Composite aramid insulation paper and method of making the same

Abstract

The application discloses a kind of composite aramid insulation paper and preparation method thereof, it is related to insulating material technical field, composite aramid insulation paper includes polyvinylpyrrolidone, aramid fiber and aminated carbon nanotube, aminated carbon nanotube is evenly dispersed in aramid fiber matrix, and the mass ratio of aminated carbon nanotube and composite aramid insulation paper is 5%-10%.The mass ratio of aramid fiber, aminated carbon nanotube, polyvinylpyrrolidone and aramid fiber is 60-70:5-10:5-15:15-20.The existing method is mostly limited to introducing single aramid fiber into composite material.The performance of composite material can be improved to some extent by simple physical mixing or surface modification, but the problems of poor interfacial bonding force and poor dispersibility cannot be fundamentally solved, which reduces the reliability of power equipment operation.

Description

Technical Field

[0001] This invention relates to the field of insulating materials technology, and in particular to a composite aramid insulating paper and its preparation method. Background Technology

[0002] With the rapid development of the power industry and high-tech equipment, the performance requirements for electrical insulation materials are becoming increasingly stringent, especially under high voltage, high temperature, and high load environments. Traditional insulation materials are gradually failing to meet these demanding requirements. Aramid fibers, due to their excellent mechanical properties, high temperature resistance, and good electrical insulation, have become an important component in power equipment, aerospace, military protection, and high-performance composite materials. Aramid fibers not only possess high tensile strength and excellent thermal stability but also good electrical insulation properties, making them widely used in insulating paper and reinforcing fiber materials for power equipment. However, traditional aramid insulating paper still has some shortcomings, particularly in impact resistance, thermal conductivity, and toughness, where there is significant room for improvement. Therefore, it is urgent to modify and composite aramid fibers to achieve higher performance.

[0003] Currently, most existing methods are limited to introducing single aramid fibers into composite materials. While simple physical mixing or surface modification can improve the performance of composite materials to some extent, they cannot fundamentally solve problems such as poor interfacial bonding and poor dispersibility, thus reducing the reliability of power equipment operation. Summary of the Invention

[0004] This invention provides a composite aramid insulating paper and its preparation method, solving the problem that most existing methods are limited to introducing single aramid fibers into composite materials. Although simple physical mixing or surface modification can improve the performance of composite materials to some extent, they cannot fundamentally solve the problems of poor interfacial bonding and poor dispersibility, which reduce the reliability of power equipment operation.

[0005] The first aspect of the present invention provides a composite aramid insulating paper, wherein the composite aramid insulating paper comprises polyvinylpyrrolidone, aramid fiber and aminated carbon nanotubes;

[0006] The aminated carbon nanotubes are uniformly dispersed in the matrix of the aramid fiber.

[0007] Optionally, the mass ratio of the aminated carbon nanotubes to the composite aramid insulating paper is 5%-10%.

[0008] Optionally, the mass ratio of the aramid fiber, the aminated carbon nanotube, the polyvinylpyrrolidone, and the aramid fiber is 60-70:5-10:5-15:15-20.

[0009] The second aspect of this invention provides a method for preparing the composite aramid insulating paper, characterized in that it comprises:

[0010] Aminated carbon nanotubes were obtained by plasma treatment of carbon nanotubes.

[0011] Aramid fibers were dissolved using a pre-obtained dimethyl sulfoxide solution to obtain aramid fiber gel.

[0012] The aminated carbon nanotubes were electrospun using pre-acquired polyvinylpyrrolidone to obtain the target composite fiber.

[0013] The target composite fiber and the aramid fiber gel are sequentially blended and subjected to high-speed shearing to obtain the target composite fiber gel.

[0014] The target composite fiber gel was subjected to vacuum filtration to obtain composite aramid insulating paper.

