A burn-resistant foam material and its preparation method and use

Abstract

The application discloses an anti-burning foam material and a preparation method and application thereof, and belongs to the technical field of composite materials. The anti-burning foam material comprises the following raw materials in parts by mass: 1-40 parts of gypsum, 1-50 parts of a foam stabilizer, 1-50 parts of a foaming agent, 1-80 parts of an auxiliary agent and 10-150 parts of water; the foam stabilizer is selected from nanoparticles, and the average particle size of the nanoparticles is 1-100 nm. The gypsum is introduced into the anti-burning foam material, the gypsum can absorb heat and release water vapor by evaporating crystal water when facing high temperature, and the gypsum can impart good flame-retardant performance to the foam material. Furthermore, the gypsum is dispersed at the high-plateau boundary of the foam to form a bridging structure, the foam stability is stabilized, the foam structure is not easily damaged when the foam is heated, and the physical barrier formed by the nanoparticles dispersed on the surface of the foam can effectively stabilize the foam and improve the fire extinguishing performance.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and in particular relates to a fire-resistant foam material, its preparation method and application. Background Technology

[0002] Foam extinguishing agents are the most common and effective method for extinguishing liquid fuel fires. Among them, water film foam (AFFF) exhibits the best extinguishing effect in petrochemical fires. Foam stability is a crucial factor determining the extinguishing efficiency of foam extinguishing agents; however, foam is a thermodynamically unstable structure and is destined to disintegrate over time. Furthermore, many hydrocarbon oils in foam extinguishing agents have a defoaming effect, which further hinders the stability of the foam film. To improve the stability of foam in the presence of oil, fluorocarbon surfactants are added to extinguishing foam formulations to help the foam maintain stability in the presence of oil, enabling it to better form a physical barrier to isolate flames and ignition sources, inhibit the release of flammable vapors, and improve reignition prevention performance.

[0003] However, a growing body of research indicates that fluorocarbon surfactants are biodegradable in the environment, exhibiting long-term non-hydrolysis and non-biodegradability, and can accumulate and migrate within the food chain. The production and application of some traditional long-chain fluorocarbon surfactants used in AFFFs have been severely restricted. Furthermore, existing fluorine-free foam extinguishing agents suffer from poor fire resistance, slow extinguishing speed, and inadequate extinguishing effect due to difficulties in ensuring foam stability. Therefore, developing a stable, high-performance fluorine-free fire extinguishing foam has significant social and environmental benefits. Summary of the Invention

[0004] In order to overcome the problems existing in the prior art, one of the objectives of the present invention is to provide a fire-resistant foam material, which has good stability and good fire resistance and extinguishing effect.

[0005] The second objective of this invention is to provide a method for preparing the above-mentioned fire-resistant foam material.

[0006] The third objective of this invention is to provide an application of the above-mentioned fire-resistant foam material in the field of fire protection.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a heat-resistant foam material comprising the following raw materials in parts by weight: 1-40 parts gypsum, 1-50 parts foam stabilizer, 1-50 parts foaming agent, 1-80 parts additives, and 10-150 parts water; wherein the foam stabilizer is selected from nanoparticles, and the average particle size of the nanoparticles is 1-100 nm.

[0009] The inventive concept of this invention is as follows: This invention introduces nanoparticles as foam stabilizers into foam materials. Based on the Pickering effect, the adsorption of solid particles at the liquid interface can reduce the surface tension of the liquid, which is beneficial to the formation of stable Pickering foam. Furthermore, the solid particles form a shell around the dispersed phase and a physical barrier in the continuous phase, preventing the liquid phase from coalescing and draining, thereby stabilizing the foam. In addition, the main component of gypsum is hydrated calcium sulfate, which contains water of crystallization. When exposed to high temperatures, gypsum absorbs heat and releases water vapor by evaporating the water of crystallization. This process can slow down the combustion rate and prevent the spread of fire. Therefore, adding gypsum can give the foam material good flame retardant properties. By adding nanoparticles and gypsum, the foam can be stabilized and the fire extinguishing performance can be improved simultaneously.

