Graphene flame-retardant thermal insulation material and preparation method thereof

Abstract

The invention discloses a graphene flame-retardant thermal insulation material and a preparation method thereof. The graphene flame-retardant thermal insulation material comprises the following components in parts by mass: 30-34 parts of water; 15 to 19 parts of phosphogypsum; 3 to 6 parts of talcum powder; 38 to 44 parts of graphene modified foam particles; 1 to 3 parts of chopped fiber; and 3-5 parts of an auxiliary agent. According to the invention, polyhedral oligomeric silsesquioxane grafted graphene oxide coated modified polystyrene foam particles are used as a functional filler, phosphogypsum is selected as a binding material, and various components such as talcum powder, chopped fibers and an auxiliary agent are added, so that the thermal insulation performance of the composite material is improved; the prepared graphene flame-retardant thermal-insulation material has the advantages of ultralow heat conductivity coefficient, ultralow dry density, A-grade flame retardance, ultrahigh compressive strength and the like; the problem that a traditional thermal insulation material is difficult to meet the requirements of building energy saving and building fireproof standards at the same time is solved.

Description

Technical Field

[0001] The invention relates to the technical field of building thermal insulation materials, in particular to a graphene flame retardant thermal insulation material and a preparation method thereof. Background Art

[0002] Under the dual pressures of the global energy crisis and climate change, building energy conservation has become the core battlefield for achieving the goal of carbon neutrality. According to statistics from the International Energy Agency, energy consumption in the construction sector accounts for more than 40% of the world's total energy consumption, of which heat loss in the building envelope accounts for 50%-70% of building energy consumption. Traditional building insulation systems mainly rely on organic polymer materials (such as EPS / XPS polystyrene foam, PU polyurethane, etc.), whose thermal conductivity is as low as 0.023-0.035W / (m·K), but they are prone to produce droplets and release toxic gases when exposed to fire. In the Grenfell Tower fire in London in 2017, the flammability of exterior wall insulation materials caused 72 deaths, exposing the fatal defects of organic insulation materials. Although inorganic insulation materials (such as rock wool, glass wool, aerogel, etc.) have non-combustible properties (Class A fireproof), their thermal conductivity is generally higher than 0.04W / (m·K), and there are problems such as poor construction performance and high moisture absorption. Take rock wool as an example. Its fibrous structure can easily cause respiratory diseases, and professional protective equipment is required during construction. Test data from the China Academy of Building Research shows that at the same insulation thickness, the heat transfer coefficient of rock wool exterior walls is 38% higher than that of XPS, resulting in a significant increase in building energy consumption. This binary opposition in performance makes it difficult for the existing insulation system to simultaneously meet the stringent requirements of the building design fire protection code for fire protection levels and the technical indicators of the civil building energy-saving design standard for insulation performance. Therefore, it is difficult for traditional insulation materials to simultaneously meet the requirements of building energy conservation and building fire protection standards. Summary of the invention

[0003] The object of the present invention is to provide a graphene flame retardant thermal insulation material and a preparation method thereof, so as to solve the problem that the thermal insulation materials in the prior art are difficult to simultaneously meet the requirements of building energy conservation and building fire protection standards.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a graphene flame retardant thermal insulation material, comprising the following components in parts by mass: water: 30 to 34 parts; phosphogypsum: 15 to 19 parts; talcum powder: 3 to 6 parts; graphene modified foam particles: 38 to 44 parts; short-cut fibers: 1 to 3 parts; and additives: 3 to 5 parts.

[0005] The chopped fibers are at least one of aluminum silicate fibers, polypropylene fibers, glass fibers, basalt fibers, polyacrylonitrile fibers, and polyvinyl alcohol fibers.

[0006] Preferably, the phosphogypsum is hemihydrate phosphogypsum, and the particle size of the phosphogypsum is 5 to 50 μm.

[0007] Preferably, the auxiliary agent includes a dispersant, a retarder and a water retaining agent.

[0008] Preferably, the whiteness of the talcum powder is not less than 75%, and the fineness of the talcum powder is 300-1000 mesh.

