Fluoride-free environment-friendly aqueous film-forming foam extinguishing agent as well as preparation method and application thereof

Abstract

The invention discloses a fluoride-free environment-friendly aqueous film-forming foam extinguishing agent as well as a preparation method and application thereof, and the aqueous film-forming foam extinguishing agent comprises the following raw materials in percentage by mass: 10-13% of a compound bio-based surfactant, 8-10% of compound bio-based polyol, 1-2% of nano aluminum oxide sol, 0.5-1% of carboxylated nano calcium silicate and the balance of pure water. The preparation process is simple, the prepared aqueous film-forming foam extinguishing agent adopts the easily biodegradable compound bio-based surfactant as a core component, and the compound bio-based polyol is introduced, so that the freezing resistance, the solubilization property and the spreading rate are synergistically improved; the nano aluminum oxide sol and the carboxylated nano calcium silicate are used for enhancing the liquid film strength and cooling capacity, reducing the interfacial tension and improving the fire extinguishing performance, so that the biological risk and environmental problems caused by a traditional aqueous film-forming foam fire extinguishing agent are avoided, and meanwhile, effective control and efficient extinguishing of a fire disaster are realized; and an efficient and safe fire extinguishing agent alternative scheme is provided for the field of fire fighting.

Description

Technical field:

[0001] The present invention relates to the technical field of fire protection, and in particular to a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent, a preparation method thereof, and applications thereof. Background technology:

[0002] Aqueous film-forming foam (AFFF) forms a water film on the surface of hydrocarbon liquids, rapidly extinguishing fires through the synergistic effects of rapid coverage, cooling, and oxygen isolation. AFFF fire extinguishing is currently one of the most effective methods for combating liquid fires. However, the core components of AFFF contain C8-C12 long-chain fluorocarbon surfactants, such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid amine (PFOA), which are extremely environmentally persistent and have been listed as persistent organic pollutants (POPs) under the Stockholm Convention. The European Union, the United States, and other regions have also passed regulations to restrict or ban the production and sale of PFAS-containing fire extinguishing agents. China has also gradually phased out AFFF containing PFAS since the Stockholm Convention came into effect in 2014.

[0003] To solve the environmental problem, researchers have tried a variety of alternative solutions. One of the solutions is to reduce toxicity by shortening the fluorocarbon chain (such as C4-C6), but experiments show that its surface activity and thermal stability decrease significantly with the shortening of the fluorocarbon chain; another solution is to use hydrocarbon surfactants, silicone surfactants, etc. to replace PFOS to produce fluorine-free aqueous film-forming foam fire extinguishing agents. The wastewater and residues generated by these fire extinguishing agents during the fire extinguishing process have less impact on the environment, fundamentally avoiding the biological risks and environmental problems caused by fluorocarbon surfactants. However, the hydrophobic chains of hydrocarbon surfactants are similar to those of hydrocarbon fuels, which makes the foam easily dissolved by the fuel and difficult to form a stable liquid film. It is difficult to achieve the effect of fluorine-containing aqueous film-forming foam fire extinguishing agents in terms of fire extinguishing performance and spreading performance; and silicone surfactants have poor hydrophilicity and need to add a high content of organic solvents to improve foaming performance, which still poses an environmental risk.

[0004] In this context, the development of fluorine-free, biodegradable and highly efficient aqueous film-forming foam fire extinguishing agents has become an urgent need in the field of fire protection technology. Summary of the invention:

[0005] To address the above problems, the first object of the present invention is to provide a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent, which uses easily biodegradable bio-based surfactants as core components to solve the ecological hazards caused by fluorocarbon surfactants in traditional AFFF and achieve effective control and efficient fire extinguishing.

[0006] The second object of the present invention is to provide a method for preparing a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0007] The third object of the present invention is to provide an application of a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0008] The first object of the present invention is implemented by the following technical solutions:

[0009] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent. The raw materials of the aqueous film-forming foam fire extinguishing agent include, by mass percentage, 10-13% of a compounded bio-based surfactant, 8-10% of a compounded bio-based polyol, 1-2% of a nano-alumina sol, 0.5-1% of a carboxylated nano-calcium silicate, and the balance being pure water (the pure water having a conductivity of ≤6 μS / cm, a TOC of <10 ppb, and a bacterial content of <1 CFU / mL).

[0010] The rigid support structure formed by the nano-alumina sol in the foam liquid film can enhance the mechanical strength of the liquid film and resist disturbances from the external environment; the spatial steric hindrance effect of the nano-alumina sol can slow down the rate of water loss in the foam liquid film, which is beneficial to prolonging the action time of the fire extinguishing agent; and the phase change reaction of the nano-alumina sol at high temperature absorbs heat, which can significantly reduce the temperature of the fire scene; the nano-alumina sol, with its nano-particle dispersion advantages and dynamic film-forming ability, can achieve a synergistic improvement in flame retardancy, foam stability and environmental protection performance in the fire extinguishing agent.

