A heptafluoropropane fire extinguishant and a method for its preparation

Abstract

The application provides a heptafluoropropane extinguishing agent and a preparation method thereof, and belongs to the technical field of fire fighting, and comprises the following steps: step S1, calcium fluoride nanoparticles are added into anhydrous ethanol, ZIF-8 is added after complete dispersion, ultrasonic treatment is carried out, standing is carried out, filtration is carried out, drying is carried out, and ZIF-8 loaded with calcium fluoride is obtained; step S2, tris(tribromophenoxy) triazine is put into a pulverizer for crushing, gaseous nanosilica is added, dry mixing is carried out, and a composite powder is obtained; step S3, perfluorohexanone and a perfluoropolyether-based surfactant are mixed, continuous stirring is carried out, modified nanosilica and ZIF-8 loaded with calcium fluoride are sequentially added, high-speed shearing is carried out, finally, the composite powder is added, and after uniform mixing, heptafluoropropane is mixed to obtain the heptafluoropropane extinguishing agent. The heptafluoropropane extinguishing agent can realize efficient fire extinguishing and reduce pollution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fire-fighting technology, in particular to a heptafluoro-propane extinguishing agent and a preparation method thereof. BACKGROUND

[0002] Halon and chlorofluorocarbon extinguishing agents were once widely used in special scenarios such as electronic equipment rooms, cultural heritage sites, ships and aircrafts due to their characteristics of rapid extinguishing, low toxicity, long-term storage and no damage to the protected objects. However, their chemical stability makes them difficult to decompose in the stratosphere, and the chlorine / bromine radicals released by ultraviolet radiation can catalyze nearly 100,000 times of ozone molecule decomposition, causing ozone layer destruction. Therefore, the development of environmentally friendly substitutes has become the focus of research in the field of fire-fighting and extinguishing.

[0003] At present, the transition-type substitutes represented by heptafluoro-propane (HFC-227ea) and hexafluoro-propane (HFC-236fa) account for 70% of the market share due to their similar physical and chemical properties to halon and ozone depletion potential (ODP≈0). They are suitable for precision instruments, data centers and other scenarios by blocking the combustion chain reaction through gas phase diffusion. However, at high temperatures (>400℃), heptafluoro-propane, hexafluoro-propane and other substances will decompose to generate toxic by-products such as hydrogen fluoride (HF) and carbon monoxide. For example, the amount of HF generated by heptafluoro-propane at an extinguishing concentration of 10% can reach 8-10 times that of bromotrifluoromethane, increasing the potential harm.

[0004] The patent application file with publication number CN106621158A discloses a high-efficiency heptafluoro-propane-based extinguishing agent, which comprises, by weight percentage, heptafluoro-propane 35-45%, dry ice 10-14%, sodium dihydrogen phosphate 6-10%, sodium carbonate 8-12%, sodium acetate trihydrate 6-10%, sodium chloride 8-12%, carbamide 1-3%, and water 8-12%. The sodium dihydrogen phosphate, sodium carbonate, sodium acetate trihydrate, sodium chloride, carbamide and water are mixed and stirred to obtain a mixture. The heptafluoro-propane is pressurized to obtain liquid heptafluoro-propane. The dry ice is added according to the ratio, and the above-mentioned materials are mixed uniformly and loaded into an extinguishing device to obtain the extinguishing agent. The extinguishing efficiency of the extinguishing agent prepared by the above-mentioned scheme is still insufficient, and the harmful gases such as HF generated during the extinguishing of heptafluoro-propane are only absorbed to a small extent, making it difficult to achieve the purpose of efficient extinguishing and reducing pollution.

[0005] Therefore, it is necessary to provide a preparation method of heptafluoro-propane extinguishing agent to solve the problems existing in the prior art. SUMMARY

[0006] Therefore, the present application provides a heptafluoro-propane extinguishing agent and a preparation method thereof, which can achieve the purpose of efficient extinguishing and reducing pollution of the heptafluoro-propane extinguishing agent.

[0007] The specific scheme of the application is as follows, a preparation method of heptafluoropropane extinguishing agent, comprising the following steps:

[0008] Step S1, calcium fluoride nanoparticles are added to anhydrous ethanol, after complete dispersion, ZIF-8 is added, ultrasonic treatment, standing, filtration, drying, to obtain ZIF-8 loaded with calcium fluoride;

[0009] Step S2, tris(tribromophenoxy) triazine is put into a pulverizer for crushing, then fumed nano-silicon dioxide is added for dry mixing, to obtain a composite powder;

[0010] Step S3, perfluorohexanone is mixed with a perfluoropolyether-based surfactant, continuous stirring is carried out, modified nano-SiO2 and ZIF-8 loaded with calcium fluoride are sequentially added, high-speed shearing is carried out, finally the composite powder is added, after uniform mixing, heptafluoropropane is mixed, to obtain heptafluoropropane extinguishing agent.

[0011] ZIF-8 is synthesized by a solvothermal method using 2-methyl imidazole and zinc nitrate, ZIF-8 has a zeolite imidazolate framework structure and a high specific surface area, the microporous structure thereof can efficiently adsorb free radicals and toxic gases generated by combustion, reduce the flame chain reaction rate, and effectively improve the extinguishing efficiency of the extinguishing agent. And ZIF-8 remains stable below 550 DEG C, and can continuously play a role in the initial stage of the fire.

[0012] Calcium fluoride is embedded into the pore channels and surface of ZIF-8 by ultrasonic dispersion, after loading calcium fluoride, the porous structure of ZIF-8 can avoid the agglomeration of calcium fluoride, and realize the controlled release of fluoride ions. Moreover, ZIF-8 can decompose Zn 2+ at high temperatures, which can combine with F - to generate ZnF2, block the formation of HF, and greatly reduce the emission of HF. Meanwhile, Ca 2+ generated by the decomposition of calcium fluoride can combine with Cl - , SO4 2- in the combustion products, to reduce the emission of corrosive gases.

[0013] The composite powder is obtained by mixing tris(tribromophenoxy) triazine and fumed silicon dioxide, the triazine structure decomposes at 200-300 DEG C, releases bromine radicals, captures hydrogen radicals and hydroxyl radicals in the combