Fireproof toughened composite aerogel coating and preparation method thereof

Abstract

The present application relates to the technical field of fireproof coating, in particular to a fireproof and toughened composite aerogel coating and a preparation method thereof. In order to solve the problem of brittleness of the aerogel coating, modified whisker material is added to the composite aerogel coating as a reinforcing agent. Phosphorus element, fluorine element and epoxy group are introduced on the surface of the whisker, so that the whisker has the ability of synergistic flame retardation and participates in the curing and combination of the epoxy resin. The whisker can have better combination with the resin crosslinking network, improve the toughness of the resin coating, and avoid the cracking and falling of the resin coating caused by external vibration. In this process, the introduced fluorine element can effectively improve the hydrophobic property of the resin and improve the resistance to external erosion, thereby being beneficial to the service life of the aerogel coating in natural open-air environment.

Description

Technical Field

[0001] This invention relates to the field of fire-retardant coating technology, specifically to a fire-retardant and toughening composite aerogel coating and its preparation method. Background Technology

[0002] As the core load-bearing system of modern buildings, the widespread application of steel structures places higher demands on building safety. Although steel is non-combustible, its strength decreases sharply under the high temperatures generated by a fire, leading to structural softening and collapse. Therefore, reliable fire protection is essential. Aerogel, with its excellent thermal insulation properties due to its nanoporous structure, has become a highly promising fire-retardant coating material, effectively blocking heat transfer to the steel substrate. However, existing aerogel coatings are mostly epoxy resin systems, which are inherently brittle. This makes the coating prone to cracking and peeling under mechanical stress, substrate deformation, and environmental aging. Once the integrity is lost, its fire barrier function will fail. Therefore, developing a coating system that combines excellent thermal insulation performance with sufficient toughness is a key technical requirement to ensure that aerogel fire-retardant coatings maintain structural integrity and achieve durable and reliable protection during long-term service. Summary of the Invention

[0003] The purpose of this invention is to provide a fire-retardant and toughening composite aerogel coating and its preparation method, so as to solve the toughening problem of epoxy resin aerogel coatings.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] In a first aspect, the present invention provides a method for preparing a fire-retardant and toughening composite aerogel coating, comprising the following steps:

[0006] After washing and drying the aluminum borate whiskers, disperse them in the mixture. After uniform dispersion, add silane modifier, mix well, add deionized water, stir the reaction, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0007] Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene. After uniform dispersion, a polymerization inhibitor and triallyl phosphate were added and mixed evenly. The mixture was cooled to a constant temperature in an ice-water bath, and Karstedt catalyst was added. After heating and reaction, the precipitate was separated by centrifugation, washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers.

[0008] Phosphorus-modified aluminum borate whiskers were dispersed in DMF (N,N-dimethylformamide), mixed thoroughly, and then mercaptoethylamine was added and mixed thoroughly. After UV irradiation, the precipitate was separated by centrifugation, washed with DMF and dried. The precipitate was then dispersed again in DMF, cooled to a constant temperature in an ice-water bath, and then 1,4-bis(2',3'-epoxypropyl)perfluorobutane was added. After heating and reaction, the precipitate was separated by centrifugation, washed with DMF, and dried to obtain the modified whisker material.

[0009] After mixing epoxy resin 601 with n-butanol, modified whisker material is added and stirred until completely dispersed. Then, aerogel particles, silane coupling agent, and ammonium polyphosphate are added and stirred. After mixing, curing agent is added and mixed evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0010] Furthermore, in the process of synthesizing silane-modified aluminum borate whiskers, the mass ratio of aluminum borate whiskers, silane modifier and deionized water used is 10:(0.5~1):(0.5~1).

[0011] Furthermore, in the process of synthesizing silane-modified aluminum borate whiskers, the mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of (8~10):1; the silane modifier is trimethoxysilane.

[0012] During the stirring reaction, the reaction temperature is 15~25℃ and the stirring reaction time is 1~1.5h.

