A modified aramid fiber, a high-strength, high-uniformity, high-water-absorption aramid paper and a preparation method and application thereof

Abstract

The application belongs to the field of high-performance fiber material modification and special paper preparation, and discloses a modified aramid fiber, a high-strength, high-uniformity and high-water-absorbing aramid paper and a preparation method and application thereof.The modified aramid fiber comprises bacterial cellulose and aramid fiber with a mass ratio of 0.1-1.5:2-15.The aramid paper comprises 2-16.5 parts of the modified aramid fiber, 0.16-1.2 parts of hot-melt fiber, 0.4-2 parts of a surfactant and 0.01-0.1 parts of a dispersing agent.The application effectively increases the hydrophilic groups on the surface of the aramid fiber by utilizing the interaction between the bacterial cellulose and the aramid fiber, and the prepared aramid paper not only has high strength, but also has a significant improvement of 244% to 1294% in tensile property compared with the aramid paper without modification by the bacterial cellulose, and exhibits good uniformity and greatly enhanced water-absorbing property.In addition, the aramid paper has excellent absorption capacity for silica sol, and has a very broad application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-performance fiber material modification and special paper preparation, and relates to a modified aramid fiber, a high-strength, high-uniformity and high-water-absorptivity aramid paper and a preparation method and application thereof. BACKGROUND

[0002] Aramid fiber, as a kind of high-performance synthetic fiber, has excellent high modulus, high strength and excellent heat resistance and flame resistance, and has shown wide application potential in many fields such as aerospace, building materials and sports equipment. Its unique molecular structure and chemical stability make aramid fiber an ideal choice for many high-tech products and industrial applications. However, although aramid fiber has many advantages, its surface hydrophobicity and easy agglomeration to some extent limit its use in certain specific application scenarios. Especially in those occasions where materials need to have high strength or high hydrophilicity and good liquid absorption capacity, such as biomedical materials, filter media and aerogel composites, the hydrophobicity and easy agglomeration of aramid fiber have become an obstacle that cannot be ignored. In order to solve these problems, researchers have tried many methods. Patent CN 113389080 B uses aramid nanofiber dispersion liquid to modify aramid short-cut fibers, and by constructing a multi-level micro / nano rough structure on the surface of aramid fibers, a composite fiber coated with aramid nanofiber is prepared, which effectively improves the strength of aramid paper. However, unfortunately, although this method enhances the strength, the water absorption problem of aramid paper has not been solved. Another patent CN 114481677 B obtains modified p-aramid coarse fibers by polymerizing p-phenylenediamine, terephthaloyl chloride and a fluorescent unit with aggregation-induced emission characteristics, and then through stirring, crushing, washing and drying processes. Although this method improves the mechanical strength of aramid paper, the uniformity and water absorption performance problems have not been properly solved. Therefore, in the process of preparing aramid paper, how to effectively improve the strength, uniformity, water absorption and absorption capacity of specific liquids of aramid paper has become a key technical challenge to broaden the application range of aramid fiber and its paper products. SUMMARY

[0003] In view of the problems of aramid fiber surface hydrophobicity, easy agglomeration, and water absorption of aramid paper, the primary object of the present application is to provide a modified aramid fiber.

[0004] Another object of the present application is to provide a high-strength, high-uniformity and high-water-absorptivity aramid paper.

[0005] Another object of the present application is to provide a preparation method of a high-strength, high-uniformity and high-water-absorptivity aramid paper.

[0006] Another object of the present application is to provide the application of the above-mentioned aramid paper with high strength, high uniformity and high water absorption.

[0007] The present application combines bacterial cellulose and foam forming technology, increases hydrophilic groups by attaching bacterial cellulose on the surface of aramid fibers, improves dispersibility, and uses foam forming technology to prepare aramid paper with high strength, high uniformity and excellent water absorption.

[0008] To achieve the above-mentioned object, the technical solution of the present application is as follows:

[0009] A modified aramid fiber, comprising bacterial cellulose and aramid fiber, the mass ratio of the bacterial cellulose and aramid fiber is 0.1-1.5:2-15, more preferably 0.1-0.5:5.

[0010] The hydroxyl groups of the bacterial cellulose are combined with the functional groups on the surface of the aramid fiber by hydrogen bonds.

