High-efficiency environment-friendly foam extinguishing agent for converter station or substation and preparation method thereof

Abstract

The application discloses a high-efficiency environment-friendly foam extinguishing agent for a converter station or a transformer substation and a preparation method thereof. A structural formula of a quaternary ammonium salt modified tetrasiloxane surfactant used in the extinguishing agent is shown in the specification. The surface tension of the quaternary ammonium salt modified tetrasiloxane surfactant is less than or equal to 20.8 mN / m. The quaternary ammonium salt modified tetrasiloxane surfactant can be specifically applied to development of the high-efficiency environment-friendly foam extinguishing agent for the converter station or the transformer substation. The high-efficiency environment-friendly foam extinguishing agent has excellent foaming performance, stability, extinguishing performance and film forming performance.

Description

Technical Field

[0001] This invention relates to the field of foam fire extinguishing agent technology, specifically to a high-efficiency and environmentally friendly foam fire extinguishing agent for converter stations or substations and its preparation method. Background Technology

[0002] Foam extinguishing agents are widely used to extinguish fires involving flammable liquids (such as oils and solvents). Traditional fluorinated surfactants (such as PFOS and PFOA) were once widely used in aqueous film-forming foam (AFFF) extinguishing agents due to their excellent film-forming properties, foam stability, and oil resistance. However, fluorinated surfactants have extremely strong chemical stability, are difficult to degrade in the environment, and can accumulate in organisms, posing potential risks to human health and ecosystems. Therefore, with the advancement of international regulations such as the Stockholm Convention, their use has been gradually banned or restricted globally, and the development of efficient and environmentally friendly alternative technologies has become an urgent need for industry development.

[0003] Trisiloxane organosilicon surfactants possess excellent surface activity, wettability, and spreadability, making them a core component in the construction of fluorine-free foam fire extinguishing agents. However, existing trisiloxane surfactants exhibit decreased stability and surface activity in high-salt environments (such as seawater and high-hardness water), leading to a significant reduction in the stability of the foam fire extinguishing agent, affecting fire extinguishing efficiency, and making it difficult to meet the application requirements in extreme environments. This limits their use in converter stations or substations. Summary of the Invention

[0004] The technical problem to be solved by this invention is how to improve the performance of surfactants used in foam fire extinguishing agents and to prepare high-performance foam fire extinguishing agents.

[0005] The present invention solves the above-mentioned technical problems through the following technical means:

[0006] A quaternary ammonium salt modified tetrasiloxane surfactant has the following structural formula:

[0007] .

[0008] This invention also proposes a method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant, comprising the following steps:

[0009] S1. Using tris(trimethylsiloxy)silane as a raw material, in an organic solvent and in the presence of sodium triphenylmethyl, a reaction is carried out with ethylene oxide (EO) to obtain a sodium alkoxide intermediate. ;

[0010] S2. Using 5-bromo-1,3-pentadiene as a raw material, trimethylamine is reacted in an organic solvent to obtain a conjugated diene quaternary ammonium salt; then, using the conjugated diene quaternary ammonium salt as a raw material, m-chloroperoxybenzoic acid is reacted in an organic solvent to obtain an amination-modified dicyclooxyethylene derivative.

[0011] S3. Using sodium alkoxide intermediate and amination of diethylene oxide derivative as raw materials, the reaction is carried out in an organic solvent, and hydrolysis is performed under acidic conditions to obtain the quaternary ammonium salt modified tetrasiloxane surfactant.

[0012] Preferably, in S1, trichlorosilane is used as a raw material, and trimethylsilanol is added in an organic solvent in the presence of an alkali and a hydrogen chloride scavenger to carry out a substitution reaction to obtain tris(trimethylsiloxy)silane.

[0013] Preferably, the organic solvent used in the preparation of tris(trimethylsiloxy)silane is anhydrous n-hexane.

[0014] Preferably, in the preparation of tris(trimethylsiloxy)silane, the base and hydrogen chloride scavenger are pyridine.

[0015] Preferably, in the preparation of tris(trimethylsiloxy)silane, the reaction is carried out in two steps: first, the mixture is stirred at 0-5°C under nitrogen protection for 2-4 hours; then, the system is heated to 40-50°C and stirred for 0.5-1 hour until the reaction is complete.

[0016] Preferably, in the preparation process of tri(trimethylsiloxy)silane, the mass ratio of trichlorosilane, alkali and hydrogen chloride scavenger, and trimethylsilanol is 10-18:20-31.5:30-38.

[0017] This invention presents a novel, highly efficient process for synthesizing quaternary ammonium tetrasiloxane surfactants based on trichlorosilane raw materials. The process route is simple, and the synthesis yield remains consistently above 75%.

[0018] Preferably, in S1, the organic solvent used is one or a mixture of two of anhydrous toluene or anhydrous dichloromethane.

[0019] Preferably, in S1, the reaction temperature is 60~80℃ and the reaction time is 0.5-2 hours.

[0020] Preferably, in S1, the mass ratio of tris(trimethylsiloxy)silane, ethylene oxide, and triphenylmethyl sodium is 15-20:40:1.

