Low-temperature water-based fire extinguishing agent and preparation method thereof

Abstract

The invention relates to the technical field of fire extinguishing agents, and particularly discloses a low-temperature water-based fire extinguishing agent and a preparation method thereof.The low-temperature water-based fire extinguishing agent comprises, by weight, 3-6 parts of a surfactant, 2-3 parts of a stabilizer, 5-8 parts of an anti-freezing agent, 15-20 parts of a modified water absorption composite material, 60-85 parts of water and 1-2 parts of a foaming agent; nano calcium carbonate and ammonium polyphosphate in the modified water-absorbing composite material have a synergistic effect, so that the permeability and adhesiveness of the water-based fire extinguishing agent can be effectively improved, the fire extinguishing efficiency of the fire extinguishing agent is improved, the fire resistance is good, the stability is good, the water retention rate and the viscosity of the fire extinguishing agent are improved, and the water utilization rate and the fire extinguishing efficiency are improved; the anti-freezing agent can reduce the freezing point of water and prevent the fire extinguishing agent from freezing at low temperature, so that the fire extinguishing agent can be normally used in a low-temperature environment, all the raw materials have a synergistic effect, and the prepared low-temperature water-based fire extinguishing agent has low-temperature stability, can extinguish fire efficiently, and is environmentally friendly, non-toxic and wide in application range.

Description

Technical Field

[0001] The invention relates to the technical field of fire extinguishing agents, in particular to a low-temperature water-based fire extinguishing agent and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of my country's economic construction, the types of fires have become more and more diverse, and the fire situation has become increasingly serious. The frequent occurrence of fire accidents not only poses a huge safety hazard to people's personal and property safety, but also pollutes and damages the ecological environment. Therefore, the application and research of fire extinguishing agents have become increasingly important. Traditional fire extinguishing agents mainly include water-based fire extinguishing agents, foam fire extinguishing agents, gas fire extinguishing agents, and dry powder fire extinguishing agents. Among them, water-based fire extinguishing agents are one of the most commonly used fire extinguishing agents in the field of fire protection, with the advantages of wide sources, low prices, and strong fire extinguishing properties.

[0003] However, water has high fluidity and is easy to lose after being sprayed out, resulting in high waste rate. It has a short residence time in the combustion zone and poor anti-reignition performance. In addition, since the water-based fire extinguishing agent contains a large amount of water and has a high freezing point, the water-based fire extinguishing agent will solidify and become unusable in a low-temperature environment, limiting its scope of use. Chinese patent application CN106693267A discloses a polymer water-based fire extinguishing agent, which includes polyacrylamide, aluminum oxide, sodium silicate, diatomaceous earth, ammonium carbonate, penetrant, dispersant, and water. The water-based fire extinguishing agent can expand the scope of fire extinguishing, has the characteristics of high water saving, stable structure, low cost, and is easy to use and has good fire extinguishing performance, but the water-based fire extinguishing agent is not suitable for use in a low-temperature environment. Chinese patent application CN1530152A discloses an environmentally friendly enhanced water-based fire extinguishing agent, which includes 25-40% by weight of fluorocarbon surfactant, 10-25% of composite antifreeze agent, 20-40% of foam stabilizer, 2-8% of flame retardant, and 15-25% of solvent. The fire extinguishing agent has a high fire extinguishing ability both at normal temperature and low temperature environment, but a large amount of fluorine-based surfactant is used, which is not easy to degrade after fire extinguishing and is environmentally toxic.

[0004] Therefore, developing a water-based fire extinguishing agent that can reduce water consumption, has good flame retardant properties and can be used in low-temperature environments has broad application prospects. Summary of the invention

[0005] 1. Technical issues to be resolved In order to solve the above technical problems, the present invention provides a low-temperature water-based fire extinguishing agent and a preparation method thereof, which solves the problems of poor flame retardancy and general water-saving performance of water-based fire extinguishing agents, and provides a water-based fire extinguishing agent with excellent fire extinguishing performance that can be used in low-temperature environments.

[0006] (II) Technical solution In order to achieve the above-mentioned purpose, the present invention discloses a low-temperature water-based fire extinguishing agent, comprising the following raw materials in parts by weight: 3-6 parts of a surfactant, 2-3 parts of a stabilizer, 5-8 parts of an antifreeze agent, 15-20 parts of a modified water-absorbing composite material, 60-85 parts of water, and 1-2 parts of a foaming agent.