[0015] Optionally, the step of using carbon nanotubes for plasma treatment to obtain amination-modified carbon nanotubes includes:

[0016] Carbon nanotubes are treated with a pre-set mixed cleaning solution to remove impurities, thereby obtaining the target carbon nanotubes. The mixed cleaning solution is a mixed solution of concentrated nitric acid and sulfuric acid.

[0017] Based on a preset reaction temperature range, the target carbon nanotubes are bonded using a preset ammonia solution to obtain initial aminated carbon nanotubes.

[0018] The initial aminated carbon nanotubes were subjected to ultrasonic dispersion treatment to obtain aminated carbon nanotubes.

[0019] Optionally, the step of dissolving aramid fibers in a pre-obtained dimethyl sulfoxide solution to obtain an aramid fiber gel includes:

[0020] Aramid fibers are pretreated by dissolution to obtain the target aramid fibers;

[0021] The target aramid fiber is added to a pre-prepared dimethyl sulfoxide solution to generate an aramid fiber mixture.

[0022] The aramid fiber mixture was subjected to ultrasonic dispersion and stirring to obtain an aramid fiber gel.

[0023] Optionally, the step of electrospinning the aminated carbon nanotubes based on pre-obtained polyvinylpyrrolidone to obtain the target composite fiber includes:

[0024] The aminated carbon nanotubes were added to a pre-prepared polyvinylpyrrolidone solution and subjected to ultrasonic dispersion to obtain the target spinning solution, wherein the concentration of the target spinning solution was 10%-15%.

[0025] Based on a preset spinning voltage range, the target spinning solution is electrospun to obtain the target composite fiber.

[0026] Optionally, the aramid fiber includes Kevlar fiber, Nomex fiber, Twaron fiber, or Technora fiber.

[0027] Optionally, the reaction temperature range is 60-80 degrees Celsius.

[0028] Optionally, the spinning voltage range is 10-20 kV.

[0029] As can be seen from the above technical solutions, the present invention has the following advantages:

[0030] 1. The composite aramid insulating paper provided by this invention is composed of polyvinylpyrrolidone, aramid fibers, and aminated carbon nanotubes, which significantly improves the overall strength of the composite aramid insulating paper. At the same time, the aminated carbon nanotubes are uniformly dispersed in the aramid fiber matrix, which enables the composite aramid insulating paper to effectively disperse stress when subjected to force, avoid local stress concentration, and thus greatly improve the toughness of the composite aramid insulating paper.

[0031] 2. This invention disperses aminated carbon nanotubes uniformly in an aramid fiber matrix, creating a highly efficient heat-conducting channel in the composite aramid insulating paper. This allows for rapid heat transfer, effectively reducing the operating temperature of electrical equipment, improving its efficiency and reliability, and minimizing the risk of malfunctions and damage caused by overheating.

[0032] 3. This invention combines aminated carbon nanotubes with aramid fibers through electrospinning to form composite aramid insulating paper. This process maintains the original electrical insulation and high-temperature resistance properties of aramid fibers. At the same time, through amination modification, the dispersibility of carbon nanotubes is improved, enabling them to form a strong interfacial bond with aramid fibers, thereby improving the thermal conductivity and toughness of the composite aramid insulating paper. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1A schematic diagram comparing the mechanical and thermal conductivity properties of the composite aramid insulating paper provided in this embodiment of the invention with those of traditional aramid insulating paper.

[0035] Figure 2 A schematic diagram of the preparation process of aramid fiber gel provided in an embodiment of the present invention;

[0036] Figure 3 Provided for embodiments of the present invention Schematic diagram of the vacuum filtration process of composite fiber / ANF aramid fiber;

[0037] Figure 4 This is a schematic diagram comparing the experimental results of Embodiments 1 to 7 and Comparative Examples 1 to 3 of the present invention. Detailed Implementation

[0038] This invention provides a composite aramid insulating paper and its preparation method, addressing the problem that most existing methods are limited to introducing single aramid fibers into composite materials. While simple physical mixing or surface modification can improve the performance of composite materials to some extent, they cannot fundamentally solve the problems of poor interfacial bonding and poor dispersibility, thus reducing the reliability of power equipment operation.

