon nanotubes is 0.35%-8.5%; the mass percentage content of the polyaniline / MXene composite nano material is 0.2%-6.5%. The conductive polyester fiber provided by the invention not only has the advantages of common polyester fibers, but also has more excellent and stable conductivity.

Description

Technical Field

[0001] The present invention relates to the field of fiber technology, in particular to a conductive polyester fiber and a preparation method thereof. Background Art

[0002] With the rapid development of the chemical fiber industry, fibers with novel, diverse and high added value are emerging in an endless stream, and conductive fibers are one of the important ones. Conductive fibers have a wide range of applications, such as the textile industry, electronic manufacturing, automotive industry, military industry, etc. In recent years, the rise of flexible smart wearable textiles and the continuous expansion of the market scale have made conductive fibers once again the focus of people's attention. The research and development of conductive fibers with lower resistivity and more stable conductive properties has become an urgent problem to be solved. At present, the common methods for preparing conductive fibers in the chemical fiber industry mainly include various types of spinning methods and conductive layer plating methods. Commonly used conductive materials include carbon materials such as conductive carbon black, carbon nanotubes, and graphene, metal materials such as stainless steel, silver, copper, and MXene, and polymer materials such as polyaniline, polypyrrole, and polythiophene.

[0003] Chinese invention patent CN103451771A discloses an antistatic composite fiber made by spinning a conductive composite polymer substrate containing 10-30wt% conductive carbon black and a fibrous polymer substrate. The conductive composite polymer substrate accounts for 20%-60% of the total volume of the antistatic composite fiber precursor. Chinese invention patent CN116770458A discloses a polylactic acid two-component composite conductive monofilament. The conductive material used in its embodiments is a mixture of one or two of MXene, carbon black, single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene, vapor-phase nanofibers, fullerenes, titanium carbide, copper sulfide, cuprous sulfide, and cuprous iodide, with the addition amount ranging from 0.05% to 8% of the polymer. Chinese invention patent CN112831178A discloses a conductive hybrid particle / polyamide composite material, the conductive material of which is a conductive polymer of polyaniline, polypyrrole, polythiophene, polyphenylene ethylene and a metal material of gold, silver, platinum, copper, and rhodium. However, the conductive materials mentioned above, such as carbon nanotubes and graphene, are easily agglomerated due to the van der Waals force and cannot be efficiently dispersed in polymer materials such as polyester. If a lower resistivity is required, a higher proportion of conductive material must be added, which is bound to lead to a deterioration of spinning properties and a decrease in mechanical properties. As for metal materials, their easy oxidation and corrosion resistance also greatly affect the conductive stability. At the same time, in order to achieve a lower resistivity, it is also necessary to increase the amount of addition, which will also promote the thermal degradation of polymer materials such as polyester during processing. In addition, for polymer conductive materials such as polyaniline, their conductivity currently mainly comes from the doping process of proton acid. Simply using this type of conductive polymer cannot achieve a better conductive effect. At the same time, during high-temperature processing, this type of conductive polymer will undergo dedoping, that is, the conductivity will decrease, which will lead to the deterioration of the conductive performance of the fiber.

[0004] In view of the problems caused by the above treatment methods, it is necessary to research and develop a conductive fiber technology with relatively simple process, which does not affect basic properties such as mechanical properties and can achieve lower resistivity. Nowadays, the research on modifying and compounding conductive materials has become a trend. Summary of the Invention

[0005] The object of the present invention is to provide a conductive polyester fiber and a preparation method thereof, so as to solve the deficiencies in the related art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] According to a first aspect of an embodiment of the present invention, a conductive polyester fiber is provided; the conductive polyester fiber comprises modified carbon nanotubes, polyester, and a polyaniline / MXene composite nanomaterial; wherein, based on the total mass of the conductive polyester fiber, the mass percentage of the modified carbon nanotubes is 0.35%-8.5%; the mass percentage of the polyaniline / MXene composite nanomaterial is 0.2%-6.5%.

[0008] In one aspect of the embodiments of the present invention, the modified carbon nanotubes are carbon nanotubes whose surfaces are modified with carboxyl groups, wherein the concentration of the carboxyl groups is 0.2%-10% relative to the modified carbon nanotubes.

