A self-healing geopolymer-based curing agent and method of preparation

Abstract

The present application relates to the field of curing agent, especially to a kind of based on self-healing geopolymer curing agent and preparation method. By weight parts, above-mentioned based on self-healing geopolymer curing agent includes the following raw materials: fly ash 42-53 parts, granulated blast furnace slag 18-24 parts, activator 8-15 parts, self-healing agent 2.5-3.5 parts, sodium lignosulfonate derivative 1-5 parts, modified kevlar fiber 0.5-2 parts. Above-mentioned based on self-healing geopolymer curing agent can improve the mechanical properties and crack resistance of geopolymer matrix composite.

Description

Technical Field

[0001] This invention relates to the field of curing agents, and more particularly to a curing agent based on a self-healing geopolymer and its preparation method. Background Technology

[0002] With the acceleration of urbanization, a large amount of construction waste is generated during engineering construction. Traditional disposal methods (such as landfill or stockpiling) not only occupy land resources but may also cause environmental pollution. Therefore, the resource utilization of construction waste has become a research hotspot, and solidification and stabilization technology is one of the effective ways to achieve its recycling.

[0003] Geopolymer solidifiers are a new type of energy-saving and environmentally friendly engineering material, made primarily from industrial waste (such as fly ash and slag) combined with various functional additives. This material can independently bind soil materials to improve their strength, and possesses advantages such as high temperature resistance, acid and alkali corrosion resistance, high early strength, and high energy efficiency, showing great potential in the resource utilization of engineering waste. However, traditional geopolymer-based composite materials still suffer from problems such as high brittleness and easy cracking; the propagation of microcracks during long-term service can reduce their mechanical properties and durability.

[0004] In recent years, microbial-based self-healing geopolymers have offered a novel approach to addressing this problem. Microorganisms (such as Bacillus subtilis) can be activated in cracked environments, achieving self-repair through metabolic products (such as calcium carbonate). However, this method has limited effectiveness in improving the mechanical properties of materials, and the highly alkaline environment of geopolymers significantly affects the survival rate of microorganisms and mineralization efficiency. Therefore, it is necessary to optimize and improve the formulation of geopolymer curing agents to further enhance the mechanical properties and durability of geopolymer-based composites, meeting the needs of engineering applications. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a curing agent based on self-healing geopolymers, which can improve the mechanical properties and crack resistance of geopolymer-based composite materials.

[0006] The second objective of this invention is to provide a simple method for preparing a curing agent based on a self-healing geopolymer.

[0007] One of the objectives of this invention is achieved through the following technical solution:

[0008] A curing agent based on a self-healing geopolymer, comprising the following raw materials by weight: 42-53 parts fly ash, 18-24 parts granulated blast furnace slag, 8-15 parts activator, 2.5-3.5 parts self-healing agent, 1-5 parts sodium lignosulfonate derivative, and 0.5-2 parts modified Kevlar fiber.

[0009] The structural formula of the sodium lignosulfonate derivative is as follows: ;

[0010] In the formula, R is: .

[0011] Furthermore, the preparation process of the sodium lignosulfonate derivative is as follows:

[0012] (1) Sodium lignosulfonate and urea were added to deionized water, and then formaldehyde solution was added for heating reaction. After the heating reaction was completed, the temperature was lowered to room temperature, the pH of the system was adjusted with hydrochloric acid, the precipitate was obtained by centrifugation, and the precipitate was dried to obtain intermediate 1.

[0013] (2) Phytic acid was added to deionized water, and then intermediate 1 was added to react. After the reaction was completed, anhydrous ethanol was added, and the product was obtained by centrifugation. After washing and drying, sodium lignosulfonate derivative was obtained.

[0014] Further, in step (1), the ratio of sodium lignosulfonate, urea, formaldehyde solution and deionized water is 1g:(3-4)g:(1-2)mL:(20-25)mL; and the concentration of the formaldehyde solution is 35-37wt%.

[0015] Further, the heating reaction temperature in step (1) is 50-60℃, the heating reaction time is 3-6h; the concentration of the hydrochloric acid is 0.5mol / L; and the pH of the system is adjusted to 3-3.2.

