A thermal insulation board based on nano thermal insulation material, a preparation method and application thereof

Abstract

The application relates to the technical field of refractory materials, and discloses a heat-insulation plate based on a nano heat-insulation material, a preparation method and application. The preparation method comprises the following steps: introducing modified hydroxyethyl cellulose into polycarboxylic acid water reducing agent to prepare a water reducing agent aqueous solution, adding the water reducing agent aqueous solution into magnesium sulphate cement and foaming to obtain a heat-insulation plate crude product; coating a photocuring coating material containing methylpropenyl modified polysilazane, gamma-methylacryloyloxypropyl trimethoxysilane, nano tin antimony oxide and methylpropenoic acid dodecafluoroheptyl ester on the surface of the heat-insulation plate crude product to obtain the heat-insulation plate based on the nano heat-insulation material. The heat-insulation plate has good heat-insulation and heat-preservation effects, good mechanical properties, and can be applied to a kiln as a heat-insulation and heat-preservation material.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, specifically to an insulation board based on nano-insulation and heat insulation materials, its preparation method, and its application. Background Technology

[0002] Nanomaterials are a type of heat-insulating and fire-resistant material. Adding them to a matrix material can improve its heat insulation performance. Foamed lightweight insulation material is a new type of porous building material that uses cement as the main binder. Through physical or chemical foaming, gases such as oxygen and carbon dioxide from the air are introduced into the slurry, and lightweight aggregates are added. It achieves the desired performance requirements through a specific process and possesses excellent properties such as light weight, low thermal conductivity, good sound insulation, and fire resistance.

[0003] Existing technologies, such as Chinese patent CN103449834A, disclose a foamed cement insulation board and its preparation method. The raw materials include: ordinary silicate cement, fly ash, nano-bentonite, silica aerogel, emulsified paraffin wax, styrene-acrylic emulsion, benzenesulfonic acid, alumina, polyethylene glycol 1000, polypropylene fiber, sodium fatty alcohol polyoxyethylene ether sulfate, waste engine oil, butyl acrylate, Tween 60, sodium dodecylbenzenesulfonate, dodecyltrimethylammonium chloride, dimethyl silicone oil, sodium persulfate, and water. This board is lightweight, provides thermal insulation, and is waterproof. However, the main material is ordinary silicate cement, which limits its fire resistance and application range. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an insulation board based on nano-insulation materials, its preparation method and application. The insulation board has good insulation effect and excellent mechanical properties, and can be used as an insulation material in kilns.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a thermal insulation board based on nano-thermal insulation materials includes the following steps:

[0007] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water, add initiator, acrylic acid aqueous solution, and a mixed aqueous solution of reducing agent and chain transfer agent, react, and after the reaction is completed, neutralize to neutral to obtain water-reducing agent aqueous solution;

[0008] Modified hydroxyethyl cellulose is prepared by the following steps:

[0009] S11. N-methyldiallylamine was mixed with water until homogeneous. The pH value was adjusted by adding a regulator. Epichlorohydrin was added dropwise. After the addition was complete, the reaction was allowed to proceed. After the reaction was completed, the mixture was purified to obtain (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride.

[0010] S12. Hydroxyethyl cellulose and water are mixed and dissolved, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride is added, sodium hydroxide is added, the reaction is carried out, and after the reaction is completed, the mixture is neutralized, filtered, and rotary evaporated to obtain modified hydroxyethyl cellulose.

[0011] Step (2): Mix and stir the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add foaming agent, stir and foam to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, let stand to demold, cure, and obtain the coarse insulation board.

[0012] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methacrylate dropwise, and after the addition is complete, react. After the reaction is complete, filter and rotary evaporate to obtain methacrylyl-modified polysilazane.

[0013] A coating material is obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-antimony tin oxide, dodecafluoroheptyl methacrylate, a photoinitiator, and butyl acetate solvent.

[0014] The coating material is applied to the surface of the raw insulation board to form a coating. After the coating is completed, it is cured to obtain an insulation board based on nano-insulation material.

