High expansion seawater resistant foam concentrate for methanol fires on board ships

Abstract

This invention relates to the field of foaming agents for methanol fires on ships, and discloses a high-expansion, seawater-resistant, and alcohol-resistant foaming agent for methanol fires on ships, comprising a gemini-type fluorocarbon surfactant, a betaine surfactant, a polar film-forming agent, a stabilizer, and water. Based on the excellent surface chemical capabilities and stability of the gemini-type fluorocarbon surfactant, the foaming agent of this invention, when compounded, can significantly improve the foaming capacity, seawater resistance, alcohol resistance, and high-temperature stability, enabling it to foam rapidly in the engine room, isolating oxygen and thus extinguishing methanol fires. It can be effectively applied in the field of extinguishing methanol fires on ships.

Description

Technical Field

[0001] This invention relates to the field of foaming agents for methanol fires on ships, and more particularly to high-expansion seawater-resistant and alcohol-resistant foaming agents for methanol fires on ships. Background Technology

[0002] As vital carriers for maritime transportation and operations, ships pose a serious threat to life and property if fires occur in their enclosed or semi-enclosed spaces, such as engine rooms, cargo holds, and fuel tanks. These fires are characterized by rapid fire spread, difficult evacuation, and challenging rescue conditions. Meanwhile, with the International Maritime Organization's increasingly stringent emission requirements for ships, methanol, as a clean and low-carbon alternative fuel, is seeing increasing applications in marine propulsion.

[0003] However, methanol has characteristics such as low flash point, high calorific value, and flame that is difficult to identify under sunlight. In addition, it is highly polar and can be miscible with water in any proportion. This causes conventional aqueous film-forming foam or ordinary water-based foaming agents to be rapidly diluted or broken in methanol fires, making it difficult to form an effective covering layer and thus unable to achieve effective fire extinguishing and prevent reignition.

[0004] Currently, extinguishing agents for methanol fires on ships mainly include alcohol-resistant aqueous film-forming foam (AFFF) agents and alcohol-resistant fluoroprotein foam agents. Alcohol-resistant AFFF agents typically use long-chain fluorocarbon surfactants as the core component, utilizing the low surface tension of the fluorocarbon chain to spread and form a water film on the fuel surface. Simultaneously, polysaccharide polymers such as xanthan gum are added as alcohol-resistant components, forming a gel-like isolation layer on the surface of polar solvents. However, this type of extinguishing agent has the following shortcomings in practical applications: First, the polymeric alcohol-resistant components are prone to salting out or viscosity decrease in seawater or high-salt environments, leading to a significant reduction in alcohol resistance, making it difficult to meet the actual requirements of seawater mixing or dilution in ship fires; second, existing alcohol-resistant foam agents have low expansion ratios, making it difficult to generate sufficient volume of foam to quickly fill enclosed spaces such as engine rooms and fuel tanks in a short time, thus limiting extinguishing efficiency.

[0005] In addition, existing technologies also disclose some gemini surfactants and their applications in fire extinguishing agents. Gemini surfactants are composed of two single-chain surfactant molecules linked by a linking group, exhibiting a lower critical micelle concentration and higher surface activity. Theoretically, they can achieve excellent foaming and spreading performance at lower dosages. However, conventional gemini surfactants have a limited variety of hydrophilic groups in their molecular structure and lack specific solvent-resistant designs for polar solvents such as methanol. Therefore, they still suffer from insufficient foam film strength and poor alcohol resistance in methanol fires. Furthermore, their molecular structure lacks stability, resulting in insufficient foam stability and seawater resistance under high-temperature conditions, which requires further improvement.

[0006] Therefore, there is an urgent need to develop a foaming agent that combines high foaming ratio, excellent seawater resistance, good alcohol resistance, and high temperature stability to meet the needs of rapid firefighting and continuous protection against methanol fires on ships. This has significant practical importance and application value. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that the existing technology has the disadvantages of insufficient foaming ability, seawater resistance and alcohol resistance of foaming agents, which cannot effectively extinguish methanol fires on ships. To this end, we propose a high-expansion seawater-resistant and alcohol-resistant foaming agent for methanol fires on ships that has high foaming ratio, excellent seawater resistance, good alcohol resistance and high temperature stability.

