High-performance fluoride-free environment-friendly foam extinguishing agent and preparation method thereof

Abstract

The invention discloses a high-performance fluoride-free environment-friendly foam extinguishing agent and a preparation method thereof. The structural formula of a gemini tetrasiloxane surfactant is shown in the specification. The fire extinguishing agent is prepared from, by mass, 20%-25% of a surfactant compound system, 0.5%-1% of a foam stabilizer, 1%-2% of a chelating agent, 0.5%-1% of a preservative, 1%-1.5% of a corrosion inhibitor and the balance water, and the sum of all the components is 100%. The surfactant compound system is composed of a gemini tetrasiloxane surfactant and a trisiloxane surfactant. According to the foam extinguishing agent, the gemini tetrasiloxane surfactant serves as a core, the excellent film forming performance is achieved, and the film forming speed is larger than 1.2 cm < 2 > / s; in addition, the foam extinguishing agent does not contain PFOS and is environmentally friendly, and the 28-day biodegradation rate is larger than 95%.

Description

Technical Field

[0001] This invention relates to the field of foam fire extinguishing agent technology, specifically to a high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent and its preparation method. Background Technology

[0002] With the widespread use of large oil-filled equipment in power systems (such as transformers and reactors), the fire risks and environmental protection requirements are becoming increasingly prominent. These devices store large amounts of insulating oil, and fires involving this type of equipment are characterized by high temperatures, rapid spread of flowing fire, and a high risk of reignition. While traditional aqueous fluorinated foam (AFFF) offers high extinguishing efficiency, its fluorocarbon surfactants are restricted by the Stockholm Convention due to their difficulty in degradation and bioaccumulation, and face elimination. Existing environmentally friendly foam extinguishing agent alternatives mostly focus on improving foam stability, but because they cannot form a film, they cannot achieve the same extinguishing effect as AFFF.

[0003] Currently, most environmentally friendly foam fire extinguishing agents rely on the compounding of hydrocarbon or trisiloxane organosilicon surfactants. However, hydrocarbon surfactants have a high surface tension (about 30 mN / m) and contain lipophilic groups. The compounding system formed by the two has insufficient film-forming properties and oil resistance on flammable oil surfaces, making it difficult to effectively extinguish oil fires. This technical bottleneck restricts the research and development of environmentally friendly foam fire extinguishing agents for oil fires. Summary of the Invention

[0004] The technical problem to be solved by this invention is how to improve the performance of foam fire extinguishing agents.

[0005] The present invention solves the above-mentioned technical problems through the following technical means: A gemini tetrasiloxane surfactant, the structural formula of which is shown below: .

[0006] This invention also proposes a method for preparing the aforementioned gemini tetrasiloxane surfactant, comprising the following steps: S1. Reaction of tris(trimethylsiloxy)silane with ethylene oxide: In an organic solvent, tris(trimethylsiloxy)silane is reacted with ethylene oxide under the alkaline reagent triphenylmethyl sodium, and then acidified with hydrochloric acid to obtain tris(trimethylsiloxy)silylethyl alcohol. S2, Hydroxyl bromination reaction: In an organic solvent, using tris(trimethylsiloxy)silylethyl alcohol as a raw material, phosphorus tribromide is used to carry out the reaction to obtain tris(trimethylsiloxy)silylethyl bromide; S3, Amino Substitution Reaction: In an organic solvent, tris(trimethylsiloxy)silylethyl bromide is used as a starting material and dimethylamine is used to react to obtain tris(trimethylsiloxy)silylethyl dimethylamine; S4. Quaternization reaction: In an organic solvent, using tris(trimethylsiloxy)silylethyldimethylamine as a raw material, and employing ether derivatives... The mixture was reacted with anhydrous potassium carbonate to obtain the gemini tetrasiloxane surfactant.

[0007] Preferably, in S1, the preparation of the tris(trimethylsiloxy)silane includes the following steps: in an organic solvent, using trichlorosilane (SiHCl3) as a raw material, reacting with trimethylsilanol, and using pyridine to promote the reaction, to obtain tris(trimethylsiloxy)silane.

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

[0009] Preferably, in the preparation of tris(trimethylsiloxy)silane, the reaction includes stirring at 0-5°C under nitrogen protection for 2-4 hours; then raising the system temperature to 40-50°C and stirring for 0.5-1 hours until the reaction is complete.

[0010] Preferably, in S1, the mass ratio of tris(trimethylsiloxy)silane to ethylene oxide is 20:3-4; more preferably 20:3.5; and the mass ratio of tris(trimethylsiloxy)silane to triphenylmethyl sodium is 20:0.04-0.1; more preferably 20:0.05.

[0011] Preferably, in S2, the mass ratio of tris(trimethylsiloxy)silylethyl alcohol to phosphorus tribromide is 25:6-7.5; more preferably 25:6.5.

[0012] Preferably, in S3, the mass ratio of tris(trimethylsiloxy)silylethyl bromide to dimethylamine is 30:15-19.5; more preferably 30:17.

[0013] Preferably, in S4, the mass ratio of tris(trimethylsiloxy)silylethyldimethylamine to the ether derivative is 20:9.6-10.4; more preferably 20:10; the mass ratio of tris(trimethylsiloxy)silylethyldimethylamine to anhydrous potassium carbonate is 20:13-15; more preferably 20:13.8.