[0039] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] See Figures 1-3 As shown, the present invention provides a composite aramid insulating paper, which includes polyvinylpyrrolidone, aramid fibers and aminated carbon nanotubes, wherein the aminated carbon nanotubes are uniformly dispersed in the matrix of aramid fibers.

[0041] In this embodiment of the invention, the composite aramid insulating paper exhibits a nanocomposite structure at the microscopic level. Aminated carbon nanotubes are uniformly dispersed within the aramid fiber matrix, and the two are tightly bonded together. The carbon nanotubes act as tiny "reinforcing skeletons," enhancing the stability and strength of the overall structure at the nanoscale. Simultaneously, it possesses a fiber network structure. Through processes such as electrospinning, blending, high-speed shearing, and vacuum filtration, the composite fibers and aramid fibers intertwine and entangle, forming a complex yet ordered fiber network. This network structure not only facilitates the uniform transfer and dispersion of stress within the material, greatly improving its toughness and strength, but also provides multi-dimensional pathways for heat conduction, contributing to high thermal conductivity. Therefore, the composite aramid insulating paper exhibits a high degree of structural synergy and optimization.

[0042] All raw materials and reagents involved in the embodiments of this invention are commercially available.

[0043] To further illustrate the present invention, the following detailed description of a composite aramid insulating paper and its preparation method provided by the present invention is provided in conjunction with embodiments.

[0044] Example 1

[0045] Embodiment 1 of this invention relates to the preparation of a composite aramid insulating paper, wherein the composite aramid insulating paper is made by amination treatment of carbon nanotubes (CNTs). It is then compounded with aramid fiber (ANF). A method for preparing a composite aramid insulating paper includes:

[0046] Step 101: Starting with carbon nanotubes (CNTs), amino functional groups are grafted onto their surface through plasma treatment to obtain aminated carbon nanotubes. );

[0047] Further, step 101 includes the following sub-steps:

[0048] S11. React multi-walled carbon nanotubes (MWCNTs) with a mixed solution of concentrated nitric acid and sulfuric acid to remove surface impurities and increase surface activity.

[0049] It should be noted that during the reaction with the mixed solution of concentrated nitric acid and sulfuric acid, the power was 100 W, the treatment time was 30 minutes, the gas flow rate was 20 sccm, and the pressure was controlled at 0.2 mbar.

[0050] S12. Mix the cleaned carbon nanotubes with ammonia water (25%). The mixture reacts at 60-80°C to form aminated carbon nanotubes.

[0051] It should be noted that the reaction at 60-80°C for 2 hours results in the amino group ( The functional groups react with the surface of carbon nanotubes to form aminated carbon nanotubes.

[0052] S13, after the reaction Ultrasonic dispersion was performed to obtain the treated product. .

[0053] It should be noted that after the reaction It needs to be dispersed by ultrasound to ensure uniform dispersion and avoid agglomeration.

[0054] It is worth mentioning that carbon nanotubes ( After amination treatment, carbon nanotubes are combined with aramid fibers (ANF) to form a composite structure with high toughness and high strength. Amination of carbon nanotubes not only improves the mechanical properties of the fibers, giving them higher tensile strength and wear resistance, but also effectively enhances the overall rigidity of the composite material due to their nanoscale size, thus improving tear resistance and compressive strength.

[0055] Step 102: Aramid fibers (ANF) are treated in a dimethyl sulfoxide (DMSO) system to obtain ANF gel;

[0056] It should be noted that step 102 specifically involves: cutting aramid fibers (such as Kevlar®) into 2 cm long segments, and placing the aramid fibers into DMSO at a ratio of 20 wt% aramid fibers to 80 wt% DMSO. Heating and stirring are used to help dissolve the aramid fibers, forming a gel state (the reaction temperature is set at 80°C, and the reaction time is 2 hours), ensuring that the aramid fibers are completely dissolved and uniformly dispersed. The final product is an aramid fiber gel (ANF gel).