[0011] The functional groups on the surface of the aramid fiber include but are not limited to phenolic hydroxyl groups and carboxyl groups.

[0012] Preferably, the length of the aramid fiber is 3-9mm, and the moisture content is 4-5% m / m.

[0013] Preferably, the diameter of the bacterial cellulose is 20-150nm, and the length is >20μm.

[0014] An aramid paper with high strength, high uniformity and high water absorption, comprising the above-mentioned modified aramid fiber, the components are as follows in parts by weight:

[0015]

[0016]

[0017] Preferably, the surfactant is at least one of amine-based gemini quaternary ammonium salt, sodium dodecyl sulfonate and dodecyl dimethyl amine oxide.

[0018] Preferably, the dispersant is polyethylene oxide.

[0019] The melting point of the hot melt fiber is 90-110℃, the diameter is 10-15μm, and the length is 3-5mm.

[0020] Preferably, the addition amount of the hot melt fiber is 8wt.% of the aramid fiber.

[0021] Preferably, the basis weight of the aramid paper is 278-556g / m 2 .

[0022] Preferably, the tensile stress of the aramid paper is 0.1-3MPa.

[0023] Preferably, the aramid paper uniformity value is 70.0-120.

[0024] A preparation method of high-strength, high-uniformity, high-water-absorption aramid paper, which is prepared by using a foaming forming technology and comprises the following steps:

[0025] (1) 1000 parts by weight of water are added with aramid fibers, hot-melt fibers, and a dispersant, the fibers are defibrated, a bacterial cellulose dispersion liquid is added, and the mixture is left to stand and defibrated again for a period of time to obtain a mixed liquid;

[0026] (2) The mixed liquid is poured into a foaming device, a surfactant is added, and a stirrer is used for stirring and foaming, and after the stirring is stopped, the mixture is poured into a former, and a high-strength, high-uniformity, high-water-absorption aramid paper is obtained by vacuum extrusion and drying.

[0027] Preferably, the defibration speed in step (1) is 4000-6000 rpm.

[0028] The defibration time of the fibers is 110-130 s, and the defibration time again is 80-100 s.

[0029] Preferably, the bacterial cellulose dispersion liquid in step (1) is obtained by treating bacterial cellulose with a 3.5 wt.% NaOH solution and then high-speed dispersing, and the concentration of the bacterial cellulose dispersion liquid is 0.8 wt.%.

[0030] Preferably, the stirring speed in step (2) is 1500-2000 rpm, and the foaming time is 5-15 min.

[0031] The high-strength, high-uniformity, high-water-absorption aramid paper is applied to aerogel composites.

[0032] Compared with the prior art, the present application has the following advantages and beneficial effects

[0033] (1) The aramid paper prepared in the present application has high strength, the tensile property of which is increased by 244%-1294% compared with that of aramid paper without bacterial cellulose modification, has good uniformity, and has significantly improved water absorption, and has good absorption capacity for silica sol.

[0034] (2) In the present application, defibration and polyethylene oxide can disperse part of the aramid fibers, and the tiny bubbles in the foaming forming process can physically block the aramid fibers. When the aramid fibers are uniformly dispersed in the foam, the foam bubbles can limit the free movement of the fibers, prevent the uniformly dispersed aramid fibers from re-flocculating and settling, and this physical blocking effect helps the fibers to maintain a uniformly dispersed state.

[0035] (3) The stability of the foam needs to be controlled in the present application so as to keep it in a suitable half-life range to achieve the best effect of dispersing fibers. The bacterial cellulose adsorbed on the surface of aramid fibers is attached to the hydrophilic end of the surfactant through hydroxyl groups to form a three-dimensional network structure, which can effectively prevent the rupture and coalescence of bubbles.

[0036] (4) The hydroxyl groups of the bacterial cellulose in the present application can form hydrogen bonds with the functional groups (such as phenolic hydroxyl groups and carboxyl groups) on the surface of aramid fibers. Such hydrogen bonding is a strong intermolecular force, which helps the bacterial cellulose to be stably adsorbed on the surface of aramid fibers.

