A small-scale production method of conductive polyurethane fibers

Abstract

The application discloses a kind of preparation methods of electrically conductive polyurethane fiber small test, comprising the following steps: polyurethane stock solution and conductive component are premixed to form spinning solution under inert atmosphere, spinning solution is circulated and mixed by gear pump, and after being filtered by filter, it is discharged from spinneret, and is spun into silk through spinning duct, drawing and winding.The application directionally selects N-isopropyl acrylamide or acrylic acid polymer as conductive component base and conductive substance to form conductive component, its polarity, chain segment structure and polyurethane stock solution are highly matched, can be spontaneously and uniformly dispersed in solvent-free system, completely solve the core problem that traditional conductive filler is easy to agglomerate, phase separation;Specific flexible polymer base can form physical entanglement with polyurethane chain segment, the original elasticity and mechanical properties of polyurethane are not damaged after the addition of conductive component, the interaction between conductive component and polyurethane in polyurethane is solved, so that the performance upgrading of electrically conductive polyurethane is realized, and the requirement of spinning performance is met.

Description

Technical Field

[0001] This invention belongs to the field of functional material preparation technology, specifically relating to a small-scale preparation method for conductive polyurethane fibers. Background Technology

[0002] Conductive fibers have become a research hotspot in the field of functional materials due to their wide applications in electromagnetic shielding, electronic devices, information storage, smart sensing, and textiles and apparel. Polyurethane, with its excellent mechanical properties and good processability, is one of the important matrix materials for preparing conductive fibers.

[0003] Currently, the main method for preparing conductive polyurethane fibers is to introduce conductive fillers into a polyurethane matrix and then form them through dry spinning or melt spinning processes. Various conductive filler systems have been reported in the prior art, such as carbon black (CN202011012946.1), metal particles (CN201410356274.4, CN201911283199.2), graphene (CN202210072628.7), and carbon nanotubes (CN202011503033.X). Based on these systems, studies have attempted to prepare conductive spandex fibers (such as CN119405299A, CN119736795A). However, despite numerous related studies and patent applications, technical solutions that can achieve stable spinning and meet the requirements of industrial production remain extremely scarce.

[0004] The reasons for this are mainly due to the following key problems faced by existing technologies: First, conductive fillers are prone to agglomeration in the polyurethane matrix, resulting in poor dispersibility and insufficient conductivity and instability of the material. Second, and more importantly, the introduction of conductive fillers often disrupts the continuous phase structure of polyurethane, leading to a significant decrease in the fiber's tensile strength and other mechanical properties. In actual production, it is difficult to maintain the original excellent mechanical properties of polyurethane while simultaneously imparting stable conductivity. This inherent contradiction between conductivity and mechanical properties is the main technical bottleneck restricting the industrial-scale mass production of conductive polyurethane fibers.

[0005] Therefore, how to maintain or even improve the mechanical properties of polyurethane fibers, especially their tensile strength, while improving their electrical conductivity remains a technical challenge that urgently needs to be addressed in this field. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a small-scale preparation method for conductive polyurethane fibers. This method involves mixing a polymer substrate and a conductive component of a conductive material with a polyurethane stock solution, followed by dry spinning to prepare conductive polyurethane. The monomers used to prepare the polymer substrate in the conductive component include N-isopropylacrylamide and / or acrylic acid to improve the compatibility between the conductive component and the polyurethane stock solution, thereby solving the problem that the conductivity and tensile strength of existing conductive fibers cannot be simultaneously improved.

[0007] To achieve the above objectives, the present invention first provides a small-scale preparation method for conductive polyurethane fibers, comprising the following steps: Polyurethane raw material and conductive component are premixed in an inert atmosphere to form spinning solution. The spinning solution is circulated and mixed by a gear pump, filtered and exited from the spinneret, and then passed through the spinning tunnel, drawn and wound into filaments. The conductive component includes a conductive material and a polymer substrate. The monomers for preparing the polymer substrate include N-isopropylacrylamide and / or acrylic acid.