[0009] In one aspect of the embodiments of the present invention, the modified carbon nanotubes are obtained by modifying single-walled carbon nanotubes, multi-walled carbon nanotubes, or a mixture of single-walled carbon nanotubes and multi-walled carbon nanotubes.

[0010] In one aspect of the embodiments of the present invention, the polyaniline / MXene composite nanomaterial includes: MXene nanosheets, and a polyaniline layer coated on the surface of the MXene nanosheets.

[0011] In one aspect of the embodiments of the present invention, the polyester is at least one of polyethylene terephthalate, polypropylene terephthalate, or polybutylene terephthalate.

[0012] According to a second aspect of an embodiment of the present invention, a method for preparing the conductive polyester fiber is provided, wherein the method comprises the following steps:

[0013] S1: adding carbon nanotube powder to deionized water, adding a small amount of polypyrrolidone dispersant, and ultrasonically treating the carbon nanotubes at room temperature, then filtering out the carbon nanotubes, drying, and grinding the carbon nanotubes to obtain a carbon nanotube pretreatment; then carboxyl-modifying the surface of the carbon nanotube pretreatment using a low-temperature plasma to obtain modified carbon nanotubes;

[0014] S2: adding MXene nanosheets to deionized water, adding dilute hydrochloric acid while stirring, continuing to stir for 0.5-2 hours, then adding aniline monomer, continuing to stir for 0.5-2 hours, so that the MXene nanosheets and aniline monomer are evenly mixed; then adding a polymerization initiator ammonium persulfate, stirring for 1-3 hours, and then standing for 12-24 hours to allow the aniline monomer to polymerize in situ on the surface of the MXene nanosheets; the resulting product is washed with deionized water and filtered, and then vacuum dried for 8-12 hours, and then ground to obtain the polyaniline / MXene composite nanomaterial;

[0015] S3: doping and mixing the modified carbon nanotube powder with the polyaniline / MXene composite nanomaterial to obtain a doped mixture; then adding the doped mixture together with polyester chips, a dispersant, and an antioxidant into a twin-screw extruder, and obtaining a conductive masterbatch by melt extrusion, strand cooling, and pelletizing;

[0016] S4: The conductive masterbatch and polyester chips are vacuum-dried and then put into a melt spinning machine to form a spinning melt through melting. The melt is then passed through the spinning box pipe to the spinning assembly and spinneret to obtain filaments, which are then cooled, bundled, oiled, and wound to form the conductive polyester fiber.

[0017] In one aspect of the embodiment of the present invention, in S1 to S3, the ultrasonic treatment time is 3 hours or more, and the grinding treatment time is 2 hours or more.

[0018] In one aspect of the embodiment of the present invention, in S1 , the low-temperature plasma treatment power is 100-500 W, the treatment time is 5-20 minutes, and the treatment gas is a mixture of argon and oxygen with a volume ratio of 3:1.

[0019] In one aspect of the embodiment of the present invention, in S2, the mass ratio of the aniline monomer to the MXene nanosheet is (0.2-1):1.

[0020] In one aspect of the embodiment of the present invention, in S3, the mass ratio of the modified carbon nanotube powder to the polyaniline / MXene composite nanomaterial is 1:(0.42-1).

[0021] In one aspect of the embodiment of the present invention, in S3, based on the total mass of the conductive masterbatch, the mass percentage of the doping mixture is selected from 5% to 25%.

[0022] In one aspect of the embodiment of the present invention, in S3, the doping mixture is added to the polyester chips by continuous metering through a volumetric powder metering device.

[0023] In one aspect of an embodiment of the present invention, in S3, the dispersant is any one or more of polyethylene glycol, polyvinyl pyrrolidone, sodium stearate, magnesium stearate or calcium stearate; based on the total mass of the conductive masterbatch, the mass percentage of the dispersant is selected from 0.5%-1.5%.

[0024] In one aspect of the embodiment of the present invention, in S3, the antioxidant is any one or more of the hindered phenol antioxidant 1010, the antioxidant 1024 or the antioxidant 1076; based on the total mass of the conductive masterbatch, the mass percentage of the antioxidant is selected from 0.1%-0.8%.