[0016] Furthermore, in step (2), the ratio of intermediate 1, phytic acid, and deionized water is 1g:(5-10)mL:(20-30)mL.

[0017] Furthermore, the reaction temperature in step (2) is 50-60℃, and the reaction time is 4-6h.

[0018] Furthermore, the preparation process of the modified Kevlar fiber is as follows:

[0019] Kevlar fibers and potassium hydroxide were added to dimethyl sulfoxide and stirred at room temperature for 6-7 days. Epichlorohydrin was then added, and the mixture was heated to carry out the reaction. After the reaction was completed, the mixture was purified to obtain modified Kevlar fibers.

[0020] Furthermore, the ratio of Kevlar fiber, potassium hydroxide, dimethyl sulfoxide, and epichlorohydrin is 1:(1-2)g:(200-250)mL:(0.5-2)mL; the temperature is raised to 30-45℃; and the reaction time is 18-24h.

[0021] Further, the activator is sodium silicate; the modulus of the sodium silicate is 1-2; the self-healing agent is Bacillus subtilis bacterial solution; the concentration of Bacillus subtilis in the Bacillus subtilis bacterial solution is (1-2)×10⁻⁶. 9 per mL.

[0022] Furthermore, the fly ash is Class F fly ash with an activity index of 50-80% and a particle size of 25-300μm; the granulated blast furnace slag has an activity index of >95%, a particle size of 25-300μm, and a calcium oxide content of ≥40%.

[0023] The second objective of this invention is achieved by the following technical solution:

[0024] The preparation method of the above-mentioned curing agent based on self-healing geopolymer includes the following steps:

[0025] (a) Mix the self-healing agent and the activator and stir for 2-3 minutes to obtain mixture A;

[0026] (b) Mix fly ash, granulated blast furnace slag, sodium lignosulfonate derivative, and modified Kevlar fiber for 2-3 minutes to obtain mixture B;

[0027] (c) Mix the mixture A with the mixture B for 3-5 minutes to obtain the final product.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The curing agent formulation of this invention includes sodium lignosulfonate derivatives and modified Kevlar fibers. Experimental results show that the combined use of sodium lignosulfonate derivatives and modified Kevlar fibers can improve the mechanical properties and crack resistance of geopolymer-based composites. This may be because, on the one hand, the sulfonic acid groups and hydroxyl groups in sodium lignosulfonate participate in the geopolymer reaction, forming a cross-linked structure; simultaneously, phytic acid molecules react with Ca in the geopolymer... 2+ Al 3+ The complexation with metal ions further enhances the crosslinking density, thereby significantly improving the mechanical properties and crack resistance of the geopolymer-based composite material. Furthermore, the weak acidity of phytic acid may locally neutralize the high alkalinity of sodium silicate, slowing down the geopolymerization reaction rate and preventing cracks caused by excessively rapid curing. On the other hand, the introduction of epoxy groups into the modified Kevlar fiber allows it to undergo ring-opening reactions with the silanol and aluminol groups in the geopolymer or the phosphate groups in phytic acid. This not only improves its compatibility but also forms a multi-level crosslinked structure of "fiber-lignin-geomer," further enhancing the mechanical properties and crack resistance of the geopolymer-based composite material. Attached Figure Description

[0030] Figure 1The infrared spectra of the sodium lignosulfonate derivative obtained in Example 1 are shown, where a is the infrared spectrum of sodium lignosulfonate and b is the infrared spectrum of the sodium lignosulfonate derivative.

[0031] Figure 2 The image shows the infrared spectrum of the modified Kevlar fiber obtained in Preparation Example 4, where c is the infrared spectrum of the Kevlar fiber and d is the infrared spectrum of the modified Kevlar fiber. Detailed Implementation

[0032] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0033] In the following embodiments, the fly ash is Class F fly ash with an activity index of 50-80% and a particle size of 25-300μm; the granulated blast furnace slag has an activity index of >95%, a particle size of 25-300μm, and a calcium oxide content of ≥40%; the activator is sodium silicate with a modulus of 1-2; and the self-healing agent is Bacillus subtilis bacterial solution.