[0021] Preferably, in S1, the mass ratio of tris(trimethylsiloxy)silane to organic solvent is 15-20:30-35.

[0022] Preferably, in S2, the route for synthesizing the amination-modified diethylene oxide derivative is as follows:

[0023] .

[0024] Preferably, in S2, the reaction is carried out in two steps: in the preparation of the conjugated diene quaternary ammonium salt, the organic solvent is anhydrous acetonitrile, and in the reaction with m-chloroperoxybenzoic acid, the organic solvent is anhydrous dichloromethane.

[0025] Preferably, in S2, the reaction is carried out in two steps: the reaction with trimethylamine is carried out at a temperature of 25°C for a reaction time of 6-8 hours; the reaction with m-chloroperoxybenzoic acid is carried out at a temperature of 25°C for a reaction time of 8 hours.

[0026] Preferably, in S2, the molar ratio of 5-bromo-1,3-pentadiene to trimethylamine is 1:1.5.

[0027] Preferably, in S2, the molar ratio of conjugated diene quaternary ammonium salt to m-chloroperoxybenzoic acid is 1:1.2.

[0028] Preferably, in S2, the ratio of 5-bromo-1,3-pentadiene to organic solvent is 10 g: 150 mL.

[0029] Preferably, in S2, the ratio of the conjugated diene quaternary ammonium salt to the organic solvent is 10g:120mL.

[0030] Preferably, in S3, the organic solvent is anhydrous dichloromethane.

[0031] Preferably, in S3, the reaction temperature is 50~60°C and the reaction time is 8~12 hours.

[0032] Preferably, in S3, the mass ratio of the sodium alkoxide intermediate to the amination of the diethylene oxide derivative is 20-25:30.

[0033] Preferably, in S3, acidity is maintained by using one or a mixture of two of the acidic reagents hydrochloric acid (HCl) or sulfuric acid (H2SO4).

[0034] Preferably, in S3, the mass ratio of sodium alkoxide intermediate to organic solvent is 20-25:35-40.

[0035] The synthetic route of the quaternary ammonium salt modified tetrasiloxane surfactant of the present invention is as follows:

[0036]

[0037] The present invention also proposes the application of the aforementioned quaternary ammonium salt modified tetrasiloxane surfactant in foam fire extinguishing agents.

[0038] The present invention also proposes a foam fire extinguishing agent containing the aforementioned quaternary ammonium salt modified tetrasiloxane surfactant.

[0039] Preferably, the foam fire extinguishing agent comprises, by mass percentage, 15%-20% quaternary ammonium salt modified tetrasiloxane surfactant, 10%-15% trisiloxane surfactant, 1%-1.3% foam stabilizer, 0.5%-0.8% preservative, 0.3%-0.5% chelating agent, 1%-2% cosolvent, and the balance being water.

[0040] Preferably, the trisiloxane surfactant is CoatOsil-77; the foam stabilizer is one or a mixture of two of xanthan gum and guar gum; the preservative is one or a mixture of two of potassium sorbate and sodium benzoate; the chelating agent is dipotassium EDTA; and the cosolvent is ethylenediamine.

[0041] The present invention also proposes a method for preparing the foam fire extinguishing agent, comprising the following steps: mixing a quaternary ammonium salt modified tetrasiloxane surfactant with other raw materials to obtain the foam fire extinguishing agent.

[0042] Preferably, the preparation method of the foam fire extinguishing agent includes the following steps: taking a portion of water, adding a quaternary ammonium salt modified tetrasiloxane surfactant and a trisiloxane surfactant, and stirring to obtain a surfactant solution; adding a chelating agent to the obtained surfactant solution, and stirring to obtain a mixture; mixing a foam stabilizer and a co-solvent, grinding and stirring evenly, adding the mixture to the obtained mixture, stirring, adding a preservative and the remaining water, and stirring to obtain the foam fire extinguishing agent.

[0043] The present invention also proposes a fire extinguishing device containing the aforementioned foam fire extinguishing agent.

[0044] The advantages of this invention are:

[0045] (1) Based on the self-synthesized quaternary ammonium salt tetrasiloxane surfactant, this invention develops a high-efficiency and environmentally friendly foam extinguishing agent formula to address the technical bottleneck that existing environmentally friendly foam extinguishing agents cannot meet the application requirements in extreme water quality environments. This product fully complies with the requirements of the national standard GB 15308-2006 "Foam Extinguishing Agents" and has good foam performance and fire extinguishing performance.

[0046] (2) For transformer oil fires, the high-efficiency and environmentally friendly foam extinguishing agent of this invention has excellent foaming performance, foam stability, fire extinguishing performance and film-forming performance. Its foaming ratio is 8-9 times; the 25% liquid separation time is 11-15 min; the fire extinguishing time is 58s-95s; the fire resistance time is 10 min 25s-14 min 39s; and the film-forming speed is 1.6-2cm. 2 / s. Under the same conditions, compared with commercial 3% aqueous film-forming foam extinguishing agent, the foaming ratio is increased by 2.12-3.12 times, the liquid separation time of 25% is extended by 7 min 25s-11 min 25s, the extinguishing time is shortened by 101-138s, the anti-burning time is extended by 1 min 08s-5 min 22s, and the film-forming speed is increased by 0.4-0.8cm. 2 / s.

