High-fracture-resistance plate and preparation method thereof

Abstract

The invention relates to the technical field of building materials, and particularly discloses a high-fracture-resistance plate and a preparation method thereof. The preparation method of the high-fracture-resistance plate comprises the following steps: S1, uniformly mixing a main material, water glass, calcium sulfate, triethanolamine, a retarder and a solvent A to obtain slurry; s2, uniformly mixing modified polyvinyl alcohol, modified starch and a solvent B, heating to 40-60 DEG C, adding a cross-linking agent, reacting for 20-40 minutes, adjusting the pH value to 8-10, then adding a double-coupling agent, uniformly mixing, continuously reacting for 15-25 minutes, and cooling to obtain an organic phase; s3, uniformly mixing the slurry and an organic phase, pouring the mixture into a mold, and performing vibration, vacuum pumping and compression molding to obtain a preliminarily molded plate; s4, curing and cutting the primarily formed plate to obtain a high-fracture-resistance plate; the high-fracture-resistance plate prepared by the invention has relatively high fracture resistance and compressive strength and relatively low water absorption rate.

Description

Technical Field

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

[0002] High flexural resistance boards, 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 boards within a certain limit by adding materials such as mineral fibers or reinforcing fibers or organic polymers to the substrate. However, these methods still have many problems in practical applications. For example, the dispersion of mineral fibers in the substrate is poor, which can easily lead to local stress concentration; the orientation of reinforcing fibers is unreasonable, making it difficult to fully exert their reinforcement effect; the compatibility between organic polymers and inorganic materials is poor, which can easily form weak areas at the interface, thereby weakening the overall performance of the board.

[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, 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 a small experimental 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 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] In the patent application, only sodium polyacrylate and silane coupling agent solution are directly mixed with the slurry. Due to the lack of effective regulation of the hydrolysis conditions of the silane coupling agent, the silane coupling agent is not fully hydrolyzed, and cannot form a strong connection with the slag surface, and cannot effectively improve the interface performance. The mechanical properties of the prepared plate are limited. In addition, although sodium polyacrylate and silane coupling agent can improve the interface performance to a certain extent, there are problems such as uneven dispersion and insufficient reaction with other components, which will lead 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-bending-resistance sheet material, using the following technical solution: A method for preparing a high-bending-resistance plate comprises the following steps: 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 cross-linking 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 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 initially 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 1.0-1.5.

[0007] By adopting the above technical solution, firstly, a strong alkaline environment is provided by using low modulus water glass, and the glass structure in the slag is gradually destroyed, which makes the calcium ions and aluminum ions therein have more opportunities to dissolve, and the silicate, aluminate and other minerals in the fly ash will also depolymerize, releasing the active components of silicon and aluminum. These dissolved ions are recombined in the solution to form a dense CASH gel (calcium aluminum silicon hydrate gel), which is the main phase of the geopolymer, which can fill the pores inside the slag and enhance the structural strength of the board. At the same time, after adding calcium sulfate, the sulfate radical combines with the aluminum ions in the solution to form ettringite, which is the source of early strength, and the ettringite crystals are needle-shaped or columnar, which can fill the pores during the growth process inside the board and increase the early strength of the board. In addition, calcium sulfate can also supplement the lack of calcium ion dissolution and promote the formation of CASH gel and ettringite.

[0008] 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.

[0009] In the hydration process of slag and fly ash, triethanolamine can accelerate the dissolution of calcium ions, aluminum ions and other ions, promote the formation rate of CASH gel, and improve the 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.

[0010] Secondly, in the process of preparing 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, which 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 phase and the organic phase, achieving better synergy between the two phases, and further improving the overall performance of the board.

[0011] Finally, when the organic phase is mixed with the slurry, on the one hand, the inorganic phase formed by calcium aluminum silicate hydrate gel and calcium sulfonate has a complex pore structure and surface morphology, and the cross-linked network of the organic phase can penetrate into the pores and surface bumps of the inorganic phase at a microscopic scale, achieving physical mutual embedding, increasing the contact area and mechanical bite between the two phases, thereby improving compatibility. On the other hand, there are active groups such as hydroxyl groups on the surface of calcium aluminum silicate hydrate gel and calcium sulfonate, and some functional groups in the organic phase can react chemically with these active groups to form chemical bonds. This chemical bonding makes the bond between the inorganic phase and the organic phase more firm, greatly improving the compatibility of the two phases. One end of the double coupling agent molecule can bind to the active sites on the surface of calcium aluminum silicate hydrate gel and calcium sulfonate in the inorganic phase to form a stable chemical bond; the other end can react or physically entangle with the functional groups or cross-linked network in the organic phase, thereby establishing a chemical bridge between the inorganic phase and the organic phase, tightly connecting the two phases together and enhancing compatibility.

