A-grade flame-retardant aerogel felt packaging coating with high flexibility and insulating property and preparation method of A-grade flame-retardant aerogel felt packaging coating

Abstract

The invention relates to an A-grade flame-retardant aerogel felt packaging coating with high flexibility and insulating property, which is prepared from the following raw materials in percentage by mass: 18 to 24 percent of vinyl acetate-ethylene copolymer emulsion, 6 to 12 percent of PHA / PBAT / PVOH ternary blended water-based emulsion, 30 to 40 percent of flame retardant and 15 to 17 percent of additive, with the total mass of the packaging coating being 100 percent. 2-4% of an adhesion promoter and the balance of water; the flame retardant is prepared from the following components in percentage by mass: 12 to 18 percent of aluminum hydroxide, 10 to 20 percent of nitrogen-phosphorus flame retardant and 2 to 8 percent of accordion-shaped Ti < 3 > C < 2 > T < x > MXene composite material, wherein the total mass of the packaging coating is 100 percent. The coating has the advantages of A-grade flame retardance, high flexibility and high surface resistivity, and is low in wind erosion rate and good in dust locking effect.

Description

Technical Field

[0001] This application relates to the technical field, and in particular to an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation properties, and its preparation method. Background Technology

[0002] Aerogel felt is a flexible thermal insulation felt made primarily of nano-silica or metallic aerogel, combined with carbon fiber, ceramic glass fiber cotton, or pre-oxidized fiber felt through a special process. This material has low thermal conductivity, high compressive strength, and excellent thermal insulation performance. According to the Arrhenius experiment, its theoretical service life for high-temperature pipelines is close to 20 years. It also has good water repellency and fire resistance, with fire resistance ratings ranging from B1 to A. It is lightweight, can be easily cut to size, and is convenient to install. It is mainly used for thermal insulation in industrial pipelines, storage tanks, industrial furnaces, power plants, lifeboats, warship bulkheads, high-speed rail, new energy vehicles, detachable insulation sleeves, steam pipelines, and household appliances.

[0003] Fiberglass cloth and PET / PI film are commonly used byproducts for wrapping aerogel felt. Fiberglass (originally called glass fiber) is a high-performance inorganic non-metallic material with advantages such as good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength. Its disadvantages are brittleness and poor abrasion resistance. This material is often used as a composite material for aerogel felt and is widely used in industrial fields. PET heat-shrink film is a new type of heat-shrink packaging material, belonging to environmentally friendly polyester films. As a substitute for polyvinyl chloride (PVC), it is non-toxic, easily recyclable, and has excellent mechanical properties. It is mainly used for beverage bottle labels, food, electronic appliances, and the outer packaging of metal products. It can also wrap aerogel felt for industrial pipelines. Polyimide film (PI film) is a high-performance insulating material made from pyromellitic dianhydride and diaminodiphenyl ether through polycondensation, casting, and imidization processes. It has a temperature resistance range of -269℃ to 400℃, high mechanical strength, and stable dielectric properties. It can also be used to wrap materials such as aerogel felt.

[0004] Aerogel felt possesses unique properties such as hydrophobicity, temperature resistance, heat insulation, electrical insulation, high temperature resistance, and fire resistance. However, its drawbacks include a rough surface, high dust content, and poor decorative properties. While fiberglass cloth and PET / PI film wrapping of aerogel felt largely overcome these shortcomings, they still present problems such as difficulty in wrapping irregularly shaped parts, incomplete wrapping, easy powder leakage, complex processes, and low efficiency. Therefore, developing a coating that can replace fiberglass cloth and PET / PI film, is suitable for wrapping irregularly shaped parts, and possesses good flexibility, flame retardancy, and insulation has become a research goal for coating developers. Summary of the Invention

[0005] This invention develops an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulation properties, which is used for dust-locking and sealing of the surface of substrates such as aerogel felt. It has excellent flexibility and can improve the bending resistance of substrates such as aerogel felt and fiberglass insulation blankets.

