A high-performance basalt nanosheet-based paper insulation coating taking waste aramid product as raw material and a preparation method thereof

Abstract

The application provides a high-performance basalt nanosheet-based paper insulation coating taking waste aramid product as raw material and a preparation method thereof, wherein expanded basalt flakes are obtained by treating basalt flakes through alkali and then through tetrabutyl ammonium, the expanded basalt flakes are placed in a hydrogen peroxide and organic acid mixed liquid system to obtain basalt nanosheets; then, the waste aramid product is taken as raw material to react in a KOH / DMSO system under heating to prepare an ANF / DMSO mixed liquid, the basalt nanosheets containing carbonyl groups are added into the ANF / DMSO mixed liquid to obtain the high-performance basalt nanosheet-based paper insulation coating, which not only enriches the preparation process of the basalt nanosheets, improves the production efficiency of the basalt nanosheets, utilizes the waste aramid product which is harmful to the environment, solves the recycling problem of the waste aramid product, enriches the preparation method of aramid nanofibers and provides a new method and new idea for the preparation of the paper insulation coating.

Description

Technical Field

[0001] This invention belongs to the field of inorganic nanosheet-based materials and insulating coating preparation technology, and particularly relates to the preparation of nanosheet-based insulating coatings and their recycling methods. Background Technology

[0002] With the continuous development of technology, paper is no longer just a medium for writing and printing; its uses have expanded from traditional writing and printing to fields such as electronic tags and smart packaging. This development necessitates that the paper surface possess more functions, including waterproofing, stain resistance, antistatic properties, and insulation, to ensure its reliability in electronic devices.

[0003] Traditional paper faces challenges in electrical applications, such as susceptibility to moisture, high electrical conductivity, and poor heat resistance, which can affect the performance and lifespan of insulating paper. Therefore, surface treatment of paper to impart insulation properties is a necessary step to improve the quality and stability of electronic products. Adding insulating coatings to the paper surface can significantly improve the production efficiency of insulating paper. Currently, insulating coatings used on paper surfaces mainly include nanomaterials, polymer materials, polymer composites, and natural resins. Nanomaterial-based paper insulating coatings primarily consist of nanoparticles such as alumina and zinc oxide, which provide excellent waterproof performance while increasing the insulation of the paper surface. Polymer-based paper insulating coatings mainly consist of polyurethane, polyester, and epoxy resins, which have excellent abrasion resistance and chemical resistance, and can form a robust insulating film. Polymer composite-based paper insulating coatings are suitable for a variety of environments and applications. Furthermore, to increase the eco-friendliness of coatings, some natural resins such as natural rubber and chitosan have also been introduced into paper surface insulating coatings.

[0004] Basalt nanosheets have emerged as a novel nanomaterial, produced by chemically and mechanically exfoliating basalt flakes. They retain the composition and structure of the basalt flakes, exhibiting high levels of iron oxides, titanium dioxide, aluminum oxide, and calcium oxide, while containing relatively low levels of alkaline oxides. Therefore, basalt nanosheets possess unique advantages in acid and alkali resistance and corrosion resistance, as well as good corona resistance and insulation properties. Aramid fibers are also a common insulating material, containing numerous carbonyl groups in their molecular structure. Aramid nanofibers, microscale products of aramid fibers, exhibit small-scale effects, possessing more functional groups and a larger specific surface area, allowing them to form strong hydrogen bonds with most active groups in paper. However, aramid nanofibers currently suffer from long preparation cycles, non-degradability leading to environmental pollution, and high operating costs due to their inability to be recycled, severely impacting their development potential as insulating coatings. Furthermore, relying solely on aramid nanofibers as a paper coating is insufficient to guarantee the insulation performance of paper. Therefore, using waste aramid products to prepare aramid nanofibers can greatly reduce the preparation cost of aramid nanofibers. Combining them with basalt nanosheets to prepare insulating coatings can significantly enhance their insulation performance, which has great market potential. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a simple and feasible high-performance basalt nanosheet-based paper insulating coating and its preparation method using waste aramid products as raw materials. This fills the current technological gap in the industry, enriches the current preparation process of basalt nanosheets, provides new ideas and methods for the rapid preparation of basalt nanosheets, and greatly improves the production efficiency of basalt nanosheets. In addition, it utilizes environmentally harmful waste aramid products and combines them with basalt nanosheets to obtain a high-performance paper insulating coating, solving the problem of recycling waste aramid products, enriching the preparation methods of aramid nanofibers, and providing new methods and ideas for the preparation of paper insulating coatings.

[0006] This invention is achieved through the following technical solution:

[0007] A method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials, comprising,

[0008] S1, basalt flakes are etched in sodium hydroxide solution, reacted in tetrabutylammonium solution to obtain expanded basalt flakes, then dispersed in a mixed solution of hydrogen peroxide and organic acid, and ultrasonically treated to obtain basalt nanosheets.