[0025] In one aspect of the embodiment of the present invention, in S3, the processing temperature of the twin-screw extruder is 240-280° C., and the screw speed is 200-400 rpm.

[0026] In one aspect of the embodiment of the present invention, in S4, the mass ratio of the polyester chips used in S4 to the conductive masterbatch is 1:(1-5.7).

[0027] In one aspect of the embodiment of the present invention, in S4, the melt spinning temperature is 250-300° C., the spinning speed is 1500-5000 m / min, and the spinneret is a single-component structure, a core-sheath type, or a split-type two-component composite structure.

[0028] In one aspect of the embodiments of the present invention, the material of the polyester chips is at least one of polyethylene terephthalate, polypropylene terephthalate or polybutylene terephthalate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The conductive polyester fiber provided by the present invention not only has the advantages of ordinary polyester fibers, but also has more excellent and stable conductive properties. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of this application, rather than all the embodiments. The relevant embodiments described herein are illustrative and are used to provide a basic understanding of this application. The embodiments of this application should not be interpreted as limiting this application.

[0032] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0033] In this document, the terms“include,”“includes” or“including” are used interchangeably and mean that something is included, but is not limited to, that which precedes it. Similarly, the terms“comprise,”“comprises” or“comprising” are used interchangeably and mean the same.

[0034] In the description herein, the terms“above,”“below” include the number unless otherwise indicated.

[0035] Unless otherwise defined, all terms used in the disclosure, including technical or scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. By means of example, the numerical values of the various parameters set forth in the present disclosure can be measured using any method of measurement in the art (for example, they can be tested according to the methods given in the examples of the present disclosure).

[0036] The term“about” is used to describe and account for small variations. When used in connection with an event or circumstance, the term can refer to instances where the event or circumstance occurs exactly, as well as instances where the event or circumstance occurs with close approximation. For example, when used in connection with a numerical value, the term can refer to a range of variation that is less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood as having been presented, for example, with the understanding that an individual value within the range is encompassed by the disclosure, unless explicitly stated otherwise. For example, if the disclosure indicates that a dosage is between 1 and 10 mg, it is intended that dosages of 1 mg, 2 mg, 3 mg, 4 mg, 5 mg, 6 mg, 7 mg, 8 mg, 9 mg, and 10 mg are

[0037] The list of items connected by“at least one of,”“at least one,”“at least one of the items,” or other similar phrases is meant not to be limited to just those items specifically named. For example, the phrase“at least one of A and B” is meant to include just A, just B, or both A and B. For example, the phrase“at least one of A, B, and C” is meant to include A alone, B alone, C alone, both A and B, both A and C, both B and C, or all of A, B, and C. The items A can include a single component or multiple components. The items B can include a single component or multiple components. The items C can include a single component or multiple components.

[0038] In the prior art, although carbon nanotubes have excellent low resistivity and are expected to replace traditional metal materials in the field of high-performance conductive materials to achieve more efficient electrical conductivity, the strong van der Waals forces between carbon nanotubes cause them to significantly agglomerate, making it difficult for the carbon nanotubes to be evenly dispersed in polyester materials. This poor dispersion of the carbon nanotubes can reduce the polyester's electrical conductivity. The conductive polyester fiber provided by the present invention contains modified carbon nanotubes with carboxyl functional groups introduced onto their surfaces. The carboxyl-functionalized carbon nanotubes have better dispersibility in polyester materials, and the surface carboxyl concentration of the modified carbon nanotubes is 0.2% to 10%, preferably 1% to 5%, of the total amount of the modified carbon nanotubes. Within this concentration range, the carbon nanotubes can be evenly dispersed in the polyester fiber, resulting in excellent and stable electrical conductivity.

[0039] The content of modified carbon nanotubes in the conductive polyester fiber provided by the present invention is 0.35%-8.5wt%; if its content is too high, it may cause the modified carbon nanotubes to agglomerate again, and the dispersibility in polyester will deteriorate, affecting the spinnability, mechanical properties or heat resistance of the polyester fiber; if its content is too low, the conductive effect of the polyester fiber will be poor.

