A waterproof coating and its application in bamboo plywood

Abstract

This invention discloses a waterproof coating and its application in bamboo plywood, relating to the field of coating technology. The waterproof coating comprises the following raw materials by weight percentage: 50-60% epoxy resin, 5-10% diluent, 20-25% curing agent, 5-10% modified lignin sulfonate, 5-8% modified nano-silica powder, and 1-3% additives. This application uses epoxy resin as a base material, adding modified lignin sulfonate to improve the coating's lignin sulfonate content, thereby enhancing hydrophobicity and surface micro-roughness, and reducing concrete adhesion. This application also adds modified nano-silica powder, which enhances the coating's wear resistance and fills micropores. The modified nano-silica powder and modified lignin sulfonate work synergistically to increase the coating's density, further improving the coating's waterproof performance.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a waterproof coating and its application in bamboo plywood. Background Technology

[0002] With the further strengthening of the natural forest protection project, the contradiction between timber supply and demand has become increasingly prominent. China has abundant bamboo resources, and using bamboo as a substitute for forestry has become one of the important ways to alleviate this contradiction. Bamboo plywood not only has high bending strength and stiffness, but also has a large format, good dimensional stability, high surface flatness, and good overall structure. It can be made into steel frame formwork and various connectors and accessories, simplifying the construction process. Moreover, it is easy to demold, and the surface of the cast components is smooth, which has good technical and economic benefits. Bamboo plywood has a very broad development prospect. However, during use, the moisture content of bamboo plywood increases with time within a certain range, and the static bending strength and modulus of elasticity (stiffness) decrease with the increase of bamboo plywood moisture content. Concrete uses a large amount of water from pouring to curing. Therefore, improving the water resistance of bamboo plywood to reduce its moisture content is an important way to ensure the quality of the project.

[0003] In construction, the expansion and contraction properties of bamboo plywood directly affect the dimensional stability of concrete components. The expansion and contraction properties of bamboo plywood are influenced by moisture content and density, with the greatest effect in the thickness direction, followed by the width direction, and the least in the length direction. The lower the moisture content and the higher the density, the greater the expansion and contraction properties in the thickness direction. Therefore, the main way to improve the expansion and contraction properties of bamboo plywood is to enhance its waterproof performance. Coating both surfaces of the bamboo plywood with phenolic resin and then hot-pressing and curing, and applying water-resistant coatings or paints around the perimeter of the plywood, can significantly improve its expansion and contraction properties, enhance its dimensional stability, and help ensure the strength of building components. However, when using bamboo plywood with a waterproof coating as a formwork for concrete pouring, one or more layers of release agent need to be applied to the coating surface for better demolding after the concrete has cured. These release agents are mainly water-based or oil-based liquid film-forming agents, and multiple applications result in a long film-forming process, affecting the construction progress. Summary of the Invention

[0004] The purpose of this invention is to provide a waterproof coating and its application in bamboo plywood, thereby solving the following technical problems: The existing waterproof coating on the surface of bamboo plywood does not provide a release effect for concrete. When bamboo plywood is used as a formwork for concrete pouring, a release agent needs to be applied to the coating surface, which is a complicated process and affects the construction progress.

[0005] The objective of this invention can be achieved through the following technical solutions: A waterproof coating comprises the following raw materials by weight percentage: 50-60% epoxy resin, 5-10% diluent, 20-25% curing agent, 5-10% modified lignin sulfonate, 5-8% modified nano-silica powder, and 1-3% additives. The preparation method of modified lignin sulfonate includes the following steps: S1: Add hexagonal boron nitride nanosheets, γ-aminopropyltriethoxysilane, ethanol and deionized water into a reaction flask, control the temperature at 50-60℃, keep the reaction at this temperature for 1-2 hours, filter, wash and dry to obtain organic hexagonal boron nitride nanosheets. Add calcium lignosulfonate and distilled water to a reaction flask, control the temperature at 30-40℃, add maleic anhydride, adjust the pH to 9-10, keep the reaction at the temperature for 3-6 hours, add dilute sulfuric acid to cause precipitation, filter, wash and dry to obtain carboxylated calcium lignosulfonate. S2: Carboxylated calcium lignin sulfonate, organic hexagonal boron nitride nanosheets, and dimethyl sulfoxide are added to a reaction vessel and dispersed evenly. The temperature is controlled at 80-85℃ and the reaction is maintained for 4-8 hours. After centrifugation, washing, and drying, modified lignin sulfonate is obtained.