[0009] S2, add waste aramid products to potassium hydroxide solution, then add heated DMSO, and after reaction, obtain aramid nanofiber / DMSO mixture;

[0010] S3, react BSNs with polyvinylpyrrolidone solution to obtain basalt nanosheets with carbonyl groups on the surface, then disperse them in DMSO solvent and react with ultrasound to obtain a CBSNs / DMSO mixture, which is then added to an aramid nanofiber / DMSO mixture to produce a high-performance basalt nanosheet-based paper insulating coating.

[0011] Preferably, the concentration of sodium hydroxide solution in S1 is 0.1 mol / L to 1 mol / L, the ratio of basalt flakes to sodium hydroxide solution is 1 g: 100 mL to 500 mL, the surface etching reaction time is 4 to 24 h, and the reaction temperature is 60 °C to 120 °C.

[0012] Preferably, the concentration of the tetrabutylammonium solution in S1 is 0.2 mol / L to 2 mol / L, the ratio of basalt flakes to tetrabutylammonium solution is 1 g: 100 mL to 500 mL, the reaction time is 2 to 8 h, and the reaction temperature is 25 °C to 100 °C.

[0013] Preferably, the ratio of basalt flakes to the mixed solution of hydrogen peroxide and organic acid in S1 is 1g: 200-500mL, wherein the mass fraction of hydrogen peroxide in the mixed solution of hydrogen peroxide and organic acid is 10wt%-30wt%, the organic acid is maleic acid or oxalic acid, the amount of organic acid added per 500mL is 0.5g-2g, the ultrasonic power is 500W-1000W, and the reaction time is 20min-60min.

[0014] Preferably, the waste aramid product in S2 is made from used fibers, cloth, or gloves made from para-aramid.

[0015] Preferably, before use, the waste aramid product is placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to wash away surface impurities;

[0016] The concentration of the sodium dodecyl sulfate solution is 2 g / L, the ratio of waste aramid product to sodium dodecyl sulfate solution is 1 g: 100 mL to 500 mL, the reaction temperature is 60 °C to 80 °C, and the reaction time is 1 to 8 h.

[0017] Preferably, in step S2, the ratio of waste aramid product to DMSO is 1g-10g:500mL, and the reaction temperature is 25℃-80℃; the ratio of waste aramid product to potassium hydroxide in the potassium hydroxide solution is 1g-10g:1.5g; the mass fraction of the potassium hydroxide solution is 7.5wt%; and the heating temperature of DMSO is 40℃-80℃.

[0018] When preparing an aramid nanofiber / DMSO mixture, the method for determining the reaction endpoint is when no obvious fiber fragments and impurities are visible to the naked eye and the Tyndall effect is produced.

[0019] Preferably, the mass ratio of basalt nanosheets to polyvinylpyrrolidone in S3 is 1g:5-20g, the mass ratio of basalt nanosheets with carbonyl groups on the surface to DMSO is 0.2g-1g:500mL, and the ultrasonic time is 1min-10min.

[0020] The ratio of the CBSNs / DMSO mixture to the aramid nanofiber / DMSO mixture is 500 mL: 500 mL, and the reaction time is 2 h to 6 h.

[0021] A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products is prepared by the above-described method.

[0022] Preferably, the basalt nanosheets have a yield of 30.2–59.4 mg / h, an aspect ratio of 691.4–1435.4, and aramid nanofibers with a diameter of 18.4–28.4 nm.