[0057] It should be noted that the amount of aramid fiber (ANF) is typically 60%-70% of the total weight of the composite material, providing the material's main mechanical strength and electrical insulation. Aramid fibers are usually small segments or short fibers, 1-2 mm in length, and can be fully dissolved in dimethyl sulfoxide (DMSO). The solubility of aramid fibers in DMSO is approximately 10-20% (i.e., 10-20 grams of aramid fiber dissolved in 100 ml of DMSO). The aramid fibers are completely dissolved in DMSO through ultrasonication and stirring to form a homogeneous aramid gel.

[0058] It is worth mentioning that aramid fiber itself has excellent high temperature resistance and can maintain its physical properties in high temperature environments. The addition of CNT further improves the thermal conductivity of the composite material, ensuring that the material can effectively dissipate heat in environments with high heat loads and prevent damage caused by heat accumulation.

[0059] Step 103: Aminated carbon nanotubes ( The mixture was ultrasonically dispersed in polyvinylpyrrolidone (PVP) to obtain... Spinning solution;

[0060] It should be noted that the concentration of polyvinylpyrrolidone (PVP) is 0.5 wt%, and the concentration of aminated carbon nanotubes is 0.5 wt%.

[0061] It should be noted that during the ultrasonic dispersion process, the ultrasonic frequency was set to 40 kHz and the dispersion time was 1 hour.

[0062] Step 104: Obtain by electrospinning Composite fibers;

[0063] It should be noted that the required electrospinning process... The concentration of the solution is usually 10%-15%. In specific operations, The injection volume of the solution is approximately 5-10 ml, while the electrospinning voltage is set to 15 kV. The distance between the nozzle and the collection plate is typically maintained at 10 cm, and the feed rate is 0.5 mL / h.

[0064] It should be noted that the feed rate during electrospinning is 0.5 mL / h.

[0065] It should be noted that during the electrospinning process, the solution is stretched into nanoscale fibers under the influence of a strong electric field and collected onto an aluminum foil. The diameter of the spun composite fibers is controlled between 100-500 nm, and the surface is smooth, uniformly distributed, and free from agglomeration, ensuring that they can effectively perform their functions in subsequent steps.

[0066] Step 105, Composite fibers were blended with ANF gel and subjected to high-speed shearing to obtain... Composite fiber / ANF aramid fiber;

[0067] It should be noted that in step 105, the... The composite fiber and aramid fiber gel (ANF gel) are mixed in a ratio of 1:3 by mass of composite fiber to gel.

[0068] It should be noted that during high-speed shearing, the shearing rate was set to 2000 rpm and the shearing time was 30 minutes to ensure that the composite fibers and gel were fully and uniformly mixed.

[0069] It is worth mentioning that step 105 enhances the interaction between the fibers and the gel, resulting in a uniform... / ANF composite fiber / ANF aramid fiber.

[0070] Step 106, / ANF composite fiber / ANF aramid fiber is vacuum filtered to obtain composite aramid insulating paper.

[0071] It should be noted that during the filtration process, the vacuum pressure is controlled at 0.1 MPa and maintained for 2 hours to ensure that the fibers are evenly distributed on the filter medium and form a stable fiber network.

[0072] It should be noted that after filtration, the resulting composite material is dried at a temperature of 60°C for 12 hours to ensure complete removal of the solvent and obtain a strong composite material.

[0073] It is worth mentioning that the combination of the high electrical insulation properties of aramid fibers and the excellent conductivity of carbon nanotubes gives composite aramid insulating paper both good insulation properties and the flexibility to adjust for applications requiring conductivity, achieving greater adaptability. At the same time, the chemical corrosion resistance of composite aramid insulating paper has also been significantly improved, enabling it to withstand the erosion of various chemical media and adapt to long-term use in complex environments.