[0011] The carboxylated nano-calcium silicate is prepared by chemically grafting or coating organic functional groups containing carboxyl groups (-COOH) (such as polycarboxylic acid, carboxymethyl cellulose, etc.) on the surface of nano-scale calcium silicate particles. The specific composition can be expressed as: CaSiO3·nH2O-(COOH) x(x is the number of carboxyl graftings), and the particle size is usually 10-100nm; the carboxylated nano calcium silicate is used in fire extinguishing agents, and through the nano-size effect and carboxyl functional modification, it achieves a dual improvement in flame retardancy and environmental protection in the fire extinguishing agent, and is particularly suitable for extreme fire scenes. Specifically, it can play the following roles: it decomposes in the flame, absorbs a large amount of heat, reduces the temperature of the combustion zone, and the decomposed SiO2 and CaO form a dense glassy protective layer to isolate oxygen from contact with combustibles; the carboxyl group (-COOH) combines with the surfactant in AFFF through hydrogen bonding or electrostatic interaction, reduces the foam liquid film rupture speed, and prolongs the liquid separation. time, which is conducive to enhancing the stability of the foam; and, the oxygen atoms in the carboxyl groups of the carboxylated nano-calcium silicate can also react with active free radicals (such as OH·, H·) in the flame, interrupting the chain combustion reaction, and the CO2 and SiO2 gel produced by decomposition can dilute the oxygen concentration in the combustion zone; in addition, the carboxylated nano-calcium silicate and the compounded bio-based surfactant are combined through hydrogen bonds to form a stable composite system, which reduces interfacial tension and improves the spreading speed and coverage uniformity of the foam. Through the synergistic effect of the nano-alumina sol and the carboxylated nano-calcium silicate, the surface activity and foam stability of the bio-based surfactant can be significantly improved.

[0012] Furthermore, the compounded bio-based surfactant includes N-methyl-N-lauroyl-glucosamine and alkyl glycoside APG10; the mass of the N-methyl-N-lauroyl-glucosamine accounts for 2 to 3% of the aqueous film-forming foam fire extinguishing agent; the mass of the alkyl glycoside APG10 accounts for 7 to 10% of the aqueous film-forming foam fire extinguishing agent.

[0013] The CAS number of the N-methyl-N-lauroyl-glucosamine is 87246-72-8, and the chemical formula is C 19 H 39 NO6 has low surface tension and good compatibility, which can promote the fire extinguishing agent to improve the foaming performance and foam stability. The alkyl glycoside APG10 (C10 Alkyl glucoside), CAS 54549-25-6, chemical formula C 16 H 32 O6 has excellent foaming performance and foam stability. The combination of N-methyl-N-lauroyl-glucosamine and alkyl polyglycoside APG10 utilizes their synergistic effect to significantly reduce interfacial tension, improve foam spreading speed, coverage uniformity, and stability. It can replace fluorocarbon surfactants and fundamentally address the ecological hazards caused by fluorocarbon surfactants in traditional AFFF.

[0014] Furthermore, the compounded bio-based polyol includes sorbitol and erythritol; the mass of the sorbitol accounts for 5-7% of the aqueous film-forming foam fire extinguishing agent; the mass of the erythritol accounts for 2-3% of the aqueous film-forming foam fire extinguishing agent.

[0015] The sorbitol (C6H 14 O6) and the erythritol (C4H 10 O4, a natural polyol containing multiple hydroxyl groups, is used in foam fire extinguishing agent formulations. It can bind water molecules through hydrogen bonds, reducing water activity and thus inhibiting ice crystal formation, acting as an antifreeze and stabilizer. This is the first time that two environmentally friendly, non-toxic, and pollution-free bio-based polyols have been combined, breaking through the traditional single antifreeze system. By combining novel bio-based ingredients with nanomaterials, the freezing point of the fire extinguishing agent is significantly lowered to below -50°C.

[0016] The second object of the present invention is implemented by the following technical solutions:

[0017] A method for preparing a fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises the following steps:

[0018] S1. Prepare the following raw materials by mass percentage: 10-13% of a composite bio-based surfactant, 8-10% of a composite bio-based polyol, 1-2% of a nano-alumina sol, 0.5-1% of a carboxylated nano-calcium silicate, and the balance of pure water;

[0019] S2. adding the compounded bio-based polyol to the compounded bio-based surfactant under slow stirring, and mixing thoroughly to obtain a mixed solution A;

[0020] S3, dispersing the nano-alumina sol in pure water, with the mass ratio of the nano-alumina sol to the pure water being 1:5, to form a transparent colloidal solution; slowly adding the carboxylated nano-calcium silicate to the transparent colloidal solution and stirring thoroughly to obtain a mixed solution B;

[0021] S4. Add the mixed solution B to the mixed solution A, and add the remaining pure water, and stir quickly and fully to obtain an aqueous film-forming foam fire extinguishing agent.

