A high-bending-resistance plate and its preparation method

Abstract

The present application relates to the technical field of building materials, specifically disclosing a high-flexural-resistance board and its preparation method. The method comprises the following steps: S1: uniformly mixing the main ingredients, water glass, calcium sulfate, triethanolamine, a retarder, and solvent A to obtain a slurry; S2: uniformly mixing modified polyvinyl alcohol, modified starch, and solvent B, heating the mixture to 40-60°C, adding a crosslinking agent, reacting for 20-40 minutes, adjusting the pH to 8-10, then adding a double coupling agent, mixing the mixture, continuing the reaction for 15-25 minutes, and cooling the mixture to obtain an organic phase; S3: uniformly mixing the slurry and the organic phase, pouring the mixture into a mold, vibrating, vacuuming, and pressing the mold to obtain a preformed board; S4: curing and cutting the preformed board to obtain a high-flexural-resistance board. The high-flexural-resistance board produced by the present application has high flexural strength, compressive strength, and low water absorption.

Description

Technical Field

[0001] The present application relates to the technical field of building materials, and more specifically, to a high-flexural-resistance board and a preparation method thereof. Background Art

[0002] High-flexural-resistance panels, as an indispensable structural material in modern buildings, are directly related to the stability and safety of building structures when used to make structural components such as floor slabs and walls. In recent years, researchers have improved the flexural resistance of panels within a certain limit by adding materials such as mineral fibers, reinforcing fibers, or organic polymers to the matrix. However, these methods still have many problems in practical applications. For example, the dispersion of mineral fibers in the matrix is ​​poor, which easily leads to local stress concentration; the orientation of reinforcing fibers is unreasonable, making it difficult to fully exert their reinforcing effect; the compatibility between organic polymers and inorganic materials is poor, which easily forms weak areas at the interface, thereby weakening the overall performance of the panel.

[0003] The patent application document with publication number CN116354694A discloses a method for preparing a geopolymer-based organic-inorganic composite board, comprising the following steps: (1) mixing slag, water glass, a retarder and water, and stirring until the mixture is uniform to obtain a slurry; (2) mixing the slurry prepared in (1) with an organic solution containing active groups, and stirring to obtain an organic-inorganic composite plastic slurry; (3) pouring the organic-inorganic composite plastic slurry into a fixed iron mold of an experimental small press for vibration, vacuuming and pressing to obtain a fixed-size board; (4) covering the surface of the board obtained in step (3) with a waterproof film, and curing it to obtain a high-flexural-resistance geopolymer-based organic-inorganic composite board; the organic matter containing active groups in step (2) is sodium polyacrylate and a silane coupling agent.

[0004] The patent application documents only use sodium polyacrylate and silane coupling agent solutions directly mixed with the slurry. Due to the lack of effective control over the hydrolysis conditions of the silane coupling agent, the silane coupling agent is not fully hydrolyzed, unable to form a strong bond with the slag surface, and unable to effectively improve the interfacial properties. As a result, the mechanical properties of the prepared plate are limited. Furthermore, while sodium polyacrylate and silane coupling agents can improve interfacial properties to a certain extent, they suffer from uneven dispersion and insufficient reaction with other components, leading to a decrease in mechanical properties. Summary of the Invention

[0005] In order to effectively improve the mechanical properties of a plate, the present application provides a high-flexural-resistance plate and a preparation method thereof.

[0006] In a first aspect, the present application provides a method for preparing a high-flexural-resistance sheet material, which adopts the following technical solution:

[0007] A method for preparing a high-bending-resistance plate comprises the following steps:

[0008] S1: The main material, water glass, calcium sulfate, triethanolamine, retarder and solvent A are mixed uniformly to obtain a slurry;

[0009] S2: Mix the modified polyvinyl alcohol, modified starch and solvent B evenly, raise the temperature to 40-60°C, add the crosslinking agent, react for 20-40 minutes, adjust the pH to 8-10, then add the double coupling agent and mix evenly, continue to react for 15-25 minutes, cool down, and obtain the organic phase;

[0010] S3: After the slurry and the organic phase are evenly mixed, they are poured into a mold for vibration, vacuuming and pressing to obtain a preliminary formed sheet;

[0011] S4: Curing and cutting the preliminarily formed sheet to obtain a sheet with high bending resistance;

[0012] The main materials include slag and fly ash;

[0013] The mass ratio of the slag, fly ash, water glass, calcium sulfate, triethanolamine, retarder, solvent A, modified polyvinyl alcohol, modified starch, crosslinking agent, double coupling agent and solvent B is (65-75): (25-35): (8-15): (1.5-2.5): (0.2-0.4): (0.2-0.5): (40-60): (8-10): (3-5): (0.06-0.22): (0.5-2): (20-30);

[0014] The modulus of the water glass is 1.0-1.5.

[0015] The above technical solution first uses low-modulus water glass to create a strongly alkaline environment, gradually destroying the vitreous structure in the slag. This allows calcium and aluminum ions to dissolve more readily, and minerals such as silicates and aluminates in the fly ash depolymerize, releasing active silicon and aluminum components. These dissolved ions recombine in solution to form a dense CASH gel (calcium-aluminum-silicon hydrate gel), the primary phase of the geopolymer. This gel fills the pores within the slag and enhances the structural strength of the board. Simultaneously, the addition of calcium sulfate combines with aluminum ions in the solution to form ettringite, a source of early strength. These needle- or columnar crystals fill pores within the board during growth, increasing its early strength. Furthermore, calcium sulfate supplements calcium ion dissolution, promoting the formation of CASH gel and ettringite.