[0012] When subjected to external force, 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.

[0013] Preferably, the solvent A and the solvent B are both water.

[0014] Preferably, the dual 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.

[0015] Preferably, the retarder is sodium gluconate.

[0016] Preferably, the cross-linking agent is glutaraldehyde.

[0017] Preferably, the method for preparing the modified starch comprises the following steps: The starch and water are mixed uniformly, the pH is adjusted to 8-10, the temperature is raised to 35-50°C, octenyl succinic anhydride is added, the reaction is performed 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 the modified starch; the mass ratio of the starch to the octenyl succinic anhydride is 1:(0.15-0.25).

[0018] By adopting the above technical solution, the starch modified by octenyl succinic anhydride can significantly enhance the bonding performance of the components inside the board and improve the waterproof performance of the board. This is mainly because the hydrophobic group of octenyl succinic anhydride destroys the crystalline structure of starch, increases the flexibility of the molecular chain, makes the film denser and more elastic, and improves the interface bonding and waterproofness.

[0019] Preferably, 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, 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; The mass ratio of the polyvinyl alcohol, boric acid and glycerol is 1:(0.05-0.15):(0.1-0.2).

[0020] By adopting the above technical scheme, under alkaline conditions, boric acid and polyvinyl alcohol can construct a three-dimensional network structure, which significantly enhances 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 then improving the board's flexural resistance.

[0021] In addition, modified polyvinyl alcohol can work together with double coupling agent in the board. Double coupling agent strengthens the interface bonding between inorganic phase and organic phase, while modified polyvinyl alcohol enhances internal bonding and flexibility. Through the mutual cooperation of the two, the flexural strength and comprehensive performance of the board are improved.

[0022] Preferably, in step S2, after adjusting the pH, the step of adding maleic anhydride grafted polypropylene is further included, 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.

[0023] By adopting the above technical solution, the polar groups of maleic anhydride in maleic anhydride grafted polypropylene can be combined with polar groups in the organic phase (such as hydroxyl groups of modified polyvinyl alcohol and modified starch) through hydrogen bonds, chemical bonds and other interactions; at the same time, it can also chemically bond or physically adsorb with polar sites on the surface of the inorganic phase. Through the bridging effect of the polar groups, the organic phase and the inorganic phase are more closely bonded, and the interaction force at the interface is enhanced. When the plate is subjected to stress, the bridging structure formed by maleic anhydride grafted polypropylene can effectively transfer stress from one phase to another. Since the organic phase and the inorganic phase are tightly connected through maleic anhydride grafted polypropylene, the stress can be evenly distributed between the two phases, avoiding the concentration of stress in a certain phase or a local area, thereby greatly improving the flexural strength and toughness of the plate, so that the plate can withstand greater loads in practical applications.

[0024] 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.

[0025] 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: Mix the dispersant and water evenly, then add nano silicon dioxide and mix evenly to obtain; The dosage of the dispersant is 4% to 5% of the mass of the nano-silicon dioxide.

[0026] Preferably, the nano-silica is hydrophilic nano-silica.

[0027] By adopting the above technical scheme, based on the polymer network formed by the preliminary cross-linking of modified polyvinyl alcohol and modified starch, after the addition of hydrophilic nano-silica, it can be relatively stably and evenly dispersed in the organic phase, which can not only effectively fill the gaps between the modified polyvinyl alcohol and modified starch molecules, but also form 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 combination 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 being closely connected with the organic phase, thereby improving the overall flexural strength of the board.

[0028] Preferably, in step S1, after adding water glass, a step of adding a titanate coupling agent and a styrene acrylic emulsion is further included; the mass ratio of the main material, the titanate coupling agent and the styrene acrylic emulsion is 100:(0.7-0.9):(4-6).