[0010] Preferably, the gypsum is selected from β-type hemihydrate gypsum.

[0011] β-type hemihydrate gypsum, also known as building gypsum, is a flaky crystal with cracks. It has very fine crystals and a much larger specific surface area than α-type hemihydrate gypsum. β-type hemihydrate gypsum has good fire resistance and can provide good fire resistance when dispersed around foam.

[0012] Preferably, the gypsum accounts for 5-30% by mass in the raw materials for preparing the fire-resistant foam material; more preferably, 10-25%; and even more preferably, 12-20%.

[0013] Preferably, the foaming agent is selected from cationic surfactants; more preferably, the cationic surfactant is selected from nitrogen-containing organic compounds; even more preferably, the cationic surfactant includes at least one of amine salt type, quaternary ammonium salt type, heterocyclic type or onium salt type cationic surfactants.

[0014] Because gypsum has a negative zeta potential in water, a positively charged cationic surfactant is chosen as the foaming agent to better disperse gypsum particles or clusters. When gypsum particles interact with water, they release calcium and sulfate ions. Calcium ions combine with hydroxide ions in the water to form calcium hydroxide, while some sulfate ions may remain free. Sulfate ions from the gypsum particles are expected to be adsorbed onto the cationic surfactant through electrostatic interactions between their oppositely charged surfaces. The gypsum particles are uniformly dispersed around the foam, forming a shielding layer on the foam surface. This shielding layer effectively prevents the entry of flames and heat, protecting the internal foam structure from damage, thus obtaining an ultra-lightweight and ultra-stable fire-resistant foam material.

[0015] Preferably, the average particle size of the nanoparticles is 10–50 nm; more preferably, it is 15–30 nm.

[0016] Preferably, the absolute value of the zeta potential of the nanoparticles in water is ≥30mV; more preferably ≥35mV. The absolute value of the zeta potential represents its stability, and positive or negative indicates the type of charge carried by the particle. The higher the absolute value of the zeta potential (positive or negative), the more stable the system. Using nanoparticles with high absolute values ​​of zeta potential as foam stabilizers can effectively stabilize the foam system.

[0017] Preferably, the nanoparticles have a negative zeta potential in water; more preferably, the nanoparticles include at least one of nano-silicon oxide, nano-calcium carbonate, nano-titanium oxide, nano-alumina, nano-zinc oxide, or nano-zirconia.

[0018] Nanoparticles with a negative zeta potential in water carry a negative charge on their surface and have a good adsorption effect with positively charged cationic surfactants, which can be adsorbed onto the surface of cationic surfactants to stabilize foam.

[0019] In some embodiments of the present invention, the nanoparticles are selected from nano-silica. Nano-silica particles have a Zeta potential of approximately -40 mV, allowing them to disperse well in solution and adsorb onto the surface of cationic surfactants. Therefore, the negatively charged nano-silica in water exhibits good synergistic effects with the cationic surfactants, resulting in stable foam.

[0020] Preferably, the additive includes a viscosity modifier, a dispersant, or a combination thereof; more preferably, the additive includes a viscosity modifier and a dispersant.

[0021] Preferably, the viscosity modifier includes at least one of hydroxypropyl methylcellulose (HPMC), polyvinyl alcohol (PVA), or polyacrylamide (PAM).

[0022] In some embodiments of the present invention, the viscosity modifier comprises the following raw materials in parts by weight: 1 to 30 parts hydroxypropyl methylcellulose, 1 to 50 parts polyvinyl alcohol, and 1 to 30 parts polyacrylamide.

[0023] In other embodiments of the invention, the viscosity modifier is selected from hydroxypropyl methylcellulose or polyvinyl alcohol.

[0024] Preferably, the dispersant is selected from polyethylene glycol; more preferably, the average molecular weight of the polyethylene glycol is 1000-3000; even more preferably, it is 2000.

[0025] Preferably, the raw materials for preparing the anti-burn foam material contain 5 to 30 parts by mass of gypsum; more preferably 10 to 20 parts by mass.