[0006] In a first aspect of this application, this application provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties, comprising the following raw materials by mass percentage: based on the total mass of the encapsulation coating, the components and their mass percentage contents are as follows: vinyl acetate-ethylene copolymer emulsion 18-24%, PHA / PBAT / PVOH ternary blend aqueous emulsion 6-12%, flame retardant 30-40%, additives 15-17%, adhesion promoter 2-4%, and the balance being water; the flame retardant is composed of 12-18% aluminum hydroxide by mass percentage, 10-20% nitrogen-phosphorus flame retardant by mass percentage, and 2-8% accordion-shaped Ti3C2TxMXene composite material by mass percentage.

[0007] By adopting the above technical solution, this application provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulation properties. The flame retardancy reaches Class A, and it possesses excellent flexibility with a resistivity exceeding 500 megohms. This is likely because aluminum hydroxide provides low-temperature heat absorption, nitrogen-phosphorus flame retardants provide an acid / gas source and foaming, and the accordion-shaped Ti3C2TxMXene composite material forms a high-temperature inorganic framework and catalyzes a high-quality carbon layer, ultimately achieving efficient flame retardancy. The vinyl acetate-ethylene copolymer emulsion provides a rigid framework, and the PHA / PBAT / PVOH ternary blend aqueous emulsion provides flexible segments. The synergistic effect of these two components achieves the coating's high adhesion, high flexibility, and high insulation properties.

[0008] Optionally, the mass ratio of the aluminum hydroxide and the accordion-shaped Ti3C2TxMXene composite material is (1.5-9):1.

[0009] By adopting the above technical solution and adjusting the amount of aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite material according to the above mass ratio, the flame retardant effect of the coating is better when the mass ratio of aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite material is (1.5-9):1.

[0010] Optionally, the mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion is (3-8):2.

[0011] By adopting the above technical solution and adjusting the amount of vinyl acetate-ethylene copolymer emulsion and PHA / PBAT / PVOH ternary blended waterborne emulsion according to the above mass ratio, the coating exhibits better adhesion strength, flexibility, and insulation properties when the mass ratio of vinyl acetate-ethylene copolymer emulsion and PHA / PBAT / PVOH ternary blended waterborne emulsion is (3-8):2.

[0012] Optionally, the mass ratio of the aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material is (12-18):15:(2-8).

[0013] By adopting the above technical solution and adjusting the amount of aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material according to the above mass ratio, the flame retardant effect of the coating is better when the mass ratio of aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material is (12-18):15:(2-8).

[0014] Optionally, the preparation method of the PHA / PBAT / PVOH ternary blend aqueous emulsion includes the following steps: Step 1): Add PVOH to water and stir to obtain a PVOH solution; Step 2): Extrude PHA and PBTA at 140-160℃ to obtain molten PHA / PBAT melt; Step 3): Add the PVOH solution prepared in step 1) to the molten PHA / PBAT melt and stir to form an O / W emulsion; Step 4): Cool down, add glycerin, borax, and Tween 80, stir, filter, and obtain the PHA / PBAT / PVOH ternary blend aqueous emulsion.

[0015] Optionally, the preparation method of the accordion-shaped Ti3C2TxMXene composite material includes the following steps: S1: Lithium fluoride is added to a mixed solution containing hydrochloric acid aqueous solution and hydrofluoric acid, and then Ti3AlC2 is added. The mixture is heated, kept at the temperature, stirred, washed, centrifuged, and freeze-dried to obtain powder. S2: Mix water and ethanol, add the powder obtained in step S1, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, and hexamethylenetetramine, heat and keep warm for 4-8 hours; wash with water, centrifuge, and freeze dry to obtain the composite material; S3: The composite material prepared in step S2 is calcined with melamine in an inert gas atmosphere and cooled to obtain the accordion-shaped Ti3C2TxMXene composite material.

[0016] Furthermore, the concentration of the hydrochloric acid aqueous solution in step S1 is 9 mol / L.

[0017] Furthermore, the inert gas mentioned in step S3 is N2, the calcination temperature is 700℃, and the calcination time is 2h.