[0029] By adopting the above technical solution, after water glass stimulates the activity of inorganic raw materials, titanate coupling agent is added. At this time, the active sites on the surface of inorganic raw materials increase. In an alkaline environment, titanate coupling agent can better chemically bond with the surface of inorganic raw materials. At the same time, the organic group at the other end also creates conditions for subsequent combination with styrene-acrylic emulsion, which helps to enhance the interfacial bonding force between organic phase and inorganic phase. The subsequent addition of styrene-acrylic emulsion can also form a continuous network structure inside the board, improve the flexibility, crack resistance and water resistance of the board, and improve the working performance of the slurry.

[0030] In a second aspect, the present application also provides a high-bending-resistance plate material produced by the above-mentioned preparation method.

[0031] In summary, this application has the following beneficial effects: 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 calcium aluminate. By modifying the organic raw materials, more complex and firm 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 comprehensive performance of the board.

[0032] 2. The application adds maleic anhydride grafted polypropylene to the organic phase, which can enhance the compatibility and interfacial bonding between the organic phase itself and the inorganic phase, making the internal structure of the plate more stable. This allows the stress to be evenly distributed inside the plate, avoiding crack propagation caused by local stress concentration, thereby greatly improving the flexural strength and toughness of the plate, allowing the plate to withstand greater loads in practical applications.

[0033] 3. In this application, hydrophilic nano-silica is preferably used, which not only effectively enhances the strength and stability of the organic phase, but also acts as a bridge between the organic phase and the inorganic phase (slurry composed of slag, water glass, etc.) when the slurry is mixed with the organic phase, enhancing the performance of the organic phase and the interfacial bonding force of the organic-inorganic phase, and significantly improving the mechanical properties of the board. In addition, the tight structure formed by it and the organic and inorganic phases can prevent the intrusion of water. By filling the pores and optimizing the interface structure, nano-silica reduces the water absorption rate of the board and improves the water resistance and dimensional stability of the board. DETAILED DESCRIPTION

[0034] The present application is further described in detail below with reference to embodiments.

[0035] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0036] Polyvinyl alcohol is a high-polymer polyvinyl alcohol with a molecular weight distribution of 170,000 to 220,000; Hydrophilic nano-silica, particle size distribution 20~40nm; The main components of slag are: CaO 44.6%, SiO233.2%, Al2O311.7%, MgO 5.3%; The main components of fly ash are: SiO2 53.8%, Al2O3 25.2%, Fe2O3 7.5%, and CaO 4.9%.

[0037] Preparation Examples 1-3 Modified Starch Preparation Example 1 2 kg of corn starch was slowly added into 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 min to obtain a starch suspension. The pH value was adjusted to about 8-8.5 with 10% sodium hydroxide by mass, and then the temperature was raised to 35°C, and then 0.3 kg of octenyl succinic anhydride was slowly added, and the mixture was stirred for 180 min. The mixture was naturally cooled to room temperature, and the pH value was adjusted to about 6-7 with 10% hydrochloric acid solution by mass, and the mixture was allowed to stand for stratification, the supernatant was removed, and clean water was added for dilution and washing twice, and the mixture was allowed to stand for stratification each time. After the supernatant was removed, the mixture was transferred to a vacuum drying oven and dried to constant weight at 50°C to obtain modified starch.

[0038] Preparation Example 2 2 kg of corn starch was slowly added into 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 min to obtain a starch suspension. The pH value was adjusted to about 9.5-10 with 10% sodium hydroxide by mass, and then the temperature was raised to 50°C, and then 0.5 kg of octenyl succinic anhydride was slowly added, and the mixture was stirred for 120 min. The mixture was naturally cooled to room temperature, and the pH value was adjusted to about 6-7 with 10% hydrochloric acid solution by mass, and the mixture was allowed to stand for stratification, the supernatant was removed, and clean water was added for dilution and washing twice, and the mixture was allowed to stand for stratification each time. After the supernatant was removed, the mixture was transferred to a vacuum drying oven and dried to constant weight at 50°C to obtain modified starch.

[0039] Preparation Example 3 2 kg of corn starch was slowly added into 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 min to obtain a starch suspension. The pH value was adjusted to about 8.5-9.5 with 10% sodium hydroxide by mass, and then the temperature was raised to 45°C, and then 0.4 kg of octenyl succinic anhydride was slowly added, and the mixture was stirred for 150 min. The mixture was naturally cooled to room temperature, and the pH value was adjusted to about 6-7 with 10% hydrochloric acid solution by mass, and the mixture was allowed to stand for stratification, the supernatant was removed, and the mixture was diluted and washed twice with clean water, and the mixture was allowed to stand for stratification each time. After the supernatant was removed, the mixture was transferred to a vacuum drying oven and dried to constant weight at 50°C to obtain modified starch.

