Sealing glue, fireproof wave-absorbing material and application thereof

Abstract

The application discloses a sealing glue, a fireproof wave-absorbing material and application thereof, and belongs to the technical field of wave-absorbing and flame-retardant. The sealing glue is prepared by mixing, curing of aerogel, polyacrylate, titanium white, calcium carbonate, fumed nano-silicon dioxide and water; the aerogel is prepared by mixing and reacting of graphene oxide, carbon nanotube, carbon black wrapped ammonium polyphosphate and water and drying. The sealing glue has excellent flame-retardant and wave-absorbing performance and good waterproof performance through the joint action of the aerogel and other raw materials.

Description

Technical Field

[0001] This invention relates to the field of microwave absorption and flame retardant technology, and in particular to a sealant, a fireproof microwave absorbing material, and their applications. Background Technology

[0002] In the construction industry, fire safety has always been a major concern. Fire-retardant sealants are crucial for meeting fire safety requirements; they are primarily applied to the joints of building curtain walls to ensure effective fire protection at these gaps.

[0003] In the field of communications, microwave absorbing materials, as special functional materials, are widely used in radar stealth, electromagnetic protection, and wireless communication. However, in certain application scenarios, microwave absorbing materials may face extreme conditions such as high temperatures and fires. Therefore, flame retardancy has become an important indicator for microwave absorbing materials. The importance of flame retardancy for microwave absorbing materials is mainly reflected in the following aspects: First, flame retardancy can improve the safety of microwave absorbing materials and reduce the risk of fire; second, flame retardancy helps protect the safety of equipment and personnel, avoiding losses caused by fire; finally, flame retardancy can improve the reliability and stability of microwave absorbing materials and extend their service life. Therefore, flame retardancy has a significant impact on the research and development and application of microwave absorbing materials.

[0004] Currently, flame-retardant properties of microwave absorbing materials can be achieved through the following methods: (1) Adding flame retardants. Flame retardants can decompose at high temperatures to produce non-combustible gases, thereby preventing the spread of flames. (2) Changing the material composition. By adjusting the composition of the microwave absorbing material, it can be made to have better thermal stability and flame-retardant properties at high temperatures. However, achieving flame-retardant properties of microwave absorbing materials also faces some challenges, such as the addition of flame retardants may affect the electromagnetic properties of the microwave absorbing material, and new flame-retardant microwave absorbing materials need to be continuously improved to meet increasingly stringent flame-retardant requirements.

[0005] Fire safety issues related to prefabricated fireproof and electromagnetic radiation-proof buildings have always been a major concern. Therefore, it is of great significance to research a multifunctional sealant material that can be used for fireproofing of building curtain wall joints while also having excellent wave absorption and flame retardant properties. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a sealant, a fireproof and wave-absorbing material, and their applications. The sealant has excellent wave absorption and flame retardancy, as well as good mechanical and waterproof properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a sealant prepared by mixing and curing aerogel, polyacrylate, titanium dioxide, calcium carbonate, fumed nano silica and water;

[0009] The aerogel is prepared by mixing and reacting graphene oxide, carbon nanotubes, carbon black-encapsulated ammonium polyphosphate with water, followed by drying.

[0010] The ammonium polyphosphate coated with carbon black was homemade.

[0011] The sealant of this invention, through the combined action of the aerogel, polyacrylate, and other raw materials, enables the sealant to effectively retard flames and absorb waves.

[0012] Preferably, the mass ratio of graphene oxide, carbon nanotubes, and carbon black-encapsulated ammonium polyphosphate is 4:1:(1-5):more preferably 4:1:5.

[0013] Preferably, the aerogel comprises 5 wt% to 30 wt% of the sealant by weight; more preferably, the aerogel comprises 5 wt% to 15 wt% of the sealant by weight; and in some specific embodiments of the present invention, it is preferably 7.5 wt%.