[0023] After coating the surface of fiber paper with high-performance basalt nanosheet-based paper insulating coating, the breakdown strength of the composite paper increased by 113% to 198%, and the volume resistivity increased by 83% to 124%.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] This invention provides a simple and feasible high-performance basalt nanosheet-based paper insulating coating and its preparation method using waste aramid products as raw materials. This enriches the current preparation process of basalt nanosheets, enables the reuse of waste materials, achieves sustainable development, and fills a technological gap in the current paper insulating coating industry. This invention utilizes basalt flakes as raw materials. Preliminary surface etching is performed through alkali treatment to create a rough surface structure. Then, tetrabutylammonium treatment is applied. Due to the large radius of tetrabutylammonium ions and the high concentration of tetrabutylammonium ions in the external environment, ion osmotic pressure allows for exchange with metal ions inside the basalt flakes, thereby occupying the interior of the basalt flakes and creating cavities. This causes anisotropic expansion within the basalt flakes, disrupting their internal interactions. The expanded basalt flakes are placed in a mixture of hydrogen peroxide and organic acid. Hydrogen peroxide can enter the interlayer domain of the basalt flakes by displacing water molecules or forming dimers. Using water molecules as a medium, it undergoes a Fenton reaction with hydrated cations in the interlayer domain, decomposing in situ to produce oxygen. Furthermore, hydrogen peroxide can accelerate the decomposition rate under the catalysis of organic acids, producing more oxygen. These gases, under mechanical stirring combined with ultrasound, cause intense cavitation between basalt flake layers, leading to further detachment of the basalt flakes and the formation of numerous basalt nanosheets. Using waste aramid products as raw materials, a KOH / DMSO mixture is rapidly prepared by heating. Then, BSNs are modified to obtain carbonyl-containing basalt nanosheets (CBSNs), which are dispersed in a DMSO solution and then added to the ANF / DMSO mixture with thorough stirring to obtain a high-performance basalt nanosheet-based paper insulating coating. This invention not only enriches the current preparation process of basalt nanosheets, providing new ideas and methods for the rapid preparation of basalt nanosheets and greatly improving the production efficiency of basalt nanosheets, but also utilizes environmentally harmful waste aramid products and combines them with basalt nanosheets to produce high-performance paper insulating coatings. This solves the problem of recycling waste aramid products, enriches the preparation methods of aramid nanofibers, and provides new methods and ideas for the preparation of paper insulating coatings.

[0026] Furthermore, the yield of basalt nanosheets was 30.2–59.4 mg / h, the aspect ratio was 691.4–1435.4, the ANF diameter was 18.4–28.4 nm, and the breakdown strength of the composite paper increased by 113%–198% and the volume resistivity increased by 83%–124% after the insulating coating was applied to the surface of the fiber paper.

[0027] Furthermore, the invention employs a simple and effective preparation method to rapidly prepare high-performance basalt nanosheet-based paper insulating coatings. The preparation method is simple and easy to operate, requires no large-scale equipment, and is relatively easy to industrialize, thus increasing the possibility of industrial-scale mass production. Attached Figure Description

[0028] Figure 1 Transmission electron microscopy (TEM) image of basalt nanosheets;

[0029] Figure 2 Schematic diagram of the process for preparing aramid nanofibers from waste aramid fibers;

[0030] Figure 3 Optical photographs and Tyndall effect diagrams of aramid nanofibers and basalt nanosheet-based paper insulating coatings are shown. Among them, Figure (a) is an optical photograph of aramid nanofibers; Figure (b) is a Tyndall effect diagram of aramid nanofibers; Figure (c) is an optical photograph of basalt nanosheet-based paper insulating coatings; and Figure (d) is a Tyndall effect diagram of basalt nanosheet-based paper insulating coatings.

[0031] Figure 4 Schematic diagram of the process for preparing aramid nanofibers from waste aramid fabric;

[0032] Figure 5 The images show scanning electron microscope (SEM) images of plant fiber paper and plant fiber paper coated with basalt nanosheet-based insulating coating. Figure (a) is a scanning electron microscope image of plant fiber paper; Figure (b) is a magnified scanning electron microscope image of plant fiber paper; Figure (c) is a scanning electron microscope image of plant fiber paper coated with basalt nanosheet-based insulating coating; and Figure (d) is a magnified scanning electron microscope image of plant fiber paper coated with basalt nanosheet-based insulating coating.

[0033] Figure 6 Figure 1 shows the EDS (Electronic Data Structures) images of plant fiber paper coated with basalt nanosheet-based insulating coating. Figure 2 shows the SEM (Series Electron Microscopy) image of the plant fiber paper coated with basalt nanosheet-based insulating coating; Figure 3 shows the C element EDS image of the plant fiber paper coated with basalt nanosheet-based insulating coating; Figure 4 shows the N element EDS image of the plant fiber paper coated with basalt nanosheet-based insulating coating; and Figure 5 shows the Si element EDS image of the plant fiber paper coated with basalt nanosheet-based insulating coating.

[0034] Figure 7 Schematic diagram of the process for preparing aramid nanofibers from discarded aramid gloves;