[0034] (a) Preparation example

[0035] Preparation Example 1

[0036] Preparation Example 1 provides a sodium lignosulfonate derivative, and the specific preparation process is as follows:

[0037]

[0038] In the formula, R is: .

[0039] (1) Sodium lignosulfonate, urea, formaldehyde solution and deionized water were used in a ratio of 1g:3.5g:2.5mL:22mL. Sodium lignosulfonate and urea were added to deionized water, and then formaldehyde solution with a concentration of 35wt% was added. The mixture was heated at 55℃ for 4h. After the heating reaction was completed, the mixture was cooled to room temperature. The pH of the system was adjusted to 3.1 with hydrochloric acid with a concentration of 0.5mol / L. The precipitate was obtained by centrifugation and dried in a vacuum oven at 60℃ for 24h to obtain intermediate 1.

[0040] (2) With the ratio of intermediate 1, phytic acid and deionized water as 1g:8mL:22mL, phytic acid was added to deionized water, and then intermediate 1 was added. The reaction was carried out at 55℃ for 5h. After the reaction was completed, anhydrous ethanol was added, and the product was obtained by centrifugation. The product was washed with anhydrous ethanol and dried in a vacuum oven at 60℃ for 24h to obtain sodium lignosulfonate derivative.

[0041] Preparation Example 2

[0042] Preparation Example 2 provides a sodium lignosulfonate derivative, and the specific preparation process is as follows:

[0043] (1) Sodium lignosulfonate, urea, formaldehyde solution and deionized water were added in a ratio of 1g:3g:1mL:20mL. Sodium lignosulfonate and urea were added to deionized water, and then formaldehyde solution with a concentration of 35wt% was added. The mixture was heated at 50℃ for 6h. After the heating reaction was completed, the mixture was cooled to room temperature. The pH of the system was adjusted to 3 with hydrochloric acid with a concentration of 0.5mol / L. The precipitate was obtained by centrifugation and dried in a vacuum oven at 60℃ for 24h to obtain intermediate 1.

[0044] (2) With the ratio of intermediate 1, phytic acid and deionized water as 1g:5mL:20mL, concentrated phytic acid was added to deionized water, and then intermediate 1 was added. The reaction was carried out at 50℃ for 6h. After the reaction was completed, anhydrous ethanol was added, and the product was obtained by centrifugation. The product was washed with anhydrous ethanol and dried in a vacuum oven at 60℃ for 24h to obtain sodium lignosulfonate derivative.

[0045] Preparation Example 3

[0046] Preparation Example 3 provides a sodium lignosulfonate derivative, and the specific preparation process is as follows:

[0047] (1) Sodium lignosulfonate, urea, formaldehyde solution and deionized water were added in a ratio of 1g:4g:2mL:25mL. Sodium lignosulfonate and urea were added to deionized water, and then formaldehyde solution with a concentration of 37wt% was added. The mixture was heated at 60℃ for 3h. After the heating reaction was completed, the mixture was cooled to room temperature. The pH of the system was adjusted to 3.2 with hydrochloric acid with a concentration of 0.5mol / L. The precipitate was obtained by centrifugation and dried in a vacuum oven at 60℃ for 24h to obtain intermediate 1.

[0048] (2) With the ratio of intermediate 1, phytic acid and deionized water as 1g:10mL:30mL, phytic acid was added to deionized water, and then intermediate 1 was added. The reaction was carried out at 60℃ for 4h. After the reaction was completed, anhydrous ethanol was added, and the product was obtained by centrifugation. The product was washed with anhydrous ethanol and dried in a vacuum oven at 60℃ for 24h to obtain sodium lignosulfonate derivative.

[0049] Preparation Example 4

[0050] Preparation Example 4 provides a modified Kevlar fiber, and the specific preparation process is as follows:

[0051] With Kevlar fiber, potassium hydroxide, dimethyl sulfoxide, and epichlorohydrin in a ratio of 1:1.5g:220mL:1mL, Kevlar fiber was ultrasonically cleaned in anhydrous ethanol and dried. Then, it and potassium hydroxide were added to dimethyl sulfoxide and stirred at room temperature for 6 days. Epichlorohydrin was then added, and the mixture was heated to 35℃ and reacted for 20 hours. After the reaction was completed, the mixture was centrifuged, washed with deionized water until neutral, and dried in a vacuum oven at 60℃ to obtain modified Kevlar fiber.