[0009] Preferably, the method for preparing the graphene-modified foam particles comprises the following steps:

[0010] (1) dispersing 1 g of graphene oxide in 100 mL of anhydrous ethanol, adding 0.5 g of aminosilane and an appropriate amount of epoxy cage-type silsesquioxane, heating at 70 to 75° C. under reflux conditions, and reacting for 60 to 120 min to obtain a cage-type silsesquioxane-grafted graphene oxide dispersion;

[0011] (2) The polystyrene foam particles are treated with a plasma treatment machine for 30 to 120 seconds, and the plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 15 to 30 minutes, and then taken out and dried at 60 to 90° C. for 24 hours to obtain graphene-modified foam particles.

[0012] Preferably, the thickness of the graphene oxide is less than or equal to 3 nm, and the lateral size of the graphene oxide is greater than or equal to 10 μm.

[0013] Preferably, the aminosilane is at least one of 3-aminopropylmethyldimethoxysilane, aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0014] Preferably, the epoxy cage silsesquioxane is at least one of epoxycyclohexyl cage polysilsesquioxane, monoepoxy cage polysilsesquioxane, octaepoxy cage polysilsesquioxane, and triepoxy cage polysilsesquioxane, and the mass ratio of graphene oxide to epoxy cage polysilsesquioxane is 1.5:1 to 2.5:1.

[0015]

[0016] Epoxycyclohexyl cage-shaped polysilsesquioxane

[0017]

[0018] Monoepoxy cage polysilsesquioxane

[0019]

[0020] Triepoxy cage polysilsesquioxane

[0021]

[0022] Octaepoxy cage polysilsesquioxane

[0023] Preferably, the excitation frequency of the plasma processor is at least one of 40 kHz, 13.56 MHz and 2.45 GHz, and the oxygen content in the reaction gas is not less than 20%.

[0024] A method for preparing a graphene flame retardant thermal insulation material comprises the following steps:

[0025] S1. Evenly mixing phosphogypsum, talcum powder, graphene-modified foam particles, chopped fibers and additives to obtain a dry mix;

[0026] S2, mixing the dry mixed material with water to uniformly prepare a graphene flame retardant thermal insulation material to obtain a stirred material;

[0027] S3, filling the stirred material into a mold, and curing at 25° C. for 7 days to obtain a graphene flame retardant heat-insulating material.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts polystyrene foam particles coated with graphene oxide grafted with cage-type silsesquioxane as functional fillers, selects phosphogypsum as a bonding material, and adds talcum powder, chopped fibers, additives and other components to prepare a graphene flame retardant thermal insulation material with ultra-low thermal conductivity, ultra-low dry density, Class A flame retardancy, ultra-high compressive strength, etc.

[0030] 2. The preparation method of the graphene flame retardant thermal insulation material in the present invention has a simple preparation process and is easy to prepare on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0034] See also Figure 1 In an embodiment of the present invention, a graphene flame retardant thermal insulation material includes 30 to 34 parts by mass of water, 15 to 19 parts by mass of phosphogypsum, 3 to 6 parts by mass of talc, 38 to 44 parts by mass of graphene modified foam particles, 1 to 3 parts by mass of chopped fibers and 3 to 5 parts by mass of additives.

[0035] The chopped fibers are used to enhance the anti-cracking performance of the aerosol lightweight flame retardant thermal insulation mortar of the present invention. Further, the chopped fibers are preferably at least one of aluminum silicate fibers, polypropylene fibers, glass fibers, basalt fibers, polyacrylonitrile fibers, and polyvinyl alcohol fibers. Preferably, the diameter of the chopped fibers is preferably 10 to 50 microns, and the length is preferably 5 to 10 mm.

[0036] As an inorganic bonding material of the graphene-modified foam particles in the present invention, phosphogypsum has the advantages of fast coagulation and hardening, high bonding strength, stable volume, not easy to shrink and crack, good flame retardant performance, etc. Further, the phosphogypsum is preferably hemihydrate phosphogypsum with a particle size of 5 to 50 μm.

[0037] The auxiliary agent is used to adjust the problems of the graphene flame retardant thermal insulation material of the present invention, such as fast hardening, poor dispersibility, excessive foaming, poor construction performance, etc. Further, the auxiliary agent includes a dispersant, a retarder and a water retaining agent.

[0038] The talcum powder is used to promote the hardening process of phosphogypsum, shorten its curing time, and is used as a filler to improve the construction performance and appearance texture of the graphene flame retardant thermal insulation material of the present invention. Furthermore, the whiteness of the talcum powder is not less than 75%, and the fineness is 300-1000 mesh.