[0007] The preparation method of the modified water-absorbing composite material comprises the following steps: N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent, an initiator and an accelerator are added, and the mixture is stirred and mixed to react. After the reaction is completed, dialysis is used for rinsing, filtering, purification, and freeze-drying to obtain a modified water-absorbing composite material.

[0008] Preferably, the surfactant is composed of sodium dodecyl diphenyl oxide disulfonate and Tween-80 in a mass ratio of 4:1; the stabilizer is sodium benzoate; and the foaming agent is sodium lauryl sulfoacetate.

[0009] Preferably, the antifreeze agent is obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4.

[0010] Preferably, in the preparation process of the modified water-absorbing composite material, the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, crosslinking agent, initiator and accelerator is 100:1200-1500:20-30:15-35:25-35:1-3:2-4, the reaction temperature is 55-65°C, and the reaction time is 4-6h.

[0011] Preferably, during the preparation of the modified water-absorbing composite material, the cross-linking agent is methylene bisacrylamide.

[0012] Preferably, during the preparation of the modified water-absorbing composite material, the accelerator is N,N,N',N'-tetramethylethylenediamine.

[0013] Preferably, during the preparation of the modified water-absorbing composite material, the initiator is ammonium persulfate.

[0014] Preferably, the preparation method of the olefin-modified flame retardant comprises the following steps: S1. Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, stirring and mixing, heating, reacting, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60° C. for 12 h to obtain modified calcium carbonate; S2. Evenly mix the ethanol solution, modified calcium carbonate and ammonium polyphosphate, heat up and react. After the reaction is completed, filter and wash with deionized water, and dry at 80° C. for 12 hours to obtain an olefin-modified flame retardant.

[0015] Preferably, the mass ratio of nano-calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid in S1 is 100:2000-2500:20-30.

[0016] Preferably, the reaction temperature in S1 is 60-80° C., and the reaction time is 3-5 h.

[0017] Preferably, the ethanol solution in S1 consists of anhydrous ethanol and deionized water in a volume ratio of 9:1.

[0018] Preferably, the mass ratio of the ethanol solution, modified calcium carbonate and ammonium polyphosphate in S2 is 900-1200:100:55-75.

[0019] Preferably, the reaction temperature in S2 is 60-70° C., and the reaction time is 5-8 h.

[0020] Preferably, the ethanol solution in S2 consists of anhydrous ethanol and deionized water in a volume ratio of 1:3.

[0021] A preparation method of a low-temperature water-based fire extinguishing agent comprises the following steps: weighing water and a surfactant, heating them to 50-60°C, stirring and mixing, adding an antifreeze agent and a modified water-absorbing composite material, stirring and mixing at a stirring and mixing rate of 350-450 r / min, adding a foaming agent and a stabilizer after 15-20 minutes, stirring and mixing at a stirring and mixing rate of 250-300 r / min, stirring and mixing for 5-10 minutes, and obtaining the low-temperature water-based fire extinguishing agent.

[0022] 3. Beneficial technical effects In the present invention, 2-aminopent-4-enoic acid is used to modify nano calcium carbonate, amino groups and alkenyl groups are introduced on the surface of the nano calcium carbonate to obtain modified calcium carbonate, and the amino groups on the modified calcium carbonate react with ammonium polyphosphate to obtain an alkenyl modified flame retardant. The alkenyl modified flame retardant, N-isopropylacrylamide and sodium alginate react under the action of a crosslinking agent, an initiator and an accelerator to obtain a modified water-absorbing composite material. Water, a surfactant, an antifreeze agent, the modified water-absorbing composite material, a foaming agent and a stabilizer are mixed to obtain a low-temperature water-based fire extinguishing agent.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The nano calcium carbonate in the present invention has abundant specific surface area and surface active sites, and has excellent heat resistance. Due to its small size, the nano calcium carbonate is modified by ammonium polyphosphate, which effectively avoids the agglomeration of nano calcium carbonate, can increase the stability of the fire extinguishing agent, prevent it from stratification or precipitation during use, and ensure that the water-based fire extinguishing agent can be evenly sprayed on the surface of the burning object. During the combustion process, nano calcium carbonate has excellent heat absorption and cooling effects. When it comes into contact with the fire source, it will quickly decompose and absorb the surrounding heat, causing the temperature around the fire source to drop rapidly, slowing down the combustion rate. At the same time, nano calcium carbonate will produce carbon dioxide gas during the decomposition process, which can dilute the oxygen concentration in the air and reduce the speed of the combustion reaction. As an efficient flame retardant, ammonium polyphosphate can form a covering film on the surface of the combustible during the combustion process to block the combustion chain reaction. It can also react chemically with the fuel in the combustion products to form non-combustible phosphorus compounds, thereby inhibiting the spread of the flame. The synergistic effect of nano calcium carbonate and ammonium polyphosphate can effectively improve the permeability and adhesion of water-based fire extinguishing agents, significantly improve the fire extinguishing efficiency of fire extinguishing agents, have excellent flame retardant effects, and reduce the occurrence of re-ignition.