[0008] To achieve the above objectives, this application adopts the following technical solution: a high-expansion seawater-resistant and alcohol-resistant foaming agent for ship methanol fires, wherein the foaming agent comprises a gemini-type fluorocarbon surfactant, a betaine surfactant, a polar film-forming agent, a stabilizer, and water;

[0009] The gemini-type fluorocarbon surfactant has the structure shown in Formula A:

[0010] .

[0011] The foaming agent provided by this invention can form a foam liquid film on the surface of the burning methanol and generate a large amount of foam in the engine room when a methanol fire occurs on a ship. This foaming agent quickly isolates the air and forms a heat insulation barrier, suffocating the methanol combustion and preventing the methanol from continuing to heat up, vaporize and burn, thus extinguishing the methanol fire on the ship.

[0012] Preferably, the gemini-type fluorocarbon surfactant is prepared by the following steps:

[0013] (1) In a reactor, 2,3-diaminophenol, sodium p-chlorobenzenesulfonate, alkaline substances, catalyst and organic solvent are added and heated under inert gas protection. After the reaction is completed, the mixture is neutralized, separated and purified to obtain the aryl etherification intermediate.

[0014] (2) In a reactor, add the aryl etherification intermediate, the acid-binding agent and the aqueous solution of acetone, stir to dissolve and then add lauroyl chloride dropwise, stir to react, remove the solvent after the reaction is completed to obtain the amidation intermediate;

[0015] (3) In a reactor, an amidation intermediate, an alkaline catalyst and an organic solvent are added. After heating and activation, 3-(perfluorohexyl)propane oxide is added dropwise. The temperature is raised and the reaction is maintained. After the reaction is completed, the mixture is separated and purified to obtain the Gemini fluorocarbon surfactant.

[0016] In this invention, a gemini-type fluorocarbon surfactant introduces a sulfonate structure containing a benzene ring into the aminophenol structure through an aromatic etherification reaction. This not only forms a more rigid aromatic ether structure, improving the density of the foam liquid film formed by the foaming agent and effectively isolating oxygen, thus improving the fire extinguishing efficiency structurally, but also increases the proportion of highly stable benzene ring structures and hydrophobic structures in the surfactant, enhancing the high-temperature resistance of the foaming agent and the foam liquid film, and extending the fire extinguishing time.

[0017] Preferably, in step (1), the alkaline substance is selected from potassium carbonate or sodium carbonate; the catalyst is cuprous iodide; the organic solvent is selected from N,N-dimethylformamide or dimethyl sulfoxide; the inert gas is selected from nitrogen or argon; the reaction temperature is 110-130℃, the reaction time is 8-16h; and the molar ratio of sodium p-chlorobenzenesulfonate and 2,3-diaminophenol is 1.1-1.3:1.

[0018] Preferably, in step (2), the acid-binding agent is selected from sodium bicarbonate or sodium carbonate; the volume ratio of acetone to water in the acetone aqueous solution is 0.5-2:1; the reaction temperature is 10-30℃ and the reaction time is 2-6h; the molar ratio of lauroyl chloride to the aryl etherification intermediate is 2.2-2.5:1.

[0019] Preferably, in step (3), the alkaline catalyst is selected from potassium hydroxide, sodium hydroxide, or sodium methoxide; the organic solvent is selected from N,N-dimethylformamide or dimethyl sulfoxide; the activation temperature is 50-60℃, and the activation time is 1-2h; the heat preservation reaction temperature is 80-90℃, and the reaction time is 12-18h; the molar ratio of 3-(perfluorohexyl)propane oxide to the amidation intermediate is 2.2-2.5:1.

[0020] Preferably, the betaine surfactant is selected from lauramidopropyl betaine or cocamidopropyl betaine.

[0021] This invention combines a gemini-type fluorocarbon surfactant with a rigid structure and a multi-branched hydrophobic structure with a betaine surfactant with a quaternary ammonium structure, which can produce excellent synergistic effects, further improving the foaming ability and seawater resistance of the foaming agent. At the same time, the addition of film-forming agents and stabilizers can further enhance its foaming performance and storage stability.