[0015] Preferably, in step (1), the mass ratio of the modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, initiator, acrylic acid aqueous solution, reducing agent and chain transfer agent mixed aqueous solution is 5-8:100:150:3-4:15-20:15-20; the initiator is added at 40℃; and the reaction conditions are: reacting at 40℃ for 1-1.5h.

[0016] Furthermore, the initiator is a 30 wt% aqueous solution of hydrogen peroxide; the acrylic acid aqueous solution is a 50 wt% aqueous solution of acrylic acid; the mixed aqueous solution of reducing agent and chain transfer agent is prepared by mixing reducing agent vitamin C, chain transfer agent mercaptopropionic acid, and water in a mass ratio of 0.1-0.3:0.5-0.8:18-20.

[0017] Preferably, in step (1) when preparing modified hydroxyethyl cellulose, the molar ratio of N-methyldiallylamine to epichlorohydrin in S11 is 1-1.05:1; the epichlorohydrin is added dropwise for 15-20 min at a pH of 7-8; and the reaction is carried out at 30-40°C for 4-6 h.

[0018] Preferably, the purification conditions are: neutralization to neutral with alkali, standing, separation, and rotary evaporation to remove the solvent.

[0019] Preferably, in step (1), when preparing modified hydroxyethyl cellulose, the molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride, and sodium hydroxide in S12 is 2-2.1:1:0.2; the reaction conditions are: reacting at 40-50℃ for 5-7 hours.

[0020] Preferably, in step (2): the mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and foaming agent is 30-40:5-6:10-13:65-70:4-5; the foaming agent is 30wt% hydrogen peroxide aqueous solution; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 35-40:30; the stirring and foaming time is 2 min.

[0021] Preferably, in step (3), the mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:15-20:0.9-1; the reaction conditions are: reaction at 50-60℃ for 16-20h.

[0022] Preferably, in step (3), the mass ratio of methacrylyl modified polysilazane, γ-methacryloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and solvent butyl acetate is 100:2-3:40-50:8-10:0.1-0.2:100-120.

[0023] Preferably, in step (3): the coating thickness is 1-2 mm; the curing conditions are: light curing in a 365 nm ultraviolet light environment for 20-30 min, and drying at a temperature of 100-110 °C for 5-6 min.

[0024] Preferably, the insulation board based on nano-insulation material is prepared by the method described above.

[0025] Preferably, an application of an insulation board based on nano-insulation and heat insulation material as described above in a kiln.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention utilizes the autocatalytic synthesis principle to prepare (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride with a quaternary ammonium salt structure and carbon-carbon double bond functional groups by reacting N-methyldiallylamine with epichlorohydrin. Then, a substitution reaction is carried out between the chlorine substituent and hydroxyethyl cellulose to introduce a cationic quaternary ammonium salt structure and carbon-carbon double bond functional groups into the hydroxyethyl cellulose molecule, resulting in modified hydroxyethyl cellulose. The modified hydroxyethyl cellulose is then used as a monomer for polymerization, utilizing the carbon-carbon double bonds to react with methylallyl polyoxyethylene ether and acrylic acid to form a polycarboxylate superplasticizer.

[0028] Among them, the modified hydroxyethyl cellulose contains cationic quaternary ammonium salt groups. The resulting water-reducing agent has both carboxyl and cationic groups, and thus has better dispersibility in the cement matrix as an amphoteric water-reducing agent. This is because positively charged and negatively charged minerals are generated after cement hydration, and the amphoteric water-reducing agent can be adsorbed on the surface of the two minerals, thereby improving the adsorption amount and dispersibility.

[0029] Foamed concrete is a lightweight material with numerous pores, possessing excellent thermal insulation, heat insulation, and sound insulation properties. Magnesium oxysulfate cement is an air-hardening cementitious material formed by the hydration reaction of lightly calcined magnesium oxide powder and magnesium sulfate solution, exhibiting advantages such as lightweight, rapid setting, low corrosivity, fire resistance, high temperature resistance, and good adhesion. This invention utilizes magnesium oxysulfate cement to prepare foamed concrete slurry, which is then cast into molds to form a rough insulation board. The foamed concrete slurry incorporates an aqueous solution of a water-reducing agent, an aqueous solution of a foaming agent (hydrogen peroxide), and silica aerogel prepared in the previous steps. The water-reducing agent aqueous solution contains a polycarboxylate superplasticizer, which inhibits the hydration reaction of magnesium oxide, stabilizes the magnesium oxide hydration layer, inhibits the formation of magnesium hydroxide, and stabilizes the foam structure. The silica aerogel improves the thermal insulation performance of the rough insulation board. In summary, the synergistic effect of these multiple materials enhances the mechanical strength, water resistance, and thermal insulation performance of the rough insulation board.