[0039] Compared with inorganic heat-insulating fillers such as hollow glass microspheres and hollow ceramic microspheres, polystyrene foam particles have the performance advantages of low thermal conductivity, light weight, low water absorption, etc., but are easy to burn, which limits its application in flame-retardant heat-insulating materials. Therefore, the present invention is grafted with a cage-type silsesquioxane rich in silicon on the surface of graphene oxide rich in carbon, and the polystyrene foam particles treated with plasma are coated with the graphene oxide nanosheets grafted with cage-type silsesquioxane, after coating, the surface of polystyrene foam particles is rich in carbon and silicon, which enhances its flame retardant properties, and because the surface is coated, the pore structure inside is protected, reducing the penetration of the remaining components such as phosphogypsum or auxiliary agents, and degradation, aging, etc., to the destruction of the pore structure of polystyrene foam particles, so that heat-insulating properties are improved. At the same time, the inorganic silicon oxygen skeleton rich in cage-type polysilsesquioxane will also improve the interface interaction between organic polystyrene foam particles and inorganic phosphogypsum binder, and strengthen the mechanical properties of the material.

[0040] Furthermore, the graphene-modified foam particles are prepared by the following method:

[0041] (1) dispersing 1 g of graphene oxide in 100 mL of anhydrous ethanol, adding 0.5 g of aminosilane and an appropriate amount of epoxy cage-type silsesquioxane, heating under reflux conditions (70-75° C.) for a reaction of 60-120 min to obtain a cage-type silsesquioxane-grafted graphene oxide dispersion;

[0042] (2) The polystyrene foam particles are treated with a plasma treatment machine for 30 to 120 seconds, and the plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 15 to 30 minutes, and then taken out and dried at 60 to 90° C. for 24 hours to obtain graphene-modified foam particles.

[0043] Graphene oxide has a nanometer-scale thickness, and due to its rich oxygen-containing functional groups on the surface, it can graft more cage-type silsesquioxanes, and large sheets of graphene oxide can better wrap the polystyrene foam particles. Further, in the preparation method of the graphene-modified foam particles, the thickness of the graphene oxide sheet is less than or equal to 3nm, and the lateral size is greater than or equal to 10μm.

[0044] The aminosilane reacts with the epoxy cage silsesquioxane through the amino group, and the siloxy group reacts with the hydroxyl group on the surface of the graphene oxide, so that the epoxy cage silsesquioxane is grafted onto the surface of the graphene oxide. Further, in the preparation method of the graphene-modified foam particles, the aminosilane is at least one of 3-aminopropylmethyldimethoxysilane, aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0045] The siloxane cage in the molecular structure of cage-type polysilsesquioxane is a three-dimensional cage structure with six fully enclosed sides. Silicon atoms and oxygen atoms alternately form the cage skeleton. This highly ordered inorganic siloxane skeleton makes the cage-type polysilsesquioxane have good thermal stability at high temperatures and can withstand thermal oxidation, thermal decomposition and other reactions at high temperatures. The epoxy-treated cage-type silsesquioxane can be easily grafted onto the surface of graphene oxide. Furthermore, the preparation method of the graphene-modified foam particles is characterized in that the epoxy cage-type silsesquioxane is at least one of epoxycyclohexyl cage-type polysilsesquioxane, monoepoxy cage-type polysilsesquioxane, octaepoxy cage-type polysilsesquioxane, and triepoxy cage-type polysilsesquioxane, and the mass ratio of graphene oxide to epoxy cage-type silsesquioxane is 1.5:1 to 2.5:1.

[0046]

[0047] Epoxycyclohexyl cage-shaped polysilsesquioxane

[0048]

[0049] Monoepoxy cage polysilsesquioxane

[0050] Triepoxy cage polysilsesquioxane

[0051] Octaepoxy cage polysilsesquioxane

[0052] Plasma is a partially or fully ionized gas, containing electrons, ions, free radicals and excited particles. These particles have high energy (usually several to tens of electron volts), can break the chemical bonds on the surface of the material, and introduce new functional groups, thereby changing the surface properties of the material. Plasma treatment of polystyrene foam particles can generate oxygen anions and other groups on their surface, thereby adsorbing cage-type silsesquioxane-grafted graphene oxide nanosheets for coating. Furthermore, in the preparation method of the graphene-modified foam particles, the excitation frequency of the plasma treatment machine is at least one of 40kHz, 13.56MHz and 2.45GHz, and the oxygen content in the reaction gas is not less than 20%.