[0008] In one embodiment of the present invention, the polymer substrate includes at least one of poly(N-isopropylacrylamide) and its copolymers, polyacrylic acid and its copolymers, and poly(N-isopropylacrylamide-acrylic acid), wherein the copolymer of poly(N-isopropylacrylamide) may be selected from poly(N-isopropylacrylamide-4-aminostyrene), etc.; the polymer substrate may also include poly(methacrylic acid) and its copolymers, poly(ethylacrylic acid) and its copolymers, polyethylene glycol, polyurethane, etc.

[0009] In one embodiment of the present invention, the polymer substrate is a copolymer formed from two or more of the above monomers.

[0010] This invention selects poly(N-isopropylacrylamide) or polyacrylic acid polymer matrix as an important component of the conductive component. The aim is to improve its compatibility with the polyurethane raw material, enabling stable spinning during the spinning process and producing conductive polyurethane fibers with superior mechanical properties. Other types of polymer matrices, such as polyethylene glycol, polyvinyl acetate, and sulfonated polystyrene, can be added in small amounts, but these materials cannot be used exclusively as the polymer matrix; otherwise, it will be impossible to produce conductive fibers with better performance, or even to achieve stable spinning.

[0011] In one embodiment of the present invention, the conductive material is a conductive polymer and / or a metal, wherein the conductive polymer is selected from one or more of polyaniline, polypyrrole, and polythiophene; and the metal is selected from one or more of gold, silver, platinum, copper, and rhodium.

[0012] In one embodiment of the present invention, the mass ratio of the conductive material to the polymer substrate is 1:1 to 1:10, preferably 1:1 to 1:5. For example, 1:1, 1:2 or 1:5.

[0013] In one embodiment of the present invention, the mass of the conductive component is 8 to 20% of the mass of the polyurethane stock solution. As an example, the mass of the conductive component is 10%, 15%, or 20% of the mass of the polyurethane stock solution.

[0014] The mass ratio of the conductive material to the polymer matrix and the amount of conductive component added are also very critical parameters. If the amount of conductive material or conductive component added is large, although it can enhance conductivity, it will lead to poor fiber mechanical properties or even unstable spinning.

[0015] In one embodiment of the present invention, the conductive component can be prepared by conventional methods, such as adsorption, precipitation, in-situ growth, or by adding a conductive substance during the preparation of the polymer substrate. For example, the specific preparation method is as follows: The monomers, crosslinking agent, and solvent for preparing the polymer substrate are mixed, nitrogen gas is introduced, a first initiator is added to carry out an in-situ polymerization reaction, and then the mixture is mixed with the monomers of the conductive polymer. A second initiator is then added to carry out an in-situ polymerization reaction of the conductive polymer, and the conductive component is obtained through in-situ growth. Dodecylbenzenesulfonic acid is not used in the preparation process.

[0016] In one embodiment of the present invention, the content of the crosslinking agent is less than 50% of the polymer matrix mass, preferably 1 to 20%, more preferably 2 to 8%, and the crosslinking agent is selected from at least one of, for example: N,N'-methylenebisacrylamide, divinylbenzene, 4,4-dihydroxymethylstilbene, 1,4-butadiene, hexadiene, etc.

[0017] In one embodiment of the present invention, the first initiator and the second initiator may be the same or different, for example selected from water-soluble initiators and / or conductive polymer polymerization initiators. For example, the water-soluble initiator is selected from sodium persulfate, ammonium persulfate, potassium persulfate and other water-soluble initiators, and the conductive polymer polymerization initiator is selected from potassium permanganate, potassium chromate, ferric chloride, ferric sulfate and other conventional conductive polymer polymerization initiators.

