Efficient environment-friendly foam extinguishing agent for converter station or transformer substation and preparation method thereof

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foam extinguishing agent, and particularly relates to a high-efficiency environment-friendly foam extinguishing agent for converter station or transformer substation and a preparation method thereof. BACKGROUND

[0002] Foam extinguishing agent is widely used for extinguishing flammable liquid fire (such as oil, solvent, etc.). Traditional fluorine-containing surfactants (such as PFOS, PFOA, etc.) have been widely used in water film forming foam extinguishing agent (AFFF) due to their excellent film forming property, foam stability and oil resistance. However, fluorine-containing surfactants have strong chemical stability and are difficult to degrade in the environment, and can accumulate in the body, posing potential risks to human health and ecological systems. Therefore, with the promotion of international regulations such as the Stockholm Convention, the use of fluorine-containing surfactants has been gradually prohibited or restricted worldwide, and the development of high-efficiency and environmentally-friendly alternative technologies has become an urgent need for the industry.

[0003] Trisiloxane organosilicon surfactants have excellent surface activity, wettability and spreading property, and have become the core component of fluorine-free foam extinguishing agent. However, the existing trisiloxane surfactants have decreased stability and surface activity in high-salt environments (such as seawater, high-hardness water), resulting in a significant decrease in the stability of foam extinguishing agent, affecting the extinguishing efficiency, and being difficult to meet the application requirements in extreme environments, and being limited in the use in converter stations or transformer substations. SUMMARY

[0004] The technical problem to be solved by the present application is how to improve the performance of surfactants for foam extinguishing agent and prepare high-performance foam extinguishing agent.

[0005] The present application solves the above technical problems by the following technical means: A quaternary ammonium salt modified tetrasiloxane surfactant has the following structural formula: .

[0006] The present application also provides a preparation method of the quaternary ammonium salt modified tetrasiloxane surfactant, comprising the following steps: S1, using tris(trimethylsiloxy)silane as a raw material, reacting with ethylene oxide (EO) in an organic solvent in the presence of sodium triphenylmethyl to obtain a sodium alcohol intermediate ; S2, using 5-bromo-1,3-pentadiene as a raw material, reacting with trimethylamine in an organic solvent to obtain a conjugated diene quaternary ammonium salt; then using the conjugated diene quaternary ammonium salt as a raw material, reacting with m-chloroperbenzoic acid in an organic solvent to obtain an aminated bis-ethylene oxide derivative; S3, using sodium alcohol intermediate and amine bis-oxirane derivative as raw materials, carrying out reaction in organic solvent, and carrying out hydrolysis under acidic condition to obtain the quaternary ammonium salt modified tetrasiloxane surfactant.

[0007] Preferably, in S1, using trichlorosilane as raw material, carrying out substitution reaction in organic solvent in the presence of base and hydrogen chloride capturing agent, and adding trimethylsilanol to obtain tris(trimethylsiloxy)silane.

[0008] Preferably, in the preparation of tris(trimethylsiloxy)silane, the organic solvent used is anhydrous n-hexane.

[0009] Preferably, in the preparation of tris(trimethylsiloxy)silane, the base and hydrogen chloride capturing agent are pyridine.

[0010] Preferably, in the preparation of tris(trimethylsiloxy)silane, the reaction is carried out in two steps, first stirring at 0-5℃ under nitrogen protection for 2-4 hours, and then heating the system to 40-50℃ and continuing to stir for 0.5-1 hour until the reaction is completed.

[0011] Preferably, in the preparation of tris(trimethylsiloxy)silane, the mass ratio of trichlorosilane, base and hydrogen chloride capturing agent, and trimethylsilanol is 10-18:20-31.5:30-38.

[0012] The present application is based on trichlorosilane raw material, and a new process for efficiently synthesizing quaternary ammonium salt tetrasiloxane surfactant is developed. The process route is simple, and the synthesis yield is stable at more than 75%.

[0013] Preferably, in S1, the organic solvent used is one or a mixture of the two of anhydrous toluene or anhydrous dichloromethane.

[0014] Preferably, in S1, the temperature of the reaction is 60-80℃, and the reaction time is 0.5-2 hours.

[0015] Preferably, in S1, the mass ratio of tris(trimethylsiloxy)silane, oxirane, and sodium triphenylmethide is 15-20:40:1.

[0016] Preferably, in S1, the mass ratio of tris(trimethylsiloxy)silane and organic solvent is 15-20:30-35.

[0017] Preferably, in S2, the path for synthesizing amine bis-oxirane derivative is: .