[0074] It is worth mentioning that the composite aramid insulating paper has low hygroscopicity and is not easily affected by moisture, which further improves the stability of the composite aramid insulating paper in humid environments.

[0075] It should be noted that, as can be seen from the preparation steps 101-106, the aramid fibers and aminated carbon nanotubes in the composite aramid insulating paper of Example 1 are... The mass ratio of ( ) is 10:1.

[0076] Example 2

[0077] Embodiment 2 of the present invention discloses a method for preparing a composite aramid insulating paper, which comprises polyvinylpyrrolidone, aramid fibers, and aminated carbon nanotubes. The method for preparing the composite aramid insulating paper includes:

[0078] Step 201, Aminated carbon nanotubes ( Preparation of the nanotubes: First, the selected multi-walled carbon nanotubes (MWCNTs) were subjected to plasma treatment to remove surface impurities and improve their surface activity. Specifically, the treatment was carried out in an oxygen plasma environment at a power of 100 W for 30 minutes, a gas flow rate of 20 sccm, and a pressure controlled at 0.2 mbar. After treatment, the carbon nanotubes were immersed in concentrated ammonia water (25%). In this process, the reaction time is 2 hours. This step successfully grafts amino functional groups onto the surface of carbon nanotubes, resulting in amination.

[0079] Step 202, see reference Figure 2As shown, the preparation of aramid fiber (ANF) gel involves cutting aramid fibers (such as Kevlar®) into 2 cm long segments and treating them in a dimethyl sulfoxide (DMSO) solution. The aramid fibers are placed in DMSO at a ratio of 20 wt% aramid fibers to 80 wt% DMSO. Heating and stirring are used to help dissolve the aramid fibers, forming a gel. The reaction temperature is set at 80°C, and the reaction time is 2 hours to ensure complete dissolution and uniform dispersion of the aramid fibers. The final product is an aramid fiber gel (ANF gel). The key to this step is ensuring the uniformity and stability of the gel by properly controlling the dissolution temperature and time.

[0080] Step 203 Preparation of spinning solution: First, it is necessary to prepare aminated carbon nanotubes (… Ultrasonic dispersion was performed in a polyvinylpyrrolidone (PVP) solution. We used 0.5 wt% PVP solution and 0.5 wt% CNT-NH2 to ensure... Good dispersibility. In the ultrasonic cleaner, the ultrasonic frequency is set to 40 kHz, and the dispersibility time is 1 hour to ensure... It is uniformly distributed in the PVP solution. After dispersion, a homogeneous product is obtained. The spinning solution lays the foundation for the subsequent electrospinning steps.

[0081] Step 204 Electrospinning of composite fibers: The fibers prepared in step 203 are electrospinned. The spinning solution was spun using electrospinning. The voltage during electrospinning was set to 15 kV, the spinning distance to 10 cm, and the feed rate to 0.5 mL / h. The collecting plate temperature was maintained at 25°C to ensure fiber formation under favorable environmental conditions. During electrospinning, the solution was stretched into nanoscale fibers by a strong electric field and collected on an aluminum foil. The diameter of the spun composite fibers was controlled between 100-500 nm, with a smooth surface, uniform distribution, and no agglomeration, ensuring effective performance in subsequent steps.

[0082] Step 205 Preparation of / ANF composite fiber / ANF aramid fiber: ... The composite fibers were mixed with aramid fiber gel (ANF gel) at a mass ratio of 1:3. The mixture was then placed in a high-speed shear mill at a shear rate of 2000 rpm for 30 minutes to ensure thorough and uniform mixing of the composite fibers and gel. This process enhanced the interaction between the fibers and gel, resulting in a homogeneous mixture. The composite fiber / ANF aramid fiber gel will be used as the next step in vacuum filtration.