[0037] (5) In the present application, by controlling the foam forming conditions, the bacterial cellulose can not only effectively stabilize the foam to improve the ability of the foam forming technology to disperse aramid fibers, but also be uniformly and firmly adsorbed on the surface of aramid fibers to increase the hydrophilic groups on the surface of aramid fibers. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Figure is a half-life diagram of the foam slurry (containing aramid fibers);

[0039] Figure 2 Figure is an intuitive diagram of aramid paper (Example 4);

[0040] Figure 3 Figure is an SEM diagram of bacterial cellulose (a, b), aramid fibers (c, d), modified aramid fibers (e, f), unmodified aramid paper (g) and modified aramid paper (h);

[0041] Figure 4 Figure is a diagram of the surface of aramid fibers treated with a dyeing agent (the dyeing agent can dye bacterial cellulose) (a and b are unmodified aramid fibers, c and d are modified aramid fibers);

[0042] Figure 5 Figure is a tensile property diagram of aramid paper;

[0043] Figure 6 Figure is an evenness diagram of aramid paper;

[0044] Figure 7 Figure is a water absorption capacity diagram of aramid paper;

[0045] Figure 8 Figure is a silica sol absorption capacity diagram of aramid paper. DETAILED DESCRIPTION

[0046] In order to further understand the present application, the embodiments of the present application will be further described in detail below in combination with examples and comparative examples, but the embodiments of the present application are not limited thereto. For the process parameters not specifically mentioned, the conventional techniques can be referred to.

[0047] Bacterial cellulose, purchased from Guilin Qihong Technology Co., Ltd., was treated with 3.5 wt.% NaOH solution and then dispersed at high speed to obtain a bacterial cellulose dispersion liquid, the concentration of which was 0.8 wt.% and the diameter of the bacterial cellulose was 20-150 nm and the length was >20 μm.

[0048] Aramid fiber, the length of which was 6 mm and the moisture content of which was 4.5% m / m, where m / m is the mass ratio, i.e. 4.5 g of water per 100 g of aramid fiber.

[0049] Hot melt fiber, the melting point of which was 100°C, the diameter of which was 10-15 μm and the length of which was 4 mm.

[0050] Example 1

[0051] (1) 5 parts of aramid fiber and 0.4 parts of hot melt fiber and 0.04 parts of polyethylene oxide were added to 1000 parts of water, and the fibers were defibered in a defiberer for 120 s, and then the defiberer was defibered again for 90 s after standing for 2 h, and the defibering speed was 5000 rpm, to obtain a mixed liquid.

[0052] (2) The mixed liquid was poured into a foaming device, and 0.8 parts of dodecyl dimethyl amine oxide was added, and the stirring speed of the stirrer was 1800 rpm, and the foaming time was 10 min, and the stirring paddle was a three-layer three-blade stirring paddle, and the mixed liquid was poured into a former after stopping stirring, and wet aramid paper was obtained by vacuum extrusion at 0.1 MPa, and the aramid paper was dried in an oven at 130°C for 1 h, and the basis weight of the aramid paper was 326 g / cm 2 .

[0053] Example 2

[0054] (1) 5 parts of aramid fiber and 0.4 parts of hot melt fiber and 0.04 parts of polyethylene oxide were added to 1000 parts of water, and the fibers were defibered in a defiberer for 120 s, and then the defiberer was defibered again for 90 s after standing for 2 h, and the defibering speed was 5000 rpm, to obtain a mixed liquid.

[0055] (2) The mixed liquid was poured into a foaming device, and 0.8 parts of dodecyl dimethyl amine oxide was added, and the stirring speed of the stirrer was 1800 rpm, and the foaming time was 10 min, and the stirring paddle was a three-layer three-blade stirring paddle, and the mixed liquid was poured into a former after stopping stirring, and wet aramid paper was obtained by vacuum extrusion at 0.1 MPa, and the aramid paper was dried in an oven at 130°C for 1 h, and the basis weight of the aramid paper was 326 g / cm 2 .

[0056] Example 3

[0057] (1) 1000 parts of water by weight, add 5 parts of aramid fiber and 0.4 parts of hot melt fiber, and 0.04 parts of polyethylene oxide, defibrator defibrillate the fiber for 120s, stand for 2h, add 37.5 parts of bacterial cellulose dispersion liquid (equivalent to 0.3 parts of bacterial cellulose) to defibrator and defibrate again for 90s, the defibration speed is 5000rpm, to get the mixed liquid, which includes 5.3 parts of modified aramid fiber.