[0052] Preparation Example 5

[0053] Preparation Example 5 provides a modified Kevlar fiber, and the specific preparation process is as follows:

[0054] With Kevlar fiber, potassium hydroxide, dimethyl sulfoxide, and epichlorohydrin in a ratio of 1:1 g:200 mL:0.5 mL, the Kevlar fiber was ultrasonically cleaned in anhydrous ethanol and dried. Then, it and potassium hydroxide were added to dimethyl sulfoxide and stirred at room temperature for 7 days. After stirring, epichlorohydrin was added, and the mixture was heated to 30°C and reacted for 24 hours. After the reaction was completed, the mixture was centrifuged, washed with deionized water until neutral, and dried in a vacuum oven at 60°C to obtain modified Kevlar fiber.

[0055] Preparation Example 6

[0056] Preparation Example 6 provides a modified Kevlar fiber, and the specific preparation process is as follows:

[0057] With Kevlar fiber, potassium hydroxide, dimethyl sulfoxide, and epichlorohydrin in a ratio of 1:2 g:250 mL:2 mL, the Kevlar fiber was ultrasonically cleaned in anhydrous ethanol and dried. Then, it and potassium hydroxide were added to dimethyl sulfoxide and stirred at room temperature for 6 days. After stirring, epichlorohydrin was added, and the mixture was heated to 45°C and reacted for 18 hours. After the reaction was completed, the mixture was centrifuged, washed with deionized water until neutral, and dried in a vacuum oven at 60°C to obtain modified Kevlar fiber.

[0058] (II) Implementation Examples

[0059] Example 1

[0060] Example 1 provides a curing agent based on a self-healing geopolymer. By weight, the curing agent consists of the following raw materials: 50 parts fly ash, 21 parts granulated blast furnace slag, 12 parts sodium silicate, and 3 parts Bacillus subtilis bacterial solution (concentration 1.5 × 10⁻⁶). 9 (each part per mL), 4 parts of sodium lignosulfonate derivative of Preparation Example 1, and 1 part of modified Kevlar fiber of Preparation Example 4.

[0061] Example 1 also provides a method for preparing the above-mentioned curing agent based on self-healing geopolymer, as follows:

[0062] (a) Mix Bacillus subtilis bacterial culture and sodium silicate for 2 min to obtain mixture A;

[0063] (b) Mix fly ash, granulated blast furnace slag, sodium lignosulfonate derivative, and modified Kevlar fiber for 2 minutes to obtain mixture B;

[0064] (c) Mix the mixture A and the mixture B together and stir for 3 minutes to obtain the final product.

[0065] Example 2

[0066] Example 2 provides a curing agent based on a self-healing geopolymer. By weight, the curing agent consists of the following raw materials: 42 parts fly ash, 18 parts granulated blast furnace slag, 8 parts sodium silicate, and 2.5 parts Bacillus subtilis bacterial solution (concentration 1×10⁻⁶). 9 (1 part / mL), 1 part of sodium lignosulfonate derivative of Preparation Example 2, and 0.5 parts of modified Kevlar fiber of Preparation Example 5.

[0067] Example 1 also provides a method for preparing the above-mentioned curing agent based on self-healing geopolymer, as follows:

[0068] (a) Mix Bacillus subtilis bacterial culture and sodium silicate for 3 min to obtain mixture A;

[0069] (b) Mix fly ash, granulated blast furnace slag, sodium lignosulfonate derivative, and modified Kevlar fiber for 3 minutes to obtain mixture B;

[0070] (c) Mix the mixture A and the mixture B together and stir for 5 minutes to obtain the final product.

[0071] Example 3

[0072] Example 3 provides a curing agent based on a self-healing geopolymer. By weight, the curing agent consists of the following raw materials: 53 parts fly ash, 24 parts granulated blast furnace slag, 15 parts sodium silicate, and 3.5 parts Bacillus subtilis bacterial solution (concentration 2×10⁻⁶). 9 (5 parts of sodium lignosulfonate derivative of Preparation Example 3) and 2 parts of modified Kevlar fiber of Preparation Example 6.