[0014] Preferably, the organic solvent in S1 is one of anhydrous toluene or anhydrous dichloromethane; the organic solvents in S2 and S3 are both anhydrous dichloromethane; and the organic solvent in S4 is anhydrous acetonitrile.

[0015] Preferably, in reaction S1, the reaction temperature with ethylene oxide is 60-80℃ and the reaction time is 10-20 min; in reaction S2, the reaction temperature is 25℃ and the mixture is stirred for 12-14 h until the reaction is complete; in reaction S3, the reaction temperature is 50-60℃ and the reaction time is 12-15 h; and in reaction S4, the reaction temperature is 75-85℃ and the reaction time is 10-14 h.

[0016] Preferably, in the reaction process, tris(trimethylsiloxy)silane is mixed with an organic solvent, triphenylmethyl sodium is added first, and the mixture is stirred at 25°C for 2-3 hours; then ethylene oxide is added, and the mixture is stirred at 60-80°C for 10-20 minutes. Then, 5% dilute hydrochloric acid is added to adjust the pH to an acidic environment of 3-4, and the mixture is stirred continuously under acidic conditions for 15-30 minutes until the reaction is complete.

[0017] Preferably, in the S3 reaction process, tris(trimethylsiloxy)silylethyl bromide is first dissolved in anhydrous dichloromethane at 25°C, and then dimethylamine is added. The mixture is stirred at 50-60°C for 12-15 hours until the reaction is complete.

[0018] Preferably, in S1, the mass ratio of the tris(trimethylsiloxy)silane to the organic solvent is 20:80.

[0019] Preferably, in S2, the mass ratio of the tris(trimethylsiloxy)silylethyl alcohol to the organic solvent is 25:150.

[0020] Preferably, in S3, the mass ratio of the tris(trimethylsiloxy)silylethyl bromide to the organic solvent is 30:130.

[0021] Preferably, in S4, the ratio of tris(trimethylsiloxy)silylethyldimethylamine to organic solvent is 20g:150mL.

[0022] Preferably, the preparation method of the ether derivative includes the following steps: under nitrogen protection, 3-bromo-1-propanol is dissolved in anhydrous N,N-dimethylformamide, and NaH is added at 0°C with stirring; then propylene oxide is added to react and generate a hydroxy ether intermediate; under nitrogen protection, the hydroxy ether intermediate is dissolved in anhydrous N,N-dimethylformamide (DMF), and then potassium carbonate is added, heated and stirred, and then dibromomethane is added to react and obtain the ether derivative.

[0023] Preferably, the mass ratio of 3-bromo-1-propanol to NaH is 10:2.76.

[0024] Preferably, the mass ratio of 3-bromo-1-propanol to propylene oxide is 10:6.3.

[0025] Preferably, the ratio of 3-bromo-1-propanol to anhydrous N,N-dimethylformamide is 10 g: 80 mL.

[0026] Preferably, the mass ratio of the hydroxy ether intermediate to dibromomethane is 10:4.

[0027] Preferably, the ratio of the hydroxy ether intermediate to anhydrous N,N-dimethylformamide is 10g:80mL.

[0028] Preferably, the mass ratio of the hydroxy ether intermediate to potassium carbonate is 10:10.5.

[0029] Preferably, the synthetic route of the ether derivative is as follows: .

[0030] Based on trichlorosilane raw materials, this invention innovatively develops a highly efficient process for synthesizing tetrasiloxane surfactants that combine twin structures and quaternary ammonium salt groups. The process route is simple, the reaction conditions are mild, the product structure is well-defined, and the molecular structure is precisely controlled through modular design.

[0031] The present invention also proposes a high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent containing the aforementioned gemini tetrasiloxane surfactant, which is composed of the following components by mass percentage: 20%-25% surfactant compound system, 0.5%-1% foam stabilizer, 1%-2% chelating agent, 0.5%-1% preservative, 1%-1.5% corrosion inhibitor, and the balance being water, with the total of all components being 100%; wherein, the surfactant compound system is composed of gemini tetrasiloxane surfactant and trisiloxane surfactant.

[0032] Preferably, the mass ratio is 12-15:8-10.

[0033] Preferably, the high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent containing the aforementioned gemini tetrasiloxane surfactant is composed of the following components by mass percentage: 12%-15% gemini tetrasiloxane surfactant, 8%-10% trisiloxane surfactant, 0.5%-1% foam stabilizer, 1%-2% chelating agent, 0.5%-1% preservative, 1%-1.5% corrosion inhibitor, with the balance being water, and the total of all components being 100%.

[0034] Preferably, the trisiloxane surfactant is one or more of surfactants QE-80 and UF-5811.

[0035] Preferably, the foam stabilizer is one or more of xanthan gum, guerbert alcohol, and chitosan.

[0036] Preferably, the chelating agent is composed of sodium glutamate diacetate, trisodium N,N-dicarboxymethylalanine, and sodium iminodisuccinate.

[0037] Preferably, the mass ratio of sodium glutamate diacetate, trisodium N,N-dicarboxymethylalanine, and sodium iminodisuccinate is 0.3-0.6:0.45-0.9:0.25-0.5.

[0038] Preferably, the preservative is one or both of Kathon and methylparaben.

[0039] Preferably, the corrosion inhibitor is composed of AR-2 corrosion inhibitor and Inhibispheres corrosion inhibitor.

[0040] Preferably, the mass ratio of AR-2 corrosion inhibitor to Inhibispheres corrosion inhibitor is 0.5-0.8:0.5-0.7.