[0016] In addition, introducing sulfate ions into the system in advance to form ettringite can prevent sulfate ions in the later environment or sulfate ions in acid rain from corroding the board and reacting with calcium ions in large quantities to form ettringite, thereby causing volume expansion and destroying the board structure.

[0017] During the hydration process of slag and fly ash, triethanolamine can accelerate the dissolution of calcium ions, aluminum ions, and other ions, promote the formation of CASH gel, and improve early strength. At the same time, it can also improve the fluidity and dispersibility of the slurry to a certain extent, making the mixing of various components more uniform.

[0018] Secondly, during the preparation of the organic phase, the network structure formed by cross-linking modified polyvinyl alcohol and modified starch can increase the strength and stability of the organic phase. When the organic phase is mixed with the slurry, since the organic phase has formed a stable network structure, this stable network structure can remain relatively intact and is not easily destroyed. This helps the organic phase to be dispersed into the slurry in a uniform state, thereby obtaining a uniform and consistent mixed system, which helps to improve the uniformity of the overall performance of the board and avoid problems such as local strength differences. The compound use of the double coupling agent can form a strong chemical bond between the inorganic material (such as calcium aluminum silicate hydrate gel) and the organic phase through the different functional groups in its molecules in the subsequent process, significantly enhancing the interfacial bonding force between the inorganic and organic phases, achieving better synergy between the two phases, and further improving the overall performance of the board.

[0019] Finally, when the organic phase is mixed with the slurry, the inorganic phase formed by the calcium aluminum silicate hydrate gel and ettringite has a complex pore structure and surface morphology. The cross-linked network of the organic phase can penetrate into the pores and surface irregularities of the inorganic phase at the microscale, physically intercalating the two phases. This increases the contact area and mechanical interlocking between the two phases, thereby improving compatibility. Furthermore, the calcium aluminum silicate hydrate gel and ettringite contain reactive groups, such as hydroxyl groups, on their surfaces. Certain functional groups in the organic phase can react with these reactive groups to form chemical bonds. This chemical bonding strengthens the bond between the inorganic and organic phases and significantly enhances their compatibility. One end of the double coupling agent molecule can bind to the active sites on the surfaces of the calcium aluminum silicate hydrate gel and ettringite in the inorganic phase, forming a stable chemical bond. The other end can react with or physically entangle with functional groups or cross-linked networks in the organic phase, thus establishing a chemical bridge between the inorganic and organic phases, tightly connecting the two phases and enhancing compatibility.

[0020] When subjected to external forces, the two work together through good compatibility. The inorganic phase in the slurry bears the main load, and the organic phase disperses the stress through its own deformation to avoid cracks and damage in the inorganic phase. This synergistic complementarity of mechanical properties further promotes the macroscopic compatibility of the inorganic and organic phases, thereby improving the overall performance of the board.

[0021] Preferably, the solvent A and solvent B are both water.

[0022] Preferably, the double coupling agent includes a silane coupling agent KH560 and a titanate coupling agent NDZ-201, and the mass ratio of the silane coupling agent KH560 to the titanate coupling agent NDZ-201 is (1-2):1.

[0023] Preferably, the retarder is sodium gluconate.

[0024] Preferably, the cross-linking agent is glutaraldehyde.

[0025] Preferably, the preparation method of the modified starch comprises the following steps:

[0026] The starch and water are uniformly mixed, the pH is adjusted to 8-10, the temperature is raised to 35-50°C, octenyl succinic anhydride is added, the reaction is carried out for 120-180 minutes, the mixture is cooled, the pH is adjusted to 6-7, the solid-liquid separation is performed, the mixture is washed, and the mixture is dried to obtain a modified starch; the mass ratio of the starch to the octenyl succinic anhydride is 1:(0.15-0.25).

[0027] By adopting the above technical solution, starch modified with octenylsuccinic anhydride can significantly enhance the bonding properties of various components within the board and improve the board's water resistance. This is mainly because the hydrophobic groups of octenylsuccinic anhydride disrupt the starch's crystalline structure, increasing the flexibility of the molecular chain, making it denser and more elastic, while also improving interfacial adhesion and water resistance.

[0028] Preferably, the preparation method of the modified polyvinyl alcohol comprises the following steps:

[0029] Dissolve polyvinyl alcohol in water, adjust the pH to 8-10, then add boric acid and glycerol, heat to 60-80°C, react for 60-120 minutes, cool, adjust the pH to 6-7, separate the solid and liquid, wash, and dry to obtain modified polyvinyl alcohol;

[0030] The mass ratio of the polyvinyl alcohol, boric acid and glycerol is 1: (0.05-0.15): (0.1-0.2).

[0031] By adopting the above technical solution, under alkaline conditions, boric acid and polyvinyl alcohol can construct a three-dimensional network structure, significantly enhancing the bonding ability and internal cohesion; the glycerol hydroxyl groups form more hydrogen bonds with the active groups on the three-dimensional network structure, making the modified polyvinyl alcohol molecules more tightly bonded, which is also conducive to the close bonding between the modified polyvinyl alcohol and the inorganic particles, thereby improving the internal stress transfer efficiency of the board and further improving the flexural resistance of the board.