[0018] In one embodiment of the present invention, the temperature of the first in-situ polymerization reaction is 40 to 90°C, for example 50°C, 60°C, 70°C, or 80°C; the time of the in-situ polymerization reaction is 0.5 hours or more, preferably 2 to 9 hours, for example 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0019] In one embodiment of the present invention, the temperature of the in-situ polymerization reaction after adding the monomer of the conductive polymer is preferably 0-30°C.

[0020] In one embodiment of the present invention, the solvent is a solvent capable of dissolving the raw materials in the system, such as one or more of water, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethanol, methanol, acetone and toluene, preferably water.

[0021] In one embodiment of the present invention, the conductive component further comprises the following substances: N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and / or N-hydroxysuccinimide; these substances can be added during the mixing process, with an addition amount of 0.1%-10%. The role of adding these substances is to introduce chemical bonds between the conductive component and the polyurethane, thereby increasing the bonding force between the conductive component and the polyurethane, and thus improving the stable spinning ability and mechanical properties of the conductive polyurethane fiber.

[0022] In one embodiment of the present invention, the preparation of the polyurethane raw material includes four steps: (1) Prepolymerization: Diphenylmethane diisocyanate (MDI) and polytetramethylene ether glycol (PTMEG, molecular weight 1600~2400) were reacted in N,N-dimethylacetamide (DMAc) solvent. The molar ratio of MDI to PTMEG was 1.60~1.90, and the solid content of the DMAC-containing prepolymer solution was 70%. The prepolymerization reaction was carried out at a low temperature of 10℃, and the reaction was carried out at a jacket water temperature of 10℃~15℃ for 2~3 hours. (2) Chain extension polymerization: The chain extension process involves reacting with excess amine at a low temperature of 5-13℃. The main chain extender additives are selected from one or a mixture of several of ethylenediamine (EDA), propylenediamine (1,2-propanediamine, PDA), and pentanediamine (2-methyl-1,5-pentanediamine, PTDA); when EDA is the main chain extender, the main chain extender accounts for 80%-100% of the total molar number of the chain extender. The terminator is selected from diethylamine (DEA) or cyclohexylamine (CHA). The chain extender, terminator and N,N-dimethylacetamide (DMAc) solvent are mixed to prepare a mixed amine solution, wherein the molar number of amine groups of the terminator accounts for 3%-7% of the total molar number of amine groups in the mixed amine solution, and the mass concentration of the total amine in the mixed amine solution is 4%-6%; after the chain extension reaction is completed, the ratio of the total molar number of amine groups in the mixed amine solution to the molar number of isocyanate (NCO) end groups of the prepolymer is 1.015-1.050; (3) Adding excipients: After the chain extension step is completed, add titanium dioxide (TDO) (addition amount 0.2-2%), solubilizer (magnesium stearate, MG, addition amount 0.1%-0.5%), anti-yellowing agent (LDZ-9, addition amount 0.2%-0.5%) and antioxidant (OA245, addition amount 0.6%-1%) to the original solution. Stir at a speed of 30 rap / min for 90 min during the addition process.

[0023] (4) Curing of raw polyurethane solution: Place the polyurethane raw solution obtained in the above steps at 30℃-36℃ for 27-36 hours. The reaction is terminated, and the concentration of the polyurethane raw solution is 33-35%, the viscosity is 200-400 Pa s, and the temperature is 40℃.

[0024] The above preparation process does not involve dissolving polyurethane in a solvent to obtain a polyurethane solution, but instead directly synthesizes a raw polyurethane solution, i.e., a polyurethane stock solution.

[0025] In one embodiment of the present invention, an example of a specific method for preparing the conductive polyurethane fiber is as follows: (1) Place 35 kg of the stock solution into a 50 L reactor and add 4 kg of the conductive component solution. Stir at 50 °C for more than 2 hours, mix and discharge the mixture into a container with a plastic film bag, seal it tightly, and transport it to the spinning workshop for spinning. During the stirring process, a small amount of solvent DMAC can be added as needed, and nitrogen protection can be used.