[0013] Furthermore, in the preparation of phosphorus-modified aluminum borate whiskers, the mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst used is 10:(0.0006~0.0009):(0.6~1):(0.04~0.05).

[0014] The polymerization inhibitor is p-hydroxyanisole.

[0015] Furthermore, during the preparation of phosphorus-modified aluminum borate whiskers, the temperature is raised to 60-65℃ and the reaction is carried out under constant temperature stirring for 2-3 hours.

[0016] Furthermore, in the process of preparing the modified whisker material, the mass ratio of phosphorus-modified aluminum borate whiskers, mercaptoethylamine, and 1,4-bis(2',3'-epoxypropyl)perfluorobutane used is 10:(0.5~3):(2~8).

[0017] Furthermore, during the preparation of the modified whisker material, the ultraviolet light irradiation intensity during the ultraviolet light irradiation reaction was 10~20 mW / cm². 2 The irradiation reaction lasts for 1-2 hours; when heating the reaction, the temperature is raised to 45-50℃ and the reaction is stirred for 6-12 hours.

[0018] Furthermore, in the process of preparing the fire-retardant and toughened composite aerogel coating, the mass ratio of epoxy resin 601, n-butanol, modified whisker material, aerogel particles, silane coupling agent, ammonium polyphosphate, and curing agent is 80: (60~80): (10~20): (5~10.5): (0.5~1): (7~12): (18~20).

[0019] Furthermore, in the process of preparing the fire-retardant and toughened composite aerogel coating, the silane coupling agent used is KH550 or KH560.

[0020] Secondly, the present invention provides a fire-retardant and toughening composite aerogel coating, which is prepared by the above-described preparation method.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0022] To address the excessive brittleness of aerogel coatings, this invention incorporates modified whisker materials as reinforcement in composite aerogel coatings. First, cleaned aluminum borate whiskers are mixed with trimethoxysilane. The aluminum borate whiskers naturally possess numerous hydroxyl groups, providing active sites for silane grafting. Then, under the catalysis of a trace amount of deionized water, the trimethoxysilane undergoes a mild hydrolysis reaction, gradually replacing the methoxy groups in its molecules with hydroxyl groups to generate silanol groups. These silanol groups undergo a dehydration condensation reaction with the hydroxyl groups on the surface of the aluminum borate whiskers, forming stable Si–O–Al covalent bonds, thus achieving silane grafting onto the whisker surface. Finally, unreacted silane-hydrogen active groups are retained on the whisker surface.

[0023] The mixture is then combined with an excess of triallyl phosphate. Under the catalysis of the Karstedt catalyst, the silane-hydrogen bonds break, forming Si· radicals. The allyl group in the triallyl phosphate molecule has a high electron cloud density and can undergo an addition reaction with the Si· radicals to form stable covalent bonds, thus achieving the grafting of phosphate groups onto the whisker surface. Furthermore, before introducing the Karstedt catalyst into the reaction system, the reaction system is cooled to a constant temperature in an ice-water bath to avoid premature reaction between the allyl group and the silane-hydrogen bonds. After the reaction system is mixed evenly, the temperature is raised to the reaction temperature, and an excess of triallyl phosphate is dispersed on the whisker surface, resulting in an excess of allyl groups around the whiskers. This introduces unreacted free allyl groups while achieving grafting.

[0024] Based on this, the allyl groups retained on the surface of the phosphorus-modified whiskers undergo photoinitiation under ultraviolet light irradiation, breaking the double bonds to form free radicals that add to the mercapto groups in the mercaptoethylamine molecule, ultimately achieving the grafting of mercaptoethylamine onto the whisker surface and introducing amino groups into the whisker surface. Subsequently, under an ice-water bath environment, excess 1,4-bis(2',3'-epoxypropyl)perfluorobutane is added. The amino groups open the epoxy groups, and some of the epoxy groups react with the amino groups on the whisker surface, introducing some unreacted epoxy functional groups. This ultimately introduces phosphorus, fluorine, and epoxy groups onto the whisker surface, giving the whiskers the ability to synergistically retard flame and participate in curing and bonding with epoxy resin. This allows for better bonding with the resin crosslinking network, improves the toughness of the resin coating, and prevents cracking and peeling of the resin coating caused by external vibrations.