[0014] Preferably, the calcium carbonate accounts for 20 wt% to 30 wt% of the sealant. In some specific embodiments of the present invention, it is preferably 27.5 wt%.

[0015] Preferably, the fumed silica nanoparticles constitute 1 wt% of the sealant.

[0016] The mass ratio of titanium dioxide to water is 1:(1.5-3); more preferably 1:2.

[0017] Preferably, the raw materials for mixing and curing in this invention also include defoamers and dispersants.

[0018] Preferably, the drying process in this invention is freeze drying.

[0019] The freeze-drying process preferably employs liquid nitrogen freezing.

[0020] The mixing reaction is preferably carried out under ultrasound.

[0021] Preferably, the curing temperature is 60°C to 80°C; in some specific embodiments of the present invention, it is 60°C.

[0022] Preferably, the curing time is 12 hours to 24 hours. In some specific embodiments of the present invention, it is 12 hours.

[0023] The present invention also provides a fireproof and wave-absorbing material, including the above-mentioned sealant.

[0024] Preferably, the fire-resistant and wave-absorbing material of the present invention has a reflectivity of -45 to -10 dB;

[0025] Preferably, the limiting oxygen index of the fire-resistant and wave-absorbing material is 22.6 to 27.6 vol%.

[0026] The fireproof and wave-absorbing material has an L94 test rating of V-0 or V-1.

[0027] Preferably, the hydrophobicity of the fireproof and wave-absorbing material is 0.08% to 0.17%.

[0028] The present invention also provides the application of the above-mentioned fireproof and wave-absorbing materials in prefabricated fireproof and electromagnetic radiation-proof buildings.

[0029] Compared with existing technologies, the sealant provided by this invention is prepared by mixing and curing aerogel, polyacrylate, titanium dioxide, calcium carbonate, fumed silica nanoparticles, and water. The aerogel is prepared by mixing and reacting graphene oxide, carbon nanotubes, carbon black-encapsulated ammonium polyphosphate, and water, followed by drying. Through the combined action of the aerogel and other raw materials, the sealant exhibits excellent flame retardant and wave-absorbing properties, as well as good waterproof performance. Attached Figure Description

[0030] Figure 1 The microwave absorption performance diagram is shown for the sealant prepared in Example 1;

[0031] Figure 2 The image shows the appearance of the sealant prepared in Example 1 after combustion.

[0032] Figure 3 The mechanical properties of the multifunctional fire-retardant sealant prepared in Examples 1-5 and Comparative Example 1 are shown in the figure.

[0033] Figure 4 The graph shows the water absorption rate of the multifunctional fire-retardant sealant prepared in Examples 1-5 and Comparative Example 1. Detailed Implementation

[0034] To further illustrate the present invention, the sealant, fireproof and wave-absorbing material and their applications provided by the present invention will be described in detail below with reference to embodiments.

[0035] The following method for making carbon black-coated ammonium polyphosphate includes the following steps:

[0036] Under a nitrogen atmosphere, 70 g of ammonium polyphosphate (APP), 5 g of silane coupling agent KH792, and 200 mL of anhydrous ethanol were added to a round-bottom flask and stirred at room temperature for 1 h to obtain solution A. Then, nano-CB was dispersed in 100 mL of ethanol and 100 mL of deionized water by ultrasonic treatment for 30 min to obtain solution B. Solution A and solution B were ultrasonically mixed for 30 min to obtain carbon black-coated ammonium polyphosphate. Subsequently, the temperature was raised to 80 °C and maintained for 4 h. Finally, the solvent was removed with deionized water and ethanol, and the mixture was vacuum dried at 60 °C for 12 h.

[0037] The following method for making aerogel includes the following steps:

[0038] The reaction is carried out by mixing ammonium polyphosphate, which is encapsulated by graphene oxide, carbon nanotubes, and carbon black with water in a certain proportion. The mechanism is that in the sol, the ammonium polyphosphate encapsulated by graphene oxide, carbon nanotubes, and carbon black forms a network structure through mutual connection and aggregation.