[0047] (3) Through molecular structure design, trihydroxypentyl and quaternary ammonium salt functional groups are introduced into the siloxane skeleton simultaneously, so that the tetrasiloxane surfactant has high surface activity and water quality adaptability, and the surface tension can be reduced to 20.8 mN / m and below at the critical micelle concentration.

[0048] (4) The present invention establishes a high-efficiency and environmentally friendly foam fire extinguishing agent stock solution preparation process with simple process, mild conditions, good repeatability, good stability and long shelf life. The prepared foam fire extinguishing agent stock solution is uniform and stable after standing for 180 days, without stratification or changes in properties. Attached Figure Description

[0049] Figure 1 These are actual images of the solutions at the critical micelle concentration of the tetrasiloxane surfactant in Examples 1-3 of this invention.

[0050] Figure 2 The surface tension test data of the tetrasiloxane surfactant and CoatOsil-77 solution in Examples 1-3 of this invention;

[0051] Figure 3 The results of performance tests on high-efficiency and environmentally friendly foam fire extinguishing agents at different concentrations of tetrasiloxane surfactants;

[0052] Figure 4 The results of performance tests on high-efficiency and environmentally friendly foam fire extinguishing agents at different concentrations of trisiloxane surfactants;

[0053] Figure 5 The results of performance tests on high-efficiency and environmentally friendly foam fire extinguishing agents at different foam stabilizer concentrations;

[0054] Figure 6 This is a static image of the high-efficiency and environmentally friendly foam fire extinguishing agent stock solution containing tetrasiloxane surfactant prepared in Example 4 of this invention.

[0055] Figure 7 This is a static image of the high-efficiency and environmentally friendly foam fire extinguishing agent stock solution prepared in Comparative Example 6 of this invention.

[0056] Figure 8 These are experimental images showing the fire extinguishing phenomena of the high-efficiency and environmentally friendly foam fire extinguishing agent containing tetrasiloxane surfactant in Examples 4-7 of this invention.

[0057] Figure 9 Figures showing the extinguishing phenomena of comparative examples 1-5 corresponding to foam extinguishing agents and 3% AFFF in fire extinguishing experiments;

[0058] Figure 10 These are experimental images showing the film-forming phenomena of foam fire extinguishing agents and 3% AFFF corresponding to Examples 4-7 and Comparative Examples 4-5 of the present invention;

[0059] Figure 11 The test data are for the film-forming properties of foam fire extinguishing agents and 3% AFFF corresponding to Examples 4-7 and Comparative Examples 4-5 of this invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0062] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0063] Example 1

[0064] This embodiment synthesizes the target tetrasiloxane surfactant tris(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl-trimethylammonium bromide. The surfactant's structural formula and synthesis process are as follows:

[0065]

[0066]

[0067] The specific synthesis path is as follows:

[0068] Step 1: Synthesis of tris(trimethylsiloxy)silane

[0069] Under anhydrous conditions, 10 g of trichlorosilane (SiHCl3) was dissolved in 50 g of anhydrous n-hexane, followed by the addition of 20 g of pyridine, and then the slow addition of 30 g of trimethylsilanol (Me3SiOH) with stirring. This process was carried out at 0 °C and stirred for 2 hours under nitrogen protection. Subsequently, the system was heated to 40 °C and stirred for another hour to ensure complete reaction. Byproducts were then removed by vacuum distillation to obtain tris(trimethylsiloxy)silane with the molecular formula (Me3SiO)3SiH.

[0070]

[0071] Step 2: Reaction with ethylene oxide

[0072] In 30g of anhydrous toluene, 20g of tris(trimethylsiloxy)silane [(Me3SiO)3SiH] was dissolved, and 1g of triphenylmethyl sodium was slowly added. After stirring at room temperature for 2 hours, 40g of ethylene oxide was added, and the mixture was heated to 60℃ to carry out an epoxy ring-opening polymerization reaction for 30 minutes, so that Si-H and ethylene oxide could undergo an addition reaction to generate a sodium alkoxide intermediate.

[0073]

[0074] Step 3: Reaction with diethylene oxide derivatives

[0075] Dissolve 20g of sodium alkoxide intermediate in 35g of anhydrous dichloromethane, and add 30g of amination-modified diethylene oxide derivative. The temperature was controlled at 50℃, and the mixture was stirred for 8 hours to generate an intermediate product. The pH was then adjusted to 2 using 5% hydrochloric acid to hydrolyze the product under acidic conditions, promoting ring-opening of the epoxy resin to generate the desired product. The NMR data are as follows:

[0076] 13 C NMR (100 MHz, CDCl3) δ 74.8, 74.4, 72.5, 70.7, 69.2, 66.2, 63.6,53.5, 15.8, 1.7.