[0022] Compared with the preparation method of directly mixing the raw materials in proportion and adding water to stir, preparing AFFF according to steps S1-S4 as described above can realize the advantages of each component and comprehensively improve the performance indicators of AFFF such as foam stability, foaming height, foaming multiple, fire extinguishing time and anti-burning time.

[0023] Furthermore, the preparation method of the compounded bio-based surfactant comprises the following steps:

[0024] A1. Prepare N-methyl-N-lauroyl-glucosamine accounting for 2-3% of the mass of the aqueous film-forming foam fire extinguishing agent and alkyl polyglycoside APG10 accounting for 7-10% of the mass of the aqueous film-forming foam fire extinguishing agent;

[0025] A2, adding the N-methyl-N-lauroyl-glucosamine powder to pure water, mixing, heating and stirring until completely dissolved, to obtain an N-methyl-N-lauroyl-glucosamine solution;

[0026] A3, adding the alkyl glycoside APG10 powder to pure water, mixing, heating and stirring until completely dissolved, to obtain an alkyl glycoside APG10 solution;

[0027] A4. Fully mix the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution to obtain the composite bio-based surfactant.

[0028] Furthermore, in step A2, the mass ratio of the N-methyl-N-lauroyl-glucosamine powder to the pure water is 1:3, and the heating temperature is 60-70°C; in step A3, the mass ratio of the alkyl glycoside APG10 powder to the pure water is 1:3, and the heating temperature is 60-70°C.

[0029] Furthermore, the preparation method of the compounded bio-based polyol comprises the following steps:

[0030] B1. Prepare sorbitol accounting for 5-7% of the mass of the aqueous film-forming foam fire extinguishing agent and erythritol accounting for 2-3% of the mass of the aqueous film-forming foam fire extinguishing agent;

[0031] B2, adding the sorbitol powder to pure water, heating and stirring until completely dissolved, and cooling to room temperature to obtain a sorbitol solution;

[0032] B3, adding the erythritol powder to pure water, heating and stirring until completely dissolved, and cooling to room temperature to obtain an erythritol solution;

[0033] B4. Mixing the sorbitol solution and the erythritol solution to obtain the composite bio-based polyol.

[0034] Furthermore, in step B2, the mass ratio of the sorbitol powder to the pure water is 2:1, and the heating temperature is 70-80°C; in step B3, the mass ratio of the erythritol powder to the pure water is 1:5, and the heating temperature is 80-90°C.

[0035] Furthermore, the preparation method of the carboxylated nano calcium silicate comprises the following steps:

[0036] C1. Mix nano calcium silicate powder with pure water in a mass ratio of 1:10 and ultrasonically treat for 30 minutes to eliminate agglomerates and form a uniform nano calcium silicate suspension;

[0037] C2. adding 10 mol / L nitric acid solution to the nano-calcium silicate suspension to perform an acid etching reaction to form carboxylate on the surface of the nano-calcium silicate particles;

[0038] C3, adding 5% NaOH solution to the nano-calcium silicate suspension after the acid etching reaction in step C2 to neutralize the residual acid to pH 7.0, centrifuging and washing with pure water three times;

[0039] C4. Drying the washed nano-calcium silicate in step C3 to obtain the carboxylated nano-calcium silicate.

[0040] The third object of the present invention is implemented by the following technical solutions:

[0041] The invention discloses an application of a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent in fire extinguishing. When used, water is added to dilute the aqueous film-forming foam fire extinguishing agent into a solution, and the volume ratio of the aqueous film-forming foam fire extinguishing agent to water is 6:94.

[0042] Beneficial effects:

[0043] The present invention provides a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent, as well as a preparation method and application thereof. The aqueous film-forming foam fire extinguishing agent uses an easily biodegradable bio-based surfactant as a core component. While avoiding the biological risks and environmental problems caused by traditional aqueous film-forming foam fire extinguishing agents, it achieves effective control and efficient fire extinguishing, providing an efficient and safe fire extinguishing agent alternative for the fire protection field.

[0044] Specific advantages include the following:

[0045] 1. The present invention combines two non-polluting and easily degradable bio-based surfactants, N-methyl-N-lauroyl-glucosamine and alkyl polyglycoside APG10, to utilize their synergistic effect to significantly reduce interfacial tension, improve foam spreading speed, coverage uniformity and stability. This can replace fluorocarbon surfactants and fundamentally solve the ecological hazards caused by fluorocarbon surfactants in traditional AFFF.