[0026] Preferably, the mass fraction of the foam stabilizer in the raw materials for preparing the anti-burning foam material is 1 to 40 parts; more preferably, it is 1 to 30 parts.

[0027] Preferably, the foaming agent in the raw materials for preparing the anti-burn foam material is 1 to 40 parts by mass; more preferably, it is 3 to 30 parts by mass.

[0028] Preferably, the mass fraction of the additives in the raw materials for preparing the anti-burn foam material is 2 to 50 parts; more preferably, it is 2 to 25 parts.

[0029] Preferably, the water content in the raw materials for preparing the anti-burn foam material is 20-120 parts by mass; more preferably 50-90 parts by mass.

[0030] Preferably, the anti-burn foam material comprises the following raw materials in parts by weight: 5-30 parts gypsum, 1-40 parts foam stabilizer, 1-40 parts foaming agent, 1-50 parts additives, and 20-120 parts water.

[0031] More preferably, the anti-burn foam material comprises the following raw materials in parts by weight: 10-20 parts gypsum, 1-30 parts foam stabilizer, 3-30 parts foaming agent, 1-25 parts additives, and 50-90 parts water.

[0032] Preferably, the viscosity modifier comprises 1 to 30 parts by mass; more preferably 1 to 20 parts; and even more preferably 1 to 10 parts.

[0033] Preferably, the dispersant in the additive is 1 to 50 parts by mass; more preferably 1 to 30 parts; and even more preferably 1 to 15 parts.

[0034] Preferably, the anti-burn foam material comprises the following raw materials in parts by weight: 1-40 parts gypsum, 1-50 parts foam stabilizer, 1-50 parts foaming agent, 1-30 parts viscosity modifier, 1-50 parts dispersant, and 10-150 parts water.

[0035] Preferably, the anti-burn foam material comprises the following raw materials in parts by weight: 5-30 parts gypsum, 1-40 parts foam stabilizer, 1-40 parts foaming agent, 1-20 parts viscosity modifier, 1-30 parts dispersant, and 20-120 parts water.

[0036] More preferably, the anti-burn foam material comprises the following raw materials in parts by weight: 10-20 parts gypsum, 1-30 parts foam stabilizer, 3-30 parts foaming agent, 1-10 parts viscosity modifier, 1-15 parts dispersant, and 50-90 parts water.

[0037] Preferably, the expansion ratio of the anti-burn foam material is 10 to 20 times; more preferably, it is 11 to 17 times.

[0038] Preferably, the foam density of the fire-resistant foam material is 40-150 g / L; more preferably, it is 50-100 g / L.

[0039] The second aspect of the present invention provides a method for preparing the anti-burn foam material described in the first aspect of the present invention, comprising the following steps: first mixing and foaming a foam stabilizer, a foaming agent, a viscosity modifier, a dispersant and water to obtain a foaming liquid, and then adding gypsum for a second mixing to obtain the anti-burn foam material.

[0040] Preferably, in the preparation method of the anti-burning foam material, the total mass ratio of the foam stabilizer, foaming agent, viscosity modifier, and dispersant to water is 1:(10-300); more preferably, it is 1:(100-300).

[0041] Preferably, in the preparation method of the anti-burn foam material, the mass ratio of foaming liquid to gypsum is (100-300):1.

[0042] Preferably, in the preparation method of the anti-burn foam material, the foam density of the foaming liquid is 40-150 g / L.

[0043] A third aspect of the present invention provides an application of the fire-resistant foam material described in the first aspect of the present invention in the field of fire protection.

[0044] In some embodiments of the present invention, the fire protection field includes petroleum fire protection or chemical fire protection.