[0026] (2) The above spinning solution is filtered by a filter at a pressure of 2~5 MPa; the filter pore size is 20~50 μm; (3) The spinning mixture of the polyurethane and conductive component is placed in a storage tank. The spinning mixture enters the spinning tunnel through a gear pump, filter, pressure pump, pipeline, and spinneret. After passing through the spinning tunnel, conductive fibers are obtained through drawing and winding. The temperature of the spinning tunnel is selected from 230℃-260℃, preferably 240℃. The spinning rate is 500-650 m / min.

[0027] In one embodiment of the present invention, the resistivity of the conductive spandex fiber is 10. 6 -10 9 Ω.

[0028] In one embodiment of the present invention, the conductive spandex has a breaking elongation of 500%-700% and a breaking strength greater than 0.8 cN / dtex, preferably 0.8~1.0 cN / dtex.

[0029] In one embodiment of the present invention, before or during mixing the conductive component with the prepolymer or solution of polyurethane, an additive such as a metal ion, a protic acid, or a base may be added. Preferably, the amount of the additive added does not exceed 0.1% of the mass of the polyurethane.

[0030] The present invention also provides a conductive polyurethane fiber prepared by the above preparation method.

[0031] The present invention also provides an application of the above-mentioned conductive polyurethane fiber in the fields of electromagnetic shielding, electronic devices, information storage, smart sensing and textiles and clothing.

[0032] Beneficial effects: (1) This invention selectively uses poly(N-isopropylacrylamide) and its copolymers, polyacrylic acid and its copolymers, and poly(N-isopropylacrylamide-acrylic acid) as the conductive component base. Their polarity and chain segment structure are highly compatible with the polyurethane raw material, allowing for spontaneous and uniform dispersion in a solvent-free system. This completely solves the core problems of easy agglomeration and phase separation in traditional conductive fillers. The specific flexible polymer base can form physical entanglement with the polyurethane chain segments. The addition of the conductive component does not damage the original elasticity and mechanical properties of the polyurethane. The fiber breaking elongation, strength, and other indicators all meet the standards, balancing both conductivity and performance. This invention focuses on solving the interaction between the conductive component and the polyurethane in the polyurethane, thereby achieving a performance upgrade for conductive polyurethane and meeting the requirements for spinning performance.

[0033] (2) In this invention, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide and other additives are added to the conductive component. Due to the special polymer base and the substances added to the conductive component, the conductive component and polyurethane have miscibility and a certain interaction, thereby improving the dispersion and stability of the conductive material in the polyurethane, effectively improving the conductivity, thus initially solving the spinning problem of conductive polyurethane. At the same time, the prepared conductive polyurethane fiber can maintain good mechanical properties.

[0034] (3) The present invention directly uses polyurethane raw liquid to mix with conductive components, abandoning the traditional solvent blending and melt blending methods. There is no solvent residue, the viscosity of the system is suitable for spinning requirements, and continuous and stable dry spinning can be achieved, effectively avoiding problems such as spinneret blockage and filament breakage, and meeting the needs of industrial mass production of conductive polyurethane fibers. Attached Figure Description

[0035] Figure 1 This is an image showing the appearance of the conductive polyurethane fiber prepared in Example 4 of the present invention. Detailed Implementation

[0036] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0037] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0038] Example 1 A pilot-scale preparation method for conductive polyurethane fibers includes the following steps: 4 kg of conductive component and 35 kg of 33% polyurethane stock solution were poured into a 50 L stirred tank and mixed. The mixture was heated to 50 °C, nitrogen gas was introduced, and the stirring speed was 50 r / min. After stirring for 3 hours, a uniform polyurethane mixture was obtained. The mixture was then transferred into a barrel lined with a plastic bag and transported to the workshop.

[0039] The polyurethane mixture is poured into a storage tank and circulated using a gear pump to maintain uniformity. A booster pump is used to pass the mixture through a filter and a metering pump before it enters the spinneret. After exiting the spinneret, the mixture enters the spinning tunnel, where the air temperature is set at 250°C. Fibers are formed in the tunnel and then drawn and wound into filaments at a spinning rate of 550 m / min.