[0053] The present invention provides a method for preparing a graphene flame retardant thermal insulation material, comprising the following steps:

[0054] (1) mixing phosphogypsum, talcum powder, graphene-modified foam particles, chopped fibers and additives to obtain a dry mix;

[0055] (2) mixing the dry mixed material with water to uniformly prepare a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0056] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0057] In order to specifically illustrate the performance characteristics of the graphene flame retardant thermal insulation material of the present invention, the following examples and comparative examples are specifically described in detail.

[0058] Example 1

[0059] This embodiment provides a graphene-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0060] S1, 1g of graphene oxide was dispersed in 100mL of anhydrous ethanol, and 0.5g of aminosilane (3-aminopropylmethyldimethoxysilane) and 1.5g of epoxy cage-type silsesquioxane (epoxycyclohexyl cage-type polysilsesquioxane) were added, and the mixture was heated (70°C) under reflux conditions for reaction for 60min to obtain a cage-type silsesquioxane-grafted graphene oxide dispersion;

[0061] S2. The polystyrene foam particles are treated with a plasma processor (excitation frequency is 13.56 MHz, and the reaction gas is air) for 30 seconds, and the plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 15 minutes, and then taken out and dried at 60° C. for 24 hours to obtain graphene-modified foam particles.

[0062] This embodiment provides a graphene flame retardant thermal insulation material, which is prepared by the following preparation method, and the specific steps include:

[0063] (1) 15 g of phosphogypsum, 5 g of talc, 44 g of graphene-modified foam particles, 2 g of chopped fibers (aluminum silicate fibers), and 4 g of additives (1 part of PVP, 1 part of sodium polyphosphate, and 2 parts of hydroxypropyl methylcellulose) were uniformly mixed to obtain a dry blend;

[0064] (2) mixing the dry mixed material with 30 g of water and stirring uniformly to obtain a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0065] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0066] Example 2

[0067] This embodiment provides a graphene-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0068] S1, 1g of graphene oxide was dispersed in 100mL of anhydrous ethanol, and 0.5g of aminosilane (aminopropylmethyldiethoxysilane) and 2g of epoxy cage-type silsesquioxane (monoepoxy cage-type polysilsesquioxane) were added, and the mixture was heated (72°C) under reflux conditions for reaction for 90min to obtain a dispersion of graphene oxide grafted with cage-type silsesquioxane;

[0069] S2. Use a plasma processor (excitation frequency of 2.45 GHz, reaction gas is a mixture of 10% oxygen and 90% air) to treat the polystyrene foam particles for 80 seconds, soak the plasma-treated polystyrene foam particles in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 20 minutes, then take out and dry at 70°C for 24 hours to obtain graphene-modified foam particles.

[0070] This embodiment provides a graphene flame retardant thermal insulation material, which is prepared by the following preparation method, and the specific steps include:

[0071] (1) 19 g of phosphogypsum, 6 g of talc, 38 g of graphene-modified foam particles, 1 g of chopped fibers (polypropylene fibers), and 5 g of additives (2 parts of sodium dodecylbenzene sulfonate and 3 parts of methyl hydroxyethyl cellulose ether) were uniformly mixed to obtain a dry blend;

[0072] (2) mixing the dry mixed material with 31 g of water and stirring uniformly to obtain a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0073] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0074] Example 3

[0075] This embodiment provides a graphene-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0076] S1, 1g of graphene oxide was dispersed in 100mL of anhydrous ethanol, and 0.5g of aminosilane (3-aminopropyltrimethoxysilane) and 2.5g of epoxy cage-type silsesquioxane (octaepoxy cage-type polysilsesquioxane) were added, and the mixture was heated (75°C) under reflux conditions for reaction for 120min to obtain a dispersion of graphene oxide grafted with cage-type silsesquioxane;

[0077] S2. Use a plasma processor (excitation frequency of 40 kHz, reaction gas is a mixture of 20% oxygen, 30% air and 50% nitrogen) to treat the polystyrene foam particles for 90 seconds, soak the plasma-treated polystyrene foam particles in a dispersion of cage-type silsesquioxane-grafted graphene oxide for 30 minutes, then take out and dry at 90°C for 24 hours to obtain graphene-modified foam particles.