[0045] The beneficial effects of this invention are:

[0046] This invention introduces gypsum into a fire-resistant foam material. When exposed to high temperatures, gypsum absorbs heat and releases water vapor by evaporating its water of crystallization. This process slows the combustion rate and prevents the spread of fire, thus endowing the foam material with excellent flame-retardant properties. Furthermore, the gypsum dispersed at the high-altitude boundaries of the foam forms a bridging structure, stabilizing the foam and preventing damage to its structure when heated. Combined with the physical barrier formed by nanoparticles dispersed on the foam surface, this effectively stabilizes the foam and improves its fire-extinguishing performance. The fire-resistant foam material of this invention has wide applications in the fire protection field.

[0047] Specifically, compared with the prior art, the present invention has the following advantages:

[0048] 1. The fire-resistant foam material in this invention, at an extremely low density (60 kg / m³), 3 It exhibits excellent stability, maintaining a deformation of <5% for 2 hours at room temperature; and at ultra-low densities (60 kg / m³). 3It exhibits good fire resistance, showing no significant morphological change after 30 seconds of burning; it can persist for 80 seconds under high temperature conditions (approximately 120°C); when flammable liquids are on fire, the amount of extinguishing foam required is 1 / 2 or less of that used in commercially available aqueous film-forming foam extinguishing agents to extinguish the fire; and its endothermic reaction enthalpy is 10 times that of building gypsum materials.

[0049] 2. This invention uses only a small amount of gypsum to enable foam materials to achieve better fire resistance and extinguishing effects.

[0050] 3. The fire-resistant foam material in this invention has excellent stability, environmental performance and fire extinguishing performance, providing a new approach for the research and development of environmentally friendly and efficient fire extinguishing foam. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of a foam material stability testing device in a specific embodiment of the present invention.

[0052] Figure 2 This is a schematic diagram of a foam material fire extinguishing experimental device according to a specific embodiment of the present invention.

[0053] Figure 3 The initial height-time curves are for preparing foam materials of Examples 1-2, Example 1, and Comparative Example 1.

[0054] Figure 4 The liquid discharge-time curves are for the foam materials prepared in Examples 1-2, Example 1, and Comparative Example 1.

[0055] Figure 5 This is a schematic diagram of the stability test of the foam materials prepared in Example 1, Examples 1-2 and Comparative Example 3 at a high temperature of 120°C.

[0056] Figure 6 This is a schematic diagram illustrating the instantaneous burn resistance test of the foam materials prepared in Example 1, Examples 1-2, and Comparative Examples 1-3.

[0057] Figure 7 This is a schematic diagram of the fire extinguishing performance of the foam materials in Example 1 and Comparative Example 3.

[0058] Figure 8 The above are DSC diagrams of the foam material and building plaster material in Example 1. Detailed Implementation

[0059] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0060] In the preparation examples, embodiments, and comparative examples of the present invention, all materials used were purchased from Mecox Lane or Aladdin. Among them, the gypsum was building gypsum; the foaming agent was a cationic surfactant; the viscosity modifier was PVA (polyvinyl alcohol); the foam stabilizer was nano-silica with an average particle size of 15-30 nm; and the dispersant was polyethylene glycol PEG-2000.

[0061] Preparation Example 1

[0062] A nano foaming liquid, the composition of which is shown in Table 1.

[0063] Table 1 Composition of Nanofoaming Liquid

[0064]

[0065]

[0066] By foaming the nano-foaming liquid in this example, nano-foam materials can be obtained.

[0067] Preparation Example 2

[0068] A common foaming liquid, the composition of which is shown in Table 2, is provided. Compared with the nano foaming liquid of Preparation Example 1, the common foaming agent in this example does not contain foam stabilizer nanoparticles and dispersant.

[0069] Table 2 Composition of ordinary foaming liquid

[0070] Component Name Quality foaming agent 15 Viscosity modifier 1 Deionized water 200

[0071] By foaming the ordinary foaming liquid in this example, ordinary foam material can be obtained.