[0058] (2) Pour the mixed liquid into the foaming device, and add 0.8 parts of dodecyl dimethyl amine oxide, stir for 10min at 1800rpm, the stirring paddle is three layers of three-blade stirring paddle, pour into the former after stopping stirring, vacuum extrusion into wet aramid paper under 0.1MPa, oven dry at 130℃ for 1h, to get aramid paper, the basis weight is 333g / cm 2 .

[0059] Example 4

[0060] (1) 1000 parts of water by weight, add 5 parts of aramid fiber and 0.4 parts of hot melt fiber, and 0.04 parts of polyethylene oxide, defibrator defibrillate the fiber for 120s, stand for 2h, add 62.5 parts of bacterial cellulose dispersion liquid (equivalent to 0.5 parts of bacterial cellulose) to defibrator and defibrate again for 90s, the defibration speed is 5000rpm, to get the mixed liquid, which includes 5.5 parts of modified aramid fiber.

[0061] (2) Pour the mixed liquid into the foaming device, and add 0.8 parts of dodecyl dimethyl amine oxide, stir for 10min at 1800rpm, the stirring paddle is three layers of three-blade stirring paddle, pour into the former after stopping stirring, vacuum extrusion into wet aramid paper under 0.1MPa, oven dry at 130℃ for 1h, to get aramid paper, the basis weight is 340g / cm 2 .

[0062] Comparative Example 1

[0063] (1) 1000 parts of water by weight, add 5 parts of aramid fiber and 0.4 parts of hot melt fiber, and 0.04 parts of polyethylene oxide, defibrator defibrillate the fiber for 120s, stand for 2h, add 62.5 parts of bacterial cellulose dispersion liquid (equivalent to 0.5 parts of bacterial cellulose) to defibrator and defibrate again for 90s, the defibration speed is 5000rpm, to get the mixed liquid, which includes 5.5 parts of modified aramid fiber.

[0064] (2) Wet forming method is used to prepare aramid paper, first, the water level in the sheet former reaches the preset height, then the mixed liquid is slowly added. When the water level is close to the maximum capacity, stop adding water and start the drainage program, then perform the drainage and forming operation, finally, oven dry at 130℃ for 1h, to get aramid paper, the basis weight is 340g / cm2 .

[0065] Test Example 1

[0066] The mixed solution of Examples 1-5 was stirred at a speed of 1800 rpm for 10 min to obtain a foam slurry containing aramid fibers. The foam stability was tested by the Waring-Blender method, and the results are shown below:

[0067] Figure 1 Figure is a half-life chart of the foam slurry (containing aramid fibers). As can be seen from the figure, in Example 1, the half-life of the foam slurry is 380 s; in Example 2, the half-life of the foam slurry is 420 s; in Example 3, the half-life of the foam slurry is 448 s; in Example 4, the half-life of the foam slurry is 467 s. The results show that the addition of bacterial cellulose can improve the stability of the foam and prevent the foam from breaking and coalescing in a short time. Bacterial cellulose has a unique three-dimensional network structure, which can block the loss of liquid on the bubble surface and the coalescence of bubbles, and increase the stability time of the bubbles.

[0068] Test Example 2

[0069] The aramid paper prepared in Examples 1-5 was observed visually and by SEM, and the test results are as follows:

[0070] Figure 2 Figure is a visual diagram of aramid paper (Example 4), and the surface of the aramid paper is uniform and smooth, with almost no roughness. This surface improves the aesthetic appearance of the aramid paper. Figure 3 (a) and Figure 3 (b) are SEM diagrams of bacterial cellulose. The fibers in the bacterial cellulose are densely intertwined, forming a complex three-dimensional network structure with fine gaps distributed between the networks. Figure 3 (c) and Figure 3 (d) are SEM diagrams of aramid fibers. The surface of the aramid fibers is smooth, with no obvious texture or unevenness. Figure 3 (e) and Figure 3 (f) are SEM diagrams of modified aramid fibers. As can be seen from the figure, the bacterial cellulose wraps the surface of the aramid fibers by hydrogen bonds, forming a dense fiber film, indicating that the bacterial cellulose has successfully modified the surface of the aramid fibers and increased the hydrophilic groups on the surface of the aramid fibers. Figure 3 (g) is an SEM diagram of unmodified aramid paper (without bacterial cellulose). The aramid fibers are intertwined with each other, layer upon layer, forming a large number of gaps. Figure 3(h) is a SEM image of the modified aramid paper, from which it can be clearly observed that the bacterial cellulose is closely attached to the surface of the aramid fiber, forming a firm combination. What is particularly important is that the presence of the bacterial cellulose not only effectively fills the tiny gaps in the internal structure of the aramid paper, improving the internal structure of the material, but also significantly enhances the connectivity between the aramid fibers through its excellent bonding ability.