[0078] This embodiment provides a graphene flame retardant thermal insulation material, which is prepared by the following preparation method, and the specific steps include:

[0079] (1) 16 g of phosphogypsum, 4 g of talc, 42 g of graphene-modified foam particles, 3 g of chopped fibers (glass fibers) and 3 g of an additive (3 parts by mass of polyethylene glycol) were uniformly mixed to obtain a dry blend;

[0080] (2) mixing the dry mixed material with 32 g of water and stirring uniformly to obtain a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0081] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0082] Example 4

[0083] This embodiment provides a graphene-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0084] S1, 1g of graphene oxide was dispersed in 100mL of anhydrous ethanol, and 0.5g of aminosilane (3-aminopropyltriethoxysilane) and 2.2g of epoxy cage-type silsesquioxane (triepoxy cage-type polysilsesquioxane) were added, and the mixture was heated (73°C) under reflux conditions for 100min to obtain a dispersion of graphene oxide grafted with cage-type silsesquioxane;

[0085] S2. The polystyrene foam particles are treated for 120 seconds using a plasma processor (with an excitation frequency of 13.56 MHz and a reaction gas of a mixture of 30% oxygen, 20% air and 50% nitrogen). The plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 25 minutes, and then taken out and dried at 90°C for 24 hours to obtain graphene-modified foam particles.

[0086] This embodiment provides a graphene flame retardant thermal insulation material, which is prepared by the following preparation method, and the specific steps include:

[0087] (1) 17 g of phosphogypsum, 3 g of talc, 41 g of graphene-modified foam particles, 2 g of chopped fibers (basalt fibers), and 4 g of additives (1.5 parts by mass of PVP, 0.5 parts by mass of citric acid, and 2 parts by mass of methyl hydroxypropyl cellulose ether) were uniformly mixed to obtain a dry blend;

[0088] (2) mixing the dry mixed material with 33 g of water and stirring uniformly to obtain a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0089] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0090] Example 5

[0091] This embodiment provides a graphene-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0092] S1, 1g of graphene oxide was dispersed in 100mL of anhydrous ethanol, and 0.5g of aminosilane (aminopropylmethyldiethoxysilane) and 1.8g of epoxy cage-type silsesquioxane (octaepoxy cage-type polysilsesquioxane) were added, and the mixture was heated (75°C) under reflux conditions for 110min to obtain a dispersion of graphene oxide grafted with cage-type silsesquioxane;

[0093] S2. The polystyrene foam particles are treated with a plasma processor (with an excitation frequency of 13.56 MHz and a reaction gas of a mixture of 30% oxygen, 20% air and 50% nitrogen) for 100 s, and the plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 28 min, and then taken out and dried at 90°C for 24 h to obtain graphene-modified foam particles.

[0094] This embodiment provides a graphene flame retardant thermal insulation material, which is prepared by the following preparation method, and the specific steps include:

[0095] (1) 18 g of phosphogypsum, 3 g of talc, 39 g of graphene-modified foam particles, 2 g of chopped fibers (polyvinyl alcohol fibers), and 4 g of an additive (1.5 parts by mass of ECO-2260 and 2.5 parts of hydroxypropyl methylcellulose) were uniformly mixed to obtain a dry blend;

[0096] (2) mixing the dry mixed material with 34 g of water and stirring uniformly to obtain a graphene flame retardant thermal insulation material, thereby obtaining a stirred material;

[0097] (3) Filling the stirred material into a mold and curing at 25° C. for 7 days to obtain a graphene flame retardant thermal insulation material.

[0098] Comparative Example 1

[0099] This comparative example provides a thermal insulation material of polystyrene foam particles without cage-type silsesquioxane and graphene oxide, which is prepared by the following preparation method, and the specific steps include:

[0100] (1) 17 g of phosphogypsum, 3 g of talc, 41 g of polystyrene foam particles, 2 g of chopped fibers (basalt fibers), and 4 g of additives (1.5 parts by mass of PVP, 0.5 parts by mass of citric acid, and 2 parts by mass of methyl hydroxypropyl cellulose ether) were uniformly mixed to obtain a dry blend;

[0101] (2) mixing the dry blend with 33 g of water and stirring to obtain a stirred material;

[0102] (3) Filling the stirred material into a mold and curing the mold at 25° C. for 7 days to obtain a thermal insulation material free of cage-type silsesquioxane and graphene oxide.