[0035] Figure 8 The images show scanning electron microscope (SEM) images of the electrical breakdown pores in plant fiber paper and plant fiber paper coated with basalt nanosheet-based insulating coating. Figure (a) is a SEM image of the electrical breakdown pores in plant fiber paper; Figure (b) is a magnified SEM image of the electrical breakdown pores in plant fiber paper; Figure (c) is a SEM image of the electrical breakdown pores in plant fiber paper coated with basalt nanosheet-based insulating coating; and Figure (d) is a magnified SEM image of the electrical breakdown pores in plant fiber paper coated with basalt nanosheet-based insulating coating. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0037] 1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.1 mol / L to 1 mol / L sodium hydroxide solution. The ratio of basalt flakes to sodium hydroxide solution was 1 g: 100 mL to 500 mL. The surface etching reaction was carried out by stirring at a reaction temperature of 60 °C to 120 °C for 4 to 24 h. The stirring method was magnetic stirring or mechanical stirring at a stirring speed of 500 rpm to 3000 rpm. After the reaction is complete, the basalt flakes are filtered and washed until neutral to obtain pre-etched basalt flakes. Then, the pre-etched basalt flakes are placed in a tetrabutylammonium solution with a concentration of 0.2 mol / L to 2 mol / L and a volume ratio of basalt flakes to tetrabutylammonium solution of 1 g: 100 mL to 500 mL. The reaction is carried out at a temperature of 25℃ to 100℃ with stirring, using magnetic stirring or mechanical stirring at a speed of 500 rpm to 3000 rpm. After the reaction is complete, the basalt flakes are dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed at a certain concentration in a mixed solution of hydrogen peroxide and organic acid. The ratio of basalt flakes to the mixed solution was 1g:200-500mL. The mass fraction of hydrogen peroxide was 10wt%-30wt%, and the organic acid was maleic acid and oxalic acid, with an addition amount of 0.5g-2g. The reaction was carried out with stirring at a temperature of 25℃-60℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 500rpm-2500rpm, the ultrasonic power was 500W-1000W, and the reaction time was 20min-60min to obtain basalt nanosheets (BSNs).

[0038] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used fibers, fabrics, and gloves made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 100 mL to 500 mL. The reaction temperature was 60 °C to 80 °C, and the stirring method was magnetic stirring or mechanical stirring at a speed of 500 rpm to 2500 rpm. The reaction time was 1 to 8 h. The product was then washed and dried with deionized water. Then, 1 g to 10 g of the dried waste aramid products were placed in a beaker, and 1.5 g of potassium hydroxide (KOH) solid was added, followed by 20 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at a power of 100 W to 1000 W for 5 min to 10 min to allow the surface of the waste aramid products to fully adsorb the potassium hydroxide solution. The mixture was then heated to 40 °C to 80 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 40℃ to 80℃. The stirring method was magnetic stirring or mechanical stirring, with a stirring speed of 500 rpm to 2500 rpm and a reaction time of 10 min to 60 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0039] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) are stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone is 1g:5~20g, and the stirring rate is 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface are obtained. After the reaction is completed, the solid CBSNs are obtained by filtration and then dispersed in DMSO solvent. The CBSNs are placed in an ultrasonic machine. The mass ratio of CBSNs to DMSO is 0.2g~1g:500mL. The power of the ultrasonic machine is set to 100W~1000W and the ultrasonic time is 1min~10min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature. The stirring method was magnetic stirring and mechanical stirring. The stirring speed was 500 rpm to 2500 rpm. The reaction time was 2 h to 6 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0043] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.1 mol / L sodium hydroxide solution at a ratio of 1 g:100 mL. Surface etching was carried out with stirring at 60 °C for 4 h using magnetic stirring at a speed of 500 rpm. After the reaction, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a 0.2 mol / L tetrabutylammonium solution at a ratio of 1 g:100 mL. The reaction was carried out with stirring at 25 °C using magnetic stirring at a speed of 500 rpm. After the reaction, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:200mL, where the mass fraction of hydrogen peroxide was 10wt% and the organic acid was maleic acid, with an addition amount of 0.5g. The reaction was carried out by stirring at 25℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 500rpm, the ultrasonic power was 500W, and the reaction time was 20min to obtain basalt nanosheets (BSNs).

[0044] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used fibers made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 100 mL. The reaction temperature was 60 °C, the stirring method was magnetic stirring, the stirring speed was 500 rpm, and the reaction time was 1 h. Then, the product was washed and dried with deionized water. Then, 1 g of dried waste aramid products were placed in a beaker, 1.5 g of potassium hydroxide (KOH) solid was added, followed by 20 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at 100 W for 5 min to allow the surface of the waste aramid products to fully adsorb the potassium hydroxide solution. The mixture was then heated to 40 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 40 °C using magnetic stirring at a speed of 500 rpm for 40 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0045] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:5g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of 0.2g:500mL. The power of the ultrasonic machine was set to 100W and the ultrasonic time was 1min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, and the stirring methods were magnetic stirring and mechanical stirring at a speed of 500 rpm. The reaction time was 2 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0046] 2. Figure 1 This is a transmission electron microscope (TEM) image of basalt nanosheets, by... Figure 1It can be seen that the thickness of the basalt nanosheets is 1.261 nm; as shown in Table 1, the yield of basalt nanosheets is 30.2 mg / h, the aspect ratio is 691.4, the diameter of ANF is 18.4 nm, and the breakdown strength of the composite paper increases by 113% and the volume resistivity increases by 83% after the insulating coating is applied to the surface of the fiber paper.