[0040] Preparation Examples 4-6 Modified Polyvinyl Alcohol Preparation Example 4 15 kg of clean water was added to the reactor, and the stirring device was turned on, and the stirring speed was set to 200 r / min. Then 3 kg of polyvinyl alcohol was slowly added, and the temperature was slowly raised to 95 ° C. and kept stirring at this temperature for 60 minutes until the polyvinyl alcohol was completely dissolved to obtain a polyvinyl alcohol solution; when the polyvinyl alcohol solution was cooled to 40 ° C, a small amount of clean water was added to dilute it, and the amount of clean water was 15% of the volume of the original polyvinyl alcohol solution, and then a 10% mass fraction 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, and the reaction was carried out for 120 minutes, and the reaction was naturally cooled to room temperature. A 10% mass fraction 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 precipitation was precipitated, filtered, rinsed with anhydrous ethanol twice, and then transferred to a vacuum drying oven, dried at 60 ° C to constant weight to obtain modified polyvinyl alcohol.

[0041] Preparation Example 5 24 kg of clean water was added to the reactor, and the stirring device was turned on, and the stirring speed was set to 200 r / min. Then, 3 kg of polyvinyl alcohol was slowly added, and the temperature was slowly raised to 95°C, and this temperature was maintained for stirring 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 10% sodium hydroxide solution was used to adjust the pH to about 9.5-10, and then 0.45 kg of boric acid and 0.6 kg of glycerol were slowly added, the temperature was raised to 80°C, and the reaction was carried out for 60 minutes, and the reaction was naturally cooled to room temperature. A 10% 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 precipitation was precipitated, 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.

[0042] Preparation Example 6 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 for 60 minutes of stirring until the polyvinyl alcohol was completely dissolved to obtain a polyvinyl alcohol solution; the polyvinyl alcohol solution was cooled to 40°C, and then a 10% sodium hydroxide solution was used to adjust the pH to about 8.5-9.5, 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 the reaction was naturally cooled to room temperature. A 10% 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 precipitation was precipitated, filtered, rinsed twice with anhydrous ethanol, and then transferred to a vacuum drying oven at 60°C and dried to constant weight to obtain modified polyvinyl alcohol.

[0043] Example 1 This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps: S1: Add 6.5 kg of slag and 3.5 kg of fly ash into a container, turn on the stirring device, stir and mix at 150 r / min for 15 minutes, then slowly add 0.8 kg of water glass, continue to stir and mix for 25 minutes, then add 0.15 kg of calcium sulfate, 0.02 kg of triethanolamine, 0.02 kg of sodium gluconate and 4 kg of clean water in sequence, stir and mix for 40 minutes to obtain a slurry; 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 device, stir at a speed of 150 r / min, and at the same time, heat the reactor to 40°C, slowly drop 6 g of glutaraldehyde, react for 40 minutes after the addition is completed, adjust the pH to between 8 and 8.5 with 10% sodium hydroxide by mass, 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; 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 into a pre-prepared mold, place the mold on a vibration table, vibrate for 10 minutes, evacuate for 10 minutes, and then use a press to press the material in the mold. First, use a pressure of 5MPa for 5 minutes, then gradually increase the pressure, increase 5MPa every 3 minutes, until the pressure reaches 20MPa, and then press for 5 minutes to obtain a preliminary formed plate; S4: Take the preliminarily formed sheet out of the mold and put it into a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained at above 90%. The curing time is 28 days. After the curing is completed, cut it into the required size and shape to obtain a high flexural resistance sheet.

[0044] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve; The modulus of water glass is 1.5; The modified starch comes from Preparation Example 1, and the modified polyvinyl alcohol comes from Preparation Example 4.