[0006] As a further aspect of the present invention: the addition ratio of hexagonal boron nitride nanosheets, γ-aminopropyltriethoxysilane, ethanol and deionized water in S1 is 10g: 2-4g: 90-180mL: 10-20mL; The addition ratio of calcium lignosulfonate, distilled water, and maleic anhydride in S1 is 10g: 50-100mL: 8-9g.

[0007] As a further embodiment of the present invention: the addition ratio of carboxylated calcium lignin sulfonate, organic hexagonal boron nitride nanosheets, and dimethyl sulfoxide in S2 is 10g: 2-4g: 100-200mL.

[0008] As a further aspect of the present invention, the preparation method of modified nano-silicon powder includes the following steps: A1: Add nano-mesoporous silica powder, γ-aminopropyltriethoxysilane, ethanol, and deionized water to a reaction vessel and disperse them evenly. Control the temperature at 50-60℃ and keep the reaction at this temperature for 2-4 hours. Filter, wash, and dry to obtain organic nano-mesoporous silica powder. A2: In a nitrogen protective atmosphere, ethanolamine, 1,2,4-triphenyltriglycerid acid and p-toluenesulfonic acid are added to a reaction vessel, the temperature is controlled at 210-220℃, the reaction is maintained at this temperature for 3-6 hours, and then cooled to room temperature to obtain carboxyl-terminated hyperbranched polyester amide. A3: Under a nitrogen protective atmosphere, organic nanoporous silica powder and dimethyl sulfoxide were added to a reaction flask and dispersed evenly. Then, carboxyl-terminated hyperbranched polyester amide, N,N-dicyclohexylcarboimide and 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 9-12 hours. After centrifugation, washing and drying, modified nanosilica powder was obtained.

[0009] As a further aspect of the present invention: the addition ratio of nano-mesoporous silica powder, γ-aminopropyltriethoxysilane, ethanol and deionized water in A1 is 10g: 3-6g: 90-180mL: 10-20mL.

[0010] As a further embodiment of the present invention: the addition ratio of ethanolamine, 1,2,4-triphenyltriglycerid acid and p-toluenesulfonic acid in A2 is 10g: 31.5-35g: 0.2-0.3g.

[0011] As a further embodiment of the present invention: the addition ratio of organic nanoporous silica powder, dimethyl sulfoxide, carboxyl-terminated hyperbranched polyester amide, N,N-dicyclohexylcarboimide, and 4-dimethylaminopyridine in A3 is 10g: 200-400mL: 1-2g: 2-3g: 0.2-0.3g.

[0012] As a further aspect of the present invention: the curing agent is a polyetheramine curing agent; the diluent is composed of butyl glycidyl ether and ethylene glycol diglycidyl ether.

[0013] As a further aspect of the present invention: the additives include leveling agents, wetting agents, and defoamers; The leveling agent accounts for 0.1-0.5% of the total mass of the waterproof coating; the wetting agent accounts for 1-2% of the total mass of the waterproof coating; and the defoamer accounts for 0.5-1% of the total mass of the waterproof coating.

[0014] Any of the above waterproof coatings may be applied to the surface of bamboo plywood.

[0015] The beneficial effects of this invention are: This application uses epoxy resin as the film-forming matrix, providing high strength and water resistance. A curing agent and an active diluent are added to the coating. The curing agent reacts with the epoxy resin to form a dense cross-linked structure. Modified lignin sulfonate and modified nano-silica powder are also added. The modified lignin sulfonate added in this application not only improves the thermal conductivity of the waterproof coating but also constructs nano- to micro-level roughness on the coating surface. The increased thermal conductivity effectively reduces thermal adhesion during concrete curing, while the construction of nano- to micro-level roughness enhances hydrophobicity and surface micro-roughness, reducing concrete adhesion and giving the coating excellent concrete release properties.