[0071] Test Example 3

[0072] A single fiber was taken out from the aramid paper prepared in Examples 1-5 for Graff stain dyeing treatment (the stain can dye bacterial cellulose), and its pattern was observed using a polarizing microscope, and the test results are as follows:

[0073] Figure 4 (a) and Figure 4 (b) is an unmodified aramid fiber (without bacterial cellulose), and the results show that the surface of the aramid fiber cannot be dyed by the stain, and presents an uneven pattern with light and dark interlacing. Figure 4 (c) and Figure 4 (d) is a modified aramid fiber (with bacterial cellulose), and the surface of the fiber presents a dark yellow color, and the uniform distribution of the dark yellow color also implies that the coverage of the bacterial cellulose on the surface of the aramid fiber is comprehensive and uniform. It serves as an intuitive visual marker, and powerfully proves that the bacterial cellulose has successfully adsorbed and attached to the surface of the aramid fiber.

[0074] Test Example 4

[0075] The aramid papers prepared in Examples 1-5 and Comparative Example 1 were subjected to tensile property testing, and the test results are as follows:

[0076] Figure 5The tensile property test results of aramid paper are shown. The results show that the tensile stress of unmodified aramid paper (Example 1) is 0.18 MPa, and the maximum force it can withstand is 6.4 N. In contrast, the modified aramid paper has a significant improvement in both tensile stress and maximum force during the tensile stress and breaking process: the tensile stress of Example 2 increases to 0.62 MPa, the maximum force it can withstand reaches 22.27 N, and the tensile stress strength increases by 244%; the tensile stress of Example 3 is 1.73 MPa, the maximum force it can withstand is 62.17 N, and the tensile stress strength increases by 861%; the tensile stress of Example 4 is as high as 2.51 MPa, the maximum force it can withstand is 90.39 N, and the tensile stress strength increases by 1294%; the tensile stress of Comparative Example 1 is 1.89 MPa, the maximum force it can withstand is 78.6 N, and the tensile stress strength increases by 950%. Another granted patent (Patent No. CN112663382A) processes aramid paper with a strength of not more than 20 N. The strength enhancement method of aramid paper used in the present application, in which Examples 2-4 have better effect than the above-mentioned patent.

[0077] Test Example 5

[0078] The aramid papers prepared in Examples 1-5 and Comparative Example 1 were tested for uniformity, and the smaller the uniformity value, the better the uniformity of the aramid paper. The test results are as follows:

[0079] Figure 6 The aramid paper uniformity test results are shown, the uniformity value of Example 1 is 116.2; the uniformity value of Example 2 is 112.6; the uniformity value of Example 3 is 97.9; the uniformity value of Example 4 is 79.0; and the uniformity value of Comparative Example 1 is 244.2. The test results show that the surface modification of aramid fibers helps to disperse them, and the aramid paper prepared by foam molding has good uniformity, which solves the problem of easy agglomeration of aramid fibers.

[0080] Test Example 6

[0081] The aramid papers prepared in Examples 1-5 and Comparative Example 1 were tested for water absorption and silica sol absorption capacity, and the test results are as follows:

[0082] Figure 7The results of the water absorption test of aramid paper are shown. The aramid paper is accurately cut and carefully selected samples with a weight of 1 to 1.1 g. Then, it is placed in a container with 50 ml of water and waited for 60 seconds to ensure that the sample is fully soaked. After that, the sample is carefully taken out and the excess water on its surface is gently removed with filter paper, and then the weight increase after water absorption is accurately measured and recorded. Example 1 absorbs 12.5 g of water; Example 2 absorbs 14 g of water; Example 3 absorbs 14.8 g of water; Example 4 absorbs 14.9 g of water; Comparative Example 1 absorbs 14 g of water. This series of test results strongly proves that the surface modification of aramid fibers significantly improves the water absorption performance of aramid paper, and improves the hydrophobicity of aramid fibers.