[0018] Optionally, based on the total mass of the encapsulating coating as 100%, the additives consist of 4-6% by mass of anti-blocking wax paste, 0.3-0.7% by mass of dipropylene glycol methyl ether, 0.3-0.7% by mass of dipropylene glycol butyl ether, 0.3-0.7% by mass of propylene glycol, 3-7% by mass of water-based black paste, 0.1-0.2% by mass of preservative, 0.1-0.2% by mass of mildew inhibitor, 0.3-0.5% by mass of Dow additives, 0.8-1.2% by mass of wetting agent, 1.0-1.4% by mass of silicone defoamer, 0.05-0.15% by mass of pH adjuster, and 1.2-1.7% by mass of polyurethane thickener.

[0019] Optionally, the adhesion promoter is a high-temperature coating film promoter.

[0020] In a second aspect of this application, this application provides a method for preparing an aerogel felt encapsulating coating with Class A flame retardancy, high flexibility, and insulating properties as described in the first aspect of this application, comprising the following preparation steps: a1: Add vinyl acetate-ethylene copolymer emulsion and PHA / PBAT / PVOH ternary blend aqueous emulsion to water, stir, and obtain the first dispersion system; a2: Add aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material to the first dispersion system obtained in step a1, stir, and obtain the second dispersion system; a3: Add a portion of the additive to the second dispersion system obtained in step a2, stir, and obtain the third dispersion system; a4: Add the high-temperature coating film accelerator to the third dispersion system obtained in step a3, stir, and obtain the fourth dispersion system; a5: Add the remaining additive to the fourth dispersion system obtained in step a4, stir, and obtain the coating.

[0021] Optionally, the stirring speed in step a1 is 200-400 r / min.

[0022] Optionally, the stirring speed in step a2 is 800-1200 r / min; the stirring speed in steps a3 and a4 is 400-600 r / min.

[0023] Optionally, the stirring speed in step a5 is 300-500 r / min.

[0024] In a third aspect of this application, this application provides an application of the Class A flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating described in the first aspect of this application, applied by spraying or brushing onto the surface of aerogel / irregularly shaped parts.

[0025] In summary, the present invention has at least one of the following beneficial technical effects: 1. This application provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulation properties. It achieves Class A flame retardancy, possesses excellent flexibility, and has a resistivity exceeding 500 megohms. Aluminum hydroxide provides low-temperature heat absorption, nitrogen-phosphorus flame retardants provide the acid / gas source and foaming, and the accordion-shaped Ti3C2TxMXene composite material forms a high-temperature inorganic framework and catalyzes a high-quality carbon layer, ultimately achieving highly efficient flame retardancy. Vinyl acetate-ethylene copolymer emulsion provides a rigid framework, while the PHA / PBAT / PVOH ternary blend aqueous emulsion provides flexible segments. The synergistic effect of these two components achieves the coating's high adhesion, high flexibility, and high insulation properties.

[0026] 2. This application provides an application of an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties, applied by spraying or brushing onto the surface of aerogel / irregularly shaped parts. It exhibits low wind erosion rate and good dust-locking effect. Attached Figure Description

[0027] Figure 1 The image shows an irregularly shaped part coated with the paint prepared in Example 1; Figure 2 This is a drawing of an unpainted irregular-shaped part; Figure 3 Image of uncoated bare aerogel mat; Figure 4 A diagram of aerogel encapsulated with PEI / PI film; Figure 5 Image of aerogel covered with fiberglass cloth. Detailed Implementation

[0028] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0029] Vinyl acetate-ethylene copolymer emulsion was purchased from Celanese (China) Investment Co., Ltd.; aluminum hydroxide was purchased from Hefei Zhongke Flame Retardant New Materials Co., Ltd. (FR-3802); nitrogen-phosphorus flame retardant was purchased from Hefei Zhongke Flame Retardant New Materials Co., Ltd. (FR-6000-SG); Ti3C2TxMXene monolayer dispersion was purchased from Beijing Huawi Ruike Huagong Technology Co., Ltd. (105145); and high-temperature coating film accelerator was purchased from SAMASO Chemical Co., Ltd. GW-6120), polyhydroxyalkanoates (PHA) were purchased from Guangzhou Weijia Technology Co., Ltd., polybutylene adipate terephthalate (PBAT) was purchased from Xinjiang Lanshan Tunhe Technology Co., Ltd. (TH801T), polyethylene glycol (PVOH) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., anti-blocking wax paste was purchased from Wengkaier Trading (Shanghai) Co., Ltd. (3342), Dow additives were purchased from Dow Chemical (Shanghai) Co., Ltd. (731A), wetting agent was purchased from Evonik Chemical (Guangzhou) Co., Ltd. (Tego270), silicone defoamer was purchased from BYK Chemical (Shanghai) Co., Ltd. (BYK024), pH adjuster was purchased from Dow Chemical (Shanghai) Co., Ltd. (AMP95), and polyurethane thickener was purchased from Dow Chemical (Shanghai) Co., Ltd. (RM-12W).