[0046] 2. The combination of two environmentally friendly, non-toxic and pollution-free bio-based polyols, sorbitol and erythritol, binds water molecules through hydrogen bonds, reduces water activity and inhibits the formation of ice crystals. The two synergistically improve the antifreeze performance and stability of the bio-based surfactant.

[0047] 3. By introducing nano-alumina sol and carboxylated nano-calcium silicate, and utilizing the dispersion advantages and dynamic film-forming ability of nano-alumina sol, the synergistic improvement of flame retardancy, foam stability and environmental protection performance is achieved in the fire extinguishing agent; carboxylated nano-calcium silicate works synergistically with surfactants and nano-alumina sol to improve surface activity, enhance foam stability, spreading speed and coverage uniformity. Specific implementation method:

[0048] To more clearly and concisely illustrate the technical solutions, objectives, and advantages of the present invention, the present invention is further described in detail below with reference to specific embodiments. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0049] One aspect of the present invention provides a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent. The raw materials of the aqueous film-forming foam fire extinguishing agent include, by mass percentage, 10-13% of a compounded bio-based surfactant, 8-10% of a compounded bio-based polyol, 1-2% of nano-alumina sol, 0.5-1% of carboxylated nano-calcium silicate, and the balance is pure water.

[0050] Among them, the compound bio-based surfactant includes N-methyl-N-lauroyl-glucosamine and alkyl polyglycoside APG10; the mass of N-methyl-N-lauroyl-glucosamine accounts for 2-3% of the aqueous film-forming foam fire extinguishing agent; the mass of alkyl polyglycoside APG10 accounts for 7-10% of the aqueous film-forming foam fire extinguishing agent.

[0051] Among them, the compounded bio-based polyols include sorbitol and erythritol; the mass of sorbitol accounts for 5-7% of the aqueous film-forming foam fire extinguishing agent; the mass of erythritol accounts for 2-3% of the aqueous film-forming foam fire extinguishing agent.

[0052] Among them, the conductivity of pure water is ≤6μS / cm, TOC is <10ppb, and the bacterial content is <1CFU / mL.

[0053] Another aspect of the present invention provides a method for preparing a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent, comprising the following steps:

[0054] S1. Prepare the following raw materials by mass percentage: 10-13% of a composite bio-based surfactant, 8-10% of a composite bio-based polyol, 1-2% of a nano-alumina sol, 0.5-1% of a carboxylated nano-calcium silicate, and the balance of pure water;

[0055] S2. Add the compounded bio-based polyol to the compounded bio-based surfactant under slow stirring, and mix thoroughly to obtain a mixed solution A;

[0056] S3. Dispersing the nano-alumina sol in pure water at a mass ratio of 1:5 to pure water to form a transparent colloidal solution; slowly adding carboxylated nano-calcium silicate to the transparent colloidal solution and stirring thoroughly to obtain a mixed solution B;

[0057] S4. Add the mixed solution B to the mixed solution A, and add the remaining pure water, and stir quickly and thoroughly to obtain an aqueous film-forming foam fire extinguishing agent.

[0058] The preparation of the compounded bio-based surfactant comprises the following steps (wherein, the order of steps A2 and A3 can be interchanged):

[0059] A1. Prepare 2-3% of the mass of the aqueous film-forming foam fire extinguishing agent, N-methyl-N-lauroyl-glucosamine, and 7-10% of the mass of the aqueous film-forming foam fire extinguishing agent, alkyl polyglycoside APG10;

[0060] A2. Mix N-methyl-N-lauroyl-glucosamine powder and pure water in a mass ratio of 1:3, heat to 60-70°C, and stir until completely dissolved to obtain an N-methyl-N-lauroyl-glucosamine solution;

[0061] A3. Mix alkyl glycoside APG10 powder and pure water in a mass ratio of 1:3, heat to 60-70°C, and stir until completely dissolved to obtain alkyl glycoside APG10 solution;

[0062] A4. Fully mix the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution to obtain a compounded bio-based surfactant.

[0063] The preparation of the composite bio-based polyol comprises the following steps (the order of steps B2 and B3 can be interchanged):

[0064] B1. Prepare 5-7% of sorbitol and 2-3% of erythritol by weight of the aqueous film-forming foam fire extinguishing agent;

[0065] B2. Mix sorbitol powder and pure water in a mass ratio of 2:1, heat to 70-80°C, stir until completely dissolved, and cool to room temperature to obtain a sorbitol solution;

[0066] B3. Mix erythritol powder and pure water in a mass ratio of 1:5, heat to 80-90°C, stir until completely dissolved, and cool to room temperature to obtain an erythritol solution;

[0067] B4. Mixing the sorbitol solution and the erythritol solution to obtain a composite bio-based polyol.