[0030] Polysilazane is a precursor material for organosilicon ceramics that undergoes ceramization at high temperatures. As a coating, it can effectively improve the fire resistance of the substrate material. This invention prepares methacrylyl-modified polysilazane by reacting polysilazane with isocyanate methacrylate, introducing carbon-carbon double bond functional groups. This modified polysilazane is then used as the main component of the coating, mixed with γ-methacryloyloxypropyltrimethoxysilane, nano-antimony tin oxide, dodecyl fluoroheptyl methacrylate, a photoinitiator, and a solvent to form a coating material. When applied to crude insulation boards, this not only improves the fire resistance of the insulation boards but also enhances their thermal insulation and water resistance due to the introduction of nano-antimony tin oxide and dodecyl fluoroheptyl methacrylate. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the preparation of insulation board based on nano-insulation and heat insulation materials in this invention;

[0032] Figure 2 This is a bar chart showing the compressive strength in the performance tests of the embodiments and comparative examples of this invention;

[0033] Figure 3 This is a bar chart showing the compressive strength loss rate in the performance tests of the embodiments and comparative examples of this invention;

[0034] Figure 4 This is a bar chart showing the thermal conductivity in the performance tests of the embodiments and comparative examples of this invention. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1

[0036] This embodiment discloses a method for preparing a thermal insulation board based on nano-thermal insulation materials, including the following steps:

[0037] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1 hour. After the reaction is complete, add 30wt% sodium hydroxide aqueous solution to neutralize to obtain water-reducing agent aqueous solution.

[0038] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and a mixed aqueous solution of vitamin C and mercaptopropionic acid is 5:100:150:3:15:15; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.1:0.5:18.

[0039] Modified hydroxyethyl cellulose is prepared by the following steps:

[0040] S11. N-methyldiallylamine and water were mixed evenly at a volume ratio of 1:1. A 1 mol / L aqueous solution of hydrogen chloride was added to adjust the pH to 7. Epichlorohydrin was added dropwise over a period of 20 min. After the addition was complete, the mixture was reacted at 30 °C for 6 h. After the reaction was completed, the mixture was neutralized with alkali to neutrality, allowed to stand, separated, and the solvent was removed by rotary evaporation to obtain (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride.

[0041] The molar ratio of N-methyldiallylamine to epichlorohydrin is 1.05:1.

[0042] S12. Hydroxyethyl cellulose and water are mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride is added. Sodium hydroxide is added at 40°C and the mixture is reacted at 40°C for 7 hours. After the reaction is completed, 30wt% phosphoric acid aqueous solution is added to neutralize the mixture to neutrality. The mixture is filtered, and the filtrate is taken and the solvent is removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0043] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide is 2:1:0.2.

[0044] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0045] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30 wt% hydrogen peroxide aqueous solution is 30:5:10:65:4; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 35:30.

[0046] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methyl methacrylate dropwise over 20 min, and after the addition is complete, react at 50 °C for 20 h. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0047] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:15:0.9.

[0048] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:2:40:8:0.1:100.

[0049] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 1 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 20 min and dried at 100 °C for 6 min to obtain an insulation board based on nano-insulation material. Example 2

[0050] This embodiment discloses a method for preparing a thermal insulation board based on nano-thermal insulation materials, including the following steps:

[0051] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1 hour. After the reaction is complete, add 30wt% sodium hydroxide aqueous solution to neutralize to obtain water-reducing agent aqueous solution.

[0052] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and the mixed aqueous solution of vitamin C and mercaptopropionic acid is 6:100:150:3.3:16:16; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.15:0.6:18.