[0041] This invention also proposes a method for preparing the high-performance fluorine-free environmentally friendly foam fire extinguishing agent, comprising the following steps: adding a surfactant compound system to a portion of water and stirring to obtain a surfactant compound solution; preparing a chelating agent separately; adding a foam stabilizer, a chelating agent, a corrosion inhibitor, and a preservative to the surfactant compound solution in sequence and replenishing the remaining water, stirring evenly to obtain the high-performance fluorine-free environmentally friendly foam fire extinguishing agent.

[0042] Preferably, the stirring speed is 400-1000 rpm and the stirring time is 5-30 min.

[0043] Preferably, a foam stabilizer is added to the surfactant compound solution, and after stirring, a chelating agent, a corrosion inhibitor, and a preservative are added, and the remaining water is replenished.

[0044] Preferably, after adding the foam stabilizer to the surfactant compound solution, the stirring speed is 800 rpm and the stirring time is 20 min.

[0045] Preferably, the process of preparing the chelating agent includes the following steps: adding sodium glutamate diacetate to water at 40°C and 400 rpm, stirring for 15 min after the addition is complete; then, raising the temperature, adding trisodium N,N-dicarboxymethylalanine at 50°C and 600 rpm, stirring for 10 min after the addition is complete, lowering the temperature back to room temperature, and then adding sodium iminodisuccinate; after the addition is complete, ultrasonically dispersing at 20 kHz for 5 min to obtain the chelating agent.

[0046] The present invention also proposes a fire extinguishing device containing the aforementioned high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent.

[0047] The advantages of this invention are: (1) This invention develops a foam fire extinguishing agent formulation based on independently synthesized gemini tetrasiloxane surfactants. The product fully complies with the requirements of the national standard GB 15308-2006 "Foam Fire Extinguishing Agents" and has good foam performance and fire extinguishing performance.

[0048] (2) For transformer oil fires, the fluorine-free environmentally friendly foam extinguishing agent of this invention has excellent foaming performance, foam stability, fire extinguishing performance and film-forming performance. The foaming ratio is 7-8 times; the 25% liquid separation time is 12.7-15 min; the fire extinguishing time is 50-90 s; the fire resistance time is 12 min 15 s-14 min 26 s; and the film-forming speed is 1.3-1.7 cm. 2 / s, 28-day biodegradation rate: 96%-99%. Under the same conditions, compared with commercial 3% aqueous film-forming foam fire extinguishing agent, the foaming ratio is increased by 1.12-2.12 times, the liquid separation time of 25% is extended by 9 min 0.7s-11 min 2.5s, the extinguishing time is shortened by 106-146s, the anti-burning time is extended by 178-309s, and the film-forming speed is increased by 0.1-0.5cm. 2 / s.

[0049] (3) This invention utilizes a compound system of biodegradable tetrasiloxane surfactants and trisiloxane surfactants to replace the fluorocarbon surfactants in traditional aqueous film-forming foam extinguishing agents, and develops an environmentally friendly foam extinguishing agent suitable for flammable liquid fires, fundamentally solving the ecological problems caused by fluorocarbon surfactants in traditional AFFF.

[0050] (4) The present invention establishes a simple process for preparing foam fire extinguishing agent stock solution with mild conditions, 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

[0051] Figure 1 The results of performance tests on foam fire extinguishing agents at different concentrations of Gemini tetrasiloxane surfactants are presented. Figure 2 The results of performance tests on foam fire extinguishing agents at different concentrations of trisiloxane surfactants; Figure 3 The results of performance tests on foam extinguishing agents at different foam stabilizer concentrations; Figure 4 This is a static image of the foam extinguishing agent stock solution prepared in Example 1 of this invention. Figure 5 This is a static image of the foam fire extinguishing agent stock solution prepared in Comparative Example 7 of this invention. Figure 6 The images show the film-forming phenomena of the foam fire extinguishing agents and 3% AFFF prepared in Examples 1-4 and Comparative Examples 5-6 of this invention. Figure 7 These are diagrams illustrating the fire extinguishing phenomena of the fire extinguishing agents prepared in Examples 1-4 of this invention. Figure 8 These are experimental images showing the extinguishing phenomena of foam fire extinguishing agents and 3% AFFF corresponding to Comparative Examples 1-6 of this invention. Figure 9 The graph shows the film-forming performance test data of the foam fire extinguishing agents and 3% AFFF prepared in Examples 1-4 and Comparative Examples 5-6 of this invention. Detailed Implementation

[0052] 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.

[0053] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0054] 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.

[0055] A high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent is composed of the following components by mass percentage: 20%-25% surfactant compound system, 0.5%-1% foam stabilizer, 1%-2% composite chelating agent, 0.5%-1% preservative, 1%-1.5% composite corrosion inhibitor, and the balance being water, with the total of all components being 100%; the surfactant compound system is composed of the gemini tetrasiloxane surfactant and trisiloxane surfactant as described in Example 1 below.

[0056] According to the standard GB 15308-2006 "Foam Extinguishing Agents", the effects of concentration changes of key components such as Gemini tetrasiloxane surfactant, Trisiloxane surfactant and foam stabilizer on the diffusion coefficient, expansion ratio, 25% liquid separation time, extinguishing time and anti-burning time of the fluorine-free environmentally friendly foam extinguishing agent formulation were tested.

[0057] The foam extinguishing agent formulation with fixed mass concentrations of all substances except the Gemini tetrasiloxane surfactant is as follows (by mass percentage): 8.5%-18% Gemini tetrasiloxane surfactant, 9% trisiloxane surfactant UF-5811, 0.7% xanthan gum, 0.5% sodium diacetate of glutamate, 0.9% trisodium N,N-dicarboxymethylalanine, 0.5% sodium iminodisuccinate, 1% Kathon, 0.8% AR-2 corrosion inhibitor, 0.7% Inhibispheres corrosion inhibitor, with the balance being water. The performance of the foam extinguishing agent at different Gemini tetrasiloxane surfactant concentrations was tested based on this formulation. Figure 1 As shown, when the concentration of Gemini tetrasiloxane surfactant is below 12% 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 short, while its extinguishing time is long. When the concentration of Gemini tetrasiloxane surfactant is between 12% and 15%, the foam extinguishing agent has a large expansion ratio and diffusion coefficient, a long 25% exudation time and anti-burning time, and a short extinguishing time, exhibiting the best overall performance. Therefore, the optimal concentration range for Gemini tetrasiloxane surfactant is 12%-15%.

[0058] The foam extinguishing agent formulation, with a fixed mass concentration of all substances except the trisiloxane surfactant (UF-5811), is as follows (by mass percentage): 13% Gemini tetrasiloxane surfactant, 6%-12% trisiloxane surfactant UF-5811, 0.7% xanthan gum, 0.5% sodium glutamate diacetate, 0.9% trisodium N,N-dicarboxymethyl alanine, 0.5% sodium iminodisuccinate, 1% Kathon, 0.8% AR-2 corrosion inhibitor, 0.7% Inhibispheres corrosion inhibitor, with the balance being water. The performance of the foam extinguishing agent at different trisiloxane surfactant concentrations was tested based on this formulation. Figure 2 As shown, when the concentration of trisiloxane surfactant is below 8% or above 10%, the foam extinguishing agent has a large expansion ratio and diffusion coefficient, but its 25% exudation time and anti-burning time are short, while its extinguishing time is long, especially when the trisiloxane concentration reaches 12%, the extinguishing time is significantly prolonged. When the concentration of trisiloxane surfactant is between 8% and 10%, the foam extinguishing agent has a large expansion ratio and diffusion coefficient, a long 25% exudation time and anti-burning time, and a short extinguishing time, exhibiting the best overall performance. Therefore, the optimal concentration range for trisiloxane surfactant is 8%-10%.

[0059] The foam extinguishing agent formulation with fixed mass concentrations of all substances except the foam stabilizer (xanthan gum) is as follows (by mass percentage): 13% Gemini tetrasiloxane surfactant, 9% Trisiloxane surfactant UF-5811, 0.1%-1.4% Xanthan gum, 0.5% Sodium diacetate of glutamate, 0.9% Trisodium N,N-dicarboxymethylalanine, 0.5% Sodium iminodisuccinate, 1% Kathon, 0.8% AR-2 corrosion inhibitor, 0.7% Inhibispheres corrosion inhibitor, with the balance being water. Based on this formulation, the performance of the foam extinguishing agent at different foam stabilizer concentrations was tested, such as... Figure 3 As shown in the diagram, when the foam stabilizer concentration is below 0.5%, 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%, the foam extinguishing agent has a larger diffusion coefficient, but its expansion ratio is smaller, its 25% exudation time and anti-burning time are shorter, while its extinguishing time is longer. When the foam stabilizer concentration is between 0.5% and 1%, 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, exhibiting the best overall performance. Therefore, the optimal concentration range for the foam stabilizer is 0.5%-1%.

[0060] Therefore, based on the foam extinguishing agent formulation and Figure 1-3 The test results and design examples 1-4 are as follows: Example 1 A high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent was prepared according to the following method. ① Weigh out 12g of Gemini tetrasiloxane surfactant, 8g of trisiloxane surfactant UF-5811, 0.5g of xanthan gum, 0.3g of sodium glutamate diacetate, 0.45g of trisodium N,N-dicarboxymethylalanine, 0.25g of sodium iminodisuccinate, 0.5g of Kathon, 0.5g of AR-2 corrosion inhibitor, and 0.5g of Inhibispheres corrosion inhibitor; ② Add the Gemini tetrasiloxane surfactant and the trisiloxane surfactant UF-5811 sequentially to 30g of deionized water, and stir at 1000rpm for 5min to obtain a surfactant compound solution; ③ Under 800rpm, slowly add 0.5g of xanthan gum to the surfactant compound solution over 20min, and stir for 20min after the addition is complete to obtain a foam solution; ④ At 40℃ and 400rpm, add 0.3g of sodium glutamate diacetate to 20g of deionized water, and stir for 15min after the addition is complete. Then, the temperature was increased to 50℃ and the rotation speed was 600 rpm. 0.45 g of trisodium N,N-dicarboxymethylalanine was added. After the addition was complete, the mixture was stirred for 10 min to form a DCMT-GLDA synergistic chelating network. Then, the solution temperature was lowered back to room temperature, and 0.25 g of sodium iminodisuccinate was added. After the addition was complete, the mixture was ultrasonically dispersed at 20 kHz for 5 min to obtain a composite chelating agent. ⑤ At 1000 rpm, the composite chelating agent, 0.5 g of AR-2 corrosion inhibitor, and 0.5 g of Inhibispheres corrosion inhibitor were added sequentially to the foam solution obtained in step ③. Then, 0.5 g of Kathon and 27 g of deionized water were added. After stirring for 30 min, the target foam extinguishing agent was obtained. Its appearance is shown in the image below. Figure 4 As shown in the figure, after the stock solution was left to stand at room temperature and standard atmospheric pressure for 180 days, its appearance remained basically unchanged, still appearing as a pale yellow homogeneous liquid without obvious stratification or precipitation, indicating that the stock solution has good stability.

[0061] The structure and synthesis route of the gemini tetrasiloxane surfactant are as follows:

[0062]

[0063] The specific synthesis path is as follows: Step 1: Synthesis of tris(trimethylsiloxy)silane Under anhydrous conditions, 10 g of trichlorosilane (SiHCl3) was dissolved in 50 g of anhydrous n-hexane, followed by the addition of 28 g of pyridine, and then the slow addition of 30 g of trimethylsilanol (Me3SiOH) with stirring. This process was carried out at 5 °C and stirred for 3 h under nitrogen protection. Subsequently, the system was heated to 50 °C and stirred for another 1 h to ensure complete reaction. Byproducts were removed by vacuum distillation to obtain tris(trimethylsiloxy)silane.

[0064]

[0065] Step 2: Reaction with ethylene oxide 20g of tris(trimethylsiloxy)silane was dissolved in 80g of anhydrous toluene, and 0.05g of triphenylmethyl sodium was slowly added. After stirring at 25°C for 2 hours, 3.5g of ethylene oxide was added, and the mixture was heated to 80°C to carry out the epoxide ring-opening reaction. The mixture was stirred for 10 minutes to allow Si-H to undergo an addition reaction with ethylene oxide to generate a sodium alkoxide intermediate. Subsequently, an appropriate amount of 5% dilute hydrochloric acid was added to adjust the pH to 3 to create an acidic environment. The mixture was stirred continuously under acidic conditions for 30 minutes until the reaction was complete to obtain tris(trimethylsiloxy)silylethyl alcohol.

[0066]

[0067] Step 3: Hydroxybromination reaction 25g of tris(trimethylsiloxy)silylethyl alcohol was dissolved in 150g of anhydrous dichloromethane, and 6.5g of phosphorus tribromide was slowly added at 0°C. After the addition was complete, the temperature was restored to 25°C, and the reaction was carried out for 12h to obtain tris(trimethylsiloxy)silylethyl bromide.

[0068]

[0069] Step 4: Amino substitution reaction 30 g of tris(trimethylsiloxy)silylethyl bromide was dissolved in 130 g of anhydrous dichloromethane at 25 °C. Then, 17 g of industrial dimethylamine aqueous solution (40% by mass) was slowly added dropwise, and the mixture was stirred at 50 °C for 13 h to obtain tris(trimethylsiloxy)silylethyl dimethylamine.

[0070]

[0071] Step 5: Quaternization reaction Dissolve 20g of tris(trimethylsiloxy)silylethyldimethylamine and 13.8g of potassium carbonate in 150mL of anhydrous acetonitrile, and slowly add 10g of an ether derivative over 2 hours at 60℃. After the addition of the feedstock was complete, the system was heated to 80°C and stirred under reflux for 12 hours to obtain the target product, a gemini tetrasiloxane surfactant. Its NMR data are as follows: 13 C NMR (100 MHz, CDCl3) δ 75.7, 73.1, 70.9, 63.6, 51.1, 50.8, 39.0,29.4, 19.6, 15.8, 1.7, 1.6. 1 H NMR (400 MHz, CDCl3) δ 4.52 (s, 2H), 3.89 (qt, J = 6.2, 3.4 Hz, 1H), 3.56 (d, J = 3.4 Hz, 3H), 3.37 (t, J = 7.2 Hz, 2H), 3.26 (t, J = 7.1 Hz, 2H), 3.23 (t, J = 7.1 Hz, 2H), 3.11 (t, J = 7.5 Hz, 2H), 2.89 (s, 6H), 2.81 (s, 6H), 2.32 (tt, J = 7.5, 7.2 Hz, 2H), 1.43 (t, J = 7.1 Hz, 2H), 1.38 (t, J = 7.1 Hz, 2H), 1.22 (d, J = 6.2 Hz, 2H), 0.27 (s, 27H), 0.21 (s, 27H). The process is as follows:

[0072] The synthetic routes for ether derivatives are as follows:

[0073] Step 1: Ring-opening reaction of propylene oxide Under nitrogen protection, 10 g of 3-bromo-1-propanol was dissolved in 80 mL of anhydrous N,N-dimethylformamide (DMF). Then, 4.3 g of 60% NaH was added at 0 °C, and the mixture was stirred for 30 min. Next, 6.3 g of propylene oxide was added, and the mixture was reacted at 25 °C for 6 h to generate a hydroxy ether intermediate.

[0074]

[0075] Step 2: Nucleophilic substitution reaction of hydroxyl group Under nitrogen protection, 10 g of hydroxy ether intermediate was dissolved in 80 mL of anhydrous N,N-dimethylformamide (DMF), and then 10.5 g of potassium carbonate was added. The mixture was stirred at 60 °C for 30 min. Then, 4 g of dibromomethane was slowly added over 1 h, and the reaction was continued at 60 °C for 12 h to obtain the target product, an ether derivative.