[0018] Preferably, in S2, the reaction is carried out in two steps, the organic solvent is anhydrous acetonitrile in the preparation of the conjugated diene quaternary ammonium salt, and the organic solvent is anhydrous dichloromethane in the reaction with meta-chloroperoxybenzoic acid.

[0019] Preferably, in S2, the reaction is carried out in two steps, the temperature for the reaction with trimethylamine is 25℃, and the reaction time is 6-8 hours; the temperature for the reaction with meta-chloroperoxybenzoic acid is 25℃, and the reaction time is 8 hours.

[0020] Preferably, in S2, the molar ratio of 5-bromo-1,3-pentadiene to trimethylamine is 1:1.5.

[0021] Preferably, in S2, the molar ratio of the conjugated diene quaternary ammonium salt to meta-chloroperoxybenzoic acid is 1:1.2.

[0022] Preferably, in S2, the ratio of the amount of 5-bromo-1,3-pentadiene to the organic solvent is 10g:150mL.

[0023] Preferably, in S2, the ratio of the amount of the conjugated diene quaternary ammonium salt to the organic solvent is 10g:120mL.

[0024] Preferably, in S3, the organic solvent is anhydrous dichloromethane.

[0025] Preferably, in S3, the temperature for the reaction is 50-60℃, and the reaction time is 8-12 hours.

[0026] Preferably, in S3, the mass ratio of the sodium alcohol intermediate to the amine-epoxy derivative is 20-25:30.

[0027] Preferably, in S3, the acid reagent is a mixture of one or both of hydrochloric acid (HCl) and sulfuric acid (H2SO4) to maintain the acidity.

[0028] Preferably, in S3, the mass ratio of the sodium alcohol intermediate to the organic solvent is 20-25:35-40.

[0029] The synthesis path of the quaternary ammonium salt modified tetrasiloxane surfactant is as follows:

[0030] The application also provides a use of the quaternary ammonium salt modified tetrasiloxane surfactant in a foam extinguishing agent.

[0031] The application also provides a foam extinguishing agent containing the quaternary ammonium salt modified tetrasiloxane surfactant.

[0032] Preferably, the raw material composition of the foam extinguishing agent is 15%-20% of quaternary ammonium salt modified tetrasiloxane surfactant, 10%-15% of trisiloxane surfactant, 1%-1.3% of foam stabilizer, 0.5%-0.8% of preservative, 0.3%-0.5% of chelating agent, 1%-2% of cosolvent, and the rest is water.

[0033] Preferably, 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.

[0034] The application further provides a preparation method of the foam extinguishing agent, which comprises the following steps: uniformly mixing the quaternary ammonium salt modified tetrasiloxane surfactant with other raw materials to obtain the foam extinguishing agent.

[0035] Preferably, the preparation method of the foam extinguishing agent comprises the following steps: taking part of water, adding the quaternary ammonium salt modified tetrasiloxane surfactant and the trisiloxane surfactant, stirring to obtain a surfactant solution; adding the chelating agent to the obtained surfactant solution, stirring to obtain a mixed solution; uniformly mixing the foam stabilizer and the cosolvent, grinding and stirring, adding to the obtained mixed solution, stirring, adding the preservative and the remaining water, and stirring to obtain the foam extinguishing agent.

[0036] The application further provides a fire extinguishing device containing the foam extinguishing agent.

[0037] The application has the following advantages: (1) The application is based on the self-synthesis of quaternary ammonium salt tetrasiloxane surfactant, and aims at the technical bottleneck that the existing environmentally friendly foam extinguishing agent is difficult to meet the application requirements in extreme water quality environment, and develops a high-efficiency environmentally friendly foam extinguishing agent formula. The product fully meets the requirements of the national standard GB 15308-2006 "Foam extinguishing agent", and has good foam performance and extinguishing performance.

[0038] (2) For transformer oil fire, the high-efficiency environmentally friendly foam extinguishing agent has excellent foaming performance, foam stability, extinguishing performance and film forming performance, and the foaming multiple is 8-9 times; the 25% liquid separation time is 11-15 min; the extinguishing time is 58 s-95 s; the anti-burning time is 10 min 25 s-14 min 39 s; and the film forming speed is 1.6-2 cm 2Under the same conditions, compared with the commercial 3% aqueous film-forming foam extinguishing agent, the expansion ratio is increased by 2.12-3.12 times, the 25% liquid separation time is prolonged by 7min25s-11min25s, the extinguishing time is shortened by 101-138s, the anti-burning time is prolonged by 1min08s-5min22s, and the film-forming speed is increased by 0.4-0.8cm 2 / s.

[0039] (3) By molecular structure design, trihydroxy pentyl and quaternary ammonium salt functional groups are introduced into the siloxane skeleton at the same time, 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 or below at the critical micelle concentration.

[0040] (4) The present application establishes a simple process, mild conditions, good repeatability, good stability, long shelf life, and efficient environmentally friendly foam extinguishing agent preparation process, and the prepared foam extinguishing agent liquid is stable and uniform after standing for 180 days, without stratification and no change in properties. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is the solution appearance real photo of the tetrasiloxane surfactant in examples 1-3 of the present application at the critical micelle concentration; Figure 2 It is the surface tension test data of the tetrasiloxane surfactant and CoatOsil-77 solution in examples 1-3 of the present application; Figure 3 It is the performance test result of the efficient environmentally friendly foam extinguishing agent under different tetrasiloxane surfactant concentrations; Figure 4 It is the performance test result of the efficient environmentally friendly foam extinguishing agent under different trisiloxane surfactant concentrations; Figure 5 It is the performance test result of the efficient environmentally friendly foam extinguishing agent under different foam stabilizer concentrations; Figure 6 It is the appearance standing real photo of the tetrasiloxane surfactant efficient environmentally friendly foam extinguishing agent liquid prepared in example 4 of the present application; Figure 7 It is the appearance standing real photo of the efficient environmentally friendly foam extinguishing agent liquid prepared in comparative example 6 of the present application; Figure 8 It is the efficient environmentally friendly foam extinguishing agent containing tetrasiloxane surfactant in examples 4-7 of the present application extinguishing experiment phenomenon diagram; Figure 9 It is the foam extinguishing agent and 3% AFFF extinguishing experiment phenomenon diagram corresponding to comparative examples 1-5; Figure 10 It is the film-forming experiment phenomenon diagram of the foam extinguishing agent corresponding to examples 4-7 and comparative examples 4-5 of the present application and 3% AFFF; Figure 11 Foam extinguishing agent and 3% AFFF film forming performance test data corresponding to the examples 4-7 and comparative examples 4-5 of the present application. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0043] The test materials and reagents used in the following examples, and the like, can be obtained from commercial channels if not otherwise specified.

[0044] The specific techniques or conditions not specified in the examples can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0045] Example 1 In this embodiment, a target tetrasiloxane surfactant tris(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl-trimethylammonium bromide is synthesized, and the structural formula and synthesis flow of the surfactant are as follows:

[0046]

[0047] The specific synthesis path is as follows: First step: synthesis of tris(trimethylsiloxy)silane Under anhydrous environment, 10 g of trichlorosilane (SiHCl3) is dissolved in 50 g of anhydrous n-hexane, then 20 g of pyridine is added at one time, and then 30 g of trimethylsilanol (Me3SiOH) is slowly added under stirring. This process needs to be carried out at 0℃, and stirring is carried out under nitrogen protection for 2 hours. Subsequently, the system is warmed to 40℃ and continues to stir for 1 hour to ensure complete reaction. Then the by-product is removed by reduced pressure distillation to obtain tris(trimethylsiloxy)silane with a molecular formula of (Me3SiO)3SiH.

[0048]

[0049] Second step: reaction with ethylene oxide In 30 g of anhydrous toluene, 20 g of tris(trimethylsiloxy)silane [(Me3SiO)3SiH] was dissolved, and 1 g of sodium triphenylmethide was slowly added. After stirring at room temperature for 2 hours, 40 g of ethylene oxide was added, and the reaction was heated to 60°C for 30 minutes to perform the ring-opening polymerization of the epoxy group, and the Si-H group was added to the ethylene oxide to generate the sodium alcohol intermediate.

[0050]

[0051] Third step: reaction with bis-ethylene oxide derivative 20 g of the sodium alcohol intermediate was dissolved in 35 g of anhydrous dichloromethane, and 30 g of the amine bis-ethylene oxide derivative was added. The temperature was controlled at 50°C, and stirring was performed for 8 hours to generate the intermediate product. Subsequently, the pH was adjusted to 2 using 5% hydrochloric acid to hydrolyze the product under acidic conditions, and the ring-opening of the epoxy group was promoted to generate the desired product, which had the following NMR data: 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. 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). The flow is as follows:

[0052] The synthesis path of the amine bis-ethylene oxide derivative is as follows:

[0053] The specific synthesis path is as follows: First step: synthesis of conjugated diene quaternary ammonium salt 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 30% trimethylamine aqueous solution was slowly added dropwise within 30 min. After the addition was completed, the reaction was stirred at 25°C for 8 hours to obtain the target product, conjugated diene quaternary ammonium salt.