[0032] Furthermore, modified polyvinyl alcohol can be used in conjunction with a double coupling agent in the sheet material. The double coupling agent strengthens the interface between the inorganic and organic phases, while the modified polyvinyl alcohol enhances internal bonding and flexibility. This synergistic effect improves the flexural strength and overall performance of the sheet material.

[0033] Preferably, in step S2, after adjusting the pH, the step further includes adding maleic anhydride grafted polypropylene, and the amount of the maleic anhydride grafted polypropylene is 10% to 20% of the total mass of the modified polyvinyl alcohol and the modified starch.

[0034] By adopting the above technical solution, the maleic anhydride polar groups in maleic anhydride-grafted polypropylene can bind to polar groups in the organic phase (such as the hydroxyl groups of modified polyvinyl alcohol and modified starch) through hydrogen bonds, chemical bonds, and other interactions. At the same time, they can also chemically bond or physically adsorb to polar sites on the surface of the inorganic phase. Through the bridging effect of the polar groups, the bond between the organic and inorganic phases is tightened, and the interaction force at the interface is enhanced. When the sheet is subjected to stress, the bridging structure formed by the maleic anhydride-grafted polypropylene can effectively transfer stress from one phase to the other. Because the organic and inorganic phases are tightly connected by the maleic anhydride-grafted polypropylene, stress is evenly distributed between the two phases, avoiding stress concentration in a single phase or a localized area. This significantly improves the flexural strength and toughness of the sheet, enabling it to withstand greater loads in practical applications.

[0035] Preferably, in step S1, after adding the retarder, the step of adding nano-silicon dioxide is further included, and the amount of the nano-silicon dioxide is 2% to 4% of the mass of the main material.

[0036] Preferably, the nano-silicon dioxide is added in the form of a nano-silicon dioxide suspension, and the preparation method of the nano-silicon dioxide suspension comprises the following steps:

[0037] Mix the dispersant and water evenly, then add nano-silicon dioxide and mix evenly to obtain;

[0038] The amount of the dispersant used is 4% to 5% of the mass of the nano-silicon dioxide.

[0039] Preferably, the nano-silica is hydrophilic nano-silica.

[0040] By adopting the above technical solution, based on the polymer network formed by the initial cross-linking of modified polyvinyl alcohol and modified starch, the hydrophilic nano-silica can be relatively stably and evenly dispersed in the organic phase after being added. It not only effectively fills the gaps between the modified polyvinyl alcohol and modified starch molecules, but also forms hydrogen bonds and other interactions with the hydroxyl groups in the modified polyvinyl alcohol and modified starch molecules, thereby enhancing the internal structural stability of the organic phase and improving the strength and toughness of the organic phase. When the slurry is mixed with the organic phase, the hydrophilic nano-silica can act as a bridge to promote the bonding between the organic phase and the inorganic phase (slurry composed of slag, water glass, etc.). Its hydrophilicity enables it to better interact with the water molecules and inorganic components in the slurry, while also being tightly connected to the organic phase, improving the overall flexural strength of the board.

[0041] Preferably, in step S1, after adding water glass, the step of adding titanate coupling agent and styrene acrylic emulsion is further included; the mass ratio of the main material, titanate coupling agent and styrene acrylic emulsion is 100: (0.7-0.9): (4-6).

[0042] By adopting the above technical solution, the titanate coupling agent is added after the water glass activates the inorganic raw material. This increases the number of active sites on the inorganic raw material surface. In an alkaline environment, the titanate coupling agent can better chemically bond with the inorganic raw material surface. At the same time, the organic group on its other end also creates conditions for subsequent bonding with the styrene acrylic emulsion, helping to strengthen the interfacial bonding between the organic and inorganic phases. The subsequent addition of the styrene acrylic emulsion can also form a continuous network structure within the board, improving the board's flexibility, crack resistance, and water resistance, while also improving the working performance of the slurry.

[0043] In a second aspect, the present application also provides a high-flexural-resistance plate produced by the above-mentioned preparation method.

[0044] In summary, this application has the following beneficial effects:

[0045] 1. This application uses low-modulus water glass to provide a strong alkaline environment, and adds calcium sulfate to fully activate the calcium ions and aluminum ions in part of the slag and the silicates and aluminates in part of the fly ash to generate dense CASH gel and ettringite. By modifying the organic raw materials, more complex and strong chemical bonds and physical entanglements are formed between the organic phase and the inorganic phase, thereby more effectively enhancing the interfacial bonding force and improving the overall performance of the board.

[0046] 2. The addition of maleic anhydride-grafted polypropylene to the organic phase enhances the compatibility and interfacial bonding between the organic phase and the inorganic phase, further stabilizing the internal structure of the sheet. This allows for even stress distribution within the sheet, preventing crack propagation caused by localized stress concentration. This significantly improves the sheet's flexural strength and toughness, enabling it to withstand greater loads in practical applications.

[0047] 3. Hydrophilic nano-silica is preferred in this application. It not only effectively enhances the strength and stability of the organic phase, but also acts as a bridge between the organic and inorganic phases (slurries composed of slag, water glass, etc.) when the slurry is mixed with the organic phase. This enhances the performance of the organic phase and the interfacial bonding between the organic and inorganic phases, significantly improving the mechanical properties of the board. Furthermore, the tight structure it forms with the organic and inorganic phases prevents water intrusion. By filling pores and optimizing the interfacial structure, nano-silica reduces the water absorption rate of the board, improving its water resistance and dimensional stability. DETAILED DESCRIPTION

[0048] The present application is further described in detail below with reference to the embodiments.

[0049] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0050] Polyvinyl alcohol is a high-polymer polyvinyl alcohol with a molecular weight distribution of 170,000 to 220,000;

[0051] Hydrophilic nano-silica, particle size distribution 20~40nm;

[0052] The main components of slag are: CaO 44.6%, SiO233.2%, Al2O311.7%, MgO 5.3%;

[0053] The main components of fly ash are: SiO2 53.8%, Al2O3 25.2%, Fe2O3 7.5%, and CaO 4.9%.

[0054] Preparation Examples 1-3 Modified Starch

[0055] Preparation Example 1

[0056] 2 kg of corn starch was slowly added to a reactor containing 6 kg of clean water, the stirring device was turned on, and the mixture was stirred at a speed of 200 r / min for 30 minutes to obtain a starch suspension. The pH was adjusted to about 8-8.5 with 10% sodium hydroxide by mass, and then the temperature was raised to 35°C. Then, 0.3 kg of octenylsuccinic anhydride was slowly added, and the mixture was stirred and reacted for 180 minutes. The mixture was naturally cooled to room temperature, and the pH was adjusted to about 6-7 with 10% hydrochloric acid solution by mass. The mixture was allowed to stand and separate, the supernatant was removed, and the mixture was diluted and washed twice with clean water. The mixture was allowed to stand and separate each time. After removing the supernatant, the mixture was transferred to a vacuum drying oven and dried at 50°C to constant weight to obtain modified starch.

[0057] Preparation Example 2

[0058] 2 kg of corn starch was slowly added to a reactor containing 10 kg of clean water, the stirring device was turned on, and the mixture was stirred at a speed of 200 r / min for 30 minutes to obtain a starch suspension. The pH was adjusted to about 9.5-10 with 10% sodium hydroxide by mass, and then the temperature was raised to 50°C. Then, 0.5 kg of octenylsuccinic anhydride was slowly added, and the mixture was stirred and reacted for 120 minutes. The mixture was naturally cooled to room temperature, and the pH was adjusted to about 6-7 with 10% hydrochloric acid solution by mass. The mixture was allowed to stand and separate, the supernatant was removed, and the mixture was diluted and washed twice with clean water, and the mixture was allowed to stand and separate each time. After removing the supernatant, the mixture was transferred to a vacuum drying oven and dried at 50°C to constant weight to obtain modified starch.

[0059] Preparation Example 3

[0060] 2 kg of corn starch was slowly added to a reactor containing 8 kg of clean water, the stirring device was turned on, and the mixture was stirred at a speed of 200 r / min for 30 minutes to obtain a starch suspension. The pH was adjusted to about 8.5-9.5 with 10% sodium hydroxide by mass, and then the temperature was raised to 45°C. Then, 0.4 kg of octenylsuccinic anhydride was slowly added, and the mixture was stirred and reacted for 150 minutes. The mixture was naturally cooled to room temperature, and the pH was adjusted to about 6-7 with 10% hydrochloric acid solution by mass. The mixture was allowed to stand and separate, the supernatant was removed, and the mixture was diluted and washed twice with clean water, and the mixture was allowed to stand and separate each time. After removing the supernatant, the mixture was transferred to a vacuum drying oven and dried at 50°C to constant weight to obtain modified starch.

[0061] Preparation Examples 4-6 Modified Polyvinyl Alcohol

[0062] Preparation Example 4

[0063] 15 kg of clean water was added to the reactor, the stirring device was turned on, the stirring speed was set to 200 r / min, and then 3 kg of polyvinyl alcohol was slowly added, the temperature was slowly raised to 95 ° C, and this temperature was maintained and stirred for 60 minutes until the polyvinyl alcohol was completely dissolved to obtain a polyvinyl alcohol solution; after the polyvinyl alcohol solution was cooled to 40 ° C, a small amount of clean water was added to dilute it, the amount of clean water was 15% of the volume of the original polyvinyl alcohol solution, and then a 10% mass fraction of sodium hydroxide solution was used to adjust the pH to about 8~8.5, and then 0.15 kg of boric acid and 0.3 kg of glycerol were slowly added, the temperature was raised to 60 ° C, the reaction was carried out for 120 minutes, and it was naturally cooled to room temperature. A 10% mass fraction of hydrochloric acid solution was used to adjust the pH to about 6~7, and ethanol was slowly added to the reaction solution while stirring until no more precipitate was precipitated. Filter, rinse with anhydrous ethanol twice, and then transfer to a vacuum drying oven at 60 ° C to dry to constant weight to obtain modified polyvinyl alcohol.

[0064] Preparation Example 5

[0065] 24 kg of clean water was added to the reactor, the stirring device was turned on, the stirring speed was set to 200 r / min, and then 3 kg of polyvinyl alcohol was slowly added, the temperature was slowly raised to 95 ° C, and this temperature was maintained and stirred for 60 minutes until the polyvinyl alcohol was completely dissolved to obtain a polyvinyl alcohol solution; after the polyvinyl alcohol solution was cooled to 40 ° C, the pH was adjusted to about 9.5-10 with a 10% mass fraction sodium hydroxide solution, and then 0.45 kg of boric acid and 0.6 kg of glycerol were slowly added, the temperature was raised to 80 ° C, the reaction was carried out for 60 minutes, and the reaction was naturally cooled to room temperature. The pH was adjusted to about 6-7 with a 10% mass fraction hydrochloric acid solution, and ethanol was slowly added to the reaction solution while stirring until no more precipitate was precipitated. The reaction solution was filtered, rinsed with anhydrous ethanol twice, and then transferred to a vacuum drying oven and dried to constant weight at 60 ° C to obtain modified polyvinyl alcohol.

[0066] Preparation Example 6

[0067] 21 kg of clean water was added to the reactor, the stirring device was turned on, the stirring speed was set to 200 r / min, and then 3 kg of polyvinyl alcohol was slowly added, the temperature was slowly raised to 95 ° C, and this temperature was maintained and stirred for 60 minutes until the polyvinyl alcohol was completely dissolved to obtain a polyvinyl alcohol solution; after the polyvinyl alcohol solution was cooled to 40 ° C, the pH was adjusted to about 8.5~9.5 with a 10% mass fraction of sodium hydroxide solution, and then 0.3 kg of boric acid and 0.5 kg of glycerol were slowly added, the temperature was raised to 70 ° C, the reaction was carried out for 90 minutes, and it was naturally cooled to room temperature. The pH was adjusted to about 6~7 with a 10% mass fraction of hydrochloric acid solution, and ethanol was slowly added to the reaction solution while stirring until no more precipitation was precipitated. Filter, rinse with anhydrous ethanol twice, and then transfer to a vacuum drying oven and dry at 60 ° C to constant weight to obtain modified polyvinyl alcohol.

[0068] Example 1

[0069] This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps:

[0070] S1: 6.5 kg of slag and 3.5 kg of fly ash were added to a container, and the stirring device was turned on. The mixture was stirred at 150 r / min for 15 minutes. Then, 0.8 kg of water glass was slowly added and the stirring was continued for 25 minutes. Then, 0.15 kg of calcium sulfate, 0.02 kg of triethanolamine, 0.02 kg of sodium gluconate and 4 kg of water were added in sequence and stirred for 40 minutes to obtain a slurry.

[0071] S2: 0.8 kg of modified polyvinyl alcohol, 0.3 kg of modified starch and 2 kg of water were added to the reactor, the stirring device was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 40°C, and 6 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the mixture was reacted for 40 minutes, and the pH was adjusted to between 8 and 8.5 with 10% sodium hydroxide by mass. Then, 25 g of silane coupling agent KH560 and 25 g of titanate coupling agent NDZ-201 were added and stirred for 10 minutes. The temperature was maintained at 40°C, the reaction was continued for 25 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase;

[0072] S3: Add the organic phase to the slurry three times. After each addition, stir at a speed of 150r / min for 10 minutes. The amount of organic phase added each time is the same. Stir and mix evenly. Then pour it into a pre-prepared mold. Place the mold on a vibration table. After vibrating for 10 minutes, vacuum it for 10 minutes. Then use a press to press the material in the mold. First, press it at a pressure of 5MPa for 5 minutes, then gradually increase the pressure by 5MPa every 3 minutes until the pressure reaches 20MPa. Then press it for 5 minutes to obtain a preliminary formed plate.

[0073] S4: The preliminarily formed sheet is removed from the mold and placed in a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained above 90%. The curing time is 28 days. After the curing is completed, the sheet is cut into the required size and shape to obtain a high-flexural-resistance sheet.

[0074] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve;

[0075] The modulus of water glass is 1.5;

[0076] The modified starch comes from Preparation Example 1, and the modified polyvinyl alcohol comes from Preparation Example 4.

[0077] Example 2

[0078] This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps:

[0079] S1: 7.5 kg of slag and 2.5 kg of fly ash were added to a container, and the stirring device was turned on. The mixture was stirred at 150 r / min for 15 minutes. Then, 1.5 kg of water glass was slowly added and the stirring was continued for 35 minutes. Then, 0.25 kg of calcium sulfate, 0.04 kg of triethanolamine, 0.05 kg of sodium gluconate and 6 kg of water were added in sequence and stirred for 50 minutes to obtain a slurry.

[0080] S2: 1 kg of modified polyvinyl alcohol, 0.5 kg of modified starch and 3 kg of water were added to the reactor, the stirring device was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 60°C, and 22 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the mixture was reacted for 20 minutes, and the pH was adjusted to between 8.5 and 9.5 with 10% sodium hydroxide by mass. Then, 133 g of silane coupling agent KH560 and 67 g of titanate coupling agent NDZ-201 were added and stirred for 10 minutes. The temperature was maintained at 60°C, the reaction was continued for 15 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase;

[0081] S3: Add the organic phase to the slurry three times. After each addition, stir at a speed of 150r / min for 10 minutes. The amount of organic phase added each time is the same. Stir and mix evenly. Then pour it into a pre-prepared mold. Place the mold on a vibration table. After vibrating for 10 minutes, vacuum it for 10 minutes. Then use a press to press the material in the mold. First, press it at a pressure of 5MPa for 10 minutes, then gradually increase the pressure by 5MPa every 3 minutes until the pressure reaches 20MPa. Then press it for 10 minutes to obtain a preliminary formed plate.

[0082] S4: The preliminarily formed sheet is removed from the mold and placed in a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained above 90%. The curing time is 28 days. After the curing is completed, the sheet is cut into the required size and shape to obtain a high-flexural-resistance sheet.

[0083] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve;

[0084] The modulus of water glass is 1.0;

[0085] The modified starch comes from Preparation Example 2, and the modified polyvinyl alcohol comes from Preparation Example 5.

[0086] Example 3

[0087] This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps:

[0088] S1: 7 kg of slag and 3 kg of fly ash were added to a container, and the stirring device was turned on. The mixture was stirred at 150 r / min for 15 minutes. Then, 1.2 kg of water glass was slowly added and the stirring was continued for 30 minutes. Then, 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and 5 kg of water were added in sequence and the mixture was stirred for 40 minutes to obtain a slurry.

[0089] S2: 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of water were added to the reactor, the stirring device was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 50°C, and 13 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the mixture was reacted for 30 minutes, and the pH was adjusted to between 9.5 and 10 with 10% sodium hydroxide by mass. Then, 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201 were added and stirred for 10 minutes. The temperature was maintained at 50°C, the reaction was continued for 20 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase;

[0090] S3: Add the organic phase to the slurry three times. After each addition, stir at a speed of 150r / min for 10 minutes. The amount of organic phase added each time is the same. Stir and mix evenly. Then pour it into a pre-prepared mold. Place the mold on a vibration table. After vibrating for 10 minutes, vacuum it for 10 minutes. Then use a press to press the material in the mold. First, press it at a pressure of 5MPa for 8 minutes, then gradually increase the pressure by 5MPa every 3 minutes until the pressure reaches 20MPa. Then press it for another 8 minutes to obtain a preliminary formed plate.

[0091] S4: The preliminarily formed sheet is removed from the mold and placed in a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained above 90%. The curing time is 28 days. After the curing is completed, the sheet is cut into the required size and shape to obtain a high-flexural-resistance sheet.

[0092] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve;

[0093] The modulus of water glass is 1.2;

[0094] The modified starch is from Preparation Example 3, and the modified polyvinyl alcohol is from Preparation Example 6.

[0095] Example 4

[0096] The difference between this embodiment and embodiment 3 is that:

[0097] S2: 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of water were added to the reactor, the stirring device was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 50°C, and 13 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the reaction was carried out for 30 minutes. The pH was adjusted to between 9.5 and 10 with a mass fraction of 10% sodium hydroxide, and 0.13 kg of maleic anhydride grafted polypropylene was added. The mixture was stirred and mixed for 15 minutes. Then, 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201 were added and stirred and mixed for 10 minutes. The temperature was maintained at 50°C, the reaction was continued for 20 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase.

[0098] Other details are the same as in Example 3.

[0099] Example 5

[0100] The difference between this embodiment and embodiment 4 is that:

[0101] S2: 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of water were added to the reactor, the stirring device was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 50°C, and 13 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the reaction was carried out for 30 minutes. The pH was adjusted to between 9.5 and 10 with a mass fraction of 10% sodium hydroxide. 0.2 kg of maleic anhydride grafted polypropylene was added and stirred for 15 minutes. Then, 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201 were added and stirred for 10 minutes. The temperature was maintained at 50°C, the reaction was continued for 20 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase.

[0102] Other details are the same as in Example 4.

[0103] Example 6

[0104] The difference between this embodiment and embodiment 5 is that:

[0105] S1: 7 kg of slag and 3 kg of fly ash were added to a container, and a stirring device was turned on. The mixture was stirred at 150 r / min for 15 min, and then 1.2 kg of water glass was slowly added. The mixture was stirred for 30 min, and then 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and a nano-silica suspension were added in sequence. The mixture was stirred for 30 min, and then 5 kg of clean water was added. The mixture was stirred for 40 min to obtain a slurry.

[0106] S2: 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of water were added to the reactor, the stirring equipment was turned on, and the mixture was stirred at a speed of 150 r / min. At the same time, the reactor was heated to 50°C, and 13 g of glutaraldehyde was slowly added dropwise. After the addition was completed, the reaction was carried out for 30 minutes. The pH was adjusted to between 9.5 and 10 with 10% sodium hydroxide by mass, and 0.26 kg of maleic anhydride grafted polypropylene was added. The mixture was stirred and mixed for 15 minutes. Then, 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201 were added and stirred and mixed for 10 minutes. The temperature was maintained at 50°C, the reaction was continued for 20 minutes, and the mixture was naturally cooled to room temperature to obtain an organic phase.

[0107] The nano-silica suspension comprises 0.2 kg of hydrophilic nano-silica, 8 g of sodium lignin sulfonate and 400 g of water. The preparation method of the nano-silica suspension comprises the following steps:

[0108] 8 g of sodium lignin sulfonate and 400 g of water were stirred and mixed evenly, and then 0.2 kg of hydrophilic nano-silica was added, and the mixture was stirred and mixed at 1200 r / min for 20 min to obtain the product.

[0109] Other details are the same as in Example 5.

[0110] Example 7

[0111] The difference between this embodiment and embodiment 6 is that:

[0112] S1: 7 kg of slag and 3 kg of fly ash were added to a container, and a stirring device was turned on. The mixture was stirred at 150 r / min for 15 min, and then 1.2 kg of water glass was slowly added. The mixture was stirred for 30 min, and then 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and a nano-silica suspension were added in sequence. The mixture was stirred for 30 min, and then 5 kg of clean water was added. The mixture was stirred for 40 min to obtain a slurry.