[0077] 1 H NMR (400 MHz, CDCl3) δ 4.51 (s, 1H), 4.37-4.39 (m, 2H), 4.24 (dt, J = 5.5, 4.4 Hz, 1H), 3.85 (td, J = 5.3, 3.4 Hz, 1H), 3.80 (dd, J = 5.5, 3.4 Hz,1H), 3.59-3.73 (m, 16H), 3.52 (t, J = 6.5 Hz, 2H), 3.61 (d, J = 5.3 Hz, 2H), 3.22-3.33 (m, 2H), 2.91 (s, 9H), 1.37-1.49 (m, 2H), 0.06 (s, 27H).

[0078] The process is as follows:

[0079]

[0080] The synthetic route for amination of diethylene oxide derivatives is as follows:

[0081]

[0082] The specific synthesis path is as follows:

[0083] Step 1: Synthesis of conjugated diene quaternary ammonium salts

[0084] Under nitrogen protection, 10 g of 5-bromo-1,3-pentadiene was dissolved in 150 mL of anhydrous acetonitrile. At 0 °C, 25 mL of a 30% (w / w) trimethylamine aqueous solution was slowly added dropwise over 30 min. After the addition was complete, the reaction was stirred at 25 °C for 8 hours to obtain the target product, a conjugated diene quaternary ammonium salt.

[0085]

[0086] Step 2: Synthesis of amination-modified diethylene oxide derivatives

[0087] Under nitrogen protection, 10 g of conjugated diene quaternary ammonium salt was dissolved in 120 mL of anhydrous dichloromethane (CH2Cl2). Under light-protected conditions at 0 °C, 16.5 g of 77% pure m-chloroperoxybenzoic acid was slowly added over 30 min. After the addition was complete, the reaction was stirred at 25 °C for 8 hours to obtain the target product, an amination of diethylene oxide derivatives.

[0088]

[0089] Example 2

[0090] The structure and synthesis process of the tri(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl-trimethylammonium bromide tetrasiloxane surfactant are the same as in Example 1.

[0091] The specific synthesis path is as follows:

[0092] Step 1: Synthesis of tris(trimethylsiloxy)silane

[0093] Under anhydrous conditions, 15 g of trichlorosilane (SiHCl3) was dissolved in 50 g of anhydrous n-hexane, followed by the addition of 30 g of pyridine, and then the slow addition of 35 g of trimethylsilanol (Me3SiOH) with stirring. This process was carried out at 5 °C and stirred for 4 hours under nitrogen protection. Subsequently, the system was heated to 50 °C and stirred for another hour to ensure complete reaction. The byproducts were then removed by vacuum distillation to obtain tris(trimethylsiloxy)silane with the molecular formula (Me3SiO)3SiH.

[0094] Step 2: Reaction with ethylene oxide

[0095] In 35g of anhydrous toluene, 15g of tris(trimethylsiloxy)silane [(Me3SiO)3SiH] was dissolved, and 1g of triphenylmethyl sodium was slowly added. After stirring at room temperature for 2 hours, 40g of ethylene oxide was added, and the mixture was heated to 80℃ to carry out an epoxy ring-opening polymerization reaction for 30 minutes, so that Si-H and ethylene oxide could undergo an addition reaction to generate a sodium alkoxide intermediate.

[0096] Step 3: Reaction with diethylene oxide derivatives

[0097] 25g of sodium alkoxide intermediate was dissolved in 40g of anhydrous dichloromethane, and 30g of amination-modified diethylene oxide derivative was added. The mixture was stirred at 60℃ for 12 hours to generate the intermediate product. Subsequently, the pH was adjusted to 3 using 5% hydrochloric acid to hydrolyze the product under acidic conditions, promoting the ring-opening of the epoxy resin to generate the desired product.

[0098] The synthesis steps for the amination of the dicyclooxyethylene derivative are the same as in Example 1.

[0099] Example 3

[0100] The synthesis process of the tri(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl-trimethylammonium bromide tetrasiloxane surfactant is the same as in Example 1.

[0101] The specific synthesis path is as follows:

[0102] Step 1: Synthesis of tris(trimethylsiloxy)silane

[0103] Under anhydrous conditions, 18 g of trichlorosilane (SiHCl3) was dissolved in 50 g of anhydrous n-hexane, followed by the addition of 31.5 g of pyridine, and then the slow addition of 38 g of trimethylsilanol (Me3SiOH) with stirring. This process was carried out at 2 °C and stirred for 2 hours under nitrogen protection. Subsequently, the system was heated to 45 °C and stirred for another 0.5 hours to ensure complete reaction. The byproducts were then removed by vacuum distillation to obtain tris(trimethylsiloxy)silane with the molecular formula (Me3SiO)3SiH.

[0104] Step 2: Reaction with ethylene oxide

[0105] In 35g of anhydrous toluene, 15g of tris(trimethylsiloxy)silane ((Me3SiO)3SiH) was dissolved, and 1g of triphenylmethyl sodium was slowly added. After stirring at room temperature for 2 hours, 40g of ethylene oxide was added, and the mixture was heated to 70°C to carry out an epoxy ring-opening polymerization reaction for 2 hours, so that Si-H and ethylene oxide could undergo an addition reaction to generate a sodium alkoxide intermediate.