[0016] This application adds modified nano-silica powder as the core and hyperbranched polyesteramide as the shell, forming a core-shell structure. When added to a waterproof coating, it effectively enhances the coating's wear resistance and fills micropores. Specifically, the terminal carboxyl groups of the hyperbranched polyesteramide grafted onto the surface of the modified nano-silica powder form hydrogen bonds with the hydroxyl groups of the modified lignin sulfonate, further increasing the coating's density and improving the material's waterproofness and alkali resistance. The hyperbranched structure effectively absorbs stress and improves the coating's impact resistance. When bamboo plywood coated with this waterproof coating is used as a concrete pouring template, it effectively adapts to the material's deformation and impact. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0018] Example 1: The preparation method of modified nano-silicon powder includes the following steps: A1: 10g of nano-mesoporous silica powder (200nm, pore size 5-8nm), 3g of γ-aminopropyltriethoxysilane, 90mL of ethanol and 10mL of deionized water were added to a reaction vessel and dispersed evenly. The temperature was controlled at 50℃ and the reaction was kept at this temperature for 2h. The mixture was then filtered, washed and dried to obtain organic nano-mesoporous silica powder. A2: Under a nitrogen protective atmosphere, 10g of ethanolamine, 31.5g of 1,2,4-triphenyltriglycerid acid and 0.2g of p-toluenesulfonic acid were added to a reaction vessel, the temperature was controlled at 220℃ and the reaction was maintained at this temperature for 3h. After cooling to room temperature, carboxyl-terminated hyperbranched polyester amide was obtained. A3: Under a nitrogen protective atmosphere, 10g of organic nanoporous silica powder and 200mL of dimethyl sulfoxide were added to a reaction flask and dispersed evenly. Then, 1g of carboxyl-terminated hyperbranched polyesteramide, 2g of N,N-dicyclohexylcarboimide (DCC), and 0.2g of 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 9h, centrifuged, washed, and dried to obtain modified nanosilica powder.

[0019] The preparation method of modified lignin sulfonate includes the following steps: S1: Add 10g of hexagonal boron nitride nanosheets, 2g of γ-aminopropyltriethoxysilane, 90mL of ethanol and 10mL of deionized water to a reaction flask, control the temperature at 50℃, keep the reaction at 50℃ for 1h, filter, wash and dry to obtain organic hexagonal boron nitride nanosheets. Add 10g of calcium lignosulfonate and 50mL of distilled water to a reaction flask, control the temperature at 30℃, add 8g of maleic anhydride, adjust the pH to 9, keep the reaction at the temperature for 3h, add dilute sulfuric acid to precipitate, filter, wash and dry to obtain carboxylated calcium lignosulfonate. S2: 10g of carboxylated calcium lignin sulfonate, 2g of organic hexagonal boron nitride nanosheets, and 100mL of dimethyl sulfoxide were added to a reaction vessel and dispersed evenly. The temperature was controlled at 80℃ and the reaction was maintained for 4h. After centrifugation, washing, and drying, modified lignin sulfonate was obtained.

[0020] Example 2: The preparation method of modified nano-silicon powder includes the following steps: A1: 10g of nano-mesoporous silica powder (200nm, pore size 5-8nm), 4.5g of γ-aminopropyltriethoxysilane, 150mL of ethanol and 15mL of deionized water were added to a reaction vessel and dispersed evenly. The temperature was controlled at 55℃ and the reaction was kept at this temperature for 3h. The mixture was then filtered, washed and dried to obtain organic nano-mesoporous silica powder. A2: Under a nitrogen protective atmosphere, 10g of ethanolamine, 33.5g of 1,2,4-triphenyltriglycerid acid and 0.2g of p-toluenesulfonic acid were added to a reaction vessel, the temperature was controlled at 220℃ and the reaction was maintained at this temperature for 6h. After cooling to room temperature, carboxyl-terminated hyperbranched polyester amide was obtained. A3: Under a nitrogen protective atmosphere, 10g of organic nanoporous silica powder and 300mL of dimethyl sulfoxide were added to a reaction flask and dispersed evenly. Then, 1.5g of carboxyl-terminated hyperbranched polyesteramide, 2.5g of N,N-dicyclohexylcarboimide (DCC), and 0.2g of 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 9 hours, centrifuged, washed, and dried to obtain modified nanosilica powder.

[0021] The preparation method of modified lignin sulfonate includes the following steps: S1: Add 10g of hexagonal boron nitride nanosheets, 3g of γ-aminopropyltriethoxysilane, 150mL of ethanol, and 15mL of deionized water to a reaction flask, control the temperature at 55℃, keep the reaction at this temperature for 1h, filter, wash, and dry to obtain organic hexagonal boron nitride nanosheets. Add 10g of calcium lignosulfonate and 100mL of distilled water to a reaction flask, control the temperature at 35℃, add 8.5g of maleic anhydride, adjust the pH to 9, keep the reaction at this temperature for 4h, add dilute sulfuric acid to cause precipitation, filter, wash and dry to obtain carboxylated calcium lignosulfonate. S2: 10g of carboxylated calcium lignin sulfonate, 3g of organic hexagonal boron nitride nanosheets, and 200mL of dimethyl sulfoxide were added to a reaction vessel and dispersed evenly. The temperature was controlled at 80℃ and the reaction was maintained for 8h. After centrifugation, washing, and drying, modified lignin sulfonate was obtained.