[0045] Example 2 This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps: S1: 7.5 kg of slag and 2.5 kg of fly ash were added into a container, the stirring device was turned on, and the mixture was stirred at 150 r / min for 15 min, then 1.5 kg of water glass was slowly added, and the mixture was stirred for 35 min, and then 0.25 kg of calcium sulfate, 0.04 kg of triethanolamine, 0.05 kg of sodium gluconate and 6 kg of clean water were added in sequence, and the mixture was stirred for 50 min to obtain a slurry; S2: 1 kg of modified polyvinyl alcohol, 0.5 kg of modified starch and 3 kg of clean water were added to the reactor, and the stirring device was turned on. 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 min. The pH value was adjusted to between 8.5 and 9.5 with 10% sodium hydroxide by mass, and then 133 g of silane coupling agent KH560 and 67 g of titanate coupling agent NDZ-201 were added and stirred for 10 min. The temperature was maintained at 60°C, and the reaction was continued for 15 min. The mixture was naturally cooled to room temperature to obtain an organic phase. 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 into a pre-prepared mold, place the mold on a vibration table, vibrate for 10 minutes, evacuate for 10 minutes, and then use a press to press the material in the mold. First, use a pressure of 5MPa for 10 minutes, then gradually increase the pressure, increase 5MPa every 3 minutes, until the pressure reaches 20MPa, and then press for 10 minutes to obtain a preliminary formed plate; S4: Take the preliminarily formed sheet out of the mold and put it into a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained at above 90%. The curing time is 28 days. After the curing is completed, cut it into the required size and shape to obtain a high flexural resistance sheet.

[0046] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve; The modulus of water glass is 1.0; The modified starch comes from Preparation Example 2, and the modified polyvinyl alcohol comes from Preparation Example 5.

[0047] Example 3 This embodiment provides a method for preparing a high-bending-resistance plate, comprising the following steps: S1: 7 kg of slag and 3 kg of fly ash were added into a container, and a stirring device was turned on. The mixture was stirred and mixed at 150 r / min for 15 min. Then, 1.2 kg of water glass was slowly added. The mixture was stirred and mixed for 30 min. Then, 0.2 kg of calcium sulfate, 0.03 kg of triethanolamine, 0.04 kg of sodium gluconate and 5 kg of clean water were added in sequence. The mixture was stirred and mixed for 40 min to obtain a slurry. S2: Add 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of clean water into the reactor, turn on the stirring device, stir at a speed of 150 r / min, and at the same time, heat the reactor to 50°C, slowly drop 13 g of glutaraldehyde, react for 30 minutes after the addition is completed, adjust the pH to between 9.5 and 10 with 10% sodium hydroxide by mass, then add 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201, stir and mix for 10 minutes, maintain the temperature at 50°C, continue to react for 20 minutes, and naturally cool to room temperature to obtain an organic phase; 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 into a pre-prepared mold, place the mold on a vibration table, vibrate for 10 minutes, evacuate for 10 minutes, and then use a press to press the material in the mold. First, use a pressure of 5MPa for 8 minutes, then gradually increase the pressure, increase 5MPa every 3 minutes, until the pressure reaches 20MPa, and then press for 8 minutes to obtain a preliminary formed plate; S4: Take the preliminarily formed sheet out of the mold and put it into a curing room for curing. The temperature in the curing room is controlled at 20-25°C, and the relative humidity is maintained at above 90%. The curing time is 28 days. After the curing is completed, cut it into the required size and shape to obtain a high flexural resistance sheet.

[0048] Among them, slag and fly ash are ground by vertical mill before use and then passed through 325 mesh standard sieve; The modulus of water glass is 1.2; The modified starch comes from Preparation Example 3, and the modified polyvinyl alcohol comes from Preparation Example 6.

[0049] Example 4 The difference between this embodiment and embodiment 3 is that: S2: Add 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of clean water into the reactor, turn on the stirring device, stir at a speed of 150 r / min, and at the same time, heat the reactor to 50°C, slowly drop 13 g of glutaraldehyde, react for 30 minutes after the addition is completed, adjust the pH to between 9.5 and 10 with 10% sodium hydroxide by mass, add 0.13 kg of maleic anhydride grafted polypropylene, stir and mix for 15 minutes, then add 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201, stir and mix for 10 minutes, maintain the temperature at 50°C, continue to react for 20 minutes, and naturally cool to room temperature to obtain an organic phase; The rest is the same as in Example 3.

[0050] Example 5 The difference between this embodiment and embodiment 4 is that: S2: Add 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 kg of clean water into a reactor, turn on the stirring device, stir at a speed of 150 r / min, and at the same time, heat the reactor to 50°C, slowly drop 13 g of glutaraldehyde, react for 30 minutes after the addition is completed, adjust the pH to between 9.5 and 10 with 10% sodium hydroxide by mass, add 0.2 kg of maleic anhydride grafted polypropylene, stir and mix for 15 minutes, then add 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201, stir and mix for 10 minutes, maintain the temperature at 50°C, continue to react for 20 minutes, and naturally cool to room temperature to obtain an organic phase; The rest is the same as Example 4.