[0106] Step 3: Reaction with diethylene oxide derivatives

[0107] 23g of sodium alkoxide intermediate was dissolved in 38g of anhydrous dichloromethane, and 30g of amination-modified diethylene oxide derivative was added. The mixture was stirred at 55℃ for 10 hours to generate the intermediate product. Subsequently, the pH was adjusted to 3 using 5% sulfuric acid to hydrolyze the product under acidic conditions, promoting the ring-opening of the epoxy resin to generate the desired product.

[0108] The synthesis steps for the amination of the dicyclooxyethylene derivative are the same as in Example 1.

[0109] The physical appearance of the solutions of the tetrasiloxane surfactants synthesized in Examples 1-3 above at the critical micelle concentration is shown in the following figures. Figure 1 As shown, the tetrasiloxane surfactant solutions obtained in Examples 1-3 have a uniform overall texture and good dispersibility in water.

[0110] The properties of the tetrasiloxane surfactants synthesized in Examples 1-3 above were tested. Specifically, the surface tension of the surfactant at the critical micelle concentration was measured using a QBZY-3 fully automatic surface tension meter at 25°C. The synthesis yield was then calculated. The specific results are shown in Table 1 below. Figure 2 As shown:

[0111] Table 1. Performance test results of tetrasiloxane surfactants

[0112]

[0113] CoatOsil-77 is a commercial trisiloxane surfactant.

[0114] From Table 1 above and Figure 2 This invention provides a tetrasiloxane surfactant product with high surface activity and a method for synthesizing a tetrasiloxane surfactant with high yield. Compared with trisiloxane surfactants, the tetrasiloxane surfactant synthesized in this invention has higher surface activity. Specific experimental results show that the surface tension of this tetrasiloxane surfactant is 20.4-20.8 mN / m; the synthesis yield is 76%-81%.

[0115] Application examples:

[0116] Based on the tetrasiloxane surfactant prepared in Example 1 above, a high-efficiency and environmentally friendly foam fire extinguishing agent is constructed. The formulation is as follows: 15%-20% tetrasiloxane surfactant, 10%-15% trisiloxane surfactant, 1%-1.3% foam stabilizer, 0.5%-0.8% preservative, 0.3%-0.5% chelating agent, 1%-2% cosolvent, and the balance being water.

[0117] According to standard GB 15308-2006 "Foam Extinguishing Agents", the effects of changes in the concentrations of tetrasiloxane surfactant, trisiloxane surfactant, and foam stabilizer on the diffusion coefficient, expansion ratio, 25% separation time, extinguishing time, and anti-burning time of the high-efficiency and environmentally friendly foam extinguishing agent formulation were tested. The tetrasiloxane surfactant was the one prepared in Example 1, the trisiloxane surfactant was CoatOsil-77, the foam stabilizer was xanthan gum, the preservative was potassium sorbate, the chelating agent was dipotassium EDTA, and the co-solvent was ethylenediamine.

[0118] The formulation of a high-efficiency, environmentally friendly foam fire extinguishing agent with fixed mass concentrations of substances other than the tetrasiloxane surfactant is as follows (by mass percentage): 10%-25% tetrasiloxane surfactant, 12.5% ​​trisiloxane surfactant, 1.2% foam stabilizer, 0.8% preservative, 0.5% chelating agent, 2% co-solvent, and the balance being water. The performance of this high-efficiency, environmentally friendly foam fire extinguishing agent was tested based on this formulation at different concentrations of tetrasiloxane surfactant. Figure 3 As shown in the diagram, when the concentration of tetrasiloxane surfactant is below 15%, the foam extinguishing agent has a high expansion ratio and diffusion coefficient, but its 25% exudation time and anti-burning time are relatively short, while its extinguishing time is relatively long. When the concentration of tetrasiloxane surfactant is above 20%, the foam extinguishing agent has a high expansion ratio and diffusion coefficient, but its extinguishing time is relatively short, while its 25% exudation time and anti-burning time are also short. When the concentration of tetrasiloxane surfactant is between 15% and 20%, the foam extinguishing agent has a high expansion ratio and diffusion coefficient, a relatively long 25% exudation time and anti-burning time, and a relatively short extinguishing time; at this point, the overall performance of the high-efficiency and environmentally friendly foam extinguishing agent is optimal. Therefore, the optimal concentration range for tetrasiloxane surfactant is 15%-20%.