[0053] Modified hydroxyethyl cellulose is prepared by the following steps:

[0054] Hydroxyethyl cellulose and water were mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was added, and sodium hydroxide was added at 40°C. The mixture was reacted at 40°C for 7 hours. After the reaction was completed, 30 wt% phosphoric acid aqueous solution was added to neutralize the mixture. The mixture was filtered, and the filtrate was collected. The solvent was removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0055] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide was 2:1:0.2; the preparation of (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was the same as in Example 1.

[0056] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0057] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30wt% hydrogen peroxide aqueous solution is 33:5:11:66:4.5; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 36:30.

[0058] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methyl methacrylate dropwise over 25 min, and react at 50°C for 20 h after the addition is complete. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0059] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:15:0.95.

[0060] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:2.3:43:8.5:0.15:110.

[0061] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 1.5 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 25 min and dried at 100 °C for 6 min to obtain an insulation board based on nano-insulation material. Example 3

[0062] This embodiment discloses a method for preparing a thermal insulation board based on nano-thermal insulation materials, including the following steps:

[0063] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1 hour. After the reaction is complete, add 30wt% sodium hydroxide aqueous solution to neutralize to obtain water-reducing agent aqueous solution.

[0064] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and the mixed aqueous solution of vitamin C and mercaptopropionic acid is 6.5:100:150:3.5:18:18; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.2:0.65:18.

[0065] Modified hydroxyethyl cellulose is prepared by the following steps:

[0066] Hydroxyethyl cellulose and water were mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was added, and sodium hydroxide was added at 40°C. The mixture was reacted at 45°C for 6 hours. After the reaction was completed, 30 wt% phosphoric acid aqueous solution was added to neutralize the mixture. The mixture was filtered, and the filtrate was collected. The solvent was removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0067] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide was 2:1:0.2; the preparation of (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was the same as in Example 1.

[0068] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0069] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30wt% hydrogen peroxide aqueous solution is 35:5.5:12:68:4.5; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 38:30.

[0070] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methyl methacrylate dropwise over 25 min, and react at 55°C for 18 h after the addition is complete. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0071] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:18:0.95.

[0072] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:2.5:45:9:0.15:110.

[0073] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 1.5 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 25 min and dried at 105 °C for 5.5 min to obtain an insulation board based on nano-insulation material. Example 4

[0074] This embodiment discloses a method for preparing a thermal insulation board based on nano-thermal insulation materials, including the following steps:

[0075] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1.5h. After the reaction is completed, add 30wt% sodium hydroxide aqueous solution to neutralize to neutral to obtain water-reducing agent aqueous solution.

[0076] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and the mixed aqueous solution of vitamin C and mercaptopropionic acid is 7:100:150:3.8:19:19; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.25:0.7:20.

[0077] Modified hydroxyethyl cellulose is prepared by the following steps:

[0078] Hydroxyethyl cellulose and water were mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was added, sodium hydroxide was added at 40°C, and the reaction was carried out at 50°C for 5 hours. After the reaction was completed, 30 wt% phosphoric acid aqueous solution was added to neutralize to neutrality. The mixture was filtered, and the filtrate was taken and the solvent was removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0079] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide was 2.1:1:0.2; the preparation of (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was the same as in Example 1.

[0080] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0081] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30wt% hydrogen peroxide aqueous solution is 38:6:12:69:4.8; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 38:30.

[0082] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methyl methacrylate dropwise over 25 min, and react at 60 °C for 16 h after the addition is complete. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0083] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:20:1.

[0084] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:3:48:9.5:0.15:110.

[0085] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 1.5 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 25 min and dried at 110 °C for 5 min to obtain an insulation board based on nano-insulation material. Example 5

[0086] This embodiment discloses a method for preparing a thermal insulation board based on nano-thermal insulation materials, including the following steps:

[0087] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1.5h. After the reaction is completed, add 30wt% sodium hydroxide aqueous solution to neutralize to neutral to obtain water-reducing agent aqueous solution.

[0088] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and the mixed aqueous solution of vitamin C and mercaptopropionic acid is 8:100:150:4:20:20; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.3:0.8:20.