[0030] Preparation Example 1 Preparation of PHA / PBAT / PVOH ternary blend aqueous emulsion Step 1: Take 10 parts by weight of PVOH and stir with 90 parts by weight of deionized water at 90℃ for 30 minutes to obtain PVOH solution; Step 2: Take 30 parts by weight of PHA and 30 parts by weight of PBTA and continuously extrude them in a twin-screw extruder at 150°C to obtain molten PHA / PBAT melt; Step 3: Place the PVOH solution prepared in step 1) at 90℃ in a high-shear stirrer at 2000 rpm, slowly pour in the molten PHA / PBAT melt, and continue stirring for 10 min to initially form an O / W emulsion; Step 4: Cool to 50℃, add 5 parts by weight of glycerin, 1 part by weight of borax, and 1 part by weight of Tween 80, and stir for 15 minutes; filter to obtain the PHA / PBAT / PVOH ternary blended aqueous emulsion.

[0031] Preparation Example 2 Preparation of accordion-shaped Ti3C2TxMXene composite material S1: Add 1.6g of lithium fluoride to a mixed solution containing 25ml of 9mol / L hydrochloric acid aqueous solution and 5mL of hydrofluoric acid, then add 1.2g of Ti3AlC2, heat to 40℃, keep warm and stir continuously for 24h, wash repeatedly, centrifuge with deionized water several times until the pH of the supernatant is 6.5, freeze dry for 24h to obtain powder, and store under vacuum; S2: Mix 37.5 mL of deionized water and 12.5 mL of anhydrous ethanol, add 200 mg of powder, and then add 4 mmol of Co(NO3)2·6H2O, 8 mmol of Ni(NO3)2·6H2O, and 20 mmol of hexamethylenetetramine. Heat to 85 °C and keep the reaction at that temperature for 6 h. Wash with water, centrifuge, and freeze dry to obtain the composite material. S3: Take 0.2g of the composite material prepared in step S2 and 1g of melamine and place them in a tube furnace. Under N2 atmosphere, heat to 700℃ and keep at that temperature for 2h for pyrolysis. The heating and cooling rates are both 2℃ / min. Cool to room temperature to obtain the accordion-shaped Ti3C2TxMXene composite material.

[0032] The PHA / PBAT / PVOH ternary blend aqueous emulsions used in the following examples are all derived from Preparation Example 1, and the accordion-shaped Ti3C2TxMXene composite materials are all derived from Preparation Example 2.

[0033] Example 1 A Class A flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating comprises the following raw materials by weight percentage: Based on the total mass of the encapsulation coating, the components and their weight percentages are as follows: 21% vinyl acetate-ethylene copolymer emulsion, 9% PHA / PBAT / PVOH ternary blend aqueous emulsion, 35% flame retardant, 16% additives, 3% adhesion promoter, and 16% deionized water; wherein the flame retardant consists of 15% aluminum hydroxide, 15% nitrogen-phosphorus flame retardant, and 5% accordion-shaped Ti3C2TxMXene composite material by weight; the additives... It consists of 5% by weight of anti-blocking wax paste, 0.5% by weight of dipropylene glycol methyl ether, 0.5% by weight of dipropylene glycol butyl ether, 0.5% by weight of propylene glycol, 5% by weight of water-based black paste, 0.15% by weight of preservative, 0.15% by weight of mildew inhibitor, 0.4% by weight of Dow additive, 1.0% by weight of wetting agent, 1.2% by weight of silicone defoamer, 0.1% by weight of pH adjuster and 1.5% by weight of polyurethane thickener, and the adhesion promoter is a high-temperature coating film accelerator.