[0076]

[0077] The surface tension of the gemini tetrasiloxane surfactant prepared in Example 1 at the critical micelle concentration was tested using a QBZY-3 fully automatic surface tension meter at 25℃, and was found to be 20.3 mN / m. The foaming performance of a 1% (w / w) surfactant solution was tested under constant temperature (50±0.5℃) water bath conditions according to the standard Ross-Miles foaming performance test method, and the foam height was 380 mL. This gemini tetrasiloxane surfactant exhibits excellent surface activity and foaming properties.

[0078] Example 2 A high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent was prepared according to the following method: ① Weigh out 15g of Gemini tetrasiloxane surfactant, 10g of trisiloxane surfactant UF-5811, 1g of chitosan, 0.6g of sodium glutamate diacetate, 0.9g of trisodium N,N-dicarboxymethylalanine, 0.5g of sodium iminodisuccinate, 1g of methylparaben, 0.8g of AR-2 corrosion inhibitor, and 0.7g of Inhibispheres corrosion inhibitor; ② Add the Gemini tetrasiloxane surfactant and trisiloxane surfactant UF-5811 sequentially to 40g of deionized water, and stir at 1000rpm for 5min to obtain a surfactant compound solution; ③ Under 800rpm, slowly add 1g of chitosan to the surfactant compound solution over 20min, and stir for 20min after the addition is complete to obtain a foam solution; ④ At 40℃ and 400rpm, add 0.6g of sodium glutamate diacetate to 20g of deionized water, and stir for 15min after the addition is complete. Then, the temperature was increased to 50℃ and 600 rpm, and 0.9 g of trisodium N,N-dicarboxymethylalanine was added. After the addition was completed, the mixture was stirred for 10 min to form a DCMT-GLDA synergistic chelating network. After the solution temperature was lowered back to room temperature, 0.5 g of sodium iminodisuccinate was added. After the addition was completed, the mixture was ultrasonically dispersed at 20 kHz for 5 min to obtain a composite chelating agent. ⑤ At 1000 rpm, the composite chelating agent, 0.8 g of AR-2 corrosion inhibitor, and 0.7 g of Inhibispheres corrosion inhibitor were added sequentially to the foam solution obtained in ③. 1 g of methylparaben and 9.5 g of deionized water were added, and the mixture was stirred for 30 min to obtain the target foam extinguishing agent.

[0079] The method for synthesizing the gemini tetrasiloxane surfactant is the same as in Example 1.

[0080] Example 3 A high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent was prepared according to the following method: ① Weigh out 13g of Gemini tetrasiloxane surfactant, 8g of trisiloxane surfactant QE-80, 0.7g of xanthan gum, 0.5g of sodium glutamate diacetate, 0.7g of trisodium N,N-dicarboxymethylalanine, 0.3g of sodium iminodisuccinate, 0.8g of methylparaben, 0.6g of AR-2 corrosion inhibitor, and 0.6g of Inhibispheres corrosion inhibitor; ② Add the Gemini tetrasiloxane surfactant and the trisiloxane surfactant QE-80 sequentially to 35g of deionized water, and stir at 1000rpm for 5min to obtain a surfactant compound solution; ③ Under 800rpm, slowly add 0.7g of xanthan gum to the surfactant compound solution over 20min, and stir for 20min after the addition is complete to obtain a foam solution; ④ At 40℃ and 400rpm, add 0.5g of sodium glutamate diacetate to 18g of deionized water, and stir for 15min after the addition is complete. Then, the temperature was increased to 50℃ and 600 rpm, and 0.7 g of trisodium N,N-dicarboxymethylalanine was added. After the addition was completed, the mixture was stirred for 10 min to form a DCMT-GLDA synergistic chelating network. After the solution temperature was lowered back to room temperature, 0.3 g of sodium iminodisuccinate was added. After the addition was completed, the mixture was ultrasonically dispersed at 20 kHz for 5 min to obtain a composite chelating agent. ⑤ At 1000 rpm, the composite chelating agent, 0.6 g of AR-2 corrosion inhibitor, and 0.6 g of Inhibispheres corrosion inhibitor were added sequentially to the foam solution obtained in ③. 0.8 g of methylparaben and 21.8 g of water were added, and the mixture was stirred for 30 min to obtain the target foam extinguishing agent.

[0081] The method for synthesizing the gemini tetrasiloxane surfactant is the same as in Example 1.

[0082] Example 4 Same as Example 1, except that the amount of Gemini tetrasiloxane surfactant was changed from 12g to 15g, and the amount of deionized water added in step ⑤ was changed from 27g to 24g.

[0083] Comparative Example 1 Same as Example 2, except that the Gemini tetrasiloxane surfactant is removed, and the amount of deionized water added in step ⑤ is changed from 9.5g to 24.5g.

[0084] Comparative Example 2 Same as Example 2, except that 15g of Gemini tetrasiloxane surfactant is replaced with 15g of hydrocarbon surfactant SDS.

[0085] Comparative Example 3 Same as Example 1, except that 12g of Gemini tetrasiloxane surfactant is replaced with 12g of trisiloxane surfactant CoatOsil-77.

[0086] Comparative Example 4 Same as Example 1, except that the Gemini tetrasiloxane surfactant is removed and the amount of deionized water added in step ⑤ is changed from 27g to 39g.

[0087] Comparative Example 5 Same as Example 3, except that the amount of Gemini tetrasiloxane surfactant used is changed from 13g to 3g, and the amount of deionized water added in step ⑤ is changed from 21.8g to 31.8g.