[0025] The fluorine element introduced in this process can effectively improve the hydrophobic properties of the resin and enhance its resistance to external erosion. Furthermore, the phosphate ester structure introduced in this process can also promote char formation, just like ammonium polyphosphate, thereby enhancing the strength and density of the char layer, preventing cracking and peeling of the char layer, and forming a synergistic effect with ammonium polyphosphate to improve the flame retardant properties of the coating. At the same time, it can suppress the generation of molten droplets and toxic fumes during the combustion of epoxy resin. Attached Figure Description

[0026] Figure 1 This is a SEM image of the coating on the test sample prepared in Example 1 of this invention;

[0027] Figure 2 This is a morphology image of the test sample prepared in Example 1 of the present invention before flame jetting;

[0028] Figure 3 This is a morphology image of the test sample prepared in Example 1 of the present invention after flame spraying. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0030] The aluminum borate whiskers used in the embodiments and comparative examples of this invention have a diameter of 0.3~10μm and a length of 15~60μm; the aerogel particles used are Cabot ENOVA AEROGEL MT1200 hydrophobic silica aerogel particles; the curing agent used is polyamide 650; and the polymerization inhibitor used is p-hydroxyanisole.

[0031] Example 1

[0032] A method for preparing a fire-retardant and toughening composite aerogel coating includes the following steps:

[0033] S1. After washing and drying the aluminum borate whiskers, disperse them in the mixture. After the mixture is evenly dispersed, add the silane modifier, mix evenly, add deionized water, heat to 15°C, stir and react for 1.5 hours, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0034] The mass ratio of aluminum borate whiskers, silane modifier, and deionized water is 10:0.5:0.5.

[0035] The mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of 8:1;

[0036] S2. Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene. After uniform dispersion, a polymerization inhibitor and triallyl phosphate were added and mixed evenly. The mixture was cooled to a constant temperature in an ice-water bath. Karstedt catalyst was added dropwise. After the addition was completed, the mixture was mixed evenly. The reaction system was heated to 60°C and stirred at a constant temperature for 3 hours. The precipitate was separated by centrifugation, washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers.

[0037] The mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst was 10:0.006:0.6:0.04.

[0038] S3 dispersed phosphorus-modified aluminum borate whiskers in DMF, mixed evenly, added mercaptoethylamine, mixed evenly, reacted under ultraviolet light, centrifuged to separate the precipitate, washed with DMF and dried, dispersed the precipitate again in DMF, cooled to constant temperature in an ice-water bath, added 1,4-bis(2',3'-epoxypropyl)perfluorobutane and mixed evenly, heated to 45°C, stirred and reacted for 12 h, centrifuged to separate the precipitate, washed with DMF and dried to obtain modified whisker material;

[0039] The mass ratio of phosphorus-modified aluminum borate whiskers, mercaptoethylamine, and 1,4-bis(2',3'-epoxypropyl)perfluorobutane is 10:0.5:2.

[0040] During the ultraviolet light irradiation reaction, the ultraviolet light irradiation intensity was 10 mW / cm. 2 The irradiation reaction time is 2 hours;

[0041] S4. After mixing epoxy resin 601 with n-butanol, add modified whisker material and stir until completely dispersed. Then add aerogel particles, KH550 silane coupling agent, and ammonium polyphosphate. After stirring and mixing, add curing agent and mix evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0042] The mass ratio of epoxy resin 601, n-butanol, modified whisker material, aerogel particles, KH550 silane coupling agent, ammonium polyphosphate, and curing agent is 80:60:10:5:0.5:7:18.

[0043] Example 2

[0044] A method for preparing a fire-retardant and toughening composite aerogel coating includes the following steps:

[0045] S1. After washing and drying the aluminum borate whiskers, disperse them in the mixture. After the mixture is evenly dispersed, add the silane modifier, mix evenly, add deionized water, heat to 20°C, stir and react for 1.5 hours, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0046] The mass ratio of aluminum borate whiskers, silane modifier, and deionized water is 10:0.75:0.75.

[0047] The mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of 9:1;

[0048] S2. Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene. After uniform dispersion, a polymerization inhibitor and triallyl phosphate were added and mixed evenly. The mixture was cooled to a constant temperature in an ice-water bath. Karstedt catalyst was added dropwise. After the addition was completed, the mixture was mixed evenly. The reaction system was heated to 65°C and stirred at a constant temperature for 2 hours. The precipitate was separated by centrifugation, washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers.

[0049] The mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst was 10:0.008:0.8:0.045.

[0050] S3 dispersed phosphorus-modified aluminum borate whiskers in DMF, mixed evenly, added mercaptoethylamine, mixed evenly, reacted under ultraviolet light, separated the precipitate by centrifugation, washed with DMF and dried, dispersed the precipitate again in DMF, cooled to constant temperature in an ice-water bath, added 1,4-bis(2',3'-epoxypropyl)perfluorobutane and mixed evenly, heated to 50℃, stirred and reacted for 8 hours, separated the precipitate by centrifugation, washed with DMF and dried to obtain modified whisker material;

[0051] The mass ratio of phosphorus-modified aluminum borate whiskers, mercaptoethylamine, and 1,4-bis(2',3'-epoxypropyl)perfluorobutane is 10:2:5.

[0052] During the ultraviolet light irradiation reaction, the ultraviolet light irradiation intensity was 15 mW / cm. 2 The irradiation reaction time is 1.5 hours.

[0053] S4. After mixing epoxy resin 601 with n-butanol, add modified whisker material and stir until completely dispersed. Then add aerogel particles, silane coupling agent, and ammonium polyphosphate. After stirring and mixing, add curing agent and mix evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0054] The mass ratio of epoxy resin 601, n-butanol, modified whisker material, aerogel particles, silane coupling agent, ammonium polyphosphate, and curing agent is 80:70:15:7.5:0.75:9.5:19.

[0055] Example 3

[0056] A method for preparing a fire-retardant and toughening composite aerogel coating includes the following steps:

[0057] S1. After washing and drying the aluminum borate whiskers, disperse them in the mixture. After the mixture is evenly dispersed, add the silane modifier, mix evenly, add deionized water, heat to 25°C, stir and react for 1 hour, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0058] The mass ratio of aluminum borate whiskers, silane modifier, and deionized water is 10:1:1.

[0059] The mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of 10:1;

[0060] S2. Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene. After uniform dispersion, a polymerization inhibitor and triallyl phosphate were added and mixed evenly. The mixture was cooled to a constant temperature in an ice-water bath. Karstedt catalyst was added dropwise. After the addition was completed, the mixture was mixed evenly. The reaction system was heated to 65°C and stirred at a constant temperature for 2 hours. The precipitate was separated by centrifugation, washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers.

[0061] The mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst was 10:0.009:1:0.05.

[0062] S3 dispersed phosphorus-modified aluminum borate whiskers in DMF, mixed evenly, added mercaptoethylamine, mixed evenly, reacted under ultraviolet light, centrifuged to separate the precipitate, washed with DMF and dried, dispersed the precipitate again in DMF, cooled to constant temperature in an ice-water bath, added 1,4-bis(2',3'-epoxypropyl)perfluorobutane and mixed evenly, heated to 50℃, stirred and reacted for 6 h, centrifuged to separate the precipitate, washed with DMF and dried to obtain modified whisker material;

[0063] The mass ratio of phosphorus-modified aluminum borate whiskers, mercaptoethylamine, and 1,4-bis(2',3'-epoxypropyl)perfluorobutane is 10:3:8.