[0024] (2) In the modified water-absorbing composite material of the present invention, N-isopropylacrylamide is temperature-sensitive and can change its water absorption properties with temperature changes, which helps to absorb heat and reduce the temperature of the fire scene during the fire extinguishing process. Sodium alginate has high viscosity and can enhance the viscosity and adhesion of the fire extinguishing agent, so that the fire extinguishing agent can better adhere to the surface of the fuel, forming a protective film, isolating the air, and achieving the effect of suffocating the fire. The introduction of flame retardants into the modified water-absorbing composite material enhances the flame retardant properties of the fire extinguishing agent and prevents the spread of flames. The raw materials in the modified water-absorbing composite material can be cross-linked to form a uniform network structure with good stability. When added to the fire extinguishing agent, the water retention rate and viscosity of the fire extinguishing agent are improved. It contains a large number of active groups, which improves the compatibility between materials, has higher fire extinguishing efficiency and additional advantages, can effectively improve the utilization rate of water and fire extinguishing efficiency, and can use less water to control the spread of fire at the fire scene and quickly extinguish the fire. Sodium dodecylbenzene sulfonate is a commonly used anionic surfactant, and Tween-80 is a nonionic surfactant and emulsifier. The mixture of the two can improve the wetting ability of the fire extinguishing agent, reduce the surface tension of water, help the water-based fire extinguishing agent to better penetrate the surface of the burning object, and improve the fire extinguishing effect. At the same time, it also has excellent dispersing and emulsifying effects, dispersing the suspended matter and sediment in the water into smaller particles, and improving the stability and fire extinguishing performance of the fire extinguishing agent. Stabilizers can prevent the fire extinguishing agent from stratification and precipitation during storage and use, and maintain the stability and performance of the fire extinguishing agent. Foaming agents can produce a large number of tiny bubbles at the junction of water and air. These bubbles expand rapidly and connect to each other to form a stable foam layer, isolate oxygen, and further inhibit the burning of the flame. Calcium chloride is an inorganic salt antifreeze. Calcium chloride can lower the freezing point of water and prevent the fire extinguishing agent from freezing at low temperatures. Sodium tripolyphosphate not only has a corrosion inhibition effect, but also can work synergistically with calcium chloride to further improve the antifreeze effect, and can also prevent the formation of scale and protect the safe operation of fire-fighting equipment. Ethylene glycol is a highly effective antifreeze that can significantly lower the freezing point of water and decompose at high temperatures to produce inert gases, which help isolate oxygen and further suppress the spread of fire. The three ingredients in antifreeze work synergistically to lower the freezing point of water and prevent the fire extinguishing agent from freezing at low temperatures.

[0025] (3) The antifreeze in the present invention can effectively reduce the freezing point of water, ensuring that the fire extinguishing agent will not solidify in a low temperature environment and can be used normally in a low temperature environment. The modified water-absorbing composite material can improve the stability of the system, reduce the precipitation of inorganic salts in the antifreeze, and improve its solubility in a low temperature environment, so that the water-washed fire extinguishing agent can be used under low temperature conditions. When the water-based fire extinguishing agent used is dispersed on the surface of the burning object, liquid will precipitate and cool its surface, reducing the temperature of the burning object, thereby slowing down or terminating the combustion process. At the same time, a layer of water film can be formed on the surface of the burning object, which together seals the surface of the burning object, isolates the air and forms a heat insulation barrier, so that the combustion reaction is terminated. The prepared low-temperature water-based fire extinguishing agent has the characteristics of low-temperature stability, high-efficiency fire extinguishing, environmental protection and non-toxicity, wide range of application and easy storage and transportation. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Example 1 A method for preparing a low-temperature water-based fire extinguishing agent comprises the following steps: 60 parts of water and 3 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1, the temperature was raised to 50°C, and the mixture was stirred and mixed. Then, 5 parts of antifreeze agent and 15 parts of modified water-absorbing composite materials were added, wherein the antifreeze agent was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4, and the mixture was stirred and mixed at a rate of 350 r / min. After stirring and mixing for 20 minutes, 1 part of foaming agent sodium lauryl sulfoacetate and 2 parts of stabilizer sodium benzoate were added at a rate of 250 r / min. The mixture was stirred and mixed for 10 minutes to obtain a low-temperature water-based fire extinguishing agent.