[0054]

[0055] Second step: synthesis of amineated dioxolane derivative Under nitrogen protection, 10 g of conjugated diene quaternary ammonium salt was dissolved in 120 mL of anhydrous dichloromethane (CH2Cl2). At 0°C and in the dark, 16.5 g of m-chloroperoxybenzoic acid with a purity of 77% was slowly added within 30 min. After the addition was completed, the reaction was stirred at 25°C for 8 hours to obtain the target product, amineated dioxolane derivative.

[0056]

[0057] Example 2 The structure and synthesis process of tris(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl-trimethylammonium bromide tetrasiloxane surfactant are the same as those of Example 1.

[0058] The specific synthesis path is as follows: First step: synthesis of tris(trimethylsiloxy)silane Under anhydrous conditions, 15 g of trichlorosilane (SiHCl3) was dissolved in 50 g of anhydrous n-hexane, then 30 g of pyridine was added at once, and then 35 g of trimethylsilanol (Me3SiOH) was slowly added under stirring. This process needs to be carried out at 5°C and stirred for 4 hours under nitrogen protection. Subsequently, the system was warmed to 50°C and continued to stir for 1 hour to ensure complete reaction. Then, the by-products were removed by vacuum distillation to obtain tris(trimethylsiloxy)silane with a molecular formula of (Me3SiO)3SiH.

[0059] Second step: reaction with ethylene oxide In 35 g of anhydrous toluene, 15 g of tris(trimethylsiloxy)silane [(Me3SiO)3SiH] was dissolved, and 1 g of sodium triphenylmethide was slowly added. After stirring at room temperature for 2 hours, 40 g of ethylene oxide was added, and the reaction was heated to 80°C for 30 minutes to perform ring-opening polymerization of ethylene oxide, so that Si-H addition reaction with ethylene oxide occurs to generate sodium alcohol intermediate.

[0060] Third step: reaction with dioxolane derivative Dissolve 25 g of sodium alkoxide intermediate in 40 g of anhydrous dichloromethane, and add 30 g of amine bis-oxirane derivative. Control the temperature at 60 °C, and stir for 12 hours to generate the intermediate product. Then, adjust the pH to 3 using 5% hydrochloric acid by mass concentration, and hydrolyze the product under acidic conditions to promote the ring-opening of the oxirane to generate the desired product.

[0061] The synthesis of the amine bis-oxirane derivative is the same as in Example 1.

[0062] Example 3 The synthesis of the tris(trimethylsiloxy)silyl-polyoxyethylene-trihydroxypentyl- trimethylammonium bromide tetrasiloxane surfactant is the same as in Example 1.

[0063] The specific synthesis path is as follows: First step: synthesis of tris(trimethylsiloxy)silane Dissolve 18 g of trichlorosilane (SiHCl3) in 50 g of anhydrous n-hexane, and then add 31.5 g of pyridine at once. Then, slowly add 38 g of trimethylsilanol (Me3SiOH) under stirring. This process needs to be carried out at 2 °C, and stirring needs to be carried out under nitrogen protection for 2 hours. Then, continue to stir at 45 °C for 0.5 hours to ensure complete reaction. Then, remove the byproduct using reduced-pressure distillation to obtain tris(trimethylsiloxy)silane with the molecular formula (Me3SiO)3SiH.

[0064] Second step: reaction with ethylene oxide Dissolve 15 g of tris(trimethylsiloxy)silane ((Me3SiO)3SiH) in 35 g of anhydrous toluene, and slowly add 1 g of sodium triphenylmethyl. After stirring at room temperature for 2 hours, add 40 g of ethylene oxide, and heat to 70 °C to carry out the ring-opening polymerization reaction for 2 hours to generate the addition reaction of Si-H with ethylene oxide, thereby generating the sodium alkoxide intermediate.

[0065] Third step: reaction with bis-oxirane derivative Dissolve 23 g of the sodium alkoxide intermediate in 38 g of anhydrous dichloromethane, and add 30 g of the amine bis-oxirane derivative. Control the temperature at 55 °C, and stir for 10 hours to generate the intermediate product. Then, adjust the pH to 3 using 5% sulfuric acid by mass concentration, and hydrolyze the product under acidic conditions to promote the ring-opening of the oxirane to generate the desired product.

[0066] The synthesis of the amine bis-oxirane derivative is the same as in Example 1.

[0067] The solution appearance of the tetrasiloxane surfactants synthesized in Examples 1-3 at the critical micelle concentration is shown in FIG. 1, and the tetrasiloxane surfactant solutions obtained in Examples 1-3 have uniform overall texture and good dispersibility in water. Figure 1 The solution appearance of the tetrasiloxane surfactants synthesized in Examples 1-3 at the critical micelle concentration is shown in FIG. 1, and the tetrasiloxane surfactant solutions obtained in Examples 1-3 have uniform overall texture and good dispersibility in water.