[0047] Example 2

[0048] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0049] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.2 mol / L sodium hydroxide solution with a flake-to-sodium hydroxide solution ratio of 1 g: 200 mL. Surface etching was carried out by stirring at 80 °C for 8 h. The stirring methods were magnetic stirring and mechanical stirring at a speed of 1000 rpm. After the reaction was completed, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a tetrabutylammonium solution with a concentration of 0.5 mol / L and a flake-to-tetrabutylammonium solution ratio of 1 g: 200 mL. The reaction was carried out by stirring at 40 °C with a mechanical stirring speed of 1000 rpm. After the reaction was completed, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:300mL, where the mass fraction of hydrogen peroxide was 15wt% and the organic acid was maleic acid, with an addition amount of 0.8g. The reaction was carried out with stirring at 40℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 1000rpm, the ultrasonic power was 600W, and the reaction time was 30min to obtain basalt nanosheets (BSNs).

[0050] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used fibers made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 200 mL. The reaction temperature was 60 °C, and the stirring method was mechanical stirring at a speed of 1000 rpm for 2 h. The mixture was then washed and dried with deionized water. 2 g of the dried waste aramid product was then placed in a beaker, and 3 g of potassium hydroxide (KOH) solid was added, followed by 40 mL of deionized water. The mixture was then sonicated at 200 W for 8 min to allow the surface of the waste aramid product to fully adsorb the potassium hydroxide solution. The mixture was then heated to 80 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 80 °C with magnetic stirring at a speed of 1000 rpm for 10 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0051] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:10g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of 0.4g:500mL. The power of the ultrasonic machine was set to 200W and the ultrasonic time was 2min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, the stirring method was mechanical stirring, the stirring speed was 1000 rpm, and the reaction time was 4 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0052] 2. Figure 2 A process diagram for preparing aramid nanofibers from waste aramid products, by Figure 3 It can be seen that waste aramid products can be used to prepare aramid nanofibers within 10 minutes. Figure 3 Optical photographs and Tyndall effect images of aramid nanofibers and basalt nanosheet-based paper insulating coatings, by Figure 3It can be seen that the aramid nanofibers are relatively uniformly dispersed and exhibit the Tyndall effect. The color of the mixture deepens after the addition of basalt nanosheets, which also exhibits the Tyndall effect, indicating that the basalt nanosheets are relatively uniformly dispersed. As shown in Table 1, the yield of basalt nanosheets is 39.4 mg / h, the aspect ratio is 805.4, the ANF diameter is 17.1 nm, and the breakdown strength of the composite paper increases by 138% and the volume resistivity increases by 92% after the insulating coating is applied to the surface of the fiber paper.

[0053] Example 3

[0054] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0055] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.4 mol / L sodium hydroxide solution with a flake-to-sodium hydroxide solution ratio of 1 g: 300 mL. Surface etching was carried out by stirring at 100 °C for 12 h using mechanical stirring at a speed of 1500 rpm. After the reaction, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a tetrabutylammonium solution with a concentration of 0.8 mol / L and a flake-to-sodium hydroxide solution ratio of 1 g: 300 mL. The reaction was carried out by stirring at 60 °C using magnetic stirring and mechanical stirring at a speed of 1500 rpm. After the reaction, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:300mL, where the mass fraction of hydrogen peroxide was 20wt%, and the organic acid was oxalic acid, with an addition amount of 1g. The reaction was carried out with stirring at 40℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 1500rpm, the ultrasonic power was 800W, and the reaction time was 40min to obtain basalt nanosheets (BSNs).

[0056] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used fabrics made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 300 mL. The reaction temperature was 70 °C, and the stirring method was magnetic stirring at a speed of 1500 rpm. The reaction time was 4 h, and then the product was washed and dried with deionized water. Then, 5 g of the dried waste aramid products were placed in a beaker, and 7.5 g of potassium hydroxide (KOH) solid was added, followed by 100 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at 500 W for 8 min to allow the surface of the waste aramid products to fully adsorb the potassium hydroxide solution. Finally, the mixture was heated to 60 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 60 °C using magnetic or mechanical stirring at a speed of 1500 rpm for 20 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0057] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:10g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of 0.5g:500mL. The ultrasonic machine was set to a power of 500W and an ultrasonic time of 5min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, the stirring method was mechanical stirring, the stirring speed was 1500 rpm, and the reaction time was 4 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0058] 2. As shown in Table 1, the yield of basalt nanosheets is 42.6 mg / h, the aspect ratio is 1046.5, the diameter of ANF is 25.8 nm, and the breakdown strength of the composite paper increases by 152% and the volume resistivity increases by 101% after the insulating coating is applied to the surface of the fiber paper.