[0028] The preparation method of the modified water-absorbing composite material comprises the following steps: (1) Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, wherein the mass ratio of nano calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid is 100:2000:20, stirring and mixing evenly, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 9:1, heating, reacting at 60°C, the reaction time is 5 hours, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60°C for 12 hours to obtain modified calcium carbonate; (2) Evenly mixing an ethanol solution, modified calcium carbonate and ammonium polyphosphate in a mass ratio of 900:100:55, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 1:3, heating, reacting at 60°C for 8 hours, and after the reaction is completed, filtering, washing with deionized water, and drying at 80°C for 12 hours to obtain an olefin-modified flame retardant; (3) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent methylenebisacrylamide, an initiator ammonium persulfate, and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, cross-linking agent, initiator, and accelerator is 100:1200:20:15:25:1:2. The mixture is stirred and mixed, and a reaction is carried out at 55°C for 4 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified, and freeze-dried to obtain a modified water-absorbing composite material.

[0029] Example 2 A method for preparing a low-temperature water-based fire extinguishing agent comprises the following steps: 68 parts of water and 4 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1. The temperature was raised to 55°C and stirred. Then 6 parts of antifreeze and 16 parts of modified water-absorbing composite materials were added, wherein the antifreeze was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4. The mixture was stirred at a rate of 400 r / min. After stirring for 16 minutes, 1.4 parts of sodium lauryl sulfoacetate salt, a foaming agent, and 2.4 parts of sodium benzoate, a stabilizer, were added at a rate of 260 r / min and stirred for 6 minutes to obtain a low-temperature water-based fire extinguishing agent.

[0030] The preparation method of the modified water-absorbing composite material comprises the following steps: (1) Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, wherein the mass ratio of nano calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid is 100:2200:24, stirring and mixing evenly, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 9:1, heating, reacting at 65°C, the reaction time is 4 hours, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60°C for 12 hours to obtain modified calcium carbonate; (2) Evenly mixing an ethanol solution, modified calcium carbonate and ammonium polyphosphate in a mass ratio of 1000:100:62, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 1:3, heating, reacting at 65°C for 6 hours, and after the reaction is completed, filtering, washing with deionized water, and drying at 80°C for 12 hours to obtain an olefin-modified flame retardant; (3) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent methylenebisacrylamide, an initiator ammonium persulfate, and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, cross-linking agent, initiator, and accelerator is 100:1300:24:22:28:1.8:2.8. The mixture is stirred and mixed, and reacted at 60°C for 5 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified, and freeze-dried to obtain a modified water-absorbing composite material.

[0031] Example 3 A method for preparing a low-temperature water-based fire extinguishing agent comprises the following steps: 68 parts of water and 4 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1. The temperature was raised to 55°C and stirred. Then 6 parts of antifreeze and 16 parts of modified water-absorbing composite materials were added, wherein the antifreeze was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4. The mixture was stirred at a rate of 400 r / min. After stirring for 16 minutes, 1.4 parts of sodium lauryl sulfoacetate salt, a foaming agent, and 2.4 parts of sodium benzoate, a stabilizer, were added at a rate of 260 r / min and stirred for 6 minutes to obtain a low-temperature water-based fire extinguishing agent.

[0032] The preparation method of the modified water-absorbing composite material comprises the following steps: (1) Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, wherein the mass ratio of nano calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid is 100:2400:28, stirring and mixing evenly, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 9:1, heating, reacting at 75°C, the reaction time is 4 hours, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60°C for 12 hours to obtain modified calcium carbonate; (2) Evenly mixing an ethanol solution, modified calcium carbonate and ammonium polyphosphate in a mass ratio of 1100:100:70, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 1:3, heating, reacting at 65°C for 7 hours, and after the reaction is completed, filtering, washing with deionized water, and drying at 80°C for 12 hours to obtain an olefin-modified flame retardant; (3) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent methylenebisacrylamide, an initiator ammonium persulfate, and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, cross-linking agent, initiator, and accelerator is 100:1400:28:32:34:2.5:3.6. The mixture is stirred and mixed, and reacted at 60°C for 5 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified, and freeze-dried to obtain a modified water-absorbing composite material.