[0051] Example 6 The difference between this embodiment and embodiment 5 is that: S1: 7kg of slag and 3kg of fly ash are added to a container, a stirring device is turned on, and the mixture is stirred at 150r / min for 15min, then 1.2kg of water glass is slowly added, and the mixture is stirred for 30min, then 0.2kg of calcium sulfate, 0.03kg of triethanolamine, 0.04kg of sodium gluconate and a nano-silicon dioxide suspension are added in sequence, and the mixture is stirred for 30min, then 5kg of clean water is added, and the mixture is stirred for 40min to obtain a slurry; S2: Add 0.9 kg of modified polyvinyl alcohol, 0.4 kg of modified starch and 2.5 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 50°C, slowly drop 13 g of glutaraldehyde, react for 30 minutes after the addition is completed, adjust the pH to between 9.5 and 10 with 10% sodium hydroxide by mass, add 0.26 kg of maleic anhydride grafted polypropylene, stir and mix for 15 minutes, then add 90 g of silane coupling agent KH560 and 60 g of titanate coupling agent NDZ-201, stir and mix for 10 minutes, maintain the temperature at 50°C, continue to react for 20 minutes, and naturally cool to room temperature to obtain an organic phase; The nano-silicon dioxide suspension comprises 0.2 kg of hydrophilic nano-silicon dioxide, 8 g of sodium lignin sulfonate and 400 g of clean water. The preparation method of the nano-silicon dioxide suspension comprises the following steps: 8 g of sodium lignin sulfonate and 400 g of clean water were stirred and mixed evenly, and then 0.2 kg of hydrophilic nano-silicon dioxide was added, and the mixture was stirred and mixed at 1200 r / min for 20 min to obtain the product.

[0052] The rest is the same as Example 5.

[0053] Example 7 The difference between this embodiment and embodiment 6 is that: S1: 7kg of slag and 3kg of fly ash are added to a container, a stirring device is turned on, and the mixture is stirred and mixed at 150r / min for 15min, then 1.2kg of water glass is slowly added, and the mixture is stirred and mixed for 30min, then 0.2kg of calcium sulfate, 0.03kg of triethanolamine, 0.04kg of sodium gluconate and nano-silicon dioxide suspension are added in sequence, and the mixture is stirred and mixed for 30min, then 5kg of clean water is added, and the mixture is stirred and mixed for 40min to obtain a slurry; The nano-silicon dioxide suspension comprises 0.4 kg of hydrophilic nano-silicon dioxide, 20 g of sodium lignin sulfonate and 700 g of clean water. The preparation method of the nano-silicon dioxide suspension comprises the following steps: 20 g of sodium lignin sulfonate and 700 g of clean water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silicon dioxide was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0054] The rest is the same as Example 6.

[0055] Example 8 The difference between this embodiment and embodiment 7 is that: S1: 7kg of slag and 3kg of fly ash are added to a container, a stirring device is turned on, and stirring and mixing is carried out at 150r / min for 15min, then 1.2kg of water glass is slowly added, and stirring and mixing is continued for 30min, then 0.07kg of titanate coupling agent NDZ-201 is added, and stirring and mixing is continued for 20min, then 0.4kg of styrene acrylic emulsion is added, and stirring and mixing is continued for 30min, then 0.2kg of calcium sulfate, 0.03kg of triethanolamine, 0.04kg of sodium gluconate and nano-silicon dioxide suspension are added in sequence, and stirring and mixing is continued for 30min, then 5kg of clean water is added, and stirring and mixing is continued for 40min to obtain a slurry; The nano-silicon dioxide suspension comprises 0.4 kg of hydrophilic nano-silicon dioxide, 20 g of sodium lignin sulfonate and 700 g of clean water. The preparation method of the nano-silicon dioxide suspension comprises the following steps: 20 g of sodium lignin sulfonate and 700 g of clean water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silicon dioxide was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0056] The rest is the same as Example 7.