[0072] Example 1

[0073] A heat-resistant foam material is prepared in two stages. The first stage involves preparing a foaming liquid (the foaming liquid is the nano-foaming liquid from Preparation Example 1, and the raw material composition is shown in Table 1). The second stage involves preparing a gypsum-containing heat-resistant foam material (the raw material composition is shown in Table 3). The specific preparation process includes the following steps:

[0074] Step 1: Take deionized water into a three-necked flask equipped with a stirrer according to the mass proportions in Table 1. Place the three-necked flask in a water bath and adjust the temperature to 70°C. Slowly add the viscosity modifier and stir for 6 hours to fully dissolve it. Turn off the water bath and wait for the solution to cool to room temperature for later use.

[0075] Step 2: Add the foaming agent and foam stabilizer (if needed) slowly in batches to the three-necked flask, and continue stirring for 1 hour until they are completely dissolved.

[0076] Step 3: After adding the dispersant, continue stirring for 30 minutes. After stirring, transfer the three-necked flask to an ultrasonic disperser and sonicate for 30 minutes to obtain the foaming liquid.

[0077] Step 4: Use a mechanical stirrer to vigorously stir the foaming liquid for 5 minutes to obtain stable foam with a density of 40g / L to 120g / L.

[0078] Step 5: Add the building plaster to the well-foamed foam and stir at low speed with a mechanical mixer for 30 seconds to obtain the fire-resistant foam material.

[0079] Example 2

[0080] The only difference between this example and Example 1 is the amount of gypsum added. The specific amounts of raw materials are shown in Table 3. The preparation process is the same as in Example 1.

[0081] Comparative Examples 1-2

[0082] The difference between Comparative Examples 1 and 2 and Example 1 is that the foaming liquid in Comparative Examples 1 and 2 is the same as that in Example 2 (raw material composition is shown in Table 2), and the amount of gypsum added is different. The specific raw material amounts are shown in Table 3. The preparation process is the same as that in Example 1.

[0083] Comparative Example 3

[0084] A foam material, wherein the foaming liquid is commercially available AFFF, and the foaming method includes the following steps:

[0085] Step 1: Mix 6% AFFF stock solution with 94% water.

[0086] Step 2: Use a mechanical stirrer to vigorously stir the foaming liquid for 5 minutes to obtain stable foam with a density of 80g / L to 90g / L.

[0087] Table 3. Raw material composition of the examples and comparative examples (unit: parts by mass)

[0088]

[0089] Performance testing

[0090] 1. The foaming ratio is calculated using the following formula: For details, please refer to Appendix 3 of the "Technical Standard for Foam Fire Extinguishing Systems GB50151-2021".

[0091] 2. Foam density is calculated by weighing a container of a certain volume using existing density measurement methods. In this invention, a 100mL glass cup is selected as the fixed container.

[0092] 3. Burn resistance test: Burn resistance here specifically refers to immediate burn resistance. Place the foam material on an alcohol lamp flame and burn it. If the foam does not show significant volume change after 30 seconds under the influence of the alcohol lamp, it is considered to have immediate burn resistance.

[0093] 4. The half-life and discharge volume were tested using... Figure 1 The foam material stability testing device shown is based on the testing principle of Appendix A, "Foam Settling Distance and Bleeding Rate Measuring Instrument," in "JC2199T-2013 Foaming Agent for Foamed Concrete." This invention uses two indicators—half-life and drainage volume—to represent foam stability; a longer half-life and a smaller drainage volume indicate higher foam stability.

[0094] 5. Fire extinguishing performance test: using methods such as... Figure 2 The fire extinguishing experimental apparatus for foam materials shown is illustrated in (A) as a structural schematic diagram and (B) as a physical image. 5 mL of n-heptane was placed in a 14 cm diameter stainless steel fire tray as fuel and ignited. 3.5 g of foam material was spread evenly in a 14 cm diameter sieve with a 40-mesh aperture as a foam plate. The foam plate was moved towards the center of the combustion as the fire extinguishing material, and the fire extinguishing effect was observed.

[0095] 6. DSC test: Analyze the heat absorption and release capabilities of different materials through test results.

[0096] The expansion ratio, foam density, and fire resistance of the foam material are shown in Table 4.