[0040] The conductive component is a conductive hybrid particle of poly(N-isopropylacrylamide-4-aminostyrene) and polyaniline, with a mass ratio of 1:1. The preparation method of the conductive hybrid particle of poly(N-isopropylacrylamide-4-aminostyrene) and polyaniline is as follows: 0.25 g N-isopropylacrylamide, 0.0575 g N,N'-methylenebisacrylamide, and 0.03 g 4-aminostyrene were dispersed in 35 mL N,N-dimethylacetamide. 0.02 g ammonium persulfate was added, and the mixture was heated and stirred under nitrogen atmosphere at 70 °C for 4 hours to obtain poly(N-isopropylacrylamide-4-aminostyrene). 200 mL deionized water, 2.66 g aniline, 106.6 mL 37% hydrochloric acid, and 2.85 g ammonium persulfate were added and stirred. The mixture was then reacted at 70 °C for 4 hours to obtain conductive hybrid particles.

[0041] The preparation method of the polyurethane raw material includes the following steps: (1) Prepolymerization: Diphenylmethane diisocyanate (MDI) and polytetramethylene ether glycol (PTMEG, molecular weight 2000) were reacted in N,N-dimethylacetamide (DMAc) solvent. The molar ratio of MDI to PTMEG was 1.8, and the solid content of the prepolymer solution containing DMAc was 70%. The prepolymerization reaction was carried out at a low temperature of 10°C, and the reaction was carried out under jacket water insulation at 10°C for 3 hours.

[0042] (2) Chain extension polymerization: The prepolymer solution obtained in step (1) is further diluted with solvent to a prepolymer concentration of 47%. The diluted prepolymer solution is then cooled to below 10°C with a coolant. A mixed amine solution is added to carry out the chain extension reaction. The mixed amine solution is a mixed solution of N,N-dimethylacetamide (DMAc), ethylenediamine and diethylamine (DEA). The number of moles of amino groups in diethylamine accounts for 5% of the total number of amino groups in the total amine. The mass concentration of the total amine in the mixed amine solution is 4.5%. The ratio of the total number of moles of amino groups in diethylamine and ethylenediamine to the number of moles of NCO groups in the prepolymer is 1.05. (3) Adding excipients: Add titanium dioxide (1% of the mass of the mixture), a soothing agent (magnesium stearate, MG, 0.5%), an anti-yellowing agent (LDZ-9, 0.5%) and an antioxidant (OA245, 0.8%) to the chain-extended mixture obtained in step (2). Stir at a speed of 30 rap / min for 90 min during the addition process. (4) Curing of raw polyurethane solution: The polyurethane raw solution obtained in the above steps is placed at 35°C for curing for 30 hours. The reaction is terminated, and the mass concentration of the polyurethane raw solution is 33%.

[0043] Example 2 The difference between Example 2 and Example 1 is that the air temperature in the spinning tunnel is set at 240°C during spinning.

[0044] Example 3 The difference between Example 3 and Example 2 is that poly(N-isopropylacrylamide-4-aminostyrene) is replaced with poly(N-isopropylacrylamide-acrylic acid), and 1% N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride is added to the conductive component. The preparation method of poly(N-isopropylacrylamide-acrylic acid) is as follows: 0.25gN Isopropylacrylamide, 0.0575g N,N' Methylenebisacrylamide, 0.01 g acrylic acid, and 0.02 g ammonium persulfate were dispersed in 35 mL of water and reacted at 70 °C for 4 hours to obtain poly(N-isopropylacrylamide-acrylic acid).

[0045] The spinning rate in Example 3 was 510 m / min.

[0046] Example 4 The difference between Example 4 and Example 3 is that the conductive component contains poly(N-isopropylacrylamide-acrylic acid), polyaniline and polyethylene glycol in a mass ratio of 1:1:1. In addition, 1% of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added to the conductive component in a mass ratio of 1:1.