[0022] Example 3: The preparation method of modified nano-silicon powder includes the following steps: A1: 10g of nano-mesoporous silica powder (200nm, pore size 5-8nm), 6g of γ-aminopropyltriethoxysilane, 180mL of ethanol and 20mL of deionized water were added to a reaction vessel and dispersed evenly. The temperature was controlled at 60℃ and the reaction was kept at this temperature for 4h. The mixture was then filtered, washed and dried to obtain organic nano-mesoporous silica powder. A2: Under a nitrogen protective atmosphere, 10g of ethanolamine, 35g of 1,2,4-triphenyltriglycerid acid and 0.3g of p-toluenesulfonic acid were added to a reaction vessel, the temperature was controlled at 220℃ and the reaction was maintained at this temperature for 6h. After cooling to room temperature, carboxyl-terminated hyperbranched polyesteramide was obtained. A3: Under a nitrogen protective atmosphere, 10g of organic nanoporous silica powder and 400mL of dimethyl sulfoxide were added to a reaction flask and dispersed evenly. Then, 2g of carboxyl-terminated hyperbranched polyester amide, 3g of N,N-dicyclohexylcarboimide (DCC), and 0.3g of 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 12h, centrifuged, washed, and dried to obtain modified nanosilica powder.

[0023] The preparation method of modified lignin sulfonate includes the following steps: S1: Add 10g of hexagonal boron nitride nanosheets, 4g of γ-aminopropyltriethoxysilane, 180mL of ethanol and 20mL of deionized water to a reaction flask, control the temperature at 60℃, keep the reaction at 2h, filter, wash and dry to obtain organic hexagonal boron nitride nanosheets. Add 10g of calcium lignosulfonate and 100mL of distilled water to a reaction flask, control the temperature at 40℃, add 9g of maleic anhydride, adjust the pH to 10, keep the reaction at the temperature for 6h, add dilute sulfuric acid to precipitate, filter, wash and dry to obtain carboxylated calcium lignosulfonate. S2: 10g of carboxylated calcium lignin sulfonate, 4g of organic hexagonal boron nitride nanosheets, and 200mL of dimethyl sulfoxide were added to a reaction vessel and dispersed evenly. The temperature was controlled at 85℃ and the reaction was maintained for 8h. After centrifugation, washing, and drying, modified lignin sulfonate was obtained.

[0024] Example 4 A method for preparing a waterproof coating includes the following steps: After mixing 8g of the modified lignin sulfonate prepared in Example 1 and 8g of the modified nano-silica powder prepared in Example 1, 54g of epoxy resin (E-44 type), 4g of butyl glycidyl ether, 4g of ethylene glycol diglycidyl ether, 20g of polyetheramine curing agent (T-403), 0.5g of leveling agent (BYK-333), 1g of wetting agent (CoatOSil 7001), and 0.5g of defoamer (BYK-066N) were added.

[0025] Example 5: A method for preparing a waterproof coating includes the following steps: After mixing 8g of the modified lignin sulfonate prepared in Example 2 and 8g of the modified nano-silica powder prepared in Example 2, 54g of epoxy resin (E-44 type), 4g of butyl glycidyl ether, 4g of ethylene glycol diglycidyl ether, 20g of polyetheramine curing agent (T-403), 0.5g of leveling agent (BYK-333), 1g of wetting agent (CoatOSil 7001), and 0.5g of defoamer (BYK-066N) were added.

[0026] Example 6 A method for preparing a waterproof coating includes the following steps: After mixing 8g of the modified lignin sulfonate prepared in Example 3 and 8g of the modified nano-silica powder prepared in Example 3, 54g of epoxy resin (E-44 type), 4g of butyl glycidyl ether, 4g of ethylene glycol diglycidyl ether, 20g of polyetheramine curing agent (T-403), 0.5g of leveling agent (BYK-333), 1g of wetting agent (CoatOSil 7001), and 0.5g of defoamer (BYK-066N) were added.

[0027] Comparative Example 1: The preparation method of modified nano-silicon powder includes the following steps: 10g of nano-mesoporous silica powder (200nm, pore size 5-8nm), 4.5g of γ-aminopropyltriethoxysilane, 150mL of ethanol and 15mL of deionized water were added to a reaction vessel and dispersed evenly. The temperature was controlled at 55℃ and the reaction was maintained for 3h. After filtration, washing and drying, modified nano-silica powder was obtained.