[0034] The mass ratio of aluminum hydroxide to accordion-shaped Ti3C2TxMXene composite material is 3:1, and the mass ratio of vinyl acetate-ethylene copolymer emulsion to PHA / PBAT / PVOH ternary blend aqueous emulsion is 7:3.

[0035] Preparation method a1: While stirring, slowly add vinyl acetate-ethylene copolymer emulsion and PHA / PBAT / PVOH ternary blend aqueous emulsion to 12wt% deionized water, and continue stirring at 300r / min for 15min to fully mix the emulsion and water to obtain the first dispersion system. a2: Slowly add aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material to the first dispersion system obtained in step a1, and continue stirring at 1000 r / min for 10 min to obtain the second dispersion system; a3: First, dipropylene glycol methyl ether and dipropylene glycol butyl ether are diluted with 4wt% deionized water. Then, anti-adhesion wax paste, propylene glycol, water-based black paste, preservative, mildew inhibitor and diluted dipropylene glycol methyl ether and dipropylene glycol butyl ether are slowly added to the second dispersion system obtained in step a2. Stir at 500 r / min for 10 min to obtain the third dispersion system. a4: Slowly add the high-temperature coating film accelerator to the third dispersion system obtained in step a3, and continue stirring at 500 r / min for 10 min to obtain the fourth dispersion system; a5: Slowly add Dow additives, wetting agents, silicone defoamers, pH adjusters and polyurethane thickeners to the fourth dispersion system obtained in step a4, and continue stirring at 400 r / min for 25 min to obtain the coating.

[0036] Example 2 Example 2 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation properties. The difference from Example 1 is that the total mass of aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite material remains unchanged, and the mass ratio of aluminum hydroxide to accordion-shaped Ti3C2TxMXene composite material is 1.5:1.

[0037] The preparation method is the same as in Example 1.

[0038] Example 3 Example 3 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the total mass of aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite material remains unchanged, and the mass ratio of aluminum hydroxide to accordion-shaped Ti3C2TxMXene composite material is 9:1.

[0039] The preparation method is the same as in Example 1.

[0040] Example 4 Example 4 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulation properties. The difference from Example 1 is that the total mass of the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion remains unchanged, and the mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion is 6:4.

[0041] The preparation method is the same as in Example 1.

[0042] Example 5 Example 5 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulation properties. The difference from Example 1 is that the total mass of the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion remains unchanged, and the mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion is 8:2.

[0043] The preparation method is the same as in Example 1.

[0044] Comparative Example 1 Comparative Example 1 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation properties. The difference from Example 1 is that aluminum hydroxide is replaced by an accordion-shaped Ti3C2TxMXene composite material.

[0045] The preparation method is the same as in Example 1.

[0046] Comparative Example 2 Comparative Example 2 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the accordion-shaped Ti3C2TxMXene composite material is replaced by aluminum hydroxide by an equal mass.

[0047] The preparation method is the same as in Example 1.

[0048] Comparative Example 3 Comparative Example 3 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the vinyl acetate-ethylene copolymer emulsion is replaced by an equal mass of PHA / PBAT / PVOH ternary blend aqueous emulsion.

[0049] The preparation method is the same as in Example 1.

[0050] Comparative Example 4 Comparative Example 4 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the PHA / PBAT / PVOH ternary blend aqueous emulsion is replaced by an equal mass of vinyl acetate-ethylene copolymer emulsion.

[0051] The preparation method is the same as in Example 1.

[0052] Comparative Example 5 Comparative Example 5 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the accordion-shaped Ti3C2TxMXene composite material is replaced by an equal mass of Ti3C2TX MXene monolayer dispersion.

[0053] The preparation method is the same as in Example 1.

[0054] Comparative Example 6 Comparative Example 6 provides an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation performance. The difference from Example 1 is that the PHA / PBAT / PVOH ternary blend aqueous emulsion is replaced by an equal mass of the PVOH solution prepared in step 1).

[0055] The preparation method is the same as in Example 1.