[0088] Comparative Example 6 Same as Example 1, except that the amount of Gemini tetrasiloxane surfactant used is changed from 12g to 1g, and the amount of deionized water added in step ⑤ is changed from 27g to 38g.

[0089] Comparative Example 7 ① Weigh 13g of the Gemini tetrasiloxane surfactant, 8g of the trisiloxane surfactant QE-80, 0.7g of xanthan gum, 0.5g of sodium glutamate diacetate, 0.7g of trisodium N,N-dicarboxymethylalanine, 0.3g of sodium iminodisuccinate, 0.8g of methylparaben, 0.6g of AR-2 corrosion inhibitor, and 0.6g of Inhibispheres corrosion inhibitor from Example 1; ② Add the Gemini tetrasiloxane surfactant and the trisiloxane surfactant QE-80 sequentially to 35g of deionized water, and stir at 500rpm for 5min to obtain a surfactant compound solution; ③ Add 0.7g of xanthan gum to the surfactant compound solution at 400rpm within 10min, and stir for 10min after the addition is complete to obtain a foam solution; ④ Add 0.5g of sodium glutamate diacetate to 18g of deionized water at 40℃ and 400rpm, and stir for 15min after the addition is complete. Then, the temperature was increased to 50℃ and 600 rpm, and 0.7 g of trisodium N,N-dicarboxymethylalanine was added. After the addition was complete, the mixture was stirred for 10 min to form a DCMT-GLDA synergistic chelating network. The solution temperature was then lowered to room temperature, and 0.3 g of sodium iminodisuccinate was added. After the addition was complete, the mixture was ultrasonically dispersed at 20 kHz for 5 min to obtain a composite chelating agent. ⑤ At 1000 rpm, the composite chelating agent, 0.6 g of AR-2 corrosion inhibitor, and 0.6 g of Inhibispheres corrosion inhibitor were added sequentially to the foam solution obtained in step ③. 0.8 g of methylparaben and 21.8 g of water were added, and the mixture was stirred for 30 min to obtain the target foam extinguishing agent. Figure 6 As shown. Compared to Example 3, the difference in this comparative example process is that the rotation speed when adding xanthan gum was reduced from 800 rpm to 400 rpm, the sample addition time was changed from 20 min to 10 min, and the stirring time after sample addition was changed from 20 min to 10 min. Figure 5 It can be seen that at day 0, the stock solution was uniformly pale yellow, homogeneous, and without stratification or sedimentation. After 15 days, small bubbles or flocculent matter appeared inside the stock solution, with slight turbidity or flocculation in some areas, and stratification began at the top. After 30 days, clear stratification was observed, with the upper layer being a transparent or light-colored liquid and the lower layer being a thick precipitate, with a clear interface. This result indicates that the prepared foam fire extinguishing agent sample has poor stability and a short shelf life.

[0090] Based on the fluorine-free environmentally friendly foam extinguishing agent stock solution described in Examples 1-4 and Comparative Examples 1-6 above, a 3% foam extinguishing agent solution was obtained by diluting it at a volume ratio of stock solution:water = 3:97. Based on the characteristics of fires involving large oil-filled equipment in converter stations (substations) and existing mainstream foam extinguishing systems, and targeting the combustion characteristics of transformer oil fires, a 4.52m... 2A transformer oil pool fire source model was used (oil pool dimensions and 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 (referring to standard GB 27897-2011 "Class A Foam Extinguishing Agents"), the foaming ratio, 25% separation time, extinguishing time, and fire resistance time of the foam extinguishing agent were tested. Simultaneously, the 28-day biodegradation rate of the foam extinguishing agent was determined according to standard GB / T21801-2008 "Rapid Biodegradability of Chemicals - Respiratory Measurement Method". In addition, the film-forming performance of the foam extinguishing agent solution on the surface of transformer oil was tested. The specific test method was as follows: ① The device used 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 obtained by dividing the maximum spreading area by the time to reach the maximum area. The performance of the foam extinguishing agents in Examples 1-4 and Comparative Examples 1-6 was measured using the above method. A commercially available 3% AFFF was used as a comparison. The test results are shown in Table 2 below. Figure 6-9 As shown: Table 2 Performance test results of foam extinguishing agents

[0091] From Table 2 and Figure 6-9 It is evident that the fluorine-free environmentally friendly foam fire extinguishing agents of Examples 1-4 exhibit a faster film-forming speed and shorter extinguishing time compared to the fire extinguishing agents of Comparative Examples 1-6; and a higher expansion ratio, shorter extinguishing time, and longer anti-burning time compared to 3% AFFF. Therefore, the fluorine-free environmentally friendly foam fire extinguishing agent possesses excellent foaming performance, film-forming performance, and fire extinguishing performance. Experimental results show that the foam fire extinguishing agent has an expansion ratio of 7-8 times; a 25% separation time of 12.7-15 min; an extinguishing time of 50-90 s; an anti-burning time of 12 min 15 s-14 min 26 s; and a film-forming speed of 1.3-1.7 cm. 2 / s, 28-day biodegradation rate: 96%-99%.