[0073] Example 1 also provides a method for preparing the above-mentioned curing agent based on self-healing geopolymer, as follows:

[0074] (a) Mix Bacillus subtilis bacterial culture and sodium silicate for 2 min to obtain mixture A;

[0075] (b) Mix fly ash, granulated blast furnace slag, sodium lignosulfonate derivative, and modified Kevlar fiber for 2 minutes to obtain mixture B;

[0076] (c) Mix the mixture A and the mixture B together and stir for 3 minutes to obtain the final product.

[0077] (III) Comparative Example

[0078] Comparative Example 1

[0079] The difference between Comparative Example 1 and Example 1 is that the sodium lignosulfonate derivative of Preparation Example 1 was replaced with sodium lignosulfonate, and the rest was the same as in Example 1.

[0080] Comparative Example 2

[0081] The difference between Comparative Example 2 and Example 1 is that the modified Kevlar fiber in Preparation Example 4 was replaced with Kevlar fiber, and the rest was the same as in Example 1.

[0082] (iv) Test Cases

[0083] Experimental Example 1

[0084] The sodium lignosulfonate derivative obtained in Preparation Example 1 and the modified Kevlar fiber obtained in Preparation Example 4 were analyzed by Fourier transform infrared spectroscopy (FT-IR), and the results are as follows: Figure 1-2 As shown.

[0085] Figure 1 The infrared spectra of the sodium lignosulfonate derivative obtained in Preparation Example 1 are shown, where a is the infrared spectrum of sodium lignosulfonate and b is the infrared spectrum of the sodium lignosulfonate derivative. Figure 2 The images show the infrared spectra of the modified Kevlar fibers obtained in Preparation Example 4, where c is the infrared spectrum of the Kevlar fiber and d is the infrared spectrum of the modified Kevlar fiber. (Observation) Figure 1 It can be seen that, compared to sodium lignosulfonate, sodium lignosulfonate derivatives have a lower content of 1642 cm⁻¹. -1 1564cm -1 1245cm -1 The presence of characteristic peaks for NH, NP, and P=O indicates the successful synthesis of sodium lignosulfonate derivatives. (Observation) Figure 2 It can be seen that, compared to Kevlar fiber, modified Kevlar fiber has a lower content of 2915cm. -1 947cm -1 The presence of characteristic peaks for -CH2- and -O- indicates that epoxy groups have been grafted onto the Kevlar fibers.

[0086] Experimental Example 2

[0087] The water content was 30% of the curing agent mass, and the curing agent content was 15% of the mass of the soil to be cured. The curing agents prepared in Examples 1-3 and Comparative Examples 1-2 were respectively added to the soil to be cured, thoroughly mixed, and then water was added and stirred evenly. After compaction, geopolymer-stabilized soil was obtained. The samples were then placed in a standard curing room (temperature 20±2℃, relative humidity ≥95%) for curing until the test age, and mechanical property tests were conducted. Referring to JTG 3441-2024 "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering", the unconfined compressive strength of the geopolymer-stabilized soils at 7d, 28d, and 90d were tested, and the cracking condition of the samples after 90d was observed. The results are shown in Table 1.

[0088] Table 1

[0089]

[0090] As can be seen from the above, the samples obtained using the curing agent of this invention exhibit excellent mechanical properties and crack resistance. Compared with Example 1, the mechanical properties and crack resistance of the samples obtained by replacing the sodium lignosulfonate derivative of Preparation Example 1 with sodium lignosulfonate in Comparative Example 1, and by replacing the modified Kevlar fiber of Preparation Example 4 with Kevlar fiber in Comparative Example 2, are both reduced. The above results indicate that the combined use of sodium lignosulfonate derivative and modified Kevlar fiber can improve the mechanical properties and crack resistance of geopolymer-based composite materials. This may be because, on the one hand, the sulfonic acid groups, hydroxyl groups, and other active groups in sodium lignosulfonate participate in the geopolymer reaction, forming a cross-linked structure; and on the other hand, phytic acid molecules react with Ca in the geopolymer. 2+ Al 3+ The complexation with metal ions further enhances the crosslinking density, thereby significantly improving the mechanical properties and crack resistance of the geopolymer-based composite material. Furthermore, the weak acidity of phytic acid may locally neutralize the high alkalinity of sodium silicate, slowing down the geopolymerization reaction rate and preventing cracks caused by excessively rapid curing. On the other hand, the introduction of epoxy groups into the modified Kevlar fiber allows it to undergo ring-opening reactions with the silanol and aluminol groups in the geopolymer or the phosphate groups in phytic acid. This not only improves its compatibility but also forms a multi-level crosslinked structure of "fiber-lignin-geomer," further enhancing the mechanical properties and crack resistance of the geopolymer-based composite material.