[0056] Performance testing The encapsulation coatings prepared in Examples 1-5 and Comparative Examples 1-6 were tested for their adhesive strength, flammability rating, and flexibility. The test results are recorded in Table 1.

[0057] Test 1: The bonding strength was tested according to the standard GB / T14907-2018 Fireproof Coatings for Rigid Structures.

[0058] Test 2: The flammability rating was tested according to the standard GB8624-2012 Classification of Flammability of Building Materials and Products.

[0059] Experiment 3: Flexibility was tested according to the standard GB / T1731-2020 Test Method for Flexibility of Coating Film. The test was conducted using shafts with diameters of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 mm. The smaller the value, the better the flexibility of the coating.

[0060] Table 1 Based on Examples 1-3 and Table 1, it can be seen that by keeping the total mass of aluminum hydroxide and the accordion-shaped Ti3C2TxMXene composite material constant, and adjusting the mass ratio of aluminum hydroxide to the accordion-shaped Ti3C2TxMXene composite material, the adhesive strength and flexibility of the encapsulation coating are superior to those of Examples 2 and 3 when the mass ratio of aluminum hydroxide to the accordion-shaped Ti3C2TxMXene composite material is 3:1 in Example 1. The encapsulation coatings prepared in Examples 1-3 all have a flammability rating of Class A. Therefore, controlling the mass ratio of aluminum hydroxide to the accordion-shaped Ti3C2TxMXene composite material within a reasonable range has little impact on the flame-retardant properties of the encapsulation coating.

[0061] Based on Examples 1, 4-5, and Table 1, it can be seen that by keeping the total mass of the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion constant, and adjusting the mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion, the adhesive strength and flexibility of the encapsulating coating are superior to those of Examples 4 and 5 when the mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion in Example 1 is 7:3.

[0062] Based on Example 1, Comparative Examples 1-2 and Table 1, it can be seen that replacing aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite materials with equal mass may disrupt the synergistic effect of aluminum hydroxide and accordion-shaped Ti3C2TxMXene composite materials, and further lead to a significant decrease in the flame retardant properties of the encapsulation coating.

[0063] Based on Example 1, Comparative Examples 3-4 and Table 1, it can be seen that replacing the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion with each other by equal mass may destroy the synergistic effect of the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion, and further lead to a significant decrease in the flexibility of the encapsulation coating.

[0064] Based on Example 1, Comparative Example 5, and Table 1, it can be seen that replacing the accordion-shaped Ti3C2TxMXene composite material with an equal mass of Ti3C2TX MXene monolayer dispersion may be because the three-dimensional structure, catalytic activity, and thermal stability of the accordion-shaped Ti3C2TxMXene complement and synergize with the endothermic cooling effect of aluminum hydroxide. In contrast, the monolayer Ti3C2TX MXene dispersion, due to its structural limitations, cannot provide the same level of skeletal support and carbon layer reinforcement, resulting in a weaker synergistic effect and a decrease in the flame retardant performance of the encapsulation coating.

[0065] Based on Example 1, Comparative Example 6, and Table 1, it can be seen that replacing the PHA / PBAT / PVOH ternary blend aqueous emulsion with an equal mass of PVOH solution resulted in a decrease in the flexibility of the encapsulating coating. This may be because the synergistic effect of the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion is better than the combined effect of the vinyl acetate-ethylene copolymer emulsion and the PVOH solution.

[0066] Experiment 4: Surface Resistivity Test A Class A flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating prepared in Examples 1 and Comparative Examples 3-4 was uniformly brushed onto the surface of a 150mm × 150mm aerogel felt, with a coating dosage of 200g / m². 2 The coating thickness was 80-120 μm. After being placed at 23℃ and 50% humidity for 24 hours, the surface resistivity properties of the aerogel felts prepared in Example 1 and Comparative Examples 3-4 were compared. The surface resistivity was tested according to GB / T1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials". The results are shown in Table 2. Three parallel samples were tested for each group, and the average value was taken for calculation.

[0067] The formula for calculating surface resistivity is as follows: ρ s =R s ×P / g In the formula, ρ s R is the surface resistivity (Ω). s Ω represents the measured surface resistance; P represents the effective perimeter of the protected electrode in a specific electrode device (m); g represents the distance between the two electrodes (m).