[0039] The carbon nanotubes described below contain hydroxyl groups.

[0040] The reaction between graphene oxide, carbon nanotubes, and ammonium polyphosphate encapsulated in carbon black.

[0041] Example 1

[0042] A preparation process for a multifunctional waterproof sealant based on aerogel includes the following steps:

[0043] S1. Aerogel preparation: Graphene oxide, carbon nanotubes, carbon black-coated ammonium polyphosphate and water are mixed evenly in a 100mL beaker at a certain mass ratio (i.e., 40mg:10mg:50mg, water 15mL) and sonicated for 1 hour.

[0044] S2, freeze drying: Place S1 in a self-made mold and freeze with liquid nitrogen. Observe that the dispersion has reached a frozen state, and then put it into a freeze dryer for drying.

[0045] S3. Preparation of Functional Sealant: Dissolve titanium dioxide in an appropriate amount of water, stir for ten minutes, then add calcium carbonate, fumed silica nanoparticles, and aerogel for dispersion (wherein, the aerogel is 5 wt% of the functional sealant mass, calcium carbonate is 30 wt% of the functional sealant mass, and fumed silica nanoparticles are 1 wt% of the functional sealant mass), and stir at a speed of 500-600 r / min; at the same time, add defoamer and dispersant, and after ten minutes add 60 wt% polyacrylate, set the power to 60%, stir at high speed (speed of 2000-3000 r / min), disperse the mixture to a fineness of less than 10 μm, and then place the mixture in a vacuum to eliminate air bubbles;

[0046] S4, Curing Functional Sealant: Place S3 in a drying oven for curing at 60℃ for 12 hours;

[0047] S5. The performance tests of the cured functional sealant are shown in Table 1.

[0048] Figure 1 The image shows the microwave absorption performance of the sealant prepared in Example 1. The results show that at frequencies of 2-18, with a thickness of 2 mm, the reflectivity reaches -10 dB.

[0049] Example 2

[0050] A preparation process for a multifunctional waterproof sealant based on aerogel includes the following steps:

[0051] S1. Aerogel preparation: Graphene oxide, carbon nanotubes, carbon black-encapsulated ammonium polyphosphate and water are mixed evenly in a 100mL beaker at a certain mass ratio (i.e., 40mg:10mg:50mg, water 15mL) and sonicated for 1 hour.

[0052] S2, freeze drying: Place S1 in a self-made mold and freeze with liquid nitrogen. Observe that the dispersion has reached a frozen state, and then put it into a freeze dryer for drying.

[0053] S3. Preparation of Functional Sealant: Dissolve titanium dioxide in an appropriate amount of water, stir for ten minutes, then add calcium carbonate, fumed silica nanoparticles, and aerogel for dispersion (wherein, the aerogel is 7.5 wt% of the functional sealant mass, the calcium carbonate is 27.5 wt% of the functional sealant mass, and the fumed silica nanoparticles are 1 wt% of the functional sealant mass), and stir at a speed of 500-600 r / min; at the same time, add defoamer and dispersant, and after ten minutes add 60 wt% polyacrylate, set the power to 60%, stir at high speed (speed of 2000-3000 r / min), disperse the mixture to a fineness of less than 10 μm, and then place the mixture in a vacuum to eliminate air bubbles;

[0054] S4, Curing Functional Sealant: Place S3 in a drying oven for curing at 60℃ for 12 hours;

[0055] S5. The performance tests of the cured functional sealant are shown in Table 1.

[0056] Example 3

[0057] A preparation process for a multifunctional waterproof sealant based on aerogel includes the following steps:

[0058] S1. Aerogel preparation: Graphene oxide, carbon nanotubes, carbon black-coated ammonium polyphosphate and water are mixed evenly in a 100mL beaker at a certain mass ratio (i.e., 40mg:10mg:50mg, water 15mL) and sonicated for 1 hour.