[0091] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A curing agent based on a self-healing geopolymer, characterized in that, By weight, it includes the following raw materials: 42-53 parts fly ash, 18-24 parts granulated blast furnace slag, 8-15 parts activator, 2.5-3.5 parts self-healing agent, 1-5 parts sodium lignosulfonate derivative, and 0.5-2 parts modified Kevlar fiber. The structural formula of the sodium lignosulfonate derivative is as follows: ; In the formula, R is: ; The preparation process of the modified Kevlar fiber is as follows: Kevlar fiber and potassium hydroxide are added to dimethyl sulfoxide, stirred at room temperature for 6-7 days, epichlorohydrin is added, the temperature is raised and the reaction is carried out. After the reaction is completed, the mixture is purified to obtain the modified Kevlar fiber.

2. The curing agent based on self-healing geopolymer according to claim 1, characterized in that, The preparation process of the sodium lignosulfonate derivative is as follows: (1) Sodium lignosulfonate and urea were added to deionized water, and then formaldehyde solution was added for heating reaction. After the heating reaction was completed, the temperature was lowered to room temperature, the pH of the system was adjusted with hydrochloric acid, the precipitate was obtained by centrifugation, and the precipitate was dried to obtain intermediate 1. (2) Phytic acid was added to deionized water, and then intermediate 1 was added to react. After the reaction was completed, anhydrous ethanol was added, and the product was obtained by centrifugation. After washing and drying, sodium lignosulfonate derivative was obtained.

3. The curing agent based on self-healing geopolymer according to claim 2, characterized in that, In step (1), the ratio of sodium lignosulfonate, urea, formaldehyde solution, and deionized water is 1g:(3-4)g:(1-2)mL:(20-25)mL; and the concentration of the formaldehyde solution is 35-37wt%.

4. The curing agent based on self-healing geopolymer according to claim 2, characterized in that, The heating reaction in step (1) is carried out at a temperature of 50-60℃ for 3-6 hours; the concentration of hydrochloric acid is 0.5 mol / L; and the pH of the system is adjusted to 3-3.

2.

5. The curing agent based on self-healing geopolymer according to claim 2, characterized in that, In step (2), the ratio of intermediate 1, phytic acid, and deionized water is 1g: (5-10)mL: (20-30)mL.

6. The curing agent based on self-healing geopolymer according to claim 2, characterized in that, The reaction temperature in step (2) is 50-60℃, and the reaction time is 4-6h.

7. The curing agent based on self-healing geopolymer according to claim 1, characterized in that, The ratio of Kevlar fiber, potassium hydroxide, dimethyl sulfoxide, and epichlorohydrin is 1:(1-2)g:(200-250)mL:(0.5-2)mL; the temperature is raised to 30-45℃; and the reaction time is 18-24h.

8. The curing agent based on self-healing geopolymer according to claim 1, characterized in that, The activator is sodium silicate; the modulus of the sodium silicate is 1-2; the self-healing agent is Bacillus subtilis bacterial solution; the concentration of Bacillus subtilis in the Bacillus subtilis bacterial solution is (1-2)×10⁻⁶. 9 per mL.

9. The method for preparing a curing agent based on a self-healing geopolymer according to any one of claims 1-8, characterized in that, Includes the following steps: (a) Mix the self-healing agent and the activator and stir for 2-3 minutes to obtain mixture A; (b) Mix fly ash, granulated blast furnace slag, sodium lignosulfonate derivative, and modified Kevlar fiber for 2-3 minutes to obtain mixture B; (c) Mix the mixture A with the mixture B for 3-5 minutes to obtain the final product.

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