[0033] Example 4 A method for preparing a low-temperature water-based fire extinguishing agent comprises the following steps: 80 parts of water and 5 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1, the temperature was raised to 55°C, and the mixture was stirred and mixed. Then, 7 parts of antifreeze and 18 parts of modified water-absorbing composite materials were added, wherein the antifreeze was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4, and the mixture was stirred and mixed at a rate of 420 r / min. After stirring and mixing for 18 minutes, 1.8 parts of sodium lauryl sulfoacetate salt of a foaming agent and 2.8 parts of sodium benzoate, a stabilizer, were added at a rate of 280 r / min, and the mixture was stirred and mixed for 8 minutes to obtain a low-temperature water-based fire extinguishing agent.

[0034] The preparation method of the modified water-absorbent composite material in this embodiment is the same as the preparation method of the modified water-absorbent composite material in Example 3.

[0035] Example 5 A method for preparing a low-temperature water-based fire extinguishing agent comprises the following steps: 85 parts of water and 6 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1, the temperature was raised to 60°C, and the mixture was stirred and mixed. Then 8 parts of antifreeze and 20 parts of modified water-absorbing composite materials were added, wherein the antifreeze was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4, and the mixture was stirred and mixed at a rate of 450 r / min. After stirring and mixing for 15 minutes, 2 parts of foaming agent sodium lauryl sulfoacetate and 3 parts of stabilizer sodium benzoate were added at a rate of 300 r / min, and the mixture was stirred and mixed for 5 minutes to obtain a low-temperature water-based fire extinguishing agent.

[0036] The preparation method of the modified water-absorbing composite material comprises the following steps: (1) Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, wherein the mass ratio of nano calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid is 100:2500:30, stirring and mixing evenly, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 9:1, heating, reacting at 80°C, the reaction time is 3 hours, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60°C for 12 hours to obtain modified calcium carbonate; (2) Evenly mixing an ethanol solution, modified calcium carbonate and ammonium polyphosphate in a mass ratio of 1200:100:75, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 1:3, heating, reacting at 70°C for 5 hours, and after the reaction is completed, filtering, washing with deionized water, and drying at 80°C for 12 hours to obtain an olefin-modified flame retardant; (3) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent methylenebisacrylamide, an initiator ammonium persulfate, and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, cross-linking agent, initiator, and accelerator is 100:1500:30:35:35:3:4. The mixture is stirred and mixed, and reacted at 65°C for 4 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified, and freeze-dried to obtain a modified water-absorbing composite material.

[0037] Comparative Example 1 A method for preparing a water-based fire extinguishing agent comprises the following steps: 80 parts of water and 5 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1, the temperature was raised to 55°C, and the mixture was stirred and mixed. Then, 7 parts of antifreeze and 18 parts of water-absorbing composite materials were added, wherein the antifreeze was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4, and the mixture was stirred and mixed at a rate of 420 r / min. After stirring and mixing for 18 minutes, 1.8 parts of sodium lauryl sulfoacetate salt, a foaming agent, and 2.8 parts of sodium benzoate, a stabilizer, were added at a rate of 280 r / min, and the mixture was stirred and mixed for 8 minutes to obtain a water-based fire extinguishing agent.

[0038] The preparation method of the water-absorbing composite material comprises the following steps: (1) Ultrasonic dispersion of nano calcium carbonate in an ethanol solution, after uniform dispersion, adding γ-aminopropyl triethoxysilane, wherein the mass ratio of nano calcium carbonate, ethanol solution and γ-aminopropyl triethoxysilane is 100:2400:28, stirring and mixing evenly, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 9:1, heating, reacting at 75°C, the reaction time is 4 hours, after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and vacuum drying at 60°C for 12 hours to obtain amino-modified calcium carbonate; (2) Evenly mixing an ethanol solution, amino-modified calcium carbonate and ammonium polyphosphate in a mass ratio of 1100:100:70, wherein the ethanol solution is composed of anhydrous ethanol and deionized water in a volume ratio of 1:3, heating, reacting at 65°C for 7 hours, and after the reaction is completed, filtering, washing with deionized water, and drying at 80°C for 12 hours to obtain a modified flame retardant; (3) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, a modified flame retardant, a cross-linking agent methylenebisacrylamide, an initiator ammonium persulfate and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, modified flame retardant, cross-linking agent, initiator and accelerator is 100:1400:28:32:34:2.5:3.6. The mixture is stirred and mixed, and reacted at 60°C for 5 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified and freeze-dried to obtain a water-absorbent composite material.