[0064] During the ultraviolet light irradiation reaction, the ultraviolet light irradiation intensity was 20 mW / cm. 2 The irradiation reaction time is 1 hour;

[0065] S4. After mixing epoxy resin 601 with n-butanol, add modified whisker material and stir until completely dispersed. Then add aerogel particles, KH560 silane coupling agent, and ammonium polyphosphate. After stirring and mixing, add curing agent and mix evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0066] The mass ratio of epoxy resin 601, n-butanol, modified whisker material, aerogel particles, KH560 silane coupling agent, ammonium polyphosphate, and curing agent is 80:80:20:10.5:1:12:20.

[0067] Comparative Example 1

[0068] Compared with Example 1, this comparative example did not add any modified whisker material, but only added aluminum borate whiskers and other mass substitutes;

[0069] A method for preparing a fire-retardant and toughening composite aerogel coating includes the following steps:

[0070] After mixing epoxy resin 601 with n-butanol, aluminum borate whisker material is added and stirred until completely dispersed. Then, aerogel particles, KH550 silane coupling agent, and ammonium polyphosphate are added and stirred. After mixing, curing agent is added and mixed evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0071] The mass ratio of epoxy resin 601, n-butanol, aluminum borate whiskers, aerogel particles, KH550 silane coupling agent, ammonium polyphosphate, and curing agent is 80:60:10:5:0.5:7:18.

[0072] Comparative Example 2

[0073] Compared with Example 1, this comparative example did not perform step S3, but only used an equal mass of phosphorus-modified aluminum borate whiskers to replace the modified whisker material in step S4.

[0074] A method for preparing a fire-retardant and toughening composite aerogel coating includes the following steps:

[0075] S1. After washing and drying the aluminum borate whiskers, disperse them in the mixture. After the mixture is evenly dispersed, add the silane modifier, mix evenly, add deionized water, heat to 15°C, stir and react for 1.5 hours, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0076] The mass ratio of aluminum borate whiskers, silane modifier, and deionized water is 10:0.5:0.5.

[0077] The mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of 8:1;

[0078] S2. Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene. After uniform dispersion, a polymerization inhibitor and triallyl phosphate were added and mixed evenly. The mixture was cooled to a constant temperature in an ice-water bath. Karstedt catalyst was added dropwise. After the addition was completed, the mixture was mixed evenly. The reaction system was heated to 60°C and stirred at a constant temperature for 3 hours. The precipitate was separated by centrifugation, washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers.

[0079] The mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst was 10:0.006:0.6:0.04.

[0080] S4. After mixing epoxy resin 601 with n-butanol, add phosphorus-modified aluminum borate whiskers and stir until completely dispersed. Then add aerogel particles, KH550 silane coupling agent, and ammonium polyphosphate. After stirring and mixing, add curing agent and mix evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0081] The mass ratio of epoxy resin 601, n-butanol, phosphorus-modified aluminum borate whiskers, aerogel particles, KH550 silane coupling agent, ammonium polyphosphate, and curing agent is 80:60:10:5:0.5:7:18.

[0082] Comparative Example 3

[0083] Compared with Example 1, this comparative example only used silane-modified aluminum borate whisker material to replace the modified whisker material in an equal amount, while the other steps remained unchanged;

[0084] S1. After washing and drying the aluminum borate whiskers, disperse them in the mixture. After the mixture is evenly dispersed, add the silane modifier, mix evenly, add deionized water, heat to 15°C, stir and react for 1.5 hours, centrifuge to separate the precipitate, wash the precipitate with anhydrous ethanol, and dry to obtain silane-modified aluminum borate whiskers.

[0085] The mass ratio of aluminum borate whiskers, silane modifier, and deionized water is 10:0.5:0.5.

[0086] The mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of 8:1;

[0087] S4. After mixing epoxy resin 601 with n-butanol, add silane-modified aluminum borate whiskers and stir until completely dispersed. Then add aerogel particles, KH550 silane coupling agent, and ammonium polyphosphate. After stirring and mixing, add curing agent and mix evenly to obtain a fire-retardant and toughened composite aerogel coating.