[0059] S2, freeze drying: Place S1 in a self-made mold and freeze with liquid nitrogen. Observe that the dispersion has reached a frozen state, and then put it into a freeze dryer for drying.

[0060] S3. Preparation of Functional Sealant: Dissolve titanium dioxide in an appropriate amount of water, stir for ten minutes, then add calcium carbonate, fumed silica nanoparticles, and aerogel for dispersion (wherein, the aerogel is 10 wt% of the functional sealant mass, the calcium carbonate is 25 wt% of the functional sealant mass, and the fumed silica nanoparticles are 1 wt% of the functional sealant mass), and stir at a speed of 500-600 r / min; at the same time, add defoamer and dispersant, and after ten minutes add 60 wt% polyacrylate, set the power to 60%, stir at high speed (speed of 2000-3000 r / min), disperse the mixture to a fineness of less than 10 μm, and then place the mixture in a vacuum to eliminate bubbles;

[0061] S4, Curing Functional Sealant: Place S3 in a drying oven for curing at 60℃ for 12 hours;

[0062] S5. The performance tests of the cured functional sealant are shown in Table 1.

[0063] Example 4

[0064] A preparation process for a multifunctional waterproof sealant based on aerogel includes the following steps:

[0065] S1. Aerogel preparation: Graphene oxide, carbon nanotubes, carbon black-coated ammonium polyphosphate and water are mixed evenly in a 100mL beaker at a certain mass ratio (40mg:10mg:50mg, water 15mL) and sonicated for 1 hour.

[0066] S2, freeze drying: Place S1 in a self-made mold and freeze with liquid nitrogen. Observe that the dispersion has reached a frozen state, and then put it into a freeze dryer for drying.

[0067] S3. Preparation of Functional Sealant: Dissolve titanium dioxide in an appropriate amount of water, stir for ten minutes, then add calcium carbonate, fumed silica nanoparticles, and aerogel for dispersion (wherein, the aerogel is 12.5 wt% of the functional sealant mass, the calcium carbonate is 22.5 wt% of the functional sealant mass, and the fumed silica nanoparticles are 1 wt% of the functional sealant mass), at a speed of 500-600 r / min; simultaneously, add defoamer and dispersant, and after ten minutes add 60 wt% polyacrylate, set the power to 60%, stir at high speed (speed of 2000-3000 r / min), disperse the mixture to a fineness of less than 10 μm, and then place the mixture in a vacuum to eliminate air bubbles;

[0068] S4, Curing Functional Sealant: Place S3 in a drying oven for curing at 60℃ for 12 hours;

[0069] S5. The performance tests of the cured functional sealant are shown in Table 1.

[0070] Example 5

[0071] A preparation process for a multifunctional waterproof sealant based on aerogel includes the following steps:

[0072] S1. Aerogel preparation: Graphene oxide, carbon nanotubes, carbon black-coated ammonium polyphosphate and water are mixed evenly in a 100mL beaker at a certain mass ratio (i.e., 40mg:10mg:50mg, water 15mL) and sonicated for 1 hour.

[0073] S2, freeze drying: Place S1 in a self-made mold and freeze with liquid nitrogen. Observe that the dispersion has reached a frozen state, and then put it into a freeze dryer for drying.

[0074] S3. Preparation of Functional Sealant: Dissolve titanium dioxide in an appropriate amount of water, stir for ten minutes, then add calcium carbonate, fumed silica nanoparticles, and aerogel for dispersion (wherein, the aerogel is 15 wt% of the functional sealant mass, calcium carbonate is 20 wt% of the functional sealant mass, and fumed silica nanoparticles are 1 wt% of the functional sealant mass), and stir at a speed of 500-600 r / min; at the same time, add defoamer and dispersant, and after ten minutes add 60 wt% polyacrylate, set the power to 60%, stir at high speed (speed of 2000-3000 r / min), disperse the mixture to a fineness of less than 10 μm, and then place the mixture in a vacuum to eliminate air bubbles;

[0075] S4, Curing Functional Sealant: Place S3 in a drying oven for curing at 60℃ for 12 hours;

[0076] S5. The performance tests of the cured functional sealant are shown in Table 1.