[0068] The preparation of carboxylated nano calcium silicate comprises the following steps:

[0069] C1. Mix nano calcium silicate powder with pure water in a mass ratio of 1:10 and ultrasonically treat for 30 minutes to eliminate agglomerates and form a uniform nano calcium silicate suspension;

[0070] C2. Adding 10 mol / L nitric acid solution to the nano-calcium silicate suspension (the amount of nitric acid solution added is 8 times the mass of the nano-calcium silicate powder) to perform an acid etching reaction to form carboxylate on the surface of the nano-calcium silicate particles; wherein the reaction conditions of the acid etching reaction are: temperature of 70° C., stirring speed of 600 rpm, and reaction time of 5 h;

[0071] C3. Add 5% NaOH solution to the nano-calcium silicate suspension after acid etching in step C2 to neutralize the residual acid to pH 7.0, centrifuge and wash thoroughly with pure water three times; wherein the centrifugation parameters include: speed of 8000 rpm and separation time of 10 min;

[0072] C4. Drying the washed nano-calcium silicate in step C3 to obtain carboxylated nano-calcium silicate; wherein the drying conditions include: vacuum drying, drying temperature of 60° C., and drying time of 12 h.

[0073] Based on the above raw material ratio and preparation method, the obtained fluorine-free environmentally friendly aqueous film-forming foam fire extinguishing agent can achieve ideal fire extinguishing performance, with a foaming multiple of not less than 7, a surface tension of not more than 18mN / m, a 25% liquid separation time of not less than 4min, a fire extinguishing time of not more than 2min, a burn-resistant time of not less than 12min, a foaming height of not less than 188mm, a freezing point below -20°C, low-temperature resistance, and high frost resistance.

[0074] Another aspect of the present invention provides a fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent for use in fire extinguishing. When used, water is added to dilute the aqueous film-forming foam fire extinguishing agent into a solution, and the volume ratio of the aqueous film-forming foam fire extinguishing agent to water is 6:94.

[0075] The present invention is further described in detail below with more specific examples and comparative examples. In the following examples and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials and reagents used are all commercially available unless otherwise specified.

[0076] Example 1

[0077] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises, by weight percentage, 3% N-methyl-N-lauroyl-glucosamine, 10% alkyl glycoside APG10, 7% sorbitol, 3% erythritol, 1.5% nano-alumina sol, 0.75% carboxylated nano-calcium silicate, and 74.75% pure water.

[0078] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0079] 3% N-methyl-N-lauroyl-glucosamine powder was added to 9% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 10% alkyl glycoside APG10 powder was added to 30% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 7% sorbitol powder was added to 3.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 3% erythritol powder was added to 10% alkyl glycoside APG10 solution. 15% pure water is added, heated to 85-90°C, stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; the compound bio-based polyol is added to a compound bio-based surfactant under slow stirring, and the mixture is fully mixed to form a mixed solution A; 1.5% nano-alumina sol is dispersed in 7.5% water to form a transparent colloidal solution, and 0.75% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 9.75% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0080] Example 2

[0081] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises, by weight percentage, 2% N-methyl-N-lauroyl-glucosamine, 8% alkyl glycoside APG10, 6% sorbitol, 2% erythritol, 1% nano-alumina sol, 0.5% carboxylated nano-calcium silicate, and 80.5% pure water.

[0082] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0083] 2% N-methyl-N-lauroyl-glucosamine powder was added to 6% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 8% alkyl glycoside APG10 powder was added to 24% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; N-methyl-N-lauroyl-glucosamine solution and alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 6% sorbitol powder was added to 3% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 2% erythritol powder was added to 24% pure water, heated to 60-70°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution. 10% pure water is added to the mixture, heated to 85-90° C., stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a composite bio-based polyol; the composite bio-based polyol is added to a composite bio-based surfactant under slow stirring, and the mixture is fully mixed to form a mixed solution A; 1% nano-alumina sol is dispersed in 5% water to form a transparent colloidal solution, and 0.5% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 32.5% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0084] Example 3

[0085] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises, by weight percentage, 3% N-methyl-N-lauroyl-glucosamine, 7% alkyl glycoside APG10, 5% sorbitol, 3% erythritol, 1.5% nano-alumina sol, 1% carboxylated nano-calcium silicate, and 79.5% pure water.