[0047] Example 5 The difference between Example 5 and Example 3 is that the conductive component contains poly(N-isopropylacrylamide-acrylic acid) and polyaniline in a mass ratio of 1:1, and then 1% of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added to the conductive component in a mass ratio of 1:1.

[0048] Example 6 The difference between Example 6 and Example 3 is that the conductive component contains poly(N-isopropylacrylamide-acrylic acid), polyaniline and lithium nitrate in a mass ratio of 1:1:1. Then, 1% of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added to the conductive component in a mass ratio of 1:1.

[0049] Table 1. Volume resistivity and mechanical properties of the conductive polyurethane fibers prepared in Examples 1-6

[0050] As shown in Table 1, Examples 1 and 2, by adding conductive components (conductive hybrid particles of poly(N-isopropylacrylamide-4-aminostyrene) and polyaniline) to the polyurethane raw solution and spinning the mixture, yielded conductive polyurethane fibers with certain conductivity and good mechanical properties, including a breaking strength greater than 0.9 cN / dtex and an elongation at break greater than 500%. Example 3 used conductive hybrid particles of poly(N-isopropylacrylamide-acrylic acid) and polyaniline mixed with the polyurethane solution, and added N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride to the mixture, further improving the conductivity of the polyurethane fibers. Similarly, the fibers in Examples 4-6 were also prepared by adding N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and other components to the mixture of conductive hybrid particles and polyurethane raw solution. The results showed that after adding additional additives, the conductivity of the conductive polyurethane fibers was significantly improved. Although the mechanical properties decreased slightly, they remained at a high level. The above results indicate that the addition of additives such as N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide helps to increase the compatibility and binding force between the conductive components and the polyurethane solution, enabling the conductive components to be dispersed more uniformly and the polyurethane fibers to be generated more stably.

[0051] In addition, the experiment also tested the conductive hybrid particles of other conductive components such as polyethylene glycol acrylate and polyaniline, as well as poly(ethylene glycol acrylate). The study investigated the properties of conductive fibers prepared by mixing conductive hybrid particles of hydroxyethyl acrylamide and polyaniline with polyurethane raw materials. The results showed that due to the poor compatibility of these materials with polyurethane, they could not be stably spun into polyurethane fibers. Even if fibers were produced, their mechanical and electrical properties were poor.

[0052] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A pilot-scale preparation method for conductive polyurethane fibers, characterized in that, Includes the following steps: Polyurethane raw material and conductive component are premixed in an inert atmosphere to form spinning solution. The spinning solution is circulated and mixed by a gear pump, filtered and exited from the spinneret, and then passed through the spinning tunnel, drawn and wound into filaments. The conductive component includes a conductive material and a polymer substrate. The monomers for preparing the polymer substrate include N-isopropylacrylamide and / or acrylic acid.

2. The small-scale preparation method according to claim 1, characterized in that, The polymer substrate includes at least one of poly(N-isopropylacrylamide) and its copolymers, polyacrylic acid and its copolymers, and poly(N-isopropylacrylamide-acrylic acid), wherein the copolymer of poly(N-isopropylacrylamide) may be selected from poly(N-isopropylacrylamide-4-aminostyrene); the polymer substrate may also include at least one of poly(methacrylic acid) and its copolymers, poly(ethylacrylic acid) and its copolymers, polyethylene glycol, and polyurethane.

3. The small-scale preparation method according to claim 1, characterized in that, The conductive material is a conductive polymer and / or a metal, wherein the conductive polymer is selected from one or more of polyaniline, polypyrrole, and polythiophene; the metal is selected from one or more of gold, silver, platinum, copper, and rhodium; and the mass ratio of the conductive material to the polymer substrate is 1:1 to 1:

10.