[0119] The formulation of a high-efficiency, environmentally friendly foam fire extinguishing agent with fixed mass concentrations of substances other than the trisiloxane surfactant is as follows (by mass percentage): 17.5% tetrasiloxane surfactant, 5%-20% trisiloxane surfactant, 1.2% foam stabilizer, 0.8% preservative, 0.5% chelating agent, 2% co-solvent, and the balance being water. Based on this formulation, the performance of the high-efficiency, environmentally friendly water foam fire extinguishing agent at different concentrations of trisiloxane surfactant was tested. Figure 4 As shown, when the concentration of trisiloxane surfactant is below 10% or above 15%, the foam extinguishing agent has a large expansion ratio and diffusion coefficient, but its 25% exudation time and anti-burning time are relatively short, while its extinguishing time is relatively long. When the concentration of trisiloxane surfactant is between 10% and 15%, the foam extinguishing agent has a large expansion ratio and diffusion coefficient, a relatively long 25% exudation time and anti-burning time, and a relatively short extinguishing time. At this concentration, the overall performance of the high-efficiency and environmentally friendly foam extinguishing agent is optimal. Therefore, the optimal concentration range for trisiloxane surfactant is 10%-15%.

[0120] The formulation of a high-efficiency, environmentally friendly foam fire extinguishing agent with fixed mass concentrations of all substances except the foam stabilizer is as follows (by mass percentage): 17.5% tetrasiloxane surfactant, 12.5% ​​trisiloxane surfactant, 0.4%-1.9% foam stabilizer, 0.8% preservative, 0.5% chelating agent, 2% co-solvent, and the balance being water. Based on this formulation, the performance of the high-efficiency, environmentally friendly foam fire extinguishing agent at different foam stabilizer concentrations was tested, such as... Figure 5 As shown in the diagram, when the foam stabilizer concentration is below 1%, the foam extinguishing agent has a larger expansion ratio and diffusion coefficient, but its 25% exudation time and anti-burning time are shorter, while its extinguishing time is longer. When the foam stabilizer concentration is above 1.3%, the foam extinguishing agent has a larger diffusion coefficient, but its expansion ratio is lower, its 25% exudation time and anti-burning time are shorter, while its extinguishing time is longer. When the foam stabilizer concentration is between 1% and 1.3%, the foam extinguishing agent has a larger expansion ratio and diffusion coefficient, a longer 25% exudation time and anti-burning time, and a shorter extinguishing time. At this concentration, the high-efficiency and environmentally friendly foam extinguishing agent exhibits the best overall performance. Therefore, the optimal concentration range for the foam stabilizer is 1%-1.3%.

[0121] Therefore, based on this highly efficient and environmentally friendly foam fire extinguishing agent formula and Figure 3-5 The test results are shown in Examples 4-7 below:

[0122] Example 4

[0123] Prepare a high-efficiency and environmentally friendly foam fire extinguishing agent using the following method:

[0124] ① Weigh out 20g of the tetrasiloxane surfactant prepared in Example 1, 15g of the trisiloxane surfactant CoatOsil-77, 1.3g of xanthan gum, 0.8g of potassium sorbate, 0.5g of dipotassium EDTA, and 2g of ethylenediamine, respectively; ② Weigh out 45g of deionized water, and add 20g of the tetrasiloxane surfactant and 15g of the trisiloxane surfactant CoatOsil-77 sequentially, stirring at 1000r / min for 10min; ③ Add 0.5g of [unspecified ingredient] to the surfactant solution obtained in ②. ④ In a quartz crucible, mix 1.3g xanthan gum and 2g ethylenediamine, grind and stir until homogeneous; ⑤ Add the mixture obtained in ④ to the solution obtained in ③, stir at 1500r / min for 60min; ⑥ Add 0.8g potassium sorbate to the solution obtained in ⑤, and supplement with 15.4g deionized water, stir at 2000r / min for 30min to obtain the target foam extinguishing agent stock solution, the appearance of which is shown in the figure below. Figure 6 As shown in the figure, after the stock solution was left to stand for 180 days, its appearance remained basically unchanged; it was still a homogeneous liquid with no obvious stratification or precipitation, indicating that the stock solution had good stability.

[0125] Example 5

[0126] High-efficiency and environmentally friendly foam fire extinguishing agent is prepared according to the following method.

[0127] ① Weigh out 15g of the tetrasiloxane surfactant prepared in Example 1, 10g of the trisiloxane surfactant CoatOsil-77, 1g of guar gum, 0.5g of sodium benzoate, 0.3g of dipotassium EDTA, and 1g of ethylenediamine, respectively; ② Weigh out 40g of deionized water, and add 15g of the tetrasiloxane surfactant and 10g of the trisiloxane surfactant CoatOsil-77 sequentially, stirring at 1000r / min for 10min; ③ Add 0.3g of [unspecified ingredient] to the surfactant solution obtained in ②. ④ In a quartz crucible, mix 1g of guar gum and 1g of ethylenediamine, grind and stir until homogeneous; ⑤ Add the mixture obtained in ④ to the solution obtained in ③, stir at 1500r / min for 60min; ⑥ Add 0.5g of sodium benzoate to the solution obtained in ⑤, and add 32.2g of deionized water, stir at 2000r / min for 30min to obtain the target foam extinguishing agent stock solution.

[0128] Example 6

[0129] Same as Example 4, except that the amount of tetrasiloxane surfactant used is changed from 20g to 15g, and the amount of deionized water added in step ⑥ is changed from 15.4g to 20.4g.

[0130] Example 7

[0131] Same as Example 5, except that the amount of trisiloxane surfactant used is changed from 10g to 15g, and the amount of deionized water added in step 6 is changed from 32.2g to 27.2g.