[0077] Comparative Example 1

[0078] The difference from Example 1 is that the aerogel prepared by S1 is not added in Example 1.

[0079] I. Experimental Verification

[0080] The multifunctional waterproof sealant based on aerogel prepared in Examples 1-5 and Comparative Example 1 was tested for combustion performance and tensile properties.

[0081] Among them, the flammability test was conducted according to GB / T 2408-2008 flammability test of plastics using the horizontal and vertical methods (IEC60695-11-10:1999, IDT); the tensile property test was conducted according to GB / T13477.8-2002 building sealant test methods - part 8: determination of tensile adhesion (ISO8339:1984, MOD).

[0082] The absorption (reflectivity) standard was as follows: the composite material and paraffin were uniformly mixed at a mass ratio of 20 wt%, and pressed into a ring-shaped sample for testing, with an inner diameter, outer diameter, and thickness of 3.04, 7.00, and 2.00 mm, respectively. Electromagnetic parameters were obtained using a vector network analyzer with a coaxial method in the frequency range of 2.0–18.0 GHz. Transmission line theory was used to calculate the reflection loss (RL) values ​​of absorbers of different thicknesses at their corresponding frequencies.

[0083] The water absorption rate was measured according to ASTM D570 standard. At room temperature, the static contact angle of the liquid on the adhesive surface was measured using a Biolin Scientific contact angle meter. The test droplet volume was 5 μL, and the liquid used in the test was deionized water.

[0084] Table 1 Performance Test Results

[0085]

[0086]

[0087] The results above show that, among the sealants described in this invention, Example 2 exhibits the best reflection loss, reaching -45 dB. Simultaneously, its flame retardant and waterproof properties are also continuously improved. When the aerogel dosage is low (Example 1), compared to Comparative Example 1, Example 1 demonstrates significantly superior wave absorption, flame retardant, mechanical, and waterproof properties. Furthermore, Example 2 of this invention achieves the best wave absorption performance.

[0088] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A sealant, characterized in that, It is prepared by mixing and curing aerogel, polyacrylate, titanium dioxide, calcium carbonate, fumed nano silica and water; The aerogel is prepared by mixing and reacting graphene oxide, carbon nanotubes, carbon black-encapsulated ammonium polyphosphate with water, followed by drying. The mass ratio of graphene oxide, carbon nanotubes, and carbon black-encapsulated ammonium polyphosphate is 4:1:(1~5). The aerogel comprises 5 wt% to 30 wt% of the sealant by weight. The calcium carbonate content is 20wt%~30wt% of the sealant mass. The fumed silica nanoparticles constitute 1 wt% of the sealant. The mass ratio of titanium dioxide to water is 1:(1.5-3).

2. The sealant according to claim 1, characterized in that, The raw materials to be mixed and cured also include defoamers and dispersants.

3. The sealant according to claim 1, characterized in that, The drying process is selected from freeze drying.

4. The sealant according to claim 1, characterized in that, The curing temperature is 60℃~80℃; The curing time is 12 h to 24 h.

5. A fireproof and wave-absorbing material, characterized in that, Includes the sealant as described in any one of claims 1 to 4.

6. The fireproof and wave-absorbing material according to claim 5, characterized in that, The reflectivity of the fireproof and wave-absorbing material is -45 to -10 dB; The limiting oxygen index of the fire-resistant and wave-absorbing material is 22.6~27.6 vol%. The fire-resistant and wave-absorbing material has a UL94 rating of V-0 or V-1. The hydrophobicity of the fireproof and wave-absorbing material is 0.08%~0.17%.

7. The application of the fireproof and wave-absorbing material as described in claim 5 or 6 in prefabricated fireproof and electromagnetic radiation-proof buildings.

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