[0022] Preferably, the polar film-forming agent is selected from ethylene glycol, propylene glycol, or glycerol; and the stabilizer is selected from xanthan gum, sodium carboxymethyl cellulose, or sodium alginate.

[0023] Preferably, based on a total mass fraction of 100%, the mass percentage of each component is as follows:

[0024] Gemini fluorocarbon surfactants 10-15%;

[0025] Betaine surfactant 15-25%;

[0026] Polar film-forming agent 3-10%;

[0027] Stabilizer 1-3%;

[0028] The remainder is water.

[0029] In another aspect, the present invention also provides a method for preparing a high-expansion seawater-resistant and alcohol-resistant foaming agent for ship methanol fires, comprising the following steps:

[0030] (1) In a stirred tank, water, stabilizer and polar film-forming agent are added in proportion under stirring, and stirred until completely dissolved to obtain a premixed solution;

[0031] (2) Gemini fluorocarbon surfactant and betaine surfactant are added to the premixed liquid in proportion, and the mixture is stirred and mixed evenly to obtain the high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire.

[0032] Preferably, in step (1), the stirring temperature is 40-50℃, the stirring speed is 300-500r / min, and the stirring time is 15-30min; in step (2), the stirring temperature is 20-30℃, the stirring speed is 50-100r / min, and the stirring time is 20-40min.

[0033] The technical effects and advantages of this invention are as follows:

[0034] (1) The high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fires provided by the present invention is prepared by compounding a gemini-type fluorocarbon surfactant with betaine surfactant and other components. Based on the excellent surface chemical ability and stability of the gemini-type fluorocarbon surfactant, the compounding can significantly improve the foaming ability, seawater resistance, alcohol resistance and high temperature stability of the foaming agent, so that it can quickly foam in the engine room, isolate oxygen and thus extinguish methanol fires. It can be effectively applied in the field of ship methanol fire extinguishing.

[0035] (2) The high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire provided by the present invention can form a layer of foam liquid film on the surface of the burning methanol when a methanol fire occurs on a ship and form a large amount of foam in the engine room space, quickly isolate the air and form a heat insulation barrier, suffocate the methanol combustion, prevent the methanol from continuing to heat up, vaporize and burn, and extinguish the ship methanol fire.

[0036] (3) In the high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fires provided by the present invention, the gemini fluorocarbon surfactant introduces a sulfonate structure containing a benzene ring into the aminophenol structure through an aromatic etherification reaction. This not only forms a rigid aromatic ether structure, improving the density of the structure when the foaming agent forms a foam liquid film, thus effectively isolating oxygen and improving the fire extinguishing efficiency in terms of structure, but also increases the proportion of high-stability benzene ring structure and hydrophobic structure in the surfactant, which can enhance the high-temperature resistance of the foaming agent and the foam liquid film and prolong the fire extinguishing time.

[0037] (4) The high expansion ratio seawater resistant and alcohol-resistant foaming agent for ship methanol fires provided by the present invention can significantly improve the foaming ratio of the foaming agent by combining the twin structure of the twin fluorocarbon surfactant and the combination of multiple hydrophobic functional groups. Furthermore, by using multiple short-chain fluorocarbon structures and multiple long-chain amide structures as hydrophobic segments, its excellent chemical stability can effectively improve the alcohol resistance, seawater resistance and high temperature resistance of the liquid film formed. At the same time, multiple short-chain fluorocarbon structures can replace the conventional long-chain fluorocarbon structures, effectively reducing the environmental impact of the foaming agent.

[0038] (5) In the high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire provided by the present invention, the gemini fluorocarbon surfactant contains aromatic ether rigid linking groups and diamide hydrogen bond network, which can give the foaming agent and the formed foam liquid film excellent high temperature resistance. On the one hand, it can be stored stably in the high temperature environment of the ship, and on the other hand, it can maintain the stability of the liquid film in the high temperature environment of methanol fire, which can effectively extinguish the fire.