[0089] Modified hydroxyethyl cellulose is prepared by the following steps:

[0090] Hydroxyethyl cellulose and water were mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was added, sodium hydroxide was added at 40°C, and the reaction was carried out at 50°C for 5 hours. After the reaction was completed, 30 wt% phosphoric acid aqueous solution was added to neutralize to neutrality. The mixture was filtered, and the filtrate was taken and the solvent was removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0091] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide was 2.1:1:0.2; the preparation of (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was the same as in Example 1.

[0092] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0093] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30wt% hydrogen peroxide aqueous solution is 40:6:13:70:5; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 40:30.

[0094] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methacrylate dropwise for 30 min, and after the dropwise addition is complete, react at 60℃ for 16 h. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0095] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:20:1.

[0096] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-antimony tin oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:3:50:10:0.2:120.

[0097] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 2 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 30 min and dried at 110 °C for 5 min to obtain an insulation board based on nano-insulation material.

[0098] Comparative Example 1

[0099] This comparative example discloses a method for preparing a thermal insulation board, including the following steps:

[0100] Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water. Add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid. React at 40℃ for 1 hour. After the reaction is complete, add 30wt% sodium hydroxide aqueous solution to neutralize to obtain water-reducing agent aqueous solution.

[0101] The mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and a mixed aqueous solution of vitamin C and mercaptopropionic acid is 5:100:150:3:15:15; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.1:0.5:18.

[0102] Modified hydroxyethyl cellulose is prepared by the following steps:

[0103] Hydroxyethyl cellulose and water were mixed and dissolved in a mass ratio of 1:5. (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was added, and sodium hydroxide was added at 40°C. The mixture was reacted at 40°C for 7 hours. After the reaction was completed, 30 wt% phosphoric acid aqueous solution was added to neutralize the mixture. The mixture was filtered, and the filtrate was collected. The solvent was removed by rotary evaporation to obtain modified hydroxyethyl cellulose.

[0104] The molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride, and sodium hydroxide was 2:1:0.2; the preparation of (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride was the same as in Example 1.

[0105] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain insulation board;

[0106] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30 wt% hydrogen peroxide aqueous solution is 30:5:10:65:4; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 35:30.

[0107] Comparative Example 2

[0108] This comparative example discloses a method for preparing a thermal insulation board, including the following steps:

[0109] Step (1): Mix methyl allyl polyoxyethylene ether and water, add 30wt% hydrogen peroxide aqueous solution at 40℃, then add 50wt% acrylic acid aqueous solution and a mixed aqueous solution of vitamin C and mercaptopropionic acid, react at 40℃ for 1 hour, after the reaction is completed, add 30wt% sodium hydroxide aqueous solution to neutralize to neutral, and obtain water-reducing agent aqueous solution.

[0110] The mass ratio of methyl allyl polyoxyethylene ether, water, 30 wt% hydrogen peroxide aqueous solution, 50 wt% acrylic acid aqueous solution, and the mixed aqueous solution of vitamin C and mercaptopropionic acid is 100:150:3:15:15; the mixed aqueous solution of vitamin C and mercaptopropionic acid is prepared by mixing vitamin C, mercaptopropionic acid, and water in a mass ratio of 0.1:0.5:18.

[0111] Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution to obtain magnesium sulfate cement paste, add 30wt% hydrogen peroxide aqueous solution, stir and foam for 2 minutes to obtain foamed concrete slurry, send the foamed concrete slurry into the board making machine to pour into mold, cover both sides with cloth and roll flat, let stand for 24 hours to demold, and cure at room temperature for 28 days to obtain the coarse product of insulation board;

[0112] The mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and 30 wt% hydrogen peroxide aqueous solution is 30:5:10:65:4; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 35:30.

[0113] Step (3): Mix polysilazane and tetrahydrofuran evenly, add isocyanate methyl methacrylate dropwise over 20 min, and after the addition is complete, react at 50 °C for 20 h. After the reaction is complete, filter, take the filtrate, and remove the solvent tetrahydrofuran by rotary evaporation to obtain methpropylene-modified polysilazane.

[0114] The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:15:0.9.

[0115] The coating material was obtained by mixing methacrylyl-modified polysilazane, γ-methacryloyloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and butyl acetate solvent in a mass ratio of 100:2:40:8:0.1:100.