[0059] Example 4

[0060] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0061] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.6 mol / L sodium hydroxide solution with a flake-to-sodium hydroxide solution ratio of 1 g: 300 mL. Surface etching was carried out by stirring at 80 °C for 12 h using magnetic stirring at a speed of 2000 rpm. After the reaction, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a tetrabutylammonium solution with a concentration of 1 mol / L and a flake-to-sodium hydroxide solution ratio of 1 g: 300 mL. The reaction was carried out by stirring at 80 °C using mechanical stirring at a speed of 2000 rpm. After the reaction, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:300mL, where the mass fraction of hydrogen peroxide was 20wt% and the organic acid was maleic acid, with an addition amount of 1g. The reaction was carried out with stirring at 50℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 1500rpm, the ultrasonic power was 600W, and the reaction time was 30min to obtain basalt nanosheets (BSNs).

[0062] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used fabrics made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 300 mL. The reaction temperature was 60 °C, and the stirring method was mechanical stirring at a speed of 1500 rpm for 4 h. The product was then washed and dried with deionized water. 10 g of the dried waste aramid product was then placed in a beaker, and 15 g of potassium hydroxide (KOH) solid was added, followed by 200 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at 1000 W for 10 min to allow the surface of the waste aramid product to fully adsorb the potassium hydroxide solution. The mixture was then heated to 80 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 80 °C with magnetic stirring at a speed of 2000 rpm for 15 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0063] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:10g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of 0.6g:500mL. The ultrasonic machine was set to a power of 500W and an ultrasonic time of 5min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, the stirring method was magnetic stirring, the stirring speed was 1500 rpm, and the reaction time was 4 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0064] 2. Figure 4 A process diagram for preparing aramid nanofibers from waste aramid products, by Figure 4 It can be seen that waste aramid products can be used to prepare aramid nanofibers within 15 minutes. Figure 5 Scanning electron microscope (SEM) images of plant fiber paper and plant fiber paper coated with a basalt nanosheet-based insulating coating, by [Author Name]. Figure 5It can be seen that the surface of plant fiber paper coated with basalt nanosheet-based paper insulating coating is relatively dense and without obvious pores, which is also the reason for its good insulation performance. As shown in Table 1, the yield of basalt nanosheets is 46.8 mg / h, the aspect ratio is 1158.6, the ANF diameter is 23.2 nm, and the breakdown strength of the composite paper increases by 168% and the volume resistivity increases by 98% after the insulating coating is applied to the surface of the fiber paper.

[0065] Example 5

[0066] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0067] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 0.8 mol / L sodium hydroxide solution with a flake-to-sodium hydroxide solution ratio of 1 g: 400 mL. Surface etching was carried out with stirring at 100 °C for 18 h using mechanical stirring at a speed of 2500 rpm. After the reaction, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a tetrabutylammonium solution with a concentration of 1.5 mol / L and a flake-to-sodium hydroxide solution ratio of 1 g: 400 mL. The reaction was carried out with stirring at 80 °C using mechanical stirring at a speed of 2500 rpm. After the reaction, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:400mL, where the mass fraction of hydrogen peroxide was 20wt% and the organic acid was maleic acid, with an addition amount of 2g. The reaction was carried out with stirring at 50℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 2000rpm, the ultrasonic power was 800W, and the reaction time was 40min to obtain basalt nanosheets (BSNs).

[0068] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used gloves made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 400 mL. The reaction temperature was 70 °C, and the stirring methods were magnetic stirring and mechanical stirring at a stirring speed of 2000 rpm. The reaction time was 6 h, and then the product was washed and dried with deionized water. Then, 5 g of the dried waste aramid products were placed in a beaker, and 7.5 g of potassium hydroxide (KOH) solid was added, followed by 100 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at 500 W for 10 min to allow the surface of the waste aramid products to fully adsorb the potassium hydroxide solution. The mixture was then heated to 60 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 60 °C using magnetic or mechanical stirring at a speed of 2000 rpm for 20 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0069] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:15g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of 0.8g:500mL. The power of the ultrasonic machine was set to 800W and the ultrasonic time was 8min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The volume ratio of the CBSNs / DMSO mixture to the ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, and the stirring methods were magnetic stirring and mechanical stirring. The stirring speed was 2000 rpm, and the reaction time was 4 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0070] 2. Figure 6The EDS diagram of plant fiber paper coated with basalt nanosheet-based insulating coating is shown. Analysis reveals that the basalt nanosheets are uniformly distributed in the coating. Table 1 shows that the basalt nanosheet yield is 52.7 mg / h, the aspect ratio is 1316.5, the ANF diameter is 31.5 nm, and the breakdown strength of the composite paper increases by 187% and the volume resistivity increases by 115% after the insulating coating is applied to the fiber paper surface.