[0088] The mass ratio of epoxy resin 601, n-butanol, silane-modified aluminum borate whiskers, aerogel particles, KH550 silane coupling agent, ammonium polyphosphate, and curing agent is 80:60:10:5:0.5:7:18.

[0089] Performance testing:

[0090] The composite aerogel coatings prepared in Examples 1-3 and Comparative Examples 1-3 were applied to the surface of a 600mm×600mm×5mm steel plate. During application, a 1.5mm layer of composite aerogel coating was first manually scraped with a putty knife, followed by another 1.5mm layer. The coating was applied evenly, without any missed areas or uneven surfaces. After reaching the required thickness, the coating surface was rolled to smooth out the edges and compact the coating, completing the first layer of composite aerogel coating. Then, a fiber mesh was smoothly attached to the first layer of composite aerogel coating and gently pressed and smoothed with a scraper. This process involves full mesh coverage. Before the first layer of composite aerogel coating was fully dry, the second layer of composite aerogel coating was applied using the aforementioned method. The surface was smoothed with a scraper until it was flat, uniform, and free of undulations. After standing for 5 days at a temperature of 25±2℃ and a relative humidity of 70±2%, the composite aerogel coating application was completed.

[0091] Subsequently, the test samples were tested for crack resistance, heat exposure resistance, damp heat resistance and freeze-thaw cycle resistance in accordance with GB / T 14907-2018.

[0092] Artificial aging tests were conducted on the test samples according to GB 14522-2008, and their surfaces were observed.

[0093] The microstructure of the coating portion of the sample tested in Example 1 was examined, as detailed in the following figures. Figure 1 The composite aerogel coating surface of the test sample was sprayed with a flame with a flame temperature of 1050~1100℃. The temperature of the steel plate on the back of the test sample was measured using a thermocouple. The temperature of the steel plate was measured after heating for 1 hour. The morphological changes of the test sample in Example 1 before and after heating were observed. For each test, five groups were set up. The average value of the test results was taken. The test results are shown in the table below.

[0094] Table 1. Performance test results of the fire-retardant and toughening composite aerogel coatings prepared in Examples 1-3 and Comparative Examples 1-3.

[0095]

[0096] As shown in the table above, the fire-retardant and toughened composite aerogel coatings prepared in Examples 1-3 of this invention exhibit excellent temperature resistance. Furthermore, a comparison of the data from Comparative Example 1 and Example 1 reveals that, without modification of the whisker material, the crack resistance and UV aging resistance of the Comparative Example 1 product showed a significant decrease. This is because, in Comparative Example 1, the whisker material was not modified; the whisker surface lacked phosphorus and fluorine loading and epoxy end-capping, resulting in a decrease in the bonding strength between the whisker material and the epoxy resin, thus leading to a decline in crack resistance and other properties. In contrast, Comparative Example 2 used an equal mass of phosphorus-modified aluminum borate. As a whisker additive, the phosphorus-modified aluminum borate whisker material, after graft modification, improved surface polarity and reduced its tendency to agglomerate compared to the unmodified whiskers in Comparative Example 1, thereby improving the dispersibility of the material in the resin. Consequently, all data showed a certain degree of recovery compared to Comparative Example 1. In Comparative Example 3, only silane-modified aluminum borate whisker material was used to replace the modified whisker material in equal amounts. Since the silane modifier used in Comparative Example 3 of this invention is trimethoxysilane, its end group is silane, which is not water-resistant and is prone to hydrolysis to produce oxygen when exposed to water. Therefore, its resistance to damp heat actually decreased further.

[0097] like Figure 1 The SEM image of the coating in Example 1 shows that the whisker material in the coating can be effectively blended and combined with the aerogel material and resin material, thereby effectively improving the toughening effect of the coating; Figure 2 , Figure 3 As can be seen, after being sprayed with flame, the coating of the present invention remains adhered to the surface of the steel plate without obvious peeling, and can provide heat insulation for a long time in a flame environment.