[0116] The coating material was applied to the surface of the raw insulation board to form a coating with a thickness of 1 mm. After coating, it was cured in a 365 nm ultraviolet light environment for 20 min and dried at 100 °C for 6 min to obtain the insulation board.

[0117] In the above examples and comparative examples: the silica aerogel was from Elisen High-Tech Co., Ltd., product name: nanoporous silica aerogel, pore size ≤70nm; the nano-tin antimony oxide was from Maclean Biochemical Technology Co., Ltd., particle size 20-80nm; the methyl allyl polyoxyethylene ether was from Xinyuhong Biomedical Technology Co., Ltd., product name: HPEG-2400; the hydroxyethyl cellulose was from Bied Pharmaceutical Technology Co., Ltd., product number: BD01430697; the polysilazane was from Aiyota Silicon Oil Co., Ltd., product name: organopolysilazane IOTA-OPSZ-9150, molecular weight 800-900; the isocyanate methyl methacrylate was from Wengjiang Chemical Reagent Co., Ltd., CAS number: 30674-80-7; the photoinitiator was from Milan Chemical Co., Ltd., product name: photoinitiator 651; and the lightly calcined magnesium oxide was commercially available.

[0118] Test case

[0119] (1) Mechanical properties and fire resistance tests

[0120] The mechanical and fire-resistant properties of Examples 1-5 and Comparative Examples 1-2 were tested, and the specific test results are shown in Table 1:

[0121] Table 1

[0122]

[0123] The testing of the indicators in Table 1 is based on the following standards: compressive strength is determined according to JGT266-2011 "Foamed Concrete"; fire resistance is expressed by the compressive strength loss rate, and is determined according to GB / T9978.1-2008 "Test Method for Fire Resistance of Building Components", with a test temperature of 800℃ and a test time of 3h.

[0124] As can be seen from the test results in Table 1, the insulation board prepared by this invention has excellent mechanical properties and good fire resistance.

[0125] Comparative Example 1 was not coated, and the lack of coating prevented the insulation board from being ceramicized under high temperature conditions, thus its fire resistance was not as good as that of the Example.

[0126] In Comparative Example 2, no modified hydroxyethyl cellulose was added during the preparation of the water-reducing agent. The resulting water-reducing agent was not an amphoteric polycarboxylate water-reducing agent, resulting in reduced dispersibility and adsorption capacity, which affected the mechanical properties of the insulation board. Therefore, the compressive strength of Comparative Example 2 was lower than that of the Example.

[0127] (2) Thermal insulation performance test

[0128] The thermal insulation performance of Examples 1-5 and Comparative Examples 1-2 was tested, and the specific test results are shown in Table 2:

[0129] Table 2

[0130]

[0131] The test results for the indicators in Table 2 are based on the following standards: the thermal conductivity is measured according to GB / T10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Insulation Materials - Protective Hot Plate Method".

[0132] As can be seen from the test results in Table 2, the insulation board prepared by this invention has good thermal insulation effect.

[0133] Comparative Example 1 was not coated, and therefore lacked the effect of nano-tin antimony oxide in the coating on improving thermal insulation performance. As a result, the thermal insulation performance of Comparative Example 1 was not as good as that of the Example.