[0028] Comparative Example 2: The preparation method of modified lignin sulfonate includes the following steps: Add 10g of calcium lignosulfonate and 100mL of distilled water to a reaction flask, control the temperature at 35℃, add 8.5g of maleic anhydride, adjust the pH to 9, keep the reaction at this temperature for 4h, add dilute sulfuric acid to cause precipitation, filter, wash, and dry to obtain modified lignosulfonate.

[0029] The preparation method of the modified lignin sulfonate in Comparative Example 3 includes the following steps: S1: Add 10g of hexagonal boron nitride nanosheets, 3g of γ-aminopropyltriethoxysilane, 150mL of ethanol, and 15mL of deionized water to a reaction flask, control the temperature at 55℃, keep the reaction at this temperature for 1h, filter, wash, and dry to obtain organic hexagonal boron nitride nanosheets. S2: 10g of calcium lignosulfonate and 3g of organic hexagonal boron nitride nanosheets were blended to obtain modified lignosulfonate.

[0030] Comparative Example 4: A method for preparing a waterproof coating. Compared with Example 5, Comparative Example 4 simply replaces the modified nano-silicon powder prepared in Example 2 with the modified nano-silicon powder prepared in Comparative Example 1 in equal amounts. The remaining components and preparation methods are completely consistent with those of Example 5.

[0031] Comparative Example 5: A method for preparing a waterproof coating. Compared with Example 5, Comparative Example 4 simply replaces the modified lignin sulfonate prepared in Example 2 with an equal amount of the modified lignin sulfonate prepared in Comparative Example 2 in Example 5. The remaining components and preparation methods are completely consistent with Example 5.

[0032] Comparative Example 6: A method for preparing a waterproof coating. Compared with Example 5, Comparative Example 4 simply replaces the modified lignin sulfonate prepared in Example 2 with the modified lignin sulfonate prepared in Comparative Example 3 in equal amounts. The remaining components and preparation methods are completely consistent with Example 5.

[0033] Performance testing (1) Concrete demolding property: After the waterproof coating is applied to the surface of the bamboo strips and dried, concrete is poured on the surface of the waterproof bamboo strips (concrete formula: P·O 42.5 grade ordinary Portland cement: sand: stone: water = 1:1.7:2.8:0.9). Curing conditions: temperature 20±2℃, humidity 60±5%. Demolding is performed after curing for 24 hours. After 50 cycles, the surface condition of the coating is observed according to ASTM D4060 standard. The test results are shown in Table 1. (2) Alkali resistance: According to GB / T 9265-2009 "Determination of alkali resistance of building coating", bamboo strips coated with waterproof coating were immersed in saturated calcium hydroxide solution for 500h and the condition of the coating on the surface of the bamboo strips was observed. The test results are shown in Table 1. (3) Waterproof performance: According to GB / T 1934.1-2009 "Test Method for Water Absorption of Wood", bamboo strips coated with waterproof coating were immersed in deionized water at 20℃ for 800h, and the water absorption rate of the material was calculated. Table 1: Performance Test Data Statistics of Examples 4-6 and Comparative Examples 4-6

[0034] As shown in Table 1, the waterproof coating prepared in this application not only imparts excellent waterproof performance to the bamboo plywood surface, but also has good alkali resistance and good concrete demolding properties. When bamboo plywood is used in concrete pouring, the concrete is easy to demold after curing.

[0035] (4) Adhesion: The adhesion was tested according to GB / T 9286-1998 "Cross-cut test of paint and varnish film" on the surface of bamboo-based material. The test results are shown in Table 2. (5) Aging resistance: Paints and varnishes were aged under xenon lamps for 1000 hours according to GB / T 1865-2009 "Artificial climate aging and artificial radiation exposure to filtered xenon arc radiation", and the gloss retention rate and secondary adhesion were tested; the test results are shown in Table 2. Table 2: Statistical Table of Adhesion Performance Test Data for Examples 4-6 and Comparative Examples 4-6

[0036] As shown in Table 2, the waterproof coating prepared in this application has high adhesion strength to bamboo-based materials when applied to the surface of bamboo plywood, and still has high adhesion and gloss retention after aging.