[0083] Figure 8 The results of the silica sol absorption test of aramid paper are shown. The aramid paper is accurately cut and selected aramid paper samples with a length of 13 cm and a width of 1.5 cm. The top end of the sample is fixed with a clamp, and the bottom end is below the silica sol liquid with red dye added. Timing starts when the bottom end contacts the liquid, and after 180 seconds, the silica sol liquid is removed, the absorption height is measured, and recorded. The results show that Example 1 absorbs silica sol liquid to a height of 2.9 cm; Example 2 absorbs silica sol liquid to a height of 5 cm; Example 3 absorbs silica sol liquid to a height of 5.5 cm; Example 4 absorbs silica sol liquid to a height of 6.8 cm; Comparative Example 1 absorbs silica sol liquid to a height of 5.8 cm. This series of test data not only fully verifies that aramid paper has good absorption capacity for silica sol, but also further proves that the surface treatment technology of the present patent can significantly improve the absorption performance of aramid paper for silica sol liquid, providing a strong scientific basis for the application of aerogel composite materials and other related fields.

[0084] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. A high-strength, high-uniformity, high-water-absorption aramid paper, characterized by, The components are as follows in parts by weight: Modified aramid fiber 5~10.5 parts Hot melt fiber 0.4~0.8 parts Surfactant 0.8~1.2 parts Dispersant 0.01~0.05 parts The modified aramid fiber comprises bacterial cellulose and aramid fiber, and the mass ratio of the bacterial cellulose to the aramid fiber is 0.1~0.5:5; the hydroxyl group of the bacterial cellulose is combined with the functional group on the surface of the aramid fiber by hydrogen bond; The high-strength, high-uniformity and high-water-absorbing aramid paper is prepared by using a foaming forming technique, comprising the following steps: (1) adding aramid fiber, hot melt fiber and dispersant into 1000 parts by weight of water, and then adding bacterial cellulose dispersion after defibrating the fibers, standing, and defibrating again for a period of time to obtain a mixed solution; (2) pouring the mixed solution into a foaming device, adding a surfactant, stirring and foaming by a stirrer, pouring into a former after stopping stirring, vacuum extruding into a wet aramid paper, drying, and obtaining the high-strength, high-uniformity and high-water-absorbing aramid paper.

2. The high-strength, high-uniformity, high-water-absorption aramid paper according to claim 1, characterized by, The diameter of the bacterial cellulose is 20~150 nm, and the length is >20 μm; The length of the aramid fiber is 3~9 mm, and the moisture content is 4~5% m / m.

3. The high-strength, high-uniformity, high-water-absorption aramid paper according to claim 1, characterized in that, The surfactant is at least one of amido gemini quaternary ammonium salt, sodium dodecyl sulfonate and dodecyl dimethyl amine oxide.

4. The high-strength, high-uniformity, high-water-absorption aramid paper according to claim 1, characterized in that, The melting point of the hot melt fiber is 90~110℃, the diameter is 10~15 μm, and the length is 3~5 mm.

5. The method for preparing high-strength, high-uniformity, high-water-absorption aramid paper according to any one of claims 1 to 4, characterized in that, The high-strength, high-uniformity and high-water-absorbing aramid paper is prepared by using a foaming forming technique, comprising the following steps: (1) adding aramid fiber, hot melt fiber and dispersant into 1000 parts by weight of water, and then adding bacterial cellulose dispersion after defibrating the fibers, standing, and defibrating again for a period of time to obtain a mixed solution; (2) pouring the mixed solution into a foaming device, adding a surfactant, stirring and foaming by a stirrer, pouring into a former after stopping stirring, vacuum extruding into a wet aramid paper, drying, and obtaining the high-strength, high-uniformity and high-water-absorbing aramid paper.

6. The method for preparing high-strength, high-uniformity, and high-absorbency aramid paper according to claim 5, characterized in that, The defibrating speed in step (1) is 4000~6000 rpm; the defibrating time of the fibers is 110~130 s, and the defibrating time again is 80~100 s.

7. The method for preparing high-strength, high-uniformity, and high-absorbency aramid paper according to claim 5, characterized in that, The stirring speed in step (2) is 1500~2000 rpm, and the foaming time is 5~15 min.

8. Application of the high-strength, high-uniformity and high-water-absorbing aramid paper in any one of claims 1~4 in aerogel composite material.

Images