[0092] 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 gemini tetrasiloxane surfactant, characterized in that: Its structural formula is shown below: 。 2. A method for preparing a gemini tetrasiloxane surfactant as described in claim 1, characterized in that: Includes the following steps: S1. Reaction of tris(trimethylsiloxy)silane with ethylene oxide: In an organic solvent, tris(trimethylsiloxy)silane is reacted with ethylene oxide under the conditions of the alkaline reagent triphenylmethyl sodium, and then acidified with hydrochloric acid to obtain tris(trimethylsiloxy)silylethyl alcohol. S2, Hydroxyl bromination reaction: In an organic solvent, using tris(trimethylsiloxy)silylethyl alcohol as a raw material, phosphorus tribromide is used to carry out the reaction to obtain tris(trimethylsiloxy)silylethyl bromide; S3, Amino Substitution Reaction: In an organic solvent, tris(trimethylsiloxy)silylethyl bromide is used as a starting material and dimethylamine is used to react to obtain tris(trimethylsiloxy)silylethyl dimethylamine; S4. Quaternization reaction: In an organic solvent, using tris(trimethylsiloxy)silylethyldimethylamine as a raw material, and employing ether derivatives... The mixture was reacted with anhydrous potassium carbonate to obtain the gemini tetrasiloxane surfactant.

3. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: In S1, the mass ratio of tris(trimethylsiloxy)silane to ethylene oxide is 20:3-4; the mass ratio of tris(trimethylsiloxy)silane to triphenylmethyl sodium is 20:0.04-0.

1.

4. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: In S2, the mass ratio of tris(trimethylsiloxy)silylethyl alcohol to phosphorus tribromide is 25:6-7.

5.

5. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: In S3, the mass ratio of tris(trimethylsiloxy)silylethyl bromide to dimethylamine is 30:15-19.

5.

6. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: In S4, the mass ratio of tris(trimethylsiloxy)silylethyldimethylamine to the ether derivative is 20:9.6-10.4; the mass ratio of tris(trimethylsiloxy)silylethyldimethylamine to anhydrous potassium carbonate is 20:13-15.

7. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: The organic solvent in S1 is either anhydrous toluene or anhydrous dichloromethane; the organic solvents in S2 and S3 are both anhydrous dichloromethane; and the organic solvent in S4 is anhydrous acetonitrile.

8. The method for preparing the gemini tetrasiloxane surfactant according to claim 2, characterized in that: In reaction S1, the reaction temperature with ethylene oxide is 60-80℃, and the reaction time is 10-20 min; in reaction S2, the reaction temperature is 25℃, and the mixture is stirred for 12-14 h until the reaction is complete; in reaction S3, the reaction temperature is 50-60℃, and the reaction time is 12-15 h; in reaction S4, the reaction temperature is 75-85℃, and the reaction time is 10-14 h.

9. A high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent containing the gemini tetrasiloxane surfactant as described in claim 1, characterized in that: The product is composed of the following components by mass percentage: 20%-25% surfactant compound system, 0.5%-1% foam stabilizer, 1%-2% chelating agent, 0.5%-1% preservative, 1%-1.5% corrosion inhibitor, and the balance being water, with the total of all components being 100%; wherein the surfactant compound system is composed of gemini tetrasiloxane surfactant and trisiloxane surfactant.

10. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The mass ratio of the gemini tetrasiloxane surfactant to the trisiloxane surfactant is 12-15:8-10.

11. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The trisiloxane surfactant is one or more of surfactants QE-80 and UF-5811.

12. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The foam stabilizer is one or more of xanthan gum, guerbert alcohol, and chitosan.

13. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The chelating agent is composed of sodium glutamate diacetate, trisodium N,N-dicarboxymethylalanine, and sodium iminodisuccinate.

14. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 13, characterized in that: The mass ratio of sodium glutamate diacetate, trisodium N,N-dicarboxymethylalanine, and sodium iminodisuccinate is 0.3-0.6:0.45-0.9:0.25-0.

5.

15. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The preservative is one or both of Kathon and methylparaben.

16. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 9, characterized in that: The corrosion inhibitor consists of AR-2 corrosion inhibitor and Inhibispheres corrosion inhibitor.

17. The high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent according to claim 16, characterized in that: The mass ratio of AR-2 corrosion inhibitor to Inhibispheres corrosion inhibitor is 0.5-0.8:0.5-0.

7.

18. A method for preparing a high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent as described in any one of claims 9-17, characterized in that: The process includes the following steps: adding a surfactant compound system to a portion of water and stirring to obtain a surfactant compound solution; preparing a chelating agent separately; adding a foam stabilizer, a chelating agent, a corrosion inhibitor, and a preservative to the surfactant compound solution in sequence and replenishing the remaining water, stirring evenly to obtain the high-performance fluorine-free environmentally friendly foam fire extinguishing agent.

19. The preparation method of the high-performance fluorine-free environmentally friendly foam fire extinguishing agent according to claim 18, characterized in that: The stirring speed is 400-1000 rpm, and the stirring time is 5-30 min.

20. The preparation method of the high-performance fluorine-free environmentally friendly foam fire extinguishing agent according to claim 18, characterized in that: Add a foam stabilizer to the surfactant compound solution, stir, then add a chelating agent, corrosion inhibitor, and preservative, and replenish the remaining water.

21. The preparation method of the high-performance fluorine-free environmentally friendly foam fire extinguishing agent according to claim 20, characterized in that: After adding the foam stabilizer to the surfactant compound solution, the stirring speed was 800 rpm and the stirring time was 20 min.

22. A fire extinguishing device, characterized in that: It contains a high-performance, fluorine-free, environmentally friendly foam fire extinguishing agent as described in any one of claims 9-17.

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