[0086] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0087] 3% N-methyl-N-lauroyl-glucosamine powder was added to 9% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 7% alkyl glycoside APG10 powder was added to 21% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 5% sorbitol powder was added to 2.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 3% erythritol powder was added to 21% pure water, heated to 60-70°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution. 15% pure water is added to the mixture, heated to 85-90° C., stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a composite bio-based polyol; the composite bio-based polyol is added to a composite bio-based surfactant under slow stirring, and the mixture is fully mixed to form a mixed solution A; 1.5% nano-alumina sol is dispersed in 7.5% water to form a transparent colloidal solution, and 1% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 24.5% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0088] Example 4

[0089] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises, by weight percentage, 2.5% N-methyl-N-lauroyl-glucosamine, 8.5% alkyl glycoside APG10, 7% sorbitol, 2.5% erythritol, 1% nano-alumina sol, 1% carboxylated nano-calcium silicate, and 77.5% pure water.

[0090] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0091] 2.5% N-methyl-N-lauroyl-glucosamine powder was added to 7.5% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 8.5% alkyl glycoside APG10 powder was added to 25.5% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 7% sorbitol powder was added to 3.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 2.5% 12.5% pure water is added to erythritol powder, heated to 85-90°C, stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; under slow stirring, the compound bio-based polyol is added to a compound bio-based surfactant, and the mixture is fully mixed to form a mixed solution A; 1% nano-alumina sol is dispersed in 5% water to form a transparent colloidal solution, and 1% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 23.5% pure water is added, and the mixture is quickly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0092] Comparative Example 1

[0093] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent, the raw materials of which include, by mass percentage, 4% N-methyl-N-lauroyl-glucosamine, 6% alkyl glycoside APG10, 7% sorbitol, 3% erythritol, 1.5% nano-alumina sol, 0.75% carboxylated nano-calcium silicate, and 77.75% pure water (compared with the present invention, the proportion of N-methyl-N-lauroyl-glucosamine is increased, and the proportion of alkyl glycoside APG10 is reduced).

[0094] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0095] 4% N-methyl-N-lauroyl-glucosamine powder was added to 12% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 6% alkyl glycoside APG10 powder was added to 18% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 7% sorbitol powder was added to 3.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 3% erythritol powder was added to 18% pure water, heated to 60-70°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution. 15% pure water is added, heated to 85-90°C, stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; the compound bio-based polyol is added to a compound bio-based surfactant under slow stirring, and the mixture is fully mixed to form a mixed solution A; 1.5% nano-alumina sol is dispersed in 7.5% water to form a transparent colloidal solution, and 0.75% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 21.75% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0096] Comparative Example 2

[0097] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent, the raw materials of which include, by mass percentage, 2% N-methyl-N-lauroyl-glucosamine, 8% alkyl glycoside APG10, 8% sorbitol, 1% erythritol, 1% nano-alumina sol, 0.5% carboxylated nano-calcium silicate, and 79.5% pure water (compared with the present invention, the proportion of sorbitol is increased and the proportion of erythritol is reduced).

[0098] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0099] 2% N-methyl-N-lauroyl-glucosamine powder was added to 6% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 8% alkyl glycoside APG10 powder was added to 24% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; N-methyl-N-lauroyl-glucosamine solution and alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 8% sorbitol powder was added to 4% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain sorbitol solution; 1% erythritol was added to 24% pure water, heated to 60-70°C, stirred until completely dissolved, and cooled to room temperature to obtain sorbitol solution. The powder is added with 5% pure water, heated to 85-90° C., stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; the compound bio-based polyol is added to a compound bio-based surfactant under slow stirring, and the mixture is thoroughly mixed to form a mixed solution A; 1% nano-alumina sol is dispersed in 5% water to form a transparent colloidal solution, and 0.5% carboxylated nano-calcium silicate is slowly added thereto and thoroughly stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 35.5% pure water is added, and the mixture is quickly and thoroughly stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0100] Comparative Example 3

[0101] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent, whose raw materials, calculated by mass percentage, include: 3% N-methyl-N-lauroyl-glucosamine, 7% alkyl glycoside APG10, 5% sorbitol, 3% erythritol, 0.5% nano-alumina sol, 1% carboxylated nano-calcium silicate, and 80.5% pure water (compared to the present invention, the proportion of nano-alumina sol is reduced).

[0102] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0103] 3% N-methyl-N-lauroyl-glucosamine powder was added to 9% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 7% alkyl glycoside APG10 powder was added to 21% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 5% sorbitol powder was added to 2.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 3% erythritol powder was added to 21% pure water, heated to 60-70°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution. 15% pure water is added to the mixture, heated to 85-90° C., stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; the compound bio-based polyol is added to a compound bio-based surfactant under slow stirring, and the mixture is fully mixed to form a mixed solution A; 0.5% nano-alumina sol is dispersed in 2.5% water to form a transparent colloidal solution, and 1% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 30.5% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0104] Comparative Example 4

[0105] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent, comprising, by mass percentage, 2.5% N-methyl-N-lauroyl-glucosamine, 8.5% alkyl glycoside APG10, 7% sorbitol, 2.5% erythritol, 1% nano-alumina sol, 0.3% carboxylated nano-calcium silicate, and 78.2% pure water (compared to the present invention, the proportion of carboxylated nano-calcium silicate is reduced).