[0039] (6) In the high-expansion seawater resistant and anti-alcohol foaming agent for ship methanol fire provided by the present invention, the combination of the rigid structure and multi-branched hydrophobic structure of the Gemini fluorocarbon surfactant and the quaternary ammonium structure of the betaine surfactant can produce excellent synergistic effect, further improving the foaming ability and seawater resistance of the foaming agent. At the same time, the addition of film-forming agent and stabilizer can further enhance its foaming performance and storage stability. Detailed Implementation

[0040] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following specific embodiments are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0041] The perfluoroalkyl betaine was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd. as perfluoroalkyl betaine PB10948; the other reagents and equipment were conventional reagents and equipment in this technical field.

[0042] Preparation of Gemini Fluorocarbon Surfactants

[0043] Gemini-type fluorocarbon surfactants were prepared using the following steps:

[0044] (1) In a 500mL four-necked flask equipped with a mechanical stirrer, thermometer, reflux condenser and nitrogen inlet tube, nitrogen gas is introduced to replace the air in the flask for 10 minutes, and nitrogen protection is maintained throughout the reaction.

[0045] Add 200 mL of N,N-dimethylformamide, 0.10 mol of 2,3-diaminophenol, 0.12 mol of sodium p-chlorobenzenesulfonate, 0.20 mol of anhydrous potassium carbonate, and 0.005 mol of cuprous iodide sequentially to a four-necked flask. Start stirring, and after the solids dissolve, heat to 120 °C and maintain the temperature at this level for 12 hours.

[0046] After the reaction was completed, the mixture was cooled to room temperature, and the insoluble inorganic salts were removed by filtration under reduced pressure. The filtrate was concentrated under reduced pressure to about 80 mL and poured into 300 mL of ice water with stirring. The pH of the system was slowly adjusted to 7 with 1 mol / L dilute hydrochloric acid, and a large amount of grayish-white solid precipitated. The solid was filtered, and the filter cake was recrystallized with a mixed solvent of ethanol and water. The solid was dried under vacuum at 60 °C for 8 hours to obtain 23.6 g of the aryl etherification intermediate, with a yield of 84.2%.

[0047] (2) In a 500mL three-necked flask, add 0.10mol of aryl etherification intermediate, 0.30mol of sodium bicarbonate and 250mL of acetone-water mixed solvent, wherein the volume ratio of acetone to water is 1:1;

[0048] Cool the mixture to 5°C in an ice bath, and slowly add 0.25 mol of lauroyl chloride dropwise using a constant pressure dropping funnel while stirring vigorously. Control the dropping rate so that the temperature of the reaction solution does not exceed 10°C. The addition is completed in about 1 hour. After the addition is completed, remove the ice bath and allow the mixture to rise naturally to room temperature. Continue stirring the reaction for 4 hours.

[0049] After the reaction was completed, the pH of the system was adjusted to 7 with 1 mol / L dilute hydrochloric acid, and acetone was removed by vacuum distillation. A large amount of white solid precipitated in the residual aqueous phase. The solid was filtered, and the filter cake was washed successively with deionized water and a small amount of cold ethanol. The solid was dried under vacuum at 60 °C to obtain 56.8 g of amidated intermediate, with a yield of 88.1%.

[0050] (3) In a 250 mL dry three-necked flask, nitrogen gas was introduced to purge the air. Then, 0.05 mol of the amidation intermediate, 150 mL of anhydrous N,N-dimethylformamide, and 0.2 g of potassium hydroxide were added sequentially. After stirring to dissolve, the mixture was heated to 55 °C for 1 hour to activate.

[0051] Under nitrogen protection, 0.11 mol of 3-(perfluorohexyl)propane oxide was slowly added dropwise using a constant-pressure dropping funnel, with the dropping rate controlled to complete in approximately 2 hours. After the addition was complete, the temperature was raised to 85°C and the reaction was maintained at this temperature for 16 hours.

[0052] After the reaction was completed, the mixture was cooled to room temperature, filtered under reduced pressure, and the filtrate was concentrated under reduced pressure to about 60 mL. This filtrate was then poured into 300 mL of ice water with stirring. The mixture was extracted and washed three times with 50 mL of ethyl acetate each time to remove unreacted fluorocarbon propylene oxide. The aqueous phase was freeze-dried to obtain a crude product. The crude product was recrystallized from a methanol-water mixture and dried under vacuum at 50 °C to obtain a white to pale yellow solid, which was the target product, a gemini-type fluorocarbon surfactant. The yield was 58.2 g, or 77.8%.