[0068] Table 2 Group Surface resistivity (MΩ) Example 1 560 Comparative Example 3 350 Comparative Example 4 310 Based on Examples 1, Comparative Examples 3-4, and Table 2, it can be seen that in Example 1, when the mass ratio of vinyl acetate-ethylene copolymer emulsion to PHA / PBAT / PVOH ternary blend aqueous emulsion was 7:3, the coating surface resistivity was the highest, reaching 560 MΩ, which was significantly better than that of Comparative Examples 3 and 4. This may be because the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion form a complementary polymer network structure during film formation, effectively improving the density and insulation properties of the coating; once the synergistic effect is lost, the surface resistivity of the coating decreases significantly, and the insulation performance weakens.

[0069] Test 5: Wind Erosion Resistance Test The Class A flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating prepared in Example 1 was uniformly brushed onto the surface of the irregularly shaped part, with a coating dosage of 200 g / m². 2The coating thickness is 80-120μm, and the effect after coating is as follows: Figure 1 As shown, after being placed at 23℃ and 50% humidity for 24 hours, it served as test sample 1; an A-grade flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating prepared in Comparative Examples 3-4 was uniformly brushed onto the surface of the irregularly shaped part, with a coating dosage of 200 g / m². 2 The coating thickness was 80-120μm, and after being placed at 23℃ and 50% humidity for 24 hours, it was used as test sample 2-3; the uncoated irregularly shaped parts were used as test sample 4. The uncoated irregularly shaped parts, such as... Figure 2 As shown; uncoated aerogel felt was used as test sample 5. The uncoated aerogel felt is shown in the image. Figure 3 As shown; the aerogel encapsulated with a PEI / PI film was used as test sample 6. The aerogel encapsulated with a PEI / PI film is shown in the figure. Figure 4 As shown; the aerogel wrapped in fiberglass cloth was used as test sample 7. The aerogel wrapped in fiberglass cloth is as follows. Figure 5 As shown in Table 3, test samples 1-5 were placed in a stable flow field with a wind speed of 4.5 m / s and blown for 5 minutes to test their wind erosion resistance. The results are shown in Table 3. The formula for calculating the wind erosion rate is as follows: η3 = m1 / m0 × 100% In the formula, η3 is the wind erosion rate (%); m1 is the weight of the test sample after purging (g); and m0 is the weight of the test sample before purging (g).

[0070] Table 3 Group Wind erosion rate (%) Test Sample 1 (Example 1) 0.6 Test sample 2 (comparative example 3) 0.9 Test sample 3 (comparative example 4) 1.1 Test sample 4 8.5 Test sample 5 12.3 Test sample 6 2.1 Test sample 7 3.8 Based on Examples 1, Comparative Examples 3-4, and Table 3, it can be seen that when the mass ratio of vinyl acetate-ethylene copolymer emulsion to PHA / PBAT / PVOH ternary blend aqueous emulsion in Example 1 is 7:3, the irregularly shaped part of Sample 1 exhibits the best dust-locking effect, significantly superior to Samples 2 and 3. This may be because the vinyl acetate-ethylene copolymer emulsion and the PHA / PBAT / PVOH ternary blend aqueous emulsion form a complementary polymer network structure during film formation, effectively improving the density of the coating; once the synergistic effect is lost, the density of the coating decreases, further reducing the dust-locking effect.

[0071] Based on the data from Example 1 and Table 3, it can be seen that the dust-locking effect of the irregularly shaped parts coated with the coating prepared in Example 1 is significantly better than that of the irregularly shaped parts of Test Sample 2 without coating, and also significantly better than the dust-locking effects of bare aerogel felt without coating, aerogel encapsulated with PEI / PI film, and aerogel covered with fiberglass cloth.

[0072] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the products, methods and principles of this application should be covered within the scope of protection of this application.