[0039] Comparative Example 2 A method for preparing a water-based fire extinguishing agent comprises the following steps: 80 parts of water and 5 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1. The temperature was raised to 55°C and stirred. Then, 7 parts of antifreeze agent, 15 parts of water-absorbing composite materials, 1.8 parts of nano-calcium carbonate and 1.2 parts of ammonium polyphosphate were added, wherein the antifreeze agent was obtained by mixing inorganic salt calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:4. The mixture was stirred and mixed at a rate of 420 r / min. After stirring and mixing for 18 minutes, 1.8 parts of sodium lauryl sulfoacetate salt, a foaming agent, and 2.8 parts of sodium benzoate, a stabilizer, were added at a rate of 280 r / min and stirred and mixed for 8 minutes to obtain a water-based fire extinguishing agent.

[0040] The preparation method of the water-absorbing composite material comprises the following steps: (1) N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred evenly. In a nitrogen atmosphere, a crosslinking agent methylenebisacrylamide, an initiator ammonium persulfate, and an accelerator N,N,N',N'-tetramethylethylenediamine are added, wherein the mass ratio of N-isopropylacrylamide, deionized water, sodium alginate, crosslinking agent, initiator, and accelerator is 100:1400:28:34:2.5:3.6. The mixture is stirred and reacted at 60°C for 5 hours. After the reaction is completed, the mixture is rinsed by dialysis, filtered, purified, and freeze-dried to obtain a water-absorbing composite material.

[0041] Comparative Example 3 A method for preparing a water-based fire extinguishing agent comprises the following steps: 80 parts of water and 5 parts of surfactant were weighed by mass, wherein the surfactant consisted of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:1, and the temperature was raised to 55°C, and the mixture was stirred and mixed. Then, 7 parts of antifreeze agent ethylene glycol and 18 parts of water-absorbing composite materials were added, and the mixture was stirred and mixed at a rate of 420 r / min. After stirring and mixing for 18 minutes, 1.8 parts of foaming agent sodium lauryl sulfoacetate and 2.8 parts of stabilizer sodium benzoate were added, and the stirring and mixing rate was 280 r / min. The mixture was stirred and mixed for 8 minutes to obtain a water-based fire extinguishing agent.

[0042] The preparation method of the modified water-absorbent composite material in this comparative example is the same as the preparation method of the modified water-absorbent composite material in Example 3.

[0043] The nano calcium carbonate used in the examples and comparative examples of the present invention was purchased from Guangxi Warner Technology Co., Ltd., with an average particle size of 20 nm and a purity of ≥99.99%; sodium alginate was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; ammonium polyphosphate was purchased from Shandong Shian Chemical Co., Ltd., industrial grade, type II crystal form, and polymerization degree >1000; other undisclosed raw materials and reagents are commercially available.

[0044] The water-based fire extinguishing agents prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to relevant performance tests. The test standard referred to the national standard GB 17835-2008 "Water-based Fire Extinguishing Agents", and the Class A fire test method was adopted. The specific method was as follows: 10 mm × 10 mm × 96 mm wood strips were stacked in layers, with 5 strips per layer, for a total of 10 layers. A combustion tray containing acetone was placed under the woodpile, and the acetone was ignited. After the woodpile was pre-burned for 1 minute, the water-based fire extinguishing agents prepared in Examples 1-5 and Comparative Examples 1-3 were used to extinguish the wood strips, respectively, at a flow rate of 1 L / min. At the same time, an infrared thermal imager was used to record the fire extinguishing process and temperature field changes. Each group of experiments was conducted in parallel 3 times, and the average value of each group of tests was taken, and the fire extinguishing time was recorded; The relevant test results are shown in Table 1: Table 1