[0097] Table 4. Expansion ratio, foam density, and fire resistance of foam materials

[0098] Foaming ratio Foam density (g / L) Is it heat resistant? Preparation Example 1 20 50 no Preparation Example 2 20 50 no Example 1 16.7 61 yes Example 2 11.4 85 yes Comparative Example 1 16.7 61 no Comparative Example 2 11.4 85 yes Comparative Example 3 11.4 85 no

[0099] As shown in Table 4, the expansion ratio of the fire-resistant foam materials in Examples 1 and 2 is approximately 11 to 17 times, and the foam density is 61 to 85 g / L, all exhibiting good fire resistance. While Comparative Example 1 and Example 1 have the same foam density, Comparative Example 1 is not fire-resistant; it only achieves fire resistance when the foam density is increased to 85 g / L (Comparative Example 2). This indicates that Examples 1 and 2 can achieve fire resistance at lower foam densities.

[0100] Figure 3 The initial height-time curves of the foam materials prepared in Examples 1-2, Example 1, and Comparative Example 1 are shown. Figure 4 The liquid discharge-time curves for the foam materials prepared in Examples 1-2, Example 1, and Comparative Example 1 are shown. Figures 3-4 It is evident that the fire-resistant foam materials prepared according to the methods of Examples 1 and 2 of this invention all exhibit high stability and ultra-low liquid discharge. In particular, in Example 1, the addition of foam stabilizer and gypsum significantly increased foam stability, with a half-life of 360 minutes. Compared to the nanofoam prepared in Example 1 without gypsum, the half-life was extended by 1.2 times, and the liquid discharge was greatly reduced. This demonstrates that the presence of gypsum can improve the stability of the foam system. Compared to Comparative Example 1 without nanoparticles, the half-life of Example 1 is approximately twice that of Comparative Example 1. It can be seen that foam stabilizers play a crucial role in optimizing the stability of gypsum foam materials. Many studies consider foam stability to be one of the key factors in firefighting. Improving foam stability helps to effectively isolate heat transfer between fuel and flame during a fire, which is vital for achieving fire extinguishing with foam materials.

[0101] Figure 5 This is a schematic diagram showing the stability test of the foam materials prepared in Example 1, Examples 1-2 and Comparative Example 3 at a high temperature of 120°C. (A) is Example 1, with a foam density ρ = 61 kg / m³. 3 (B) is Example 2, with a foam density ρ = 85 kg / m³. 3 (C) is Comparative Example 3, with foam density ρ = 85 kg / m³. 3 (D) is the nanofoam material prepared in Example 1, with a foam density ρ = 50 kg / m³. 3 The red area represents the surface of the high-temperature furnace; its red color indicates that the foam has evaporated. Figure 5 It can be seen that in Examples 1, 2, and Comparative Example 3, a 5mm thick foam was used for stability testing at 120°C. The experimental results show that Example 1 evaporated completely in about 80 seconds at this high temperature, Example 2 evaporated completely in about 100 seconds, while Comparative Example 3 evaporated completely within 50 seconds. It can be seen that the stability of gypsum nanofoam at high temperature (120°C) is higher than that of commercial fire extinguishing foam. Furthermore, the more gypsum particles added, the longer the foam's existence time, indicating that the presence of gypsum flame-retardant particles prolongs the foam evaporation time, and the amount of gypsum added is positively correlated with the foam's stability at high temperatures. In addition, from... Figure 5 As can be seen, after the foam evaporates in Examples 1 and 2, a dense covering layer composed of gypsum particles is formed on the surface. This layer can effectively isolate the heat transfer to the interior and may enhance its fire resistance, which plays a crucial role in the fire extinguishing of foam materials.

[0102] Figure 6 This is a schematic diagram illustrating the instantaneous burn resistance test of the foam materials prepared in Examples 1, 1-2, and 1-3. (A) shows Example 1 with a foam density ρ = 61 kg / m³. 3 (B) is Example 2, with a foam density ρ = 85 kg / m³. 3 (C) is Comparative Example 1, with foam density ρ = 61 kg / m³. 3 (D) is Comparative Example 2, with foam density ρ = 85 kg / m³. 3 (E) is Comparative Example 3, with foam density ρ = 85 kg / m³. 3 (F) shows the nanofoam material prepared in Example 1, with a foam density ρ = 50 kg / m³. 3 .from Figure 6 As can be seen, compared with Example 1, Comparative Example 1 did not exhibit fire resistance at the same density, indicating that the addition of the foam stabilizer in this invention is of great significance for the fire resistance of gypsum foam materials at low densities. This may be closely related to the stability of the foam; foams with higher stability can achieve fire resistance with less gypsum content. Furthermore, Examples 1-2 and Comparative Example 2 all showed good immediate fire resistance, while Comparative Example 3 without added gypsum particles and the nanofoam of Preparation Example 1 showed no fire resistance. This indicates that the addition of gypsum particles plays an important role in the immediate fire resistance of the foam, and the immediate fire resistance of the foam improves with increasing addition amount.

[0103] Figure 7 The diagram illustrates the fire extinguishing performance of the foam materials in Example 1 and Comparative Example 3, where (A) uses 3.5g of the foam material from Example 1, (B) uses 3.5g of the foam material from Comparative Example 3, and (C) uses 7g of the foam material from Comparative Example 3. Figure 7 It can be seen that in both Example 1 and Comparative Example 3, 5 mL of n-heptane was placed in a 14 cm diameter stainless steel dish as fuel, and 3.5 g of foam material was spread evenly in a 14 cm diameter 40-mesh sieve as extinguishing material. When the foam dish moved towards the combustion center at a constant speed, the foam in Example 1 maintained good stability and eventually extinguished the fire. That is, Example 1 only required 3.5 g of gypsum foam with a foam density of 61 g / L to achieve a good extinguishing effect on 5 mL of n-heptane. In contrast, the foam in Comparative Example 3 evaporated and broke down quickly, evaporating completely before reaching the combustion center and failing to extinguish the fire. Only when the amount in Comparative Example 3 was increased to twice that of 7 g could the fire be extinguished, but the extinguishing time was extended to 20 seconds. The experimental results show that the addition of a small amount of building gypsum greatly improves the fire extinguishing effect of the foam material, thanks to the excellent fire resistance and high-temperature resistance of building gypsum itself. Compared with commercial fire extinguishing foam, the foam material with a small amount of gypsum added has a better fire extinguishing effect.

[0104] In addition, further testing was conducted using 5 mL of alcohol as fuel, and the results are shown in Table 5. As can be seen from Table 5, the fire extinguishing effect of Example 1 is still better than that of Comparative Example 3.

[0105] Table 5. Fire extinguishing performance of foam materials in Example 1 and Comparative Example 3.

[0106] fuel Fire extinguishing materials Dosage (g) Fire extinguishing effect 1 5 mL of n-heptane Example 1 3.5 It takes about 10 seconds to extinguish the fire. 2 5 mL of n-heptane Comparative Example 3 3.5 The foam evaporates in about 20 seconds, making it impossible to extinguish the fire. 3 5 mL of n-heptane Comparative Example 3 7 It takes about 20 seconds to extinguish the fire. 4 5mL of alcohol Example 1 3.5 It takes about 10 seconds to extinguish the fire. 5 5mL of alcohol Comparative Example 3 3.5 The foam evaporates in about 20 seconds, making it impossible to extinguish the fire. 6 5mL of alcohol Comparative Example 3 5 It takes about 20 seconds to extinguish the fire.

[0107] Figure 8 Table 6 shows the DSC diagrams of the foam material and building plaster material in Example 1.

[0108] Table 6. DSC results of foam materials and building plaster materials in Example 1.

[0109]

[0110] from Figure 8 As shown in Table 5, during the heating process, Example 1 undergoes two endothermic reactions, occurring at approximately 92°C and 140°C respectively. In contrast, building gypsum material only undergoes one endothermic reaction at approximately 131°C. By integrating the endothermic peaks, the total enthalpy change of Example 1 in the endothermic reaction is 1400 J / g, while that of building gypsum is 123.5 J / g. Example 1 absorbs ten times more heat than building gypsum, thus exhibiting superior performance in fire extinguishing applications.