[0106] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0107] 2.5% N-methyl-N-lauroyl-glucosamine powder was added to 7.5% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain N-methyl-N-lauroyl-glucosamine solution; 8.5% alkyl glycoside APG10 powder was added to 25.5% pure water, heated to 60-70°C, and stirred until completely dissolved to obtain alkyl glycoside APG10 solution; the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution were fully mixed to obtain a composite bio-based surfactant; 7% sorbitol powder was added to 3.5% pure water, heated to 70-80°C, stirred until completely dissolved, and cooled to room temperature to obtain a sorbitol solution; 2.5% Erythritol powder is added to 12.5% pure water, heated to 85-90°C, stirred until completely dissolved, and cooled to room temperature to obtain an erythritol solution; the sorbitol solution and the erythritol solution are mixed to obtain a compound bio-based polyol; the compound bio-based polyol is added to a compound bio-based surfactant under slow stirring, and the mixture is thoroughly mixed to form a mixed solution A; 1% nano-alumina sol is dispersed in 5% water to form a transparent colloidal solution, and 0.3% carboxylated nano-calcium silicate is slowly added thereto and thoroughly stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution A, and finally the remaining 24.2% pure water is added, and the mixture is rapidly and thoroughly stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0108] Comparative Example 5

[0109] The whole is the same as Example 1, except that alkyl polyglycoside APG10 is replaced by alkyl polyglycoside APG1216 to prepare a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0110] Comparative Example 6

[0111] A fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent comprises, by weight percentage, 3% N-methyl-N-lauroyl-glucosamine, 10% alkyl glycoside APG10, 7% sorbitol, 3% erythritol, 1.5% nano-alumina sol, 0.75% carboxylated nano-calcium silicate, and 74.75% pure water.

[0112] The preparation method of the aqueous film-forming foam fire extinguishing agent comprises:

[0113] 3% N-methyl-N-lauroyl-glucosamine powder, 10% alkyl glycoside APG10 powder, 7% sorbitol powder, and 3% erythritol powder are added together to 57.5% pure water, heated to 85-90°C, stirred until completely dissolved, and cooled to room temperature to obtain a mixed solution C; 1.5% nano-alumina sol is dispersed in 7.5% water to form a transparent colloidal solution, and 0.75% carboxylated nano-calcium silicate is slowly added thereto and fully stirred to prepare a mixed solution B; the mixed solution B is added to the mixed solution C, and finally the remaining 9.75% pure water is added, and the mixture is rapidly and fully stirred to obtain a fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent.

[0114] Example 5

[0115] The AFFF prepared in Examples 1-4 and Comparative Examples 1-6 were tested in accordance with the national standard GB17835-2008 for foam fire extinguishing agents. Three samples were collected from each group for parallel testing, and the experimental results were averaged. The physical and chemical properties and fire extinguishing performance of the different AFFFs are shown in Table 1 below. For performance testing, the AFFF prepared in each example and comparative example was diluted and compounded at a mass ratio of 6:94 with water.

[0116] The results show that the fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent provided by the present invention uses raw materials that do not cause environmental pollution. Furthermore, through the synergistic effect of the specific components in their respective contents, it exhibits excellent foaming ability and foam stability. Its 25% liquid separation time is 4-4.2 minutes, fire extinguishing time is 1.6-2.0 minutes, anti-burning time is 12-14 minutes, foam height is 188-192 mm, surface tension is 16.8-18 mN / m, foaming multiple is 7.0-8.3, and freezing point is -20--25°C. It exhibits low freezing point, low temperature resistance, and high frost resistance. Its overall performance is superior to that of Comparative Examples 1-6.

[0117] Table 1 AFFF performance test results of Examples 1-4 and Comparative Examples 1-6

[0118]

[0119]

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent, characterized in that: Calculated by mass percentage, the raw materials of the aqueous film-forming foam fire extinguishing agent include: 10-13% of a compound bio-based surfactant, 8-10% of a compound bio-based polyol, 1-2% of nano-alumina sol, 0.5-1% of carboxylated nano-calcium silicate, and the balance is pure water.

2. A fluorine-free, environmentally friendly aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The compounded bio-based surfactant includes N-methyl-N-lauroyl-glucosamine and alkyl polyglycoside APG10; the mass of the N-methyl-N-lauroyl-glucosamine accounts for 2-3% of the aqueous film-forming foam fire extinguishing agent; the mass of the alkyl polyglycoside APG10 accounts for 7-10% of the aqueous film-forming foam fire extinguishing agent.