4. The small-scale preparation method according to claim 1, characterized in that, The conductive component accounts for 8-20% of the mass of the polyurethane stock solution, and the preparation method of the conductive component includes the following steps: The monomers, crosslinking agents, and solvents used to prepare the polymer substrate are mixed, nitrogen gas is introduced, a first initiator is added to carry out an in-situ polymerization reaction, and then the mixture is mixed with the monomers of the conductive polymer. A second initiator is then added to carry out an in-situ polymerization reaction of the conductive polymer, and the conductive component is obtained by in-situ growth. Dodecylbenzenesulfonic acid is not used in the preparation process.

5. The small-scale preparation method according to claim 4, characterized in that, The amount of crosslinking agent added is 1-20% of the polymer matrix mass, and the crosslinking agent is selected from at least one of N,N'-methylenebisacrylamide, divinylbenzene, 4,4-dihydroxymethylstilbene, 1,4-butadiene, and hexadiene.

6. The small-scale preparation method according to claim 4, characterized in that, The first initiator and the second initiator are selected from water-soluble initiators and / or conductive polymer polymerization initiators. The water-soluble initiator is selected from at least one of sodium persulfate, ammonium persulfate, potassium persulfate, and other water-soluble initiators. The conductive polymer polymerization initiator is selected from at least one of potassium permanganate, potassium chromate, ferric chloride, ferric sulfate, and other conventional conductive polymer polymerization initiators.

7. The pilot-scale preparation method according to claim 1, characterized in that, The conductive component further comprises additives, which are N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and / or N-hydroxysuccinimide, and the amount of additives added is 0.1%-10% of the mass of the conductive component.

8. The small-scale preparation method according to claim 1, characterized in that, The preparation of the polyurethane raw material includes four steps: (1) Prepolymerization: Diphenylmethane diisocyanate (MDI) and polytetramethylene ether glycol (PTMEG) are reacted in N,N-dimethylacetamide (DMAc) solvent; wherein the molar ratio of MDI to PTMEG is 1.60~1.90, the solid content of the DMAC-containing prepolymer solution is 70%, the prepolymerization reaction is carried out at a low temperature of 10℃, and the prepolymerization reaction is carried out at a jacket water temperature of 10℃~15℃ for 2~3 hours; (2) Chain extension polymerization: The chain extension process involves reacting with excess amine at a low temperature of 5-13℃; the main chain extender additives are selected from one or a mixture of several of ethylenediamine (EDA), propylenediamine (1,2-propanediamine, PDA), and pentanediamine (2-methyl-1,5-pentanediamine, PTDA); when EDA is the main chain extender, the main chain extender accounts for 80%-100% of the total molar number of the chain extender. The terminator is selected from diethylamine (DEA) or cyclohexylamine (CHA). The chain extender, terminator and N,N-dimethylacetamide (DMAc) solvent are mixed to prepare a mixed amine solution, wherein the molar number of amine groups of the terminator accounts for 3%-7% of the total molar number of amine groups in the mixed amine solution, and the mass concentration of the total amine in the mixed amine solution is 4%-6%; after the chain extension reaction is completed, the ratio of the total molar number of amine groups in the mixed amine solution to the molar number of isocyanate (NCO) end groups of the prepolymer is 1.015-1.050; (3) Adding excipients: After the chain extension step is completed, add titanium dioxide (TDO), solubilizer, anti-yellowing agent and antioxidant to the stock solution. Stir at 30 rap / min for 90 min during the addition process; (4) Curing of raw material: Place the polyurethane raw material completed in steps (1) to (3) at 30℃-36℃ for curing for 27-36 hours; the reaction is terminated, the concentration of polyurethane raw material is 33%-35%, the viscosity is 200-400 Pa s, and the temperature is 40℃.

9. The conductive polyurethane fiber prepared by the pilot-scale preparation method according to any one of claims 1 to 8.

10. The application of the conductive polyurethane fiber according to claim 9 in electromagnetic shielding, electronic devices, information storage, intelligent sensing, and textiles and clothing.

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