[0083] Step 206, see reference Figure 3 As shown, the preparation of composite aramid insulating paper: The obtained... The ANF composite fiber / ANF aramid fiber was vacuum filtered to remove excess solvent. During filtration, the vacuum pressure was controlled at 0.1 MPa and maintained for 2 hours to ensure that the fibers were evenly distributed on the filter medium, forming a stable fiber network. After filtration, the resulting composite material was dried at 60°C for 12 hours to ensure complete solvent removal and obtain a robust composite material.

[0084] It should be noted that aramid fibers and aminated carbon nanotubes ( The mass ratio of ) is 7:3.

[0085] It is worth mentioning that the dried composite aramid insulating paper has excellent high toughness, high strength and high thermal conductivity, making it suitable for high-performance thermal insulation and insulation applications.

[0086] Example 3

[0087] Compared with Example 1, this embodiment uses aramid fibers and aminated carbon nanotubes ( The mass ratio is set to 6:4, and the other steps remain unchanged.

[0088] Example 4

[0089] Compared with Example 1, this embodiment uses aramid fibers and aminated carbon nanotubes ( The mass ratio of the ingredients is 5:5, and the other steps remain unchanged.

[0090] Example 5

[0091] Compared with Example 1, the mixing ratio of composite fiber and aramid fiber gel in this embodiment is 1:2, while the other steps remain unchanged.

[0092] Comparative Example 1

[0093] Compared to Example 1, this comparative example uses aramid fibers and synthetic carbon nanotubes to obtain an aramid-carbon nanotube composite slurry through high-speed shear mixing. This slurry is then electrospun to obtain aramid-carbon nanotube paper, which is subsequently subjected to high-temperature hot pressing to obtain traditional aramid-carbon nanotube insulating paper. This comparative experiment does not use aminated carbon nanotubes (…). Surface modification was performed without going through the composite fiber / aramid fiber preparation step.

[0094] Comparative Example 2

[0095] Compared with Example 1, this comparative example uses only aramid fibers in its composite fiber, without the addition of aminated carbon nanotubes. The remaining steps remain unchanged.

[0096] Comparative Example 3

[0097] Compared to Example 1, this comparative example uses only aramid fibers and polyvinylpyrrolidone (PVP) solution for the composite fiber, without the addition of aminated carbon nanotubes. The process involves combining the aramid fiber gel with the aramid fiber gel, with the remaining steps remaining unchanged.

[0098] See Figure 4 As shown, by comparing the thermal conductivity of the composite aramid insulating paper in Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that the thermal conductivity of the composite aramid insulating paper in Examples 1 to 5 is significantly higher than that in Comparative Examples 1 to 3 (wherein, the thermal conductivity of the composite aramid insulating paper in Example 1 is...). The thermal conductivity of the composite aramid insulating paper in Comparative Example 2 is... Therefore, it can be seen that by introducing aminated carbon nanotubes ( This gives the composite aramid insulating paper better thermal conductivity.

[0099] See Figure 4 As shown, by comparing the tensile strength of the composite aramid insulating paper in Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that the tensile strength of the composite aramid insulating paper in Example 1 is 315 MPa, while the tensile strength of the composite aramid insulating paper in the comparative examples is 149.5 MPa. Therefore, it can be concluded that the preparation method of the present invention can significantly improve the mechanical strength of the composite material.

[0100] See Figure 4 As shown, by comparing the Young's modulus of the composite aramid insulating paper in Examples 1 to 3 and Comparative Examples 1 to 3, it can be seen that the Young's modulus of the composite aramid insulating paper in Example 1 is 10.14 GPa, and the Young's modulus of the composite aramid insulating paper in Comparative Example 2 is 4.83 GPa. It can be seen that the composite aramid insulating paper in this invention maintains high rigidity while improving thermal conductivity and strength, and has good mechanical properties.