Claims

1. A Class A flame-retardant, highly flexible, and insulating aerogel felt encapsulation coating, characterized in that, The raw materials include the following percentages by mass: based on the total mass of the encapsulating coating as 100%, the components and their percentage contents by mass are as follows: vinyl acetate-ethylene copolymer emulsion 18-24%, PHA / PBAT / PVOH ternary blend aqueous emulsion 6-12%, flame retardant 30-40%, additives 15-17%, adhesion promoter 2-4%, and the balance being water; Based on the total mass of the encapsulating coating as 100%, the flame retardant consists of 12-18% by mass of aluminum hydroxide, 10-20% by mass of nitrogen-phosphorus flame retardant, and 2-8% by mass of accordion-shaped Ti3C2TxMXene composite material.

2. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The mass ratio of the aluminum hydroxide and the accordion-shaped Ti3C2TxMXene composite material is (1.5-9):

1.

3. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The mass ratio of the vinyl acetate-ethylene copolymer emulsion to the PHA / PBAT / PVOH ternary blend aqueous emulsion is (3-8):

2.

4. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The mass ratio of the aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material is (12-18):15:(2-8).

5. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The preparation method of the PHA / PBAT / PVOH ternary blend aqueous emulsion includes the following steps: Step 1): Add PVOH to water and stir to obtain a PVOH solution; Step 2): Extrude PHA and PBTA at 140-160℃ to obtain molten PHA / PBAT melt; Step 3): Add the PVOH solution prepared in Step 1) to the molten PHA / PBAT melt and stir to form an O / W emulsion; Step 4): Cool down, add glycerin, borax, and Tween 80, stir, filter, and obtain the PHA / PBAT / PVOH ternary blend aqueous emulsion.

6. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The preparation method of the accordion-shaped Ti3C2TxMXene composite material includes the following steps: S1: Lithium fluoride is added to a mixed solution containing hydrochloric acid aqueous solution and hydrofluoric acid, and then Ti3AlC2 is added. The mixture is heated, kept at the temperature, stirred, washed, centrifuged, and freeze-dried to obtain powder. S2: Mix water and ethanol, add the powder obtained in step S1, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, and hexamethylenetetramine, heat and keep warm for 4-8 hours; wash with water, centrifuge, and freeze dry to obtain the composite material; S3: The composite material prepared in step S2 is calcined with melamine in an inert gas atmosphere and cooled to obtain the accordion-shaped Ti3C2TxMXene composite material.

7. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, Based on the total mass of the encapsulating coating as 100%, the additives consist of 4-6% by mass of anti-blocking wax paste, 0.3-0.7% by mass of dipropylene glycol methyl ether, 0.3-0.7% by mass of dipropylene glycol butyl ether, 0.3-0.7% by mass of propylene glycol, 3-7% by mass of water-based black paste, 0.1-0.2% by mass of preservative, 0.1-0.2% by mass of mildew inhibitor, 0.3-0.5% by mass of Dow additives, 0.8-1.2% by mass of wetting agent, 1.0-1.4% by mass of silicone defoamer, 0.05-0.15% by mass of pH adjuster, and 1.2-1.7% by mass of polyurethane thickener.

8. The aerogel felt encapsulation coating with Class A flame retardancy, high flexibility, and insulating properties according to claim 1, characterized in that, The adhesion promoter is a high-temperature coating film promoter.

9. A method for preparing an aerogel felt encapsulating coating with Class A flame retardancy, high flexibility, and insulating properties as described in any one of claims 1-7, characterized in that, The preparation steps include the following: a1: Add vinyl acetate-ethylene copolymer emulsion and PHA / PBAT / PVOH ternary blend aqueous emulsion to water, stir, and obtain the first dispersion system; a2: Add aluminum hydroxide, nitrogen-phosphorus flame retardant and accordion-shaped Ti3C2TxMXene composite material to the first dispersion system obtained in step a1, stir, and obtain the second dispersion system; a3: Add a portion of the additive to the second dispersion system obtained in step a2, stir, and obtain the third dispersion system; a4: Add the high-temperature coating film accelerator to the third dispersion system obtained in step a3, stir, and obtain the fourth dispersion system; a5: Add the remaining additives to the fourth dispersion system obtained in step a4, stir, and obtain the coating.

10. The application of an aerogel felt encapsulation coating with Class A flame retardancy, high flexibility and insulation properties as described in any one of claims 1-7, applied by spraying or brushing onto the surface of an aerogel / irregularly shaped part.

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