[0068] 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: Table 1. Performance test results of tetrasiloxane surfactants

[0069] CoatOsil-77 is a commercial trisiloxane surfactant.

[0070] 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%.

[0071] Application examples: 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.

[0072] 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. 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%.

[0073] 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%.

[0074] 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. Figure 5As 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%.

[0075] Therefore, based on this highly efficient and environmentally friendly foam fire extinguishing agent formula and Figures 3-5 The test results are shown in Examples 4-7 below: Example 4 Prepare a high-efficiency and environmentally friendly foam fire extinguishing agent using the following method: 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.

[0076] Example 5 High-efficiency and environmentally friendly foam fire extinguishing agent is prepared according to the following method. 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.

[0077] Example 6 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.

[0078] Example 7 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.

[0079] Comparative Example 1 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.

[0080] Comparative Example 2 Same as Example 5, except that the tetrasiloxane surfactant is replaced with the hydrocarbon surfactant sodium dodecyl sulfate.

[0081] Comparative Example 3 Same as Example 4, except that the tetrasiloxane surfactant is replaced with the trisiloxane surfactant COATOSIL-MP200.

[0082] Comparative Example 4 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.

[0083] Comparative Example 5 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.

[0084] Comparative Example 6 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.

[0085] 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. Figures 8-11 As shown: Table 2 Performance test results of foam extinguishing agents

[0086] From Table 2 and Figures 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.

[0087] 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 in that: Its structural formula is shown below: 。 2. A method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant as described in claim 1, characterized in that: Includes the following steps: 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 to obtain a sodium alkoxide intermediate. 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. 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.

3. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S1, the organic solvent used is one or a mixture of two of anhydrous toluene or anhydrous dichloromethane.

4. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S1, the reaction temperature is 60~80℃ and the reaction time is 0.5-2 hours.

5. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S1, the mass ratio of tris(trimethylsiloxy)silane, ethylene oxide, and triphenylmethyl sodium is 15-20:40:

1.

6. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S2, the route for synthesizing the amination of diethylene oxide derivatives is as follows: 。 7. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, 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-chloroperoxybenzoic acid, the organic solvent is anhydrous dichloromethane.

8. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S2, the reaction temperature with trimethylamine is 25°C, and the reaction time is 6-8 hours; the reaction temperature with m-chloroperoxybenzoic acid is 25°C, and the reaction time is 8 hours.

9. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S2, the molar ratio of 5-bromo-1,3-pentadiene to trimethylamine is 1:1.

5.

10. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S2, the molar ratio of conjugated diene quaternary ammonium salt to m-chloroperoxybenzoic acid is 1:1.

2.

11. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S3, the organic solvent is anhydrous dichloromethane.

12. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S3, the reaction temperature is 50~60℃ and the reaction time is 8~12 hours.

13. The method for preparing the quaternary ammonium salt modified tetrasiloxane surfactant according to claim 2, characterized in that: In S3, the mass ratio of the sodium alkoxide intermediate to the amination of the diethylene oxide derivative is 20-25:

30.

14. The application of the quaternary ammonium salt modified tetrasiloxane surfactant as described in claim 1 in foam fire extinguishing agents.

15. A foam fire extinguishing agent, characterized in that: It contains a quaternary ammonium salt modified tetrasiloxane surfactant as described in claim 1.

16. The foam extinguishing agent according to claim 15, characterized in that: Its raw material composition, by mass percentage, 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.

17. The foam extinguishing agent according to claim 16, characterized in that: 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.

18. A method for preparing a foam fire extinguishing agent as described in any one of claims 15-17, characterized in that: Includes the following steps: The foam fire extinguishing agent is obtained by uniformly mixing the quaternary ammonium salt modified tetrasiloxane surfactant with other raw materials.

19. The method for preparing the foam fire extinguishing agent according to claim 18, characterized in that: Includes the following steps: Take a portion of water, add quaternary ammonium salt modified tetrasiloxane surfactant and trisiloxane surfactant, stir to obtain surfactant solution; add chelating agent to the obtained surfactant solution, stir to obtain mixture; mix foam stabilizer and cosolvent, grind and stir evenly, add to the obtained mixture, stir, add preservative and remaining water, stir to obtain foam fire extinguishing agent.

20. A fire extinguishing device, characterized in that: It contains a foam extinguishing agent as described in any one of claims 15-17.

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