[0101] See Figure 4 As shown, the composite aramid insulating paper in Examples 1 to 7 exhibits significant advantages in thermal conductivity, tensile strength, and Young's modulus. Compared to Comparative Example 2, it significantly improves the mechanical strength, thermal conductivity, and rigidity of the composite aramid insulating paper. Compared with traditional methods for preparing composite aramid insulating paper, this invention introduces aminated carbon nanotubes (… Furthermore, the composite fiber / aramid fiber preparation process effectively improves the overall performance of the composite aramid insulating paper.

[0102] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite aramid insulating paper, characterized in that, The composite aramid insulating paper comprises polyvinylpyrrolidone, aramid fibers, and aminated carbon nanotubes. The aminated carbon nanotubes are uniformly dispersed in the matrix of the aramid fiber. The specific preparation process of the composite aramid insulating paper is as follows: The carbon nanotubes were cleaned with a pre-set mixed cleaning solution to remove impurities, and the target carbon nanotubes were obtained. Based on a preset reaction temperature range, the target carbon nanotubes are bonded using a preset ammonia solution to obtain initial aminated carbon nanotubes. The initial aminated carbon nanotubes were subjected to ultrasonic dispersion treatment to obtain aminated carbon nanotubes. Aramid fibers were dissolved using a pre-obtained dimethyl sulfoxide solution to obtain aramid fiber gel. The aminated carbon nanotubes were added to a pre-acquired polyvinylpyrrolidone and subjected to ultrasonic dispersion to obtain the target spinning solution. Based on a preset spinning voltage range, the target spinning solution is electrospun to obtain the target composite fiber; The target composite fiber and the aramid fiber gel are sequentially blended and subjected to high-speed shearing to obtain the target composite fiber gel. The target composite fiber gel was subjected to vacuum filtration to obtain composite aramid insulating paper.

2. The composite aramid insulating paper according to claim 1, characterized in that, The mass ratio of the aminated carbon nanotubes to the composite aramid insulating paper is 5%-10%.

3. A method for preparing composite aramid insulating paper as described in any one of claims 1-2, characterized in that, include: Carbon nanotubes are treated with a pre-set mixed cleaning solution to remove impurities, thereby obtaining the target carbon nanotubes. The mixed cleaning solution is a mixed solution of concentrated nitric acid and sulfuric acid. Based on a preset reaction temperature range, the target carbon nanotubes are bonded using a preset ammonia solution to obtain initial aminated carbon nanotubes. The initial aminated carbon nanotubes were subjected to ultrasonic dispersion treatment to obtain aminated carbon nanotubes. Aramid fibers were dissolved using a pre-obtained dimethyl sulfoxide solution to obtain aramid fiber gel. The aminated carbon nanotubes were electrospun using pre-acquired polyvinylpyrrolidone to obtain the target composite fiber. The target composite fiber and the aramid fiber gel are sequentially blended and subjected to high-speed shearing to obtain the target composite fiber gel. The target composite fiber gel was subjected to vacuum filtration to obtain composite aramid insulating paper. The step of electrospinning the aminated carbon nanotubes with pre-obtained polyvinylpyrrolidone to obtain the target composite fiber includes: The aminated carbon nanotubes were added to a pre-prepared polyvinylpyrrolidone solution and subjected to ultrasonic dispersion to obtain the target spinning solution, wherein the concentration of the target spinning solution was 10%-15%. Based on a preset spinning voltage range, the target spinning solution is electrospun to obtain the target composite fiber.

4. The method for preparing composite aramid insulating paper according to claim 3, characterized in that, The aramid fibers include Kevlar fibers, Nomex fibers, Twaron fibers, or Technora fibers.

5. The method for preparing composite aramid insulating paper according to claim 3, characterized in that, The reaction temperature range is 60-80℃.

6. The method for preparing composite aramid insulating paper according to claim 3, characterized in that, The spinning voltage range is 10-20 kV.

Images