[0103] Comparative Example 2

[0104] This comparative example provides a graphene-free cage-type silsesquioxane-modified foam particle, which is prepared by the following preparation method, and the specific steps include:

[0105] S1, 0.5g of aminosilane (3-aminopropyltriethoxysilane) and 2.2g of epoxy cage-type silsesquioxane (triepoxy cage-type polysilsesquioxane) were dispersed in 100mL of anhydrous ethanol, and heated (73°C) under reflux conditions for reaction for 100min to obtain a cage-type silsesquioxane grafted dispersion;

[0106] S2. The polystyrene foam particles are treated for 120 seconds using a plasma processor (with an excitation frequency of 13.56 MHz and a reaction gas of a mixture of 30% oxygen, 20% air and 50% nitrogen), and the plasma-treated polystyrene foam particles are immersed in a cage-type silsesquioxane dispersion for 25 minutes, and then taken out and dried at 90°C for 24 hours to obtain cage-type silsesquioxane-modified foam particles that do not contain graphene.

[0107] This comparative example provides a thermal insulation material of cage-type silsesquioxane modified foam particles without graphene, which is prepared by the following preparation method, and the specific steps include:

[0108] (1) 17 g of phosphogypsum, 3 g of talc, 41 g of cage-type silsesquioxane-modified foam particles, 2 g of chopped fibers (basalt fibers), and 4 g of additives (1.5 parts by mass of PVP, 0.5 parts by mass of citric acid, and 2 parts by mass of methyl hydroxypropyl cellulose ether) were uniformly mixed to obtain a dry blend;

[0109] (2) mixing the dry mixed material with 33 g of water and stirring uniformly to obtain a thermal insulation material free of graphene, thereby obtaining a stirred material;

[0110] (3) Filling the stirred material into a mold and curing it at 25° C. for 7 days to obtain a thermal insulation material free of graphene.

[0111] Comparative Example 3

[0112] This embodiment provides a graphene-modified foam particle without cage-type silsesquioxane, which is prepared by the following preparation method, and the specific steps include:

[0113] S1. Disperse 1 g of graphene oxide in 100 mL of anhydrous ethanol, add 0.5 g of aminosilane (3-aminopropyltriethoxysilane), and heat under reflux (73° C.) for 100 min to obtain a graphene oxide dispersion.

[0114] S2. The polystyrene foam particles are treated for 120 seconds using a plasma processor (with an excitation frequency of 13.56 MHz and a reaction gas of a mixture of 30% oxygen, 20% air and 50% nitrogen), and the plasma-treated polystyrene foam particles are immersed in a graphene oxide dispersion for 25 minutes, and then taken out and dried at 90°C for 24 hours to obtain graphene-modified foam particles that do not contain cage-type silsesquioxane.

[0115] This comparative example provides a thermal insulation material of graphene-modified foam particles without cage-type silsesquioxane, which is prepared by the following preparation method, and the specific steps include:

[0116] (1) 17 g of phosphogypsum, 3 g of talc, 41 g of graphene-modified foam particles not containing cage-type silsesquioxane, 2 g of chopped fibers (basalt fibers), and 4 g of additives (1.5 parts by mass of PVP, 0.5 parts by mass of citric acid, and 2 parts by mass of methyl hydroxypropyl cellulose ether) were uniformly mixed to obtain a dry blend;

[0117] (2) mixing the dry blend with 33 g of water and stirring to obtain a stirred material;

[0118] (3) Filling the stirred material into a mold and curing it at 25° C. for 7 days to obtain a thermal insulation material of graphene-modified foam particles free of cage-type silsesquioxane.

[0119] The difference between Comparative Examples 1 to 5 and Example 1 is that Comparative Example 1 is a thermal insulation material of polystyrene foam particles without cage-type silsesquioxane and graphene oxide, Comparative Example 2 is a thermal insulation material of cage-type silsesquioxane-modified foam particles without graphene, and Comparative Example 3 is a thermal insulation material of graphene-modified foam particles without cage-type silsesquioxane.