[0113] The nano-silica suspension comprises 0.4 kg of hydrophilic nano-silica, 20 g of sodium lignin sulfonate and 700 g of water. The preparation method of the nano-silica suspension comprises the following steps:

[0114] 20 g of sodium lignin sulfonate and 700 g of water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silica was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0115] Other details are the same as in Example 6.

[0116] Example 8

[0117] The difference between this embodiment and embodiment 7 is that:

[0118] S1: 7 kg of slag and 3 kg of fly ash were added to a container, and a stirring device was turned on. The mixture was stirred at 150 r / min for 15 min, and then 1.2 kg of water glass was slowly added. The mixture was stirred for 30 min, and then 0.07 kg of titanate coupling agent NDZ-201 was added. The mixture was stirred for 20 min, and then 0.4 kg of styrene acrylic emulsion was added. The mixture was stirred for 30 min, and then 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and nano-silica suspension were added in sequence. The mixture was stirred for 30 min, and then 5 kg of clean water was added. The mixture was stirred for 40 min to obtain a slurry.

[0119] The nano-silica suspension comprises 0.4 kg of hydrophilic nano-silica, 20 g of sodium lignin sulfonate and 700 g of water. The preparation method of the nano-silica suspension comprises the following steps:

[0120] 20 g of sodium lignin sulfonate and 700 g of water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silica was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0121] Other details are the same as in Example 7.

[0122] Example 9

[0123] The difference between this embodiment and embodiment 8 is that:

[0124] S1: 7 kg of slag and 3 kg of fly ash were added to a container, and a stirring device was turned on. The mixture was stirred at 150 r / min for 15 min, and then 1.2 kg of water glass was slowly added. The mixture was stirred for 30 min, and then 0.09 kg of titanate coupling agent NDZ-201 was added. The mixture was stirred for 20 min, and then 0.6 kg of styrene acrylic emulsion was added. The mixture was stirred for 30 min, and then 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and nano-silica suspension were added in sequence. The mixture was stirred for 30 min, and then 5 kg of clean water was added. The mixture was stirred for 40 min to obtain a slurry.

[0125] The nano-silica suspension comprises 0.4 kg of hydrophilic nano-silica, 20 g of sodium lignin sulfonate and 700 g of water. The preparation method of the nano-silica suspension comprises the following steps:

[0126] 20 g of sodium lignin sulfonate and 700 g of water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silica was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0127] Other details are the same as in Example 8.

[0128] Comparative Example 1

[0129] The difference between this comparative example and Example 1 is:

[0130] No calcium sulfate was added in step S1.

[0131] Other details are the same as in Example 1.

[0132] Comparative Example 2

[0133] The difference between this comparative example and Example 1 is:

[0134] S2: Add 0.8 kg of modified polyvinyl alcohol, 0.3 kg of modified starch and 2 kg of clean water into the reactor, turn on the stirring equipment, stir at a speed of 150 r / min, and at the same time, heat the reactor to 40 ° C, react for 40 minutes, use 10% sodium hydroxide with a mass fraction to adjust the pH to between 8 and 8.5, then add 25 g of silane coupling agent KH560 and 25 g of titanate coupling agent NDZ-201, stir and mix for 10 minutes, maintain the temperature at 40 ° C, continue to react for 25 minutes, and naturally cool to room temperature to obtain an organic phase;

[0135] Other details are the same as in Example 1.

[0136] Comparative Example 3

[0137] The difference between this comparative example and Example 1 is:

[0138] Polyvinyl alcohol is not modified.

[0139] Other details are the same as in Example 1.

[0140] Comparative Example 4

[0141] The difference between this comparative example and Example 1 is:

[0142] The starch is not modified.

[0143] Other details are the same as in Example 1.

[0144] Performance testing

[0145] The flexural strength, compressive strength, impact resistance and water absorption of the high flexural resistance plates prepared in Examples 1 to 9 and Comparative Examples 1 to 4 were tested according to the following testing standards. The test results are shown in Table 1.

[0146] The reference standard for flexural strength and compressive strength is GB / T 50081-2019; the reference standard for impact resistance is JC / T 2672-2022; and the reference standard for water absorption is GB / T 50082-2024.

[0147] Table 1 Performance test data of high flexural resistance plates prepared in Examples 1 to 9 and Comparative Examples 1 to 4

[0148]

[0149] Analysis of the performance test data in Table 1 shows that:

[0150] It can be seen from Example 1 and Comparative Example 1 that the addition of calcium sulfate promotes the hydration reaction and the formation of CASH gel and ettringite, filling the pores inside the board, thereby significantly enhancing the density inside the board and effectively improving the flexural and compressive strengths.

[0151] It can be seen from Example 1 and Comparative Example 2 that the addition of glutaraldehyde promotes the cross-linking reaction of the organic phase, enhances the strength and stability of the organic phase, and improves the overall performance of the board after compounding with the slurry, enhances various strength indicators, and reduces water absorption.

[0152] It can be seen from Example 1 and Comparative Examples 3-4 that: by modifying polyvinyl alcohol and starch, the modified starch is more evenly dispersed in the slurry and the contact area with other components is increased; the modified polyvinyl alcohol forms a tighter network structure with the organic phase and the slurry, thereby enhancing the synergistic effect with other components and comprehensively improving the comprehensive performance of the board in terms of strength, water resistance, etc.