[0040] In the prior art, according to the percolation theory, when conductive particles are added to a polymer substrate such as polyester, a certain concentration needs to be reached to form a conductive path in the substrate. Although in theory carbon nanotubes are relatively easy to form a conductive network, it is actually found during the composite processing with polyester that due to the agglomeration effect of carbon nanotubes, if you want to obtain more excellent conductive properties, you need to further increase the amount of carbon nanotubes added. As the amount of addition increases, the mechanical properties and spinnability of polyester show a significant decline. Therefore, in addition to surface modification of carbon nanotubes to improve dispersibility, it is also considered to use other conductive materials in combination with them, with the aim of bridging the gaps between adjacent carbon nanotubes to collaboratively construct a conductive network, so that a more excellent conductive effect can be obtained without increasing the amount of carbon nanotubes added.

[0041] In the present invention, the microstructure of the polyaniline / MXene composite nanomaterial presents a morphology in which polyaniline is coated on the surface of MXene nanosheets.

[0042] The polyaniline / MXene composite material selected in the present invention is compounded with modified carbon nanotubes for use. Polyaniline itself has poor electrical conductivity and needs to undergo a doping treatment to become a polymer conductive material with very excellent electrical conductivity. Although the doping process does not change the chemical properties of polyaniline itself, different dopants have a significant impact on the physical properties of the entire doping system, which in turn affects its application areas. Currently, the most commonly used dopants are organic acids or inorganic acids, such as hydrochloric acid, phosphoric acid, or sulfonic acid. However, this doping system is not resistant to high temperatures. In particular, when the processing temperature is higher than 200°C, the dopants will undergo large-scale thermal decomposition, resulting in dedoping, which causes the electrical conductivity of polyaniline to drop sharply or even be lost. MXene is an emerging two-dimensional material composed of transition metal carbides, nitrides, or carbonitrides. It has high electrical conductivity and high-temperature resistance similar to metals. At the same time, its large specific surface area and rich surface functional groups make it compatible with some materials, making it suitable for constructing multifunctional, high-performance hybrid materials. However, MXene, as a metal compound, can cause thermal degradation of polyester when processed at high temperatures with polyester, leading to a decrease in the mechanical properties of polyester fibers. The composite material formed by in-situ doping of polyaniline and MXene used in the present invention combines the characteristics of polymer materials with superior electrical conductivity and significantly improved high-temperature resistance, making it suitable for use in combination with carbon nanotubes.

[0043] The present invention discloses a method for preparing the conductive polyester fiber, and the specific steps are as follows:

[0044] S1: Add carbon nanotube powder to deionized water, add a small amount of polypyrrolidone dispersant at the same time, ultrasonically treat for 3-6 hours at room temperature, then filter out the carbon nanotubes, dry them, and grind them for more than 2 hours to obtain a carbon nanotube pretreatment product; the obtained carbon nanotube pretreatment product is subjected to carboxyl modification on its surface using a low-temperature plasma to obtain modified carbon nanotubes, wherein the low-temperature plasma treatment power is 100-500W, the treatment time is 5-20 minutes, the treatment gas is a mixture of argon and oxygen in a volume ratio of 3:1, the surface carboxyl concentration of the modified carbon nanotubes is 0.2%-10% of its total amount, and the modified carbon nanotubes are modified single-walled carbon nanotubes or modified multi-walled carbon nanotubes or a mixture thereof.

[0045] S2: Weigh MXene nanosheets and place them in deionized water and begin stirring. Add dilute hydrochloric acid while stirring and continue stirring for 1 hour. Then weigh aniline monomer and place it in the bucket. Continue stirring for 1 hour to fully and evenly mix the MXene nanosheets and aniline monomer. Add the polymerization initiator ammonium persulfate and stir for 2 hours. Then let it stand for more than 12 hours to allow the aniline to fully undergo in-situ polymerization on the MXene. The resulting product is washed with deionized water and filtered, then vacuum-dried at 60°C for at least 8 hours and ground for more than 2 hours to obtain a polyaniline / MXene composite nanomaterial. The mass ratio of aniline monomer to MXene nanosheets is 0.2:1-1:1, and the microstructure of the polyaniline / MXene composite nanomaterial is a morphology in which polyaniline is coated on the surface of the MXene nanosheets.