[0071] Example 6

[0072] 1. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products and its preparation method, comprising the following steps:

[0073] (1) Large-scale preparation of basalt nanosheets: Untreated basalt flakes (BS) were placed in a 1 mol / L sodium hydroxide solution with a flake-to-sodium hydroxide solution ratio of 1 g:500 mL. Surface etching was carried out by stirring at 120 °C for 24 h using mechanical stirring at a speed of 3000 rpm. After the reaction, the flakes were filtered and washed until neutral to obtain pre-etched basalt flakes. The pre-etched basalt flakes were then placed in a tetrabutylammonium solution with a concentration of 2 mol / L and a flake-to-sodium hydroxide solution ratio of 1 g:500 mL. The reaction was carried out by stirring at 100 °C using mechanical stirring at a speed of 3000 rpm. After the reaction, the flakes were dried to obtain expanded basalt flakes. Expanded basalt flakes were dispersed in a mixed solution of hydrogen peroxide and organic acid at a certain concentration. The ratio of basalt flakes to the mixed solution was 1g:500mL, where the mass fraction of hydrogen peroxide was 30wt% and the organic acid was maleic acid, with an addition amount of 2g. The reaction was carried out with stirring at 60℃. After the reaction was completed, the solution was filtered and washed until neutral. Then, it was dispersed in anhydrous ethanol. The mixture was mechanically stirred and ultrasonically treated. The mechanical stirring speed was 2500rpm, the ultrasonic power was 1000W, and the reaction time was 60min to obtain basalt nanosheets (BSNs).

[0074] (2) Rapid preparation of aramid nanofibers from waste aramid products: Waste aramid products were placed in a sodium dodecyl sulfate solution and reacted at a certain temperature to remove surface impurities. The waste aramid products were used gloves made from para-aramid. The concentration of the sodium dodecyl sulfate solution was 2 g / L, and the ratio of waste aramid products to sodium dodecyl sulfate solution was 1 g: 500 mL. The reaction temperature was 75 °C, and the stirring method was mechanical stirring at a speed of 2500 rpm. The reaction time was 8 h, and then the product was washed and dried with deionized water. Then, 10 g of the dried waste aramid products were placed in a beaker, and 15 g of potassium hydroxide (KOH) solid was added, followed by 200 mL of deionized water. The mixture was then placed in an ultrasonic machine and sonicated at 1000 W for 10 min to allow the surface of the waste aramid products to fully adsorb the potassium hydroxide solution. Finally, the mixture was heated to 80 °C. In addition, 500 mL of dimethyl sulfoxide (DMSO) solution was heated to the appropriate temperature. The heated DMSO was then added to a mixture of waste aramid product and KOH solution, and the mixture was stirred at 80 °C with magnetic stirring at a speed of 2500 rpm for 20 min. After the reaction was completed, a portion of the solution was taken out to determine the reaction endpoint and the reaction was terminated, thus obtaining an aramid nanofiber (ANF) / DMSO mixture, which was then sealed and stored for later use.

[0075] (3) Preparation of high-performance basalt nanosheet-based paper insulating coating: The BSNs obtained in step (1) were stirred and reacted with a polyvinylpyrrolidone solution. The mass ratio of BSNs to polyvinylpyrrolidone was 1g:20g, and the stirring rate was 1000rpm. Basalt nanosheets (CBSNs) with carbonyl groups on the surface were obtained. After the reaction was completed, the solid CBSNs were obtained by filtration and then dispersed in DMSO solvent. The CBSNs were placed in an ultrasonic machine with a mass ratio of CBSNs to DMSO of 1g:500mL. The ultrasonic machine was set to a power of 1000W and an ultrasonic time of 10min. Then, the CBSNs / DMSO mixture after the reaction was completed was added to the ANF / DMSO mixture and stirred thoroughly. The ratio of CBSNs / DMSO mixture to ANF / DMSO mixture was 500 mL: 500 mL. The reaction temperature was room temperature, the stirring method was mechanical stirring, the stirring speed was 2500 rpm, and the reaction time was 6 h. Finally, a high-performance basalt nanosheet-based paper insulating coating was obtained, which was then added to paper to prepare coated paper.

[0076] 2. Figure 7 A process diagram for preparing aramid nanofibers from waste aramid products, by Figure 7 It can be seen that waste aramid products can be used to prepare aramid nanofibers within 20 minutes. Figure 8 Scanning electron microscope (SEM) images of the electrical breakdown pores in plant fiber paper and plant fiber paper coated with a basalt nanosheet-based insulating coating, by [Author Name] Figure 8 It can be seen that the plant fiber paper coated with basalt nanosheet-based paper insulating coating has a small electrical breakdown area and a distinct layered structure at the edges, indicating that basalt nanosheets can block current flow in the coating, thereby improving its insulation. As shown in Table 1, the yield of basalt nanosheets is 59.4 mg / h, the aspect ratio is 1435.4, the ANF diameter is 28.4 nm, and the breakdown strength of the composite paper increases by 198% and the volume resistivity increases by 124% after the insulating coating is applied to the surface of the fiber paper.