[0037] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A waterproof coating, characterized in that, The raw materials include the following weight percentages: 50-60% epoxy resin, 5-10% diluent, 20-25% curing agent, 5-10% modified lignin sulfonate, 5-8% modified nano-silica powder, and 1-3% additives. The preparation method of the modified lignin sulfonate includes the following steps: S1: Add hexagonal boron nitride nanosheets, γ-aminopropyltriethoxysilane, ethanol and deionized water into a reaction flask, control the temperature at 50-60℃, keep the reaction at this temperature for 1-2 hours, filter, wash and dry to obtain organic hexagonal boron nitride nanosheets. Add calcium lignosulfonate and distilled water to a reaction flask, control the temperature at 30-40℃, add maleic anhydride, adjust the pH to 9-10, keep the reaction at the temperature for 3-6 hours, add dilute sulfuric acid to cause precipitation, filter, wash and dry to obtain carboxylated calcium lignosulfonate. S2: Carboxylated calcium lignin sulfonate, organic hexagonal boron nitride nanosheets, and dimethyl sulfoxide were added to a reaction vessel and dispersed evenly. The temperature was controlled at 80-85℃ and the reaction was maintained for 4-8 hours. After centrifugation, washing, and drying, modified lignin sulfonate was obtained. The preparation method of the modified nano-silicon powder includes the following steps: A1: Add nano-mesoporous silica powder, γ-aminopropyltriethoxysilane, ethanol, and deionized water to a reaction vessel and disperse them evenly. Control the temperature at 50-60℃ and keep the reaction at this temperature for 2-4 hours. Filter, wash, and dry to obtain organic nano-mesoporous silica powder. A2: In a nitrogen protective atmosphere, ethanolamine, 1,2,4-triphenyltriglycerid acid and p-toluenesulfonic acid are added to a reaction vessel, the temperature is controlled at 210-220℃, the reaction is maintained at this temperature for 3-6 hours, and then cooled to room temperature to obtain carboxyl-terminated hyperbranched polyester amide. A3: Under a nitrogen protective atmosphere, organic nanoporous silica powder and dimethyl sulfoxide were added to a reaction flask and dispersed evenly. Then, carboxyl-terminated hyperbranched polyester amide, N,N-dicyclohexylcarboimide and 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 9-12 hours. After centrifugation, washing and drying, modified nanosilica powder was obtained.

2. The waterproof coating according to claim 1, characterized in that, The addition ratio of hexagonal boron nitride nanosheets, γ-aminopropyltriethoxysilane, ethanol, and deionized water in S1 is 10g: 2-4g: 90-180mL: 10-20mL; The addition ratio of calcium lignosulfonate, distilled water, and maleic anhydride in S1 is 10g: 50-100mL: 8-9g.

3. The waterproof coating according to claim 1, characterized in that, The addition ratio of carboxylated calcium lignin sulfonate, organic hexagonal boron nitride nanosheets, and dimethyl sulfoxide in S2 is 10g: 2-4g: 100-200mL.

4. The waterproof coating according to claim 1, characterized in that, The addition ratio of nano-mesoporous silica powder, γ-aminopropyltriethoxysilane, ethanol, and deionized water in A1 is 10g: 3-6g: 90-180mL: 10-20mL.

5. A waterproof coating according to claim 1, characterized in that, The amounts of ethanolamine, 1,2,4-triphenyltriatic anhydride, and p-toluenesulfonic acid added in A2 are: 10g ethanolamine; 31.5-35g 1,2,4-triphenyltriatic anhydride; and 0.2-0.3g p-toluenesulfonic acid.

6. A waterproof coating according to claim 1, characterized in that, The addition ratio of organic nanoporous silica powder, dimethyl sulfoxide, carboxyl-terminated hyperbranched polyester amide, N,N-dicyclohexylcarboimide, and 4-dimethylaminopyridine in A3 is 10g: 200-400mL: 1-2g: 2-3g: 0.2-0.3g.

7. A waterproof coating according to claim 1, characterized in that, The curing agent is a polyetheramine curing agent; the diluent is composed of butyl glycidyl ether and ethylene glycol diglycidyl ether.

8. A waterproof coating according to claim 1, characterized in that, The additives include leveling agents, wetting agents, and defoamers; The leveling agent accounts for 0.1-0.5% of the total mass of the waterproof coating; the wetting agent accounts for 1-2% of the total mass of the waterproof coating; and the defoamer accounts for 0.5-1% of the total mass of the waterproof coating.

9. The waterproof coating according to any one of claims 1-8 is applied to the surface of bamboo plywood.

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