[0046] S3: The modified carbon nanotube powder prepared in S1 is doped and mixed with the polyaniline / MXene composite nanomaterial prepared in S2, wherein the mass ratio of the doped mixture is (50wt%:50wt%)-(70wt%:30wt%); the obtained doped mixture is fed into a twin-screw extruder together with ordinary polyester chips, dispersant, and antioxidant, and a conductive masterbatch is obtained by melt extrusion, strand cooling, and pelletizing, wherein the amount of the doped mixture added to the conductive masterbatch is 5wt%-25wt%, and the addition method is through volumetric powder metering. The adding device continuously adds a dispersant in a metered manner to the polyester polymer. The dispersant is any one or more of polyethylene glycol, polyvinyl pyrrolidone, sodium stearate, magnesium stearate or calcium stearate, and the addition amount relative to the conductive masterbatch is 0.5wt% to 1.5wt%; the antioxidant is any one or more of hindered phenol antioxidant 1010, antioxidant 1024 or antioxidant 1076, and the addition amount relative to the conductive masterbatch is 0.1wt% to 0.8wt%. The processing temperature of the twin-screw extruder is 240-280°C, and the screw speed is 200-400rpm.

[0047] S4. The conductive masterbatch and ordinary polyester chips prepared in S3 are vacuum dried respectively and then put into a melt spinning machine to form a spinning melt after melting, and then the spinning melt is fed into the electrically conductive polyester fiber through the spinning box pipe. The mass ratio of the ordinary polyester chips and the conductive masterbatch put into the melt spinning machine is (50wt%:50wt%)-(85wt%:15wt%), the melt spinning temperature is 250-300℃, the spinning speed is 1500-5000m / min, and the spinneret is a single-component structure or a core-sheath type or split-type two-component composite structure.

[0048] The particle size (measured by tube length) of the modified carbon nanotubes provided by the present invention is preferably less than or equal to 10 μm, and the particle size of the polyaniline / MXene composite nanomaterial provided by the present invention is preferably less than or equal to 5.0 μm. This size range is beneficial for spinnability during melt spinning.

[0049] The unit resistance of the conductive polyester fiber provided by the present invention is less than or equal to 10 6 Ω / cm, preferably less than or equal to 10 3 Ω / cm.

[0050] The present disclosure is further described below with reference to the following examples. It should be understood that these examples are only used to illustrate the present disclosure and are not intended to limit the scope of the present disclosure.

[0051] In the examples, the compounds used and their abbreviations are shown below:

[0052] Ethylene terephthalate (PET), trimethylene terephthalate (PTT), butylene terephthalate (PBT), carbon nanotubes (CNTs), single-walled carbon nanotubes (abbreviated as SWCNTs), multi-walled carbon nanotubes (abbreviated as MWCNTs), aniline monomer (ANI), polyaniline (PANI), and a doped mixture of modified carbon nanotube powder and polyaniline / MXene composite nanomaterials (abbreviated as CNTs_PANI / MXene).

[0053] The test methods involved in the embodiments are described as follows:

[0054] 1. Carboxyl concentration on the surface of carbon nanotubes:

[0055] By performing infrared spectroscopy analysis on the carbon nanotubes, the characteristic peak of the carboxyl group is identified, and the concentration of the carboxyl group is calculated based on the intensity of the characteristic peak.

[0056] 2. Content of modified carbon nanotubes and polyaniline / MXene composite nanomaterials:

[0057] Weigh an appropriate amount of sample weight M, accurate to 1 mg, place it in a ground-mouth conical flask, add 100 ml of phenol-chloroform mixed solvent, install a reflux condenser, heat and reflux on a heating device for 30 minutes, cool the fully dissolved mixture to room temperature, and then use a high-speed centrifuge (18000 rpm) for the first centrifugation. After the separation, the product is fully dried and weighed to obtain the weight M1. The product after the first centrifugation is then added to 50 ml of N-methylpyrrolidone solvent and fully stirred to dissolve. The dissolved mixture is centrifuged for the second time using a high-speed centrifuge (18000 rpm). After the separation, the product is fully dried and weighed to obtain the weight M2. Finally, the content of modified carbon nanotubes and polyaniline / MXene composite nanomaterials is calculated respectively; modified carbon nanotube content = M2 / M*100%.