[0077]

[0078]

[0079] Table 1 shows the performance data of basalt nanosheets.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials, characterized in that, include, S1, basalt flakes are surface-etched in sodium hydroxide solution, then reacted in tetrabutylammonium solution to obtain expanded basalt flakes, which are then dispersed in a mixed solution of hydrogen peroxide and organic acid, and ultrasonically treated to obtain basalt nanosheets; wherein the concentration of the tetrabutylammonium solution is 0.2 mol / L to 2 mol / L, the ratio of basalt flakes to tetrabutylammonium solution is 1 g: 100 mL to 500 mL, and the reaction time is 2 to 8 hours. h, reaction temperature is 25℃~100℃; the ratio of basalt flakes to hydrogen peroxide and organic acid mixed solution is 1g:200~500mL, the mass fraction of hydrogen peroxide in the mixed solution of hydrogen peroxide and organic acid is 10wt%~30wt%, the organic acid is maleic acid or oxalic acid, the amount of organic acid added per 500mL is 0.5g~2g, the ultrasonic power is 500W~1000W, and the reaction time is 20min~60min; S2, add waste aramid products to potassium hydroxide solution, then add heated DMSO, and after reaction, obtain aramid nanofiber / DMSO mixture; the waste aramid products are used fibers, cloth or gloves made from para-aramid; S3, react BSNs with polyvinylpyrrolidone solution to obtain basalt nanosheets with carbonyl groups on the surface, then disperse them in DMSO solvent and react with ultrasound to obtain a CBSNs / DMSO mixture, which is then added to an aramid nanofiber / DMSO mixture. After the reaction, a high-performance basalt nanosheet-based paper insulating coating is obtained.

2. The method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials according to claim 1, characterized in that, The concentration of sodium hydroxide solution in S1 is 0.1 mol / L to 1 mol / L, the ratio of basalt flakes to sodium hydroxide solution is 1 g: 100 mL to 500 mL, the surface etching reaction time is 4 to 24 h, and the reaction temperature is 60 °C to 120 °C.

3. The method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials according to claim 1, characterized in that, Before use, place the waste aramid product in a sodium dodecyl sulfate solution and react at a certain temperature to wash away surface impurities; The concentration of the sodium dodecyl sulfate solution is 2 g / L, the ratio of waste aramid product to sodium dodecyl sulfate solution is 1 g: 100 mL to 500 mL, the reaction temperature is 60 °C to 80 °C, and the reaction time is 1 to 8 h.

4. The method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials according to claim 1, characterized in that, In step S2, the ratio of waste aramid product to DMSO is 1g~10g:500mL, and the reaction temperature is 25℃~80℃; the ratio of waste aramid product to potassium hydroxide in the potassium hydroxide solution is 1g~10g:1.5g; the mass fraction of the potassium hydroxide solution is 7.5wt%; and the heating temperature of DMSO is 40℃~80℃. When preparing an aramid nanofiber / DMSO mixture, the method for determining the reaction endpoint is when no obvious fiber fragments and impurities are visible to the naked eye and the Tyndall effect is produced.

5. The method for preparing a high-performance basalt nanosheet-based paper insulating coating using waste aramid products as raw materials according to claim 1, characterized in that, The mass ratio of basalt nanosheets to polyvinylpyrrolidone in S3 is 1g:5~20g, the mass ratio of basalt nanosheets with carbonyl groups on the surface to DMSO is 0.2g~1g:500mL, and the ultrasonic time is 1min~10min. The ratio of the CBSNs / DMSO mixture to the aramid nanofiber / DMSO mixture is 500 mL: 500 mL, and the reaction time is 2 h to 6 h.

6. A high-performance basalt nanosheet-based paper insulating coating made from waste aramid products, characterized in that, Prepared according to the preparation method described in any one of claims 1-5.

7. The high-performance basalt nanosheet-based paper insulating coating based on waste aramid products as described in claim 6, characterized in that, The basalt nanosheets described have a yield of 30.2–59.4 mg / h and an aspect ratio of 691.4–1435.4, while the aramid nanofibers have a diameter of 18.4–28.4 nm. After coating the surface of fiber paper with high-performance basalt nanosheet-based paper insulating coating, the breakdown strength of the composite paper increased by 113%~198%, and the volume resistivity increased by 83%~124%.

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