[0057] Example 9 The difference between this embodiment and embodiment 8 is that: S1: 7kg of slag and 3kg of fly ash are added to a container, a stirring device is turned on, and stirring and mixing is performed at 150r / min for 15min, then 1.2kg of water glass is slowly added, and stirring and mixing is continued for 30min, then 0.09kg of titanate coupling agent NDZ-201 is added, and stirring and mixing is continued for 20min, then 0.6kg of styrene acrylic emulsion is added, and stirring and mixing is continued for 30min, then 0.2kg of calcium sulfate, 0.03kg of triethanolamine, 0.04kg of sodium gluconate and nano-silicon dioxide suspension are added in sequence, and stirring and mixing is continued for 30min, then 5kg of clean water is added, and stirring and mixing is continued for 40min to obtain a slurry; The nano-silicon dioxide suspension comprises 0.4 kg of hydrophilic nano-silicon dioxide, 20 g of sodium lignin sulfonate and 700 g of clean water. The preparation method of the nano-silicon dioxide suspension comprises the following steps: 20 g of sodium lignin sulfonate and 700 g of clean water were stirred and mixed evenly, and then 0.4 kg of hydrophilic nano-silicon dioxide was added, and the mixture was stirred and mixed at 1200 r / min for 30 min to obtain the product.

[0058] The rest is the same as Example 8.

[0059] Comparative Example 1 The difference between this comparative example and Example 1 is: No calcium sulfate was added in step S1.

[0060] The rest is the same as in Example 1.

[0061] Comparative Example 2 The difference between this comparative example and Example 1 is: 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 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; The rest is the same as in Example 1.

[0062] Comparative Example 3 The difference between this comparative example and Example 1 is: Polyvinyl alcohol is not modified.

[0063] The rest is the same as in Example 1.

[0064] Comparative Example 4 The difference between this comparative example and Example 1 is: The starch is not modified.

[0065] The rest is the same as in Example 1.

[0066] Performance testing 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.

[0067] 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; the reference standard for water absorption is GB / T 50082-2024.

[0068] Table 1 Performance test data of high bending resistance plates prepared in Examples 1 to 9 and Comparative Examples 1 to 4

[0069] Analysis of the performance test data in Table 1 shows that: 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.

[0070] 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.

[0071] 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, enhances the synergistic effect with other components, and comprehensively improves the comprehensive performance of the board in terms of strength, water resistance, etc.

[0072] 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 board material performs 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 board material is relatively stable and excellent.

[0073] It can be seen from Examples 3 to 5 that by introducing maleic anhydride grafted polypropylene, it can enhance the stability of the organic phase itself, and at the same time form more chemical bonds and physical entanglements with the inorganic phase, improve the interface bonding force, and at the same time make the inside of the board more dense and reduce the number of internal pores. Good structural stability and interface bonding force enhance the load-bearing capacity of the board, give the board toughness, effectively improve the impact resistance and reduce the water absorption rate.

[0074] It can be seen from Examples 5 to 9 that: with the sequential addition of hydrophilic nano-silica, titanate coupling agent and styrene acrylic emulsion and the appropriate increase in dosage, the performance of the plates of Examples 5 to 9 shows a trend of gradual improvement. The continuous improvement of flexural strength and compressive strength indicates that the bearing capacity of the plates is continuously enhanced; the significant improvement of impact resistance indicates that the resistance of the plates to impact is getting better and better; the continuous decrease in water absorption rate reflects the continuous improvement of the waterproof performance and durability of the plates. This shows that the performance of slag-based plates can be effectively optimized by rationally combining and regulating these additives.

[0075] 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 modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing a high-bending-resistance sheet material, 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 cross-linking 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 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 initially 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 1.0-1.

5.

2. The method for preparing a high-bending-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-bending-resistance sheet material according to claim 2, characterized in that: The retarder is sodium gluconate.

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

5. The method for preparing a high-bending-resistance sheet material according to claim 1, characterized in that: 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 performed 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 the modified starch; The mass ratio of the starch to octenyl succinic anhydride is 1:(0.15-0.25).

6. The method for preparing a high-bending-resistance sheet material according to claim 1, characterized in that: 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, 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; 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-bending-resistance sheet material according to claim 1, characterized in that: In step S2, after adjusting the pH, a 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-bending-resistance sheet material according to claim 1, characterized in that: In step S1, after adding the retarder, the step of adding nano silicon dioxide is also 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-bending-resistance sheet material according to claim 1, characterized in that: In step S1, after adding water glass, a step of adding titanate coupling agent and styrene acrylic emulsion is also 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 obtained by the method for preparing a high-flexural-resistance sheet material according to any one of claims 1 to 9.

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