[0058] Polyaniline / MXene composite nanomaterial content = (M1-M2) / M*100%.

[0059] 3. Particle size of various powders:

[0060] The measurement was performed by transmission electron microscopy (TEM).

[0061] 4. Unit resistance of fiber:

[0062] The test method is based on the conductive yarn conductivity test method in Appendix A of the Textile Industry Standard of the People’s Republic of China FZ / T12071-2021.

[0063] Examples and Comparative Examples:

[0064] Example 1

[0065] Single-walled carbon nanotube powder was added to deionized water, along with a small amount of polypyrrolidone dispersant. The mixture was ultrasonically treated at room temperature for at least 3 hours, then filtered, dried, and ground for at least 2 hours to obtain a pretreated single-walled carbon nanotube product. The surface of the pretreated product was carboxylated using a low-temperature plasma treatment power of 200 W for 10 minutes to obtain modified single-walled carbon nanotubes. Weigh MXene nanosheets and put them into deionized water and start stirring. Add dilute hydrochloric acid while stirring and continue stirring for 1 hour. Then weigh aniline monomer and put it into the bucket. Continue stirring for 1 hour to fully and evenly mix the MXene nanosheets and aniline monomer. The mass ratio of aniline monomer to MXene nanosheets is 0.6:1. Add polymerization initiator ammonium persulfate and stir for 2 hours. Then let it stand for more than 12 hours to allow aniline to fully undergo in situ polymerization on MXene. The resulting product is washed with deionized water and filtered, and then vacuum dried at 60°C for at least 8 hours and ground for more than 2 hours to obtain polyaniline / MXene composite nanomaterial for use. Modified single-walled carbon nanotube powder is doped and mixed with polyaniline / MXene composite nanomaterials, wherein the mass ratio of the doped mixture is 60wt%:40wt%; the obtained doped mixture is fed into a twin-screw extruder together with ordinary polyester PET chips, a dispersant, and an antioxidant, and a conductive masterbatch is prepared by melt extrusion, strand cooling, and pelletizing, wherein the doped mixture is added in an amount of 15wt% relative to the conductive masterbatch, and is added in a manner of continuous metering addition to the polyester PET polymer through a volumetric powder metering device; the dispersant is polyethylene glycol, and the addition amount relative to the conductive masterbatch is 1.0wt%; the antioxidant is a hindered phenol antioxidant 1010, and the addition amount relative to the conductive masterbatch is 0.2wt%. The processing temperature of the twin-screw extruder is 270°C, and the screw speed is 300rpm. The prepared conductive masterbatch and ordinary polyester PET chips are respectively vacuum-dried and fed into a melt spinning machine to form a spinning melt after melting. The melt is then passed through a spinning manifold pipe into a spinning assembly and a spinneret to obtain filaments. The filaments are then cooled, bundled, oiled, and wound to form conductive polyester fibers. The mass ratio of the ordinary polyester chips and the conductive masterbatch fed into the melt spinning machine is 60wt%:40wt%, the melt spinning temperature is 260°C, the spinning speed is 4000m / min, and the spinneret is a core-sheath type two-component composite structure, in which the conductive masterbatch is the sheath layer.

[0066] Example 2

[0067] The mass ratio of ordinary polyester chips and conductive masterbatch put into the melt spinning machine is 50wt%:50wt%, and the spinneret is a split-type two-component composite structure; the rest is the same as Example 1.

[0068] Example 3

[0069] The mass ratio of ordinary polyester chips and conductive masterbatch fed into the melt spinning machine was 85 wt%:15 wt%, and the rest was the same as in Example 1.

[0070] Example 4

[0071] The low-temperature plasma treatment power is 200 W, and the treatment time is 10 minutes; the rest is the same as in Example 1.

[0072] Example 5

[0073] The low-temperature plasma treatment power is 500 W, and the treatment time is 20 minutes; the rest is the same as in Example 1.