[0134] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a thermal insulation board based on nano-thermal insulation materials, characterized in that, Includes the following steps: Step (1): Mix modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, and water, add initiator, acrylic acid aqueous solution, and a mixed aqueous solution of reducing agent and chain transfer agent, react, and after the reaction is completed, neutralize to neutral to obtain water-reducing agent aqueous solution; The modified hydroxyethyl cellulose is prepared by the following steps: S11. N-methyldiallylamine was mixed with water until homogeneous. The pH value was adjusted by adding a regulator. Epichlorohydrin was added dropwise. After the addition was complete, the reaction was allowed to proceed. After the reaction was completed, the mixture was purified to obtain (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride. S12. Hydroxyethyl cellulose and water are mixed and dissolved, (3-chloro-2-hydroxypropyl)methyldiallyl ammonium chloride is added, sodium hydroxide is added, the reaction is carried out, and after the reaction is completed, the mixture is neutralized, filtered, and rotary evaporated to obtain modified hydroxyethyl cellulose. Step (2): Mix the lightly calcined magnesium oxide, silica aerogel, and water-reducing agent aqueous solution evenly, add magnesium sulfate aqueous solution and foaming agent, stir to foam, pour into a mold, let stand to demold, and cure to obtain the crude insulation board. Step (3): Mix methacrylyl modified polysilazane, γ-methacryloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and solvent to obtain the coating material; The methpropylene-modified polysilazane is prepared by the following steps: Polysilazane was mixed with tetrahydrofuran until homogeneous, and isocyanate methacrylate was added dropwise. After the addition was complete, the mixture was allowed to react. After the reaction was complete, the mixture was filtered and rotary evaporated to obtain methacrylyl-modified polysilazane. The mass ratio of polysilazane, tetrahydrofuran, and isocyanate methacrylate is 4:15-20:0.9-1; the reaction conditions are: reaction at 50-60℃ for 16-20 h. The coating material is applied to the surface of the raw insulation board to form a coating, which is then cured to obtain an insulation board based on nano-insulation material.

2. The method for preparing a thermal insulation board based on nano-thermal insulation material according to claim 1, characterized in that, In step (1), the mass ratio of modified hydroxyethyl cellulose, methyl allyl polyoxyethylene ether, water, initiator, acrylic acid aqueous solution, reducing agent and chain transfer agent mixed aqueous solution is 5-8:100:150:3-4:15-20:15-20; the initiator is added at 40℃; the reaction conditions are: react at 40℃ for 1-1.5h; the initiator is 30wt% hydrogen peroxide aqueous solution; the acrylic acid aqueous solution is 50wt% acrylic acid aqueous solution; the mixed aqueous solution of reducing agent and chain transfer agent is prepared by mixing reducing agent vitamin C, chain transfer agent mercaptopropionic acid and water in a mass ratio of 0.1-0.3:0.5-0.8:18-20.

3. The method for preparing a thermal insulation board based on nano-thermal insulation material according to claim 1, characterized in that, In step (1), when preparing modified hydroxyethyl cellulose: In S11: the molar ratio of N-methyldiallylamine to epichlorohydrin is 1-1.05:1; the epichlorohydrin is added dropwise for 15-20 min at a pH of 7-8; the reaction is carried out at 30-40℃ for 4-6 h. In S12, the molar ratio of hydroxyethyl cellulose, (3-chloro-2-hydroxypropyl)methyldiallylammonium chloride, and sodium hydroxide is 2-2.1:1:0.2; the reaction conditions are: reacting at 40-50℃ for 5-7 hours.

4. The method for preparing a thermal insulation board based on nano-thermal insulation material according to claim 1, characterized in that, In step (2), the mass ratio of lightly calcined magnesium oxide, silica aerogel, water-reducing agent aqueous solution, magnesium sulfate aqueous solution, and foaming agent is 30-40:5-6:10-13:65-70:4-5; the foaming agent is 30wt% hydrogen peroxide aqueous solution; the magnesium sulfate aqueous solution is prepared by mixing magnesium sulfate heptahydrate and water in a mass ratio of 35-40:30; the stirring and foaming time is 2 minutes.

5. The method for preparing a thermal insulation board based on nano-thermal insulation material according to claim 1, characterized in that, In step (3), the mass ratio of methacrylyl modified polysilazane, γ-methacryloxypropyltrimethoxysilane, nano-tin antimony oxide, dodecafluoroheptyl methacrylate, photoinitiator, and solvent butyl acetate is 100:2-3:40-50:8-10:0.1-0.2:100-120.

6. The method for preparing a thermal insulation board based on nano-thermal insulation material according to claim 1, characterized in that, In step (3): the coating thickness is 1-2 mm; the curing conditions are: light curing in a 365 nm ultraviolet light environment for 20-30 min, and drying at a temperature of 100-110℃ for 5-6 min.

7. An insulation board based on nano-insulation material prepared by the preparation method of the insulation board based on nano-insulation material as described in any one of claims 1-6.

8. The application of an insulation board based on nano-insulation material as described in claim 7 in a kiln.

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