[0053] Mass spectrometry data of gemini fluorocarbon surfactants: HRMS (ESI) - The product was analyzed, and the product was [M-Na]. - The m / z values ​​were 1395.13 (100.0%), 1396.13 (58.5%), 1397.13 (17.8%), and 1398.13 (3.9%).

[0054] Infrared spectral data (FT-IR, cm⁻¹) of Gemini fluorocarbon surfactants -1 The values ​​are 1650 (amide C=O), 1240-1260 (CF), 1195, 1045 (S=O), 1130-1150 (COC), 1600, 1490 (benzene ring skeleton), and 3400-3450 (alcohol OH).

[0055] Example 1

[0056] A high-expansion, seawater-resistant, and alcohol-resistant foaming agent for shipboard methanol fires is prepared using the following steps:

[0057] (1) In a stirred tank, water, sodium carboxymethyl cellulose and ethylene glycol were added in proportion at a stirring temperature of 50℃ and a stirring speed of 500r / min. After stirring for 25min, a premix was obtained.

[0058] (2) Gemini fluorocarbon surfactant and lauramide propyl betaine were added to the premixed liquid in proportion. After stirring for 30 minutes at a stirring temperature of 25°C and a stirring speed of 80 r / min, a high-expansion seawater resistant and alcohol-resistant foaming agent for ship methanol fire was prepared.

[0059] Based on a total mass fraction of 100%, the mass percentage of each component is as follows:

[0060] Gemini fluorocarbon surfactant 15%;

[0061] Lauroamide propyl betaine 20%;

[0062] 5% ethylene glycol;

[0063] Sodium carboxymethyl cellulose 3%;

[0064] The remainder is water.

[0065] Example 2

[0066] A high-expansion, seawater-resistant, and alcohol-resistant foaming agent for shipboard methanol fires is prepared using the following steps:

[0067] (1) In a stirred tank, water, sodium alginate and glycerol were added in proportion at a stirring temperature of 40℃ and a stirring speed of 300r / min. After stirring for 30min, a premix was obtained.

[0068] (2) Gemini fluorocarbon surfactant and cocamidopropyl betaine were added to the premixed liquid in proportion. After stirring for 20 minutes at a stirring temperature of 30°C and a stirring speed of 100 r / min, a high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire was obtained.

[0069] Based on a total mass fraction of 100%, the mass percentage of each component is as follows:

[0070] Gemini fluorocarbon surfactant 10%;

[0071] Cocamidopropyl betaine 25%;

[0072] Glycerol 10%;

[0073] 1% sodium alginate;

[0074] The remainder is water.

[0075] Example 3

[0076] A high-expansion, seawater-resistant, and alcohol-resistant foaming agent for shipboard methanol fires is prepared using the following steps:

[0077] (1) In a stirred tank, water, xanthan gum and ethylene glycol were added in proportion at a stirring temperature of 45℃ and a stirring speed of 300r / min. After stirring for 30min, a premix was obtained.

[0078] (2) Gemini fluorocarbon surfactant and cocamidopropyl betaine were added to the premixed liquid in proportion. After stirring for 40 minutes at a stirring temperature of 20°C and a stirring speed of 50 r / min, a high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire was obtained.

[0079] Based on a total mass fraction of 100%, the mass percentage of each component is as follows:

[0080] Gemini fluorocarbon surfactant 15%;

[0081] Cocamidopropyl betaine 15%;

[0082] 3% ethylene glycol;

[0083] Xanthan gum 2%;

[0084] The remainder is water.

[0085] Comparative Example 1

[0086] The process is basically the same as in Example 1, except that the gemini fluorocarbon surfactant is replaced with an equal amount of perfluoroalkyl betaine.

[0087] Comparative Example 2

[0088] The process is basically the same as in Example 1, except that lauramide propyl betaine is replaced with an equal amount of gemini-type fluorocarbon surfactant.

[0089] Comparative Example 3

[0090] The method is basically the same as in Example 1, except that lauramide propyl betaine is replaced with an equal amount of sodium dodecylbenzene sulfonate.