[0098] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a fire-retardant and toughening composite aerogel coating, characterized in that, Includes the following steps: Aluminum borate whiskers were washed and dried, dispersed in a mixture, and silane modifier was added. After mixing, deionized water was added, the mixture was stirred, centrifuged, and the precipitate was washed with anhydrous ethanol and dried to obtain silane-modified aluminum borate whiskers. In the process of synthesizing silane-modified aluminum borate whiskers, the mass ratio of aluminum borate whiskers, silane modifier, and deionized water used is 10:(0.5~1):(0.5~1). Silane-modified aluminum borate whiskers were dispersed in anhydrous toluene, a polymerization inhibitor and triallyl phosphate were added, the mixture was mixed, and the mixture was cooled to a constant temperature in an ice-water bath. Karstedt catalyst was added, the mixture was heated to react, centrifuged, the precipitate was washed with xylene, and dried to obtain phosphorus-modified aluminum borate whiskers. In the preparation of phosphorus-modified aluminum borate whiskers, the mass ratio of silane-modified aluminum borate whiskers, polymerization inhibitor, triallyl phosphate, and Karstedt catalyst used is 10:(0.0006~0.0009):(0.6~1):(0.04~0.05). The polymerization inhibitor is p-hydroxyanisole; Phosphorus-modified aluminum borate whiskers were dispersed in DMF, mercaptoethylamine was added, the mixture was stirred, the reaction was carried out under ultraviolet light, centrifuged, the precipitate was washed with DMF and dried, the resulting precipitate was dispersed again in DMF, cooled to a constant temperature in an ice-water bath, 1,4-bis(2',3'-epoxypropyl)perfluorobutane was added, the reaction was heated, centrifuged, the precipitate was washed with DMF and dried to obtain the modified whisker material; Epoxy resin 601 is mixed with n-butanol, modified whisker material is added, and the mixture is stirred and dispersed. Aerogel particles, silane coupling agent, and ammonium polyphosphate are added, stirred and mixed, and then a curing agent is added and mixed evenly to obtain a fire-retardant and toughened composite aerogel coating.

2. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: In the process of synthesizing silane-modified aluminum borate whiskers, the mixture is a mixture of anhydrous ethanol and toluene in a volume ratio of (8~10):1; the silane modifier is trimethoxysilane. During the stirring reaction, the reaction temperature is 15~25℃ and the stirring reaction time is 1~1.5h.

3. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: In the preparation of phosphorus-modified aluminum borate whiskers, the temperature is raised to 60-65℃ and the reaction is carried out under constant temperature and stirring for 2-3 hours.

4. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: In the preparation of modified whisker materials, the mass ratio of phosphorus-modified aluminum borate whiskers, mercaptoethylamine, and 1,4-bis(2',3'-epoxypropyl)perfluorobutane used is 10:(0.5~3):(2~8).

5. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: During the preparation of modified whisker materials, the intensity of ultraviolet light irradiation during the reaction is 10~20 mW / cm. 2 The irradiation reaction lasts for 1-2 hours; when heating the reaction, the temperature is raised to 45-50℃ and the reaction is stirred for 6-12 hours.

6. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: In the process of preparing fire-retardant and toughened composite aerogel coating, the mass ratio of epoxy resin 601, n-butanol, modified whisker material, aerogel particles, silane coupling agent, ammonium polyphosphate and curing agent used is 80: (60~80): (10~20): (5~10.5): (0.5~1): (7~12): (18~20).

7. The method for preparing a fire-retardant and toughening composite aerogel coating according to claim 1, characterized in that: In the preparation of fire-retardant and toughened composite aerogel coatings, the silane coupling agent used is KH550 or KH560.

8. A fire-retardant and toughened composite aerogel coating prepared by the preparation method according to any one of claims 1 to 7.

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