[0132] Comparative Example 1

[0133] Same as Example 4, except that the tetrasiloxane surfactant is removed and the amount of deionized water added in step 6 is changed from 15.4g to 35.4g.

[0134] Comparative Example 2

[0135] Same as Example 5, except that the tetrasiloxane surfactant is replaced with the hydrocarbon surfactant sodium dodecyl sulfate.

[0136] Comparative Example 3

[0137] Same as Example 4, except that the tetrasiloxane surfactant is replaced with the trisiloxane surfactant COATOSIL-MP200.

[0138] Comparative Example 4

[0139] Same as Example 6, except that the amount of tetrasiloxane surfactant used is changed from 15g to 1g, and the amount of deionized water added in step ⑥ is changed from 20.4g to 34.4g.

[0140] Comparative Example 5

[0141] Same as Example 7, except that the amount of tetrasiloxane surfactant used is changed from 15g to 1g, and the amount of deionized water added in step ⑥ is changed from 27.2g to 41.2g.

[0142] Comparative Example 6

[0143] ① Weigh out 15g of the tetrasiloxane surfactant prepared in Example 1, 10g of the trisiloxane surfactant CoatOsil-77, 1g of guar gum, 0.5g of sodium benzoate, 0.3g of dipotassium EDTA, and 1g of ethylenediamine, respectively; ② Weigh out 40g of deionized water, and add 15g of the tetrasiloxane surfactant and 10g of the trisiloxane surfactant CoatOsil-77 sequentially, stirring at 1000r / min for 10min; ③ Add 1g of guar gum to the surfactant solution obtained in ②, stirring at 1000r / min for 10min; ④ Add 1g of ethylenediamine to the solution obtained in ③, stirring at 1500r / min for 60min; ⑤ Add 0.3g of dipotassium EDTA and 0.5g of sodium benzoate sequentially to the solution obtained in ④, and add 32.2g of deionized water, stirring at 2000r / min for 30min to obtain the target foam extinguishing agent stock solution, as follows. Figure 7 As shown. Compared with Example 5, the difference in this comparative process is that: 1g of guar gum and 1g of ethylenediamine are added separately without prior grinding and stirring; the order of adding 1g of ethylenediamine is changed, and it is added separately; the order of adding 0.3g of dipotassium EDTA is changed from step ③ to step ⑤. Figure 7 It can be seen that the stock solution was generally homogeneous and stable at day 0. After 25 days, the stock solution began to show uneven stratification, with the upper part being slightly transparent and the lower part remaining milky white and viscous. After 50 days, the stock solution clearly separated into layers, with the upper layer being a pale yellow liquid (occupying about 1 / 3 of the bottle) and the lower layer being a viscous liquid, with a clear interface. This indicates that the foam fire extinguishing agent sample prepared by this process has poor stability and a short shelf life.

[0144] Based on the high-efficiency and environmentally friendly foam extinguishing agent concentrate described in Examples 4-7 and Comparative Examples 1-5, a 3% foam extinguishing agent solution was obtained by diluting it at a volume ratio of concentrate:water = 3:97. Based on the characteristics of fires involving large oil-filled equipment in converter stations (substations) and existing mainstream foam extinguishing systems, a 4.52m... 2A transformer oil pool fire source model was used (the size of the oil pool and the experimental procedures were based on standard GB 27897-2011 "Class A Foam Extinguishing Agents"). The initial temperature of the transformer oil was controlled at 150±5℃. Using a positive pressure foaming system (based on standard GB 27897-2011 "Class A Foam Extinguishing Agents"), the foaming ratio, 25% liquid separation time, extinguishing time, and anti-burning time of the foam extinguishing agent were tested. Simultaneously, the film-forming performance of the foam extinguishing agent solution on the transformer oil surface was tested. The specific test method was as follows: ① The apparatus included a miniature injection pump, an oil pan (15cm in diameter), and a high-speed camera; ② 50mL of transformer oil was placed in the oil pan, and the needle of the miniature injection pump was positioned 2cm directly above the center of the oil pan; ③ At 25℃, the foam solution was dripped onto the oil surface at a rate of 12μL / drop using the miniature injection pump, and the spreading process of the foam solution was recorded using the camera. The video data was processed by frame extraction to obtain the maximum spreading area and the time to reach the maximum area. The film-forming speed was calculated by dividing the maximum spreading area by the time to reach the maximum area. The extinguishing agent performance of Examples 4-7 and Comparative Examples 1-5 was measured using the above method, with commercially available 3% AFFF as a comparison. The test results are shown in Table 2 below. Figure 8-11 As shown:

[0145] Table 2 Performance test results of foam extinguishing agents

[0146]

[0147] From Table 2 and Figure 8-11 It can be seen that the high-efficiency and environmentally friendly foam fire extinguishing agent in Examples 4-7 has a shorter extinguishing time and a faster film-forming speed compared to Comparative Examples 1-5; and compared to 3% AFFF, it has a shorter extinguishing time, a higher foaming ratio, and a longer 25% separation time. Therefore, the high-efficiency and environmentally friendly foam fire extinguishing agent of the present invention has excellent foaming performance, stability, fire extinguishing performance, and film-forming properties. Experimental results show that the foam fire extinguishing agent has a foaming ratio of 8-9 times; a 25% separation time of 11-15 min; an extinguishing time of 58-95 s; a fire resistance time of 10 min 25 s-14 min 39 s; and a film-forming speed of 1.6-2 cm. 2 / s.