[0091] Performance testing

[0092] Freshwater foaming ratio test: The products of Examples 1-3 and Comparative Examples 1-3 were diluted with fresh water to 6wt% as the foaming liquid to be tested. The foaming ratio was tested according to the test standard of GB15308-2025 "Foam Extinguishing Agents" -1.

[0093] Seawater foaming ratio test: The basic method is the same as that for freshwater foaming ratio test, except that the freshwater dilution is replaced with an equal amount of artificial seawater, and the foaming ratio is tested to be -2; the artificial seawater contains NaCl (25g / L), MgCl2·6H2O (11g / L), Na2SO4 (4g / L), and CaCl2 (1.6g / L).

[0094] Methanol foaming ratio test: The basic method is the same as that for fresh water foaming ratio test, except that the fresh water dilution is replaced with an equal volume of 30% methanol aqueous solution, and the foaming ratio is tested to be -3.

[0095] High temperature stability test: After placing the products of Examples 1-3 and Comparative Examples 1-3 in an environment of 65℃ for 30 days, a fresh water foaming ratio test was conducted, and the foaming ratio was calculated as -4.

[0096] The test results are shown in Table 1 below:

[0097] Example 1 238 230 227 234 Example 2 239 232 227 233 Example 3 238 231 228 235 Comparative Example 1 108 87 74 97 Comparative Example 2 204 186 171 189 Comparative Example 3 211 191 180 201

[0098] Table 1

[0099] According to the comparison of the test results of Examples 1-3 and Comparative Example 1, the high-expansion seawater-resistant and alcohol-resistant foaming agent for ship methanol fires provided by the present invention, through the preparation of a gemini-type fluorocarbon surfactant, has superior foaming ability, seawater resistance, alcohol resistance and high temperature resistance compared with the fluorocarbon foaming agent in the prior art, and can be effectively applied in the field of ship methanol fire extinguishing foaming agents.

[0100] The comparison of the test results of Examples 1-3 and Comparative Examples 2-3 shows that the high-expansion seawater-resistant and alcohol-resistant foaming agent for ship methanol fires provided by the present invention can further improve the foaming ability, seawater resistance, alcohol resistance and high temperature resistance of the foaming agent through the synergistic effect of the gemini fluorocarbon surfactant and the betaine surfactant.

[0101] Fire extinguishing capability test: According to the test standard of 6.10.8.2 extinguishing water-soluble liquid fuel fire test in GB15308-2025 "Foam Extinguishing Agents", the fire resistance level, fire extinguishing time and fire resistance time of the products of Examples 1-3 and Comparative Examples 1-3 were tested.

[0102] The test results are shown in the table below:

[0103] Example 1 A ≤2 ≥25 Example 2 A ≤2 ≥25 Example 3 A ≤2 ≥25 Comparative Example 1 B ≤5 ≥10 Comparative Example 2 A ≤4 ≥20 Comparative Example 3 A ≤3 ≥20

[0104] Table 2

[0105] According to the test results of Examples 1-3, the high-expansion seawater-resistant alcohol-resistant foaming agent for ship methanol fires provided by this invention has a foaming ratio greater than 200, which meets the technical requirements for high-expansion foam liquids in GB15308-2025; the extinguishing time is ≤120s, and the fire resistance time is ≥25min, which meets the fire extinguishing performance requirements for ARⅠ grade alcohol-resistant foam liquids in GB 15308-2025. Furthermore, after aging at 65℃ for 30 days, the foaming ratio retention rate exceeds 98%, still meeting the technical specifications of high-expansion foam liquids.

[0106] According to the comparison of the test results of Examples 1-3 and Comparative Example 1, the high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires provided by the present invention, through the preparation of a gemini-type fluorocarbon surfactant, has a better fire extinguishing ability than the fluorocarbon foaming agent in the prior art, and can be widely used in the field of ship methanol fires.

[0107] According to the comparison of the test results of Examples 1-3 and Comparative Examples 2-3, it can be seen that the high-expansion seawater-resistant and alcohol-resistant foaming agent for ship methanol fires provided by the present invention can further improve the fire extinguishing ability of the foaming agent through the synergistic effect of the gemini fluorocarbon surfactant and the betaine surfactant.