[0074] Example 6

[0075] The mass ratio of aniline monomer to MXene nanosheets was 0.2:1. The rest was the same as in Example 1.

[0076] Example 7

[0077] The mass ratio of aniline monomer to MXene nanosheets is 1:1; the rest is the same as in Example 1.

[0078] Example 8

[0079] Single-walled carbon nanotubes were replaced with multi-walled carbon nanotubes, and polyester was replaced with PBT from PET; the rest were the same as in Example 1.

[0080] Example 9

[0081] The single-walled carbon nanotubes were changed to a mixture of single-walled and multi-walled carbon nanotubes, and the polyester was changed from PET to PTT; the rest were the same as in Example 1.

[0082] Example 10

[0083] The mass ratio of the modified single-walled carbon nanotube powder and the polyaniline / MXene composite nanomaterial doped and mixed is 50 wt %:50 wt %; the rest is the same as in Example 1.

[0084] Example 11

[0085] The modified single-walled carbon nanotube powder and the polyaniline / MXene composite nanomaterial were mixed in a mass ratio of 70 wt % to 30 wt %. Others were the same as in Example 1.

[0086] Example 12

[0087] The addition amount of the modified single-walled carbon nanotube powder and the polyaniline / MXene composite nanomaterial doping mixture relative to the conductive masterbatch is 10 wt %; the rest is the same as in Example 1.

[0088] Example 13

[0089] The modified single-walled carbon nanotube powder and polyaniline / MXene composite nanomaterial doping mixture is added in an amount of 25wt% relative to the conductive masterbatch; the rest is the same as Example 1.

[0090] Example 14

[0091] The modified single-walled carbon nanotube powder and polyaniline / MXene composite nanomaterial doping mixture is added in an amount of 5wt% relative to the conductive masterbatch, the spinneret is a single-component structure, and the conductive masterbatch is directly melt-spun; the rest is the same as Example 1.

[0092] Comparative Example 1

[0093] The single-walled carbon nanotube is not modified by low-temperature plasma, and the modified single-walled carbon nanotube powder and polyaniline / MXene composite nanomaterial doping mixture is added in an amount of 25wt% relative to the conductive masterbatch; the rest is the same as Example 1.

[0094] Comparative Example 2

[0095] No polyaniline / MXene composite nanomaterial is added, and the modified single-walled carbon nanotube powder is added in an amount of 12wt% relative to the conductive masterbatch; the rest is the same as Example 1.

[0096] Comparative Example 3

[0097] The modified single-walled carbon nanotube powder and polyaniline / MXene composite nanomaterial doping mixture is added in an amount of 50wt% relative to the conductive masterbatch; the rest is the same as Example 1.

[0098] The fiber samples of Examples 1-14 and Comparative Examples 1-3 are tested, the content of the modified carbon nanotube and polyaniline / MXene composite nanomaterial is tested, and the fiber strength and unit resistance are tested. The specific results are shown in Table 1.

[0099] Table 1:

[0100]

[0101]

[0102]

[0103] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the application embrace any and all variations of the present application that fall within the scope of the other embodiments of the present application. Accordingly, other embodiments of the application are intended to be encompassed by this specification, including any and all variations of the present application that fall within the scope of the other embodiments of the present application.

Claims

1. A conductive polyester fiber, characterized in that: The conductive polyester fiber contains modified carbon nanotubes, polyester, and polyaniline / MXene composite nanomaterials; wherein, based on the total mass of the conductive polyester fiber, the mass percentage of the modified carbon nanotubes is 0.35%-8.5%; the mass percentage of the polyaniline / MXene composite nanomaterial is 0.2%-6.5%.

2. The conductive polyester fiber according to claim 1, characterized in that The modified carbon nanotubes are carbon nanotubes whose surfaces are modified with carboxyl groups, wherein the concentration of the carboxyl groups is 0.2%-10% relative to the modified carbon nanotubes.

3. The conductive polyester fiber according to claim 1 or 2, characterized in that The modified carbon nanotubes are obtained by modifying single-walled carbon nanotubes, multi-walled carbon nanotubes, or a mixture of single-walled carbon nanotubes and multi-walled carbon nanotubes.