[0120] The thermal insulation materials formed in Examples 1 to 5 and Comparative Examples 1 to 3 were tested for dry density (GB / T20473-2021 Building thermal insulation mortar), compressive strength (GB / T5486-2008 Test method for inorganic rigid thermal insulation products), thermal conductivity (GB / T10294-2008 Determination of steady-state thermal resistance and related properties of thermal insulation materials - guarded hot plate method), and combustion performance (GB8624-2012 Classification of combustion performance of building materials and products). The results are shown in Table 1 below:

[0121] Table 1. Test results of thermal insulation material performance

[0122]

[0123]

[0124] It can be seen from the results of the above tests that the graphene flame retardant thermal insulation materials of Examples 1 to 5 of the present invention have significant performance advantages in comprehensive performance (dry density, compressive strength, thermal conductivity, combustion performance, etc.) compared with the thermal insulation materials of other comparative examples 1 to 3 due to the synergistic interaction of the graphene oxide grafted with cage-type silsesquioxane on the polystyrene foam particles.

[0125] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A graphene flame retardant thermal insulation material, characterized in that: The components include the following in parts by mass: Water: 30-34 parts; Phosphogypsum: 15-19 parts; Talc: 3-6 parts; Graphene modified foam particles: 38-44 parts; Chopped fiber: 1-3 parts; Additives: 3 to 5 parts.

2. A graphene flame retardant thermal insulation material according to claim 1, characterized in that: The chopped fibers are at least one of aluminum silicate fibers, polypropylene fibers, glass fibers, basalt fibers, polyacrylonitrile fibers, and polyvinyl alcohol fibers.

3. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The phosphogypsum is hemihydrate phosphogypsum, and the particle size of the phosphogypsum is 5 to 50 μm.

4. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The auxiliary agents include dispersants, retarders and water retaining agents.

5. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The whiteness of the talcum powder is not less than 75%, and the fineness of the talcum powder is 300-1000 meshes.

6. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The preparation method of the graphene-modified foam particles comprises the following steps: (1) dispersing 1 g of graphene oxide in 100 mL of anhydrous ethanol, adding 0.5 g of aminosilane and an appropriate amount of epoxy cage-type silsesquioxane, heating at 70 to 75° C. under reflux conditions, and reacting for 60 to 120 min to obtain a cage-type silsesquioxane-grafted graphene oxide dispersion; (2) The polystyrene foam particles are treated with a plasma treatment machine for 30 to 120 seconds, and the plasma-treated polystyrene foam particles are immersed in a dispersion of graphene oxide grafted with cage-type silsesquioxane for 15 to 30 minutes, and then taken out and dried at 60 to 90° C. for 24 hours to obtain graphene-modified foam particles.

7. The graphene flame retardant thermal insulation material according to claim 6, characterized in that: The thickness of the graphene oxide is less than or equal to 3 nm, and the lateral size of the graphene oxide is greater than or equal to 10 μm.

8. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The aminosilane is at least one of 3-aminopropylmethyldimethoxysilane, aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

9. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The epoxy cage type silsesquioxane is at least one of epoxycyclohexyl cage type polysilsesquioxane, monoepoxy cage type polysilsesquioxane, octaepoxy cage type polysilsesquioxane and triepoxy cage type polysilsesquioxane, and the mass ratio of graphene oxide to epoxy cage type silsesquioxane is 1.5:1 to 2.5:

1.

10. The graphene flame retardant thermal insulation material according to claim 1, characterized in that: The excitation frequency of the plasma treatment machine is at least one of 40 kHz, 13.56 MHz and 2.45 GHz, and the content of oxygen in the reaction gas is not less than 20%.

11. A method for preparing the graphene flame retardant thermal insulation material according to any one of claims 1 to 10, characterized in that: The following steps are involved: S1. Evenly mixing phosphogypsum, talcum powder, graphene-modified foam particles, chopped fibers and additives to obtain a dry mix; S2, mixing the dry mixed material with water to uniformly prepare a graphene flame retardant thermal insulation material to obtain a stirred material; S3, filling the stirred material into a mold, and curing at 25° C. for 7 days to obtain a graphene flame retardant heat-insulating material.

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