[0111] The fire-resistant foam material in this invention has an extremely low density (60 kg / m³). 3 It exhibits excellent stability, maintaining a deformation of <5% for 2 hours at room temperature; and at ultra-low densities (60 kg / m³). 3 It exhibits excellent fire resistance, showing no significant morphological change after 30 seconds of burning; it can persist for 80 seconds under high-temperature conditions (approximately 120°C); when flammable liquids catch fire, the amount of extinguishing foam required is only 1 / 2 or less of that used in commercially available aqueous film-forming foam extinguishing agents to achieve fire suppression; its endothermic reaction enthalpy change is 10 times that of building gypsum materials, and only a trace amount of gypsum is needed to achieve good fire resistance and extinguishing effects. The fire-resistant foam material of this invention possesses excellent stability, environmental performance, and fire extinguishing performance, providing a new approach for the development of environmentally friendly and efficient fire extinguishing foams.

[0112] In summary, this invention introduces gypsum into the fire-resistant foam material. When exposed to high temperatures, gypsum absorbs heat and releases water vapor by evaporating its water of crystallization. This process slows the combustion rate and prevents the spread of fire, thus endowing the foam material with excellent flame-retardant properties. Furthermore, the gypsum dispersed at the plateau boundaries forms a bridging structure, stabilizing the foam and preventing damage to its structure when heated. Combined with the physical barrier formed by nanoparticles dispersed on the foam surface, this effectively stabilizes the foam and improves its fire-extinguishing performance. Simultaneously, this invention selects surfactants with specific physical properties as the foaming component, significantly reducing the amount of gypsum added. This achieves excellent fire-extinguishing performance while reducing the weight of the foam material, further enhancing its operability in the fire protection field. The fire-resistant foam material of this invention has wide applications in the fire protection field.

Claims

1. A fire-resistant foam material, characterized in that, The preparation materials include the following parts by weight: 1-40 parts gypsum, 1-50 parts foam stabilizer, 1-50 parts foaming agent, 1-80 parts additives, and 10-150 parts water; the foam stabilizer is selected from nanoparticles with an average particle size of 1-100 nm; the gypsum is selected from β-type hemihydrate gypsum.

2. The fire-resistant foam material according to claim 1, characterized in that, The gypsum accounts for 5-30% of the mass percentage of the raw materials used in the preparation of the fire-resistant foam material.

3. The fire-resistant foam material according to claim 1, characterized in that, The foaming agent is selected from cationic surfactants.

4. The fire-resistant foam material according to claim 1, characterized in that, The absolute value of the Zeta potential of the nanoparticles in water is ≥30mV.

5. The fire-resistant foam material according to claim 1, characterized in that, The nanoparticles include at least one of nano-silicon oxide, nano-calcium carbonate, nano-titanium oxide, nano-aluminum oxide, nano-zinc oxide, or nano-zirconia.

6. The fire-resistant foam material according to claim 1, characterized in that, The additives include viscosity modifiers, dispersants, or combinations thereof.

7. The fire-resistant foam material according to claim 6, characterized in that, The viscosity modifier includes at least one of hydroxypropyl methylcellulose, polyvinyl alcohol, or polyacrylamide; And / or, the dispersant is selected from polyethylene glycol.

8. The fire-resistant foam material according to claim 7, characterized in that, The viscosity modifier comprises the following raw materials in parts by weight: 1-30 parts hydroxypropyl methylcellulose, 1-50 parts polyvinyl alcohol, and 1-30 parts polyacrylamide.

9. A method for preparing the anti-burning foam material according to any one of claims 1 to 8, characterized in that, The process includes the following steps: first mixing and foaming the foam stabilizer, foaming agent, viscosity modifier, dispersant and water; then adding gypsum for a second mixing to obtain the fire-resistant foam material.

10. The application of the fire-resistant foam material according to any one of claims 1 to 8 in the field of fire protection.

Images