[0108] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A high-expansion seawater-resistant and solvent-resistant foaming agent for use in methanol fires on ships, characterized in that, The foaming agent includes a gemini fluorocarbon surfactant, a betaine surfactant, a polar film-forming agent, a stabilizer, and water; The gemini-type fluorocarbon surfactant has the structure shown in Formula A: 。 2. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 1, characterized in that, The gemini-type fluorocarbon surfactant is prepared by the following steps: (1) In a reactor, 2,3-diaminophenol, sodium p-chlorobenzenesulfonate, alkaline substances, catalyst and organic solvent are added and heated under inert gas protection. After the reaction is completed, the mixture is neutralized, separated and purified to obtain the aryl etherification intermediate. (2) In a reactor, add the aryl etherification intermediate, the acid-binding agent and the aqueous solution of acetone, stir to dissolve and then add lauroyl chloride dropwise, stir to react, remove the solvent after the reaction is completed to obtain the amidation intermediate; (3) In a reactor, an amidation intermediate, an alkaline catalyst and an organic solvent are added. After heating and activation, 3-(perfluorohexyl)propane oxide is added dropwise. The temperature is raised and the reaction is maintained. After the reaction is completed, the mixture is separated and purified to obtain the Gemini fluorocarbon surfactant.

3. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 2, characterized in that, In step (1), the alkaline substance is selected from potassium carbonate or sodium carbonate; the catalyst is cuprous iodide; the organic solvent is selected from N,N-dimethylformamide or dimethyl sulfoxide; the inert gas is selected from nitrogen or argon; the reaction temperature is 110-130℃ and the reaction time is 8-16h; the molar ratio of sodium p-chlorobenzenesulfonate and 2,3-diaminophenol is 1.1-1.3:

1.

4. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 2, characterized in that, In step (2), the acid-binding agent is selected from sodium bicarbonate or sodium carbonate; the volume ratio of acetone to water in the acetone aqueous solution is 0.5-2:1; the reaction temperature is 10-30℃ and the reaction time is 2-6h; the molar ratio of lauroyl chloride to the aryl etherification intermediate is 2.2-2.5:

1.

5. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 2, characterized in that, In step (3), the alkaline catalyst is selected from potassium hydroxide, sodium hydroxide, or sodium methoxide; the organic solvent is selected from N,N-dimethylformamide or dimethyl sulfoxide; the activation temperature is 50-60℃ and the activation time is 1-2h; the heat preservation reaction temperature is 80-90℃ and the reaction time is 12-18h; the molar ratio of 3-(perfluorohexyl)propane oxide to the amidation intermediate is 2.2-2.5:

1.

6. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 1, characterized in that, The betaine surfactant is selected from lauramidopropyl betaine or cocamidopropyl betaine.

7. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 1, characterized in that, The polar film-forming agent is selected from ethylene glycol, propylene glycol, or glycerol; the stabilizer is selected from xanthan gum, sodium carboxymethyl cellulose, or sodium alginate.

8. The high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to claim 1, characterized in that, Based on a total mass fraction of 100%, the mass percentage of each component is as follows: Gemini fluorocarbon surfactants 10-15%; Betaine surfactant 15-25%; Polar film-forming agent 3-10%; Stabilizer 1-3%; The remainder is water.

9. The method for preparing the high-expansion seawater-resistant and solvent-resistant foaming agent for ship methanol fires according to any one of claims 1-8, characterized in that, Includes the following steps: (1) In a stirred tank, water, stabilizer and polar film-forming agent are added in proportion under stirring, and stirred until completely dissolved to obtain a premixed solution; (2) Gemini fluorocarbon surfactant and betaine surfactant are added to the premixed liquid in proportion, and the mixture is stirred and mixed evenly to obtain the high-expansion seawater resistant and solvent-resistant foaming agent for ship methanol fire.

10. The preparation method according to claim 9, characterized in that, In step (1), the stirring temperature is 40-50℃, the stirring speed is 300-500r / min, and the stirring time is 15-30min; in step (2), the stirring temperature is 20-30℃, the stirring speed is 50-100r / min, and the stirring time is 20-40min.

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