[0148] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quaternary ammonium salt-modified tetrasiloxane surfactant characterized by: The structural formula is as follows: ； The preparation method of the quaternary ammonium salt modified tetrasiloxane surfactant comprises the following steps: S1, taking tris(trimethylsiloxy)silane as raw material, in the presence of sodium triphenylmethyl, reacting with ethylene oxide in an organic solvent to obtain a sodium alcohol intermediate; S2, taking 5-bromo-1,3-pentadiene as raw material, reacting with trimethylamine in an organic solvent to obtain a conjugated diene quaternary ammonium salt; then taking the conjugated diene quaternary ammonium salt as raw material, reacting with m-chloroperbenzoic acid in an organic solvent to obtain an aminated bis-ethylene oxide derivative; S3, taking the sodium alcohol intermediate and the aminated bis-ethylene oxide derivative as raw materials, reacting in an organic solvent, and hydrolyzing under acidic conditions to obtain the quaternary ammonium salt modified tetrasiloxane surfactant.

2. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized by: In S1, the organic solvent used is one or a mixture of the two of anhydrous toluene or anhydrous dichloromethane.

3. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized by: In S1, the reaction temperature is 60-80℃, and the reaction time is 0.5-2 hours.

4. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized by: In S1, the mass ratio of tris(trimethylsiloxy)silane, ethylene oxide, and sodium triphenylmethyl is 15-20:40:

1.

5. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized by: In S2, the path for synthesizing the aminated bis-ethylene oxide derivative is as follows: 。 6. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S2, during the preparation of the conjugated diene quaternary ammonium salt, the organic solvent is anhydrous acetonitrile, and during the reaction with m-chloroperbenzoic acid, the organic solvent is anhydrous dichloromethane.

7. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S2, the reaction temperature with trimethylamine is 25℃, and the reaction time is 6-8 hours; the reaction temperature with m-chloroperbenzoic acid is 25℃, and the reaction time is 8 hours.

8. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S2, the molar ratio of 5-bromo-1,3-pentadiene to trimethylamine is 1:1.

5.

9. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S2, the molar ratio of the conjugated diene quaternary ammonium salt to m-chloroperbenzoic acid is 1:1.

2.

10. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S3, the organic solvent is anhydrous dichloromethane.

11. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S3, the reaction temperature is 50-60℃, and the reaction time is 8-12 hours.

12. The quaternary ammonium salt-modified tetrasiloxane surfactant according to claim 1, characterized in that: In S3, the mass ratio of the sodium alcohol intermediate to the aminated bis-ethylene oxide derivative is 20-25:

30.

13. Use of the quaternary ammonium salt modified tetrasiloxane surfactant according to any one of claims 1-12 in a foam extinguishing agent.

14. A foam extinguishing agent, characterized by: The foam extinguishing agent contains the quaternary ammonium salt modified tetrasiloxane surfactant according to any one of claims 1-12.

15. The foam extinguishing agent according to claim 14, characterized in that: The raw material composition is 15%-20% quaternary ammonium salt modified tetrasiloxane surfactant, 10%-15% trisiloxane surfactant, 1%-1.3% foam stabilizer, 0.5%-0.8% preservative, 0.3%-0.5% chelating agent, 1%-2% cosolvent, and the balance is water.

16. The foam extinguishing agent according to claim 15, characterized in that: The trisiloxane surfactant is trisiloxane surfactant CoatOsil-77; the foam stabilizer is one or a mixture of the two of xanthan gum and guar gum; the preservative is one or a mixture of the two of potassium sorbate and sodium benzoate; the chelating agent is dipotassium EDTA; and the cosolvent is ethylenediamine.

17. A process for the preparation of a foam extinguishing agent as claimed in any one of claims 14-16, characterised in that: The preparation method comprises the following steps: The quaternary ammonium salt modified tetrasiloxane surfactant is mixed with other raw materials to obtain the foam extinguishing agent.

18. A process for the preparation of a foam extinguishing agent according to claim 17, characterized in that: The preparation method comprises the following steps: Part of the water is added with the quaternary ammonium salt modified tetrasiloxane surfactant and the trisiloxane surfactant, and after stirring, a surfactant solution is obtained; a chelating agent is added to the obtained surfactant solution, and after stirring, a mixed solution is obtained; the foam stabilizer and the cosolvent are mixed, ground and stirred uniformly, and then added to the mixed solution, and after stirring, the preservative and the remaining water are added, and after stirring, the foam extinguishing agent is obtained.

19. A fire extinguishing apparatus, characterized by: The foam extinguishing agent as claimed in any one of claims 14-16.

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