4. The conductive polyester fiber according to claim 1, characterized in that The polyaniline / MXene composite nanomaterial includes: MXene nanosheets and a polyaniline layer coated on the surface of the MXene nanosheets.

5. The conductive polyester fiber according to claim 1, characterized in that The polyester is at least one of polyethylene terephthalate, polypropylene terephthalate or polybutylene terephthalate.

6. A method for preparing the conductive polyester fiber according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: S1: adding carbon nanotube powder to deionized water, adding a small amount of polypyrrolidone dispersant, and ultrasonically treating the carbon nanotubes at room temperature, then filtering out the carbon nanotubes, drying, and grinding the carbon nanotubes to obtain a carbon nanotube pretreatment; then carboxyl-modifying the surface of the carbon nanotube pretreatment using a low-temperature plasma to obtain modified carbon nanotubes; S2: adding MXene nanosheets to deionized water, adding dilute hydrochloric acid while stirring, continuing to stir for 0.5-2 hours, then adding aniline monomer, continuing to stir for 0.5-2 hours, so that the MXene nanosheets and aniline monomer are evenly mixed; then adding a polymerization initiator ammonium persulfate, stirring for 1-3 hours, and then standing for 12-24 hours to allow the aniline monomer to polymerize in situ on the surface of the MXene nanosheets; the resulting product is washed with deionized water and filtered, and then vacuum dried for 8-12 hours, and then ground to obtain the polyaniline / MXene composite nanomaterial; S3: doping and mixing the modified carbon nanotube powder with the polyaniline / MXene composite nanomaterial to obtain a doped mixture; then adding the doped mixture together with polyester chips, a dispersant, and an antioxidant into a twin-screw extruder, and obtaining a conductive masterbatch by melt extrusion, strand cooling, and pelletizing; S4: The conductive masterbatch and polyester chips are vacuum-dried and then put into a melt spinning machine to form a spinning melt through melting. The melt is then passed through the spinning box pipe to the spinning assembly and spinneret to obtain filaments, which are then cooled, bundled, oiled, and wound to form the conductive polyester fiber.

7. The preparation method according to claim 6, characterized in that The preparation method satisfies any one of the following conditions: (1) In S1 to S3, the ultrasonic treatment time is 3 hours or more, and the grinding treatment time is 2 hours or more; (2) In S1, the low-temperature plasma treatment power is 100-500W, the treatment time is 5-20 minutes, and the treatment gas is a mixture of argon and oxygen with a volume ratio of 3:1; (3) In S2, the mass ratio of the aniline monomer to the MXene nanosheet is (0.2-1):1; (4) In S3, the mass ratio of the modified carbon nanotube powder to the polyaniline / MXene composite nanomaterial is 1:(0.42-1); (5) In S3, based on the total mass of the conductive masterbatch, the mass percentage of the doping mixture is selected from 5% to 25%; (6) In S3, the doping mixture is added to the polyester chips by continuous metering through a volumetric powder metering device; (7) In S3, the dispersant is any one or more of polyethylene glycol, polyvinyl pyrrolidone, sodium stearate, magnesium stearate or calcium stearate; based on the total mass of the conductive masterbatch, the mass percentage of the dispersant is selected from 0.5% to 1.5%; (8) In S3, the antioxidant is any one or more of the hindered phenol antioxidant 1010, the antioxidant 1024, or the antioxidant 1076; based on the total mass of the conductive masterbatch, the mass percentage of the antioxidant is selected from 0.1% to 0.8%; (9) In S3, the processing temperature of the twin-screw extruder is 240-280°C and the screw speed is 200-400 rpm; (10) In S4, the mass ratio of the polyester chips used in S4 to the conductive masterbatch is 1:(1-5.7); (11) In S4, the melt spinning temperature is 250-300 °C, the spinning speed is 1500-5000 m / min, and the spinneret is a single-component structure, a core-sheath type, or a split-type two-component composite structure.

8. The preparation method according to claim 6, characterized in that The material of the polyester chips is at least one of polyethylene terephthalate, polypropylene terephthalate or polybutylene terephthalate.

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