3. The fluorine-free and environmentally friendly aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The compounded bio-based polyol includes sorbitol and erythritol; the mass of the sorbitol accounts for 5-7% of the aqueous film-forming foam fire extinguishing agent; the mass of the erythritol accounts for 2-3% of the aqueous film-forming foam fire extinguishing agent.

4. The method for preparing a fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent according to any one of claims 1 to 3, characterized in that: It includes the following steps: S1. Prepare the following raw materials by mass percentage: 10-13% of a composite bio-based surfactant, 8-10% of a composite bio-based polyol, 1-2% of a nano-alumina sol, 0.5-1% of a carboxylated nano-calcium silicate, and the balance of pure water; S2. adding the compounded bio-based polyol to the compounded bio-based surfactant under slow stirring, and mixing thoroughly to obtain a mixed solution A; S3, dispersing the nano-alumina sol in pure water, with the mass ratio of the nano-alumina sol to the pure water being 1:5, to form a transparent colloidal solution; slowly adding the carboxylated nano-calcium silicate to the transparent colloidal solution and stirring thoroughly to obtain a mixed solution B; S4. Add the mixed solution B to the mixed solution A, and add the remaining pure water, and stir quickly and fully to obtain an aqueous film-forming foam fire extinguishing agent.

5. The method for preparing a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent according to claim 4, characterized in that: The preparation method of the compounded bio-based surfactant comprises the following steps: A1. Prepare N-methyl-N-lauroyl-glucosamine accounting for 2-3% of the mass of the aqueous film-forming foam fire extinguishing agent and alkyl polyglycoside APG10 accounting for 7-10% of the mass of the aqueous film-forming foam fire extinguishing agent; A2, adding the N-methyl-N-lauroyl-glucosamine powder to pure water, mixing, heating and stirring until completely dissolved, to obtain an N-methyl-N-lauroyl-glucosamine solution; A3, adding the alkyl glycoside APG10 powder to pure water, mixing, heating and stirring until completely dissolved, to obtain an alkyl glycoside APG10 solution; A4. Fully mix the N-methyl-N-lauroyl-glucosamine solution and the alkyl glycoside APG10 solution to obtain the composite bio-based surfactant.

6. The method for preparing a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent according to claim 5, characterized in that: In the step A2, the mass ratio of the N-methyl-N-lauroyl-glucosamine powder to the pure water is 1:3, and the heating temperature is 60-70°C; in the step A3, the mass ratio of the alkyl glycoside APG10 powder to the pure water is 1:3, and the heating temperature is 60-70°C.

7. The method for preparing a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent according to claim 4, characterized in that: The preparation method of the composite bio-based polyol comprises the following steps: B1. Prepare sorbitol accounting for 5-7% of the mass of the aqueous film-forming foam fire extinguishing agent and erythritol accounting for 2-3% of the mass of the aqueous film-forming foam fire extinguishing agent; B2, adding the sorbitol powder to pure water, heating and stirring until completely dissolved, and cooling to room temperature to obtain a sorbitol solution; B3, adding the erythritol powder to pure water, heating and stirring until completely dissolved, and cooling to room temperature to obtain an erythritol solution; B4. Mixing the sorbitol solution and the erythritol solution to obtain the composite bio-based polyol.

8. The method for preparing a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent according to claim 7, characterized in that: In the step B2, the mass ratio of the sorbitol powder to the pure water is 2:1, and the heating temperature is 70-80°C; in the step B3, the mass ratio of the erythritol powder to the pure water is 1:5, and the heating temperature is 80-90°C.

9. The method for preparing a fluorine-free and environment-friendly aqueous film-forming foam fire extinguishing agent according to claim 4, characterized in that: The preparation method of the carboxylated nano calcium silicate comprises the following steps: C1. Mix nano calcium silicate powder with pure water in a mass ratio of 1:10 and ultrasonically treat for 30 minutes to eliminate agglomerates and form a uniform nano calcium silicate suspension; C2. adding 10 mol / L nitric acid solution to the nano-calcium silicate suspension to perform an acid etching reaction to form carboxylate on the surface of the nano-calcium silicate particles; C3, adding 5% NaOH solution to the nano-calcium silicate suspension after the acid etching reaction in step C2 to neutralize the residual acid to pH 7.0, centrifuging and washing with pure water three times; C4. Drying the washed nano-calcium silicate in step C3 to obtain the carboxylated nano-calcium silicate.

10. Use of a fluorine-free, environment-friendly aqueous film-forming foam fire extinguishing agent in fire extinguishing according to any one of claims 1 to 3, characterized in that: When in use, water is added to dilute the aqueous film-forming foam fire extinguishing agent into a solution, and the volume ratio of the aqueous film-forming foam fire extinguishing agent to water is 6:94.

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