[0153] It can be seen from Examples 1 to 3 that by reasonably controlling the amount of raw materials and reaction conditions, the prepared slag-based plates perform well in mechanical properties such as flexural strength and compressive strength, and indicators such as water absorption are also controlled at a low level. The overall performance of the prepared plates is relatively stable and excellent.

[0154] Examples 3-5 demonstrate that the introduction of maleic anhydride-grafted polypropylene enhances the stability of the organic phase, while also forming more chemical bonds and physical entanglements with the inorganic phase, improving interfacial bonding. This also results in a denser interior and fewer internal pores. These excellent structural stability and interfacial bonding enhance the board's load-bearing capacity, impart toughness, effectively improve impact resistance, and reduce water absorption.

[0155] Examples 5-9 demonstrate that with the sequential addition of hydrophilic nano-silica, titanate coupling agent, and styrene-acrylic emulsion in appropriately increasing amounts, the performance of the panels in Examples 5-9 shows a gradual improvement. The continuous increase in flexural and compressive strengths demonstrates the increasing load-bearing capacity of the panels; the significant improvement in impact resistance indicates the panels' increasing resistance to impact; and the continuous decrease in water absorption demonstrates the increasing waterproofness and durability of the panels. This demonstrates that the performance of slag-based panels can be effectively optimized through the rational combination and regulation of these additives.

[0156] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing a high-flexural-resistance plate, characterized in that: The steps include: S1: The main material, water glass, calcium sulfate, triethanolamine, retarder and solvent A are mixed uniformly to obtain a slurry; S2: Mix the modified polyvinyl alcohol, modified starch, and solvent B evenly, raise the temperature to 40-60°C, add the crosslinking agent, react for 20-40 minutes, adjust the pH to 8-10, then add the double coupling agent and mix evenly, continue to react for 15-25 minutes, and cool to obtain an organic phase; S3: After the slurry and the organic phase are evenly mixed, they are poured into a mold for vibration, vacuuming and pressing to obtain a preliminary formed sheet; S4: Curing and cutting the preliminarily formed sheet to obtain a sheet with high bending resistance; The main materials include slag and fly ash; The mass ratio of the slag, fly ash, water glass, calcium sulfate, triethanolamine, retarder, solvent A, modified polyvinyl alcohol, modified starch, crosslinking agent, double coupling agent and solvent B is (65-75): (25-35): (8-15): (1.5-2.5): (0.2-0.4): (0.2-0.5): (40-60): (8-10): (3-5): (0.06-0.22): (0.5-2): (20-30); The modulus of the water glass is 1.0 to 1.5; The preparation method of the modified polyvinyl alcohol comprises the following steps: Dissolve polyvinyl alcohol in water, adjust the pH to 8-10, then add boric acid and glycerol, raise the temperature to 60-80°C, react for 60-120 minutes, cool, adjust the pH to 6-7, separate the solid and liquid, wash, and dry to obtain modified polyvinyl alcohol.

2. The method for preparing a high-flexural-resistance sheet material according to claim 1, characterized in that: The double coupling agent includes a silane coupling agent KH560 and a titanate coupling agent NDZ-201, and the mass ratio of the silane coupling agent KH560 to the titanate coupling agent NDZ-201 is (1~2):

1.

3. The method for preparing a high-flexural-resistance sheet material according to claim 2, wherein: The retarder is sodium gluconate.

4. The method for preparing a high-flexural-resistance sheet material according to claim 3, characterized in that: The cross-linking agent is glutaraldehyde.

5. The method for preparing a high-flexural-resistance sheet material according to claim 1, wherein: The preparation method of the modified starch comprises the following steps: The starch and water are mixed evenly, the pH is adjusted to 8-10, the temperature is raised to 35-50°C, octenyl succinic anhydride is added, the reaction is carried out for 120-180 minutes, the mixture is cooled, the pH is adjusted to 6-7, the solid-liquid separation is carried out, the mixture is washed, and the mixture is dried to obtain the modified starch; The mass ratio of the starch to octenylsuccinic anhydride is 1:(0.15-0.25).

6. The method for preparing a high-flexural-resistance sheet material according to claim 1, wherein: The mass ratio of the polyvinyl alcohol, boric acid and glycerol is 1: (0.05-0.15): (0.1-0.2).

7. The method for preparing a high-flexural-resistance sheet material according to claim 1, wherein: In step S2, after adjusting the pH, the step of adding maleic anhydride grafted polypropylene is further included, wherein the amount of maleic anhydride grafted polypropylene is 10% to 20% of the total mass of the modified polyvinyl alcohol and the modified starch.

8. The method for preparing a high-flexural-resistance sheet material according to claim 1, wherein: In step S1, after adding the retarder, the step of adding nano-silicon dioxide is further included, and the amount of the nano-silicon dioxide is 2% to 4% of the mass of the main material.

9. The method for preparing a high-flexural-resistance sheet material according to claim 1, wherein: In step S1, after adding water glass, a step of adding titanate coupling agent and styrene acrylic emulsion is further included; the mass ratio of the main material, titanate coupling agent and styrene acrylic emulsion is 100: (0.7-0.9): (4-6).

10. A high flexural resistance sheet material produced by the method for producing a high flexural resistance sheet material according to any one of claims 1 to 9.

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