[0045] According to the test results in Table 1, it can be seen that the samples corresponding to Examples 1-5 of the present invention have excellent stability, good low temperature resistance, anti-freezing ability, fast fire extinguishing speed, low surface tension, good wettability, and help the water-based fire extinguishing agent to better penetrate into the surface of the burning object. In Comparative Example 1, γ-aminopropyltriethoxysilane is used to modify nano calcium carbonate to obtain amino-modified calcium carbonate, which reacts with ammonium polyphosphate to obtain a modified flame retardant. During the preparation of the water-absorbing composite material, the dispersibility and compatibility deteriorate, which has a certain impact on the performance of the fire extinguishing agent. In Comparative Example 2, nano calcium carbonate and ammonium polyphosphate were not modified and directly added to the fire extinguishing agent, and the comprehensive performance was greatly reduced, and the stability and fire extinguishing performance of the fire extinguishing agent were greatly reduced. In Comparative Example 3, a single ethylene glycol was used as an antifreeze agent, and the overall antifreeze property of the fire extinguishing agent deteriorated.

[0046] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that all equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A low-temperature water-based fire extinguishing agent, characterized in that: The raw materials include the following parts by weight: 3-6 parts of surfactant, 2-3 parts of stabilizer, 5-8 parts of antifreeze agent, 15-20 parts of modified water-absorbing composite material, 60-85 parts of water, and 1-2 parts of foaming agent; The preparation method of the modified water-absorbing composite material comprises the following steps: N-isopropylacrylamide and deionized water are mixed evenly, sodium alginate is added, and the mixture is stirred and mixed evenly. In a nitrogen atmosphere, an olefin-modified flame retardant, a cross-linking agent, an initiator and an accelerator are added, and the mixture is stirred and mixed to react. After the reaction is completed, the mixture is purified and dried to obtain a modified water-absorbing composite material.

2. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The surfactant consists of sodium dodecyl diphenyl ether disulfonate and Tween-80 in a mass ratio of 4:

1.

3. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The stabilizer is sodium benzoate; the foaming agent is sodium lauryl sulfoacetate.

4. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The antifreeze agent is obtained by mixing calcium chloride, corrosion inhibitor sodium tripolyphosphate and ethylene glycol in a mass ratio of 5:1:

4.

5. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The mass ratio of the N-isopropylacrylamide, deionized water, sodium alginate, olefin-modified flame retardant, crosslinking agent, initiator and accelerator is 100:(1200-1500):(20-30):(15-35):(25-35):(1-3):(2-4), the reaction temperature is 55-65°C, and the reaction time is 4-6h.

6. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The cross-linking agent is methylenebisacrylamide, the accelerator is N,N,N',N'-tetramethylethylenediamine, and the initiator is ammonium persulfate.

7. A low-temperature water-based fire extinguishing agent according to claim 1, characterized in that: The preparation method of the olefin-modified flame retardant comprises the following steps: S1. Ultrasonic dispersion of nano calcium carbonate into an ethanol solution, after uniform dispersion, adding 2-aminopent-4-enoic acid, stirring and mixing, heating, reacting, after the reaction is completed, filtering, washing, and vacuum drying at 60° C. for 12 h to obtain modified calcium carbonate; S2. Evenly mix the ethanol solution, modified calcium carbonate and ammonium polyphosphate, heat up and react. After the reaction is completed, filter, wash and dry at 80° C. for 12 hours to obtain an olefin-modified flame retardant.

8. A low-temperature water-based fire extinguishing agent according to claim 7, characterized in that: The mass ratio of nano-calcium carbonate, ethanol solution and 2-aminopent-4-enoic acid in S1 is 100:(2000-2500):(20-30), the reaction temperature is 60-80° C., and the reaction time is 3-5 hours.

9. A low-temperature water-based fire extinguishing agent according to claim 7, characterized in that: The mass ratio of the ethanol solution, modified calcium carbonate and ammonium polyphosphate in S2 is (900-1200):100:(55-75), the reaction temperature is 60-70°C, and the reaction time is 5-8h.

10. A method for preparing a low-temperature water-based fire extinguishing agent according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: weighing water and a surfactant, heating to 50-60 DEG C, stirring and mixing, adding an antifreeze agent and a modified water-absorbing composite material, stirring and mixing at a rate of 350-450 r / min, adding a foaming agent and a stabilizer after 15-20 minutes, stirring and mixing at a rate of 250-300 r / min, stirring and mixing for 5-10 minutes, and obtaining a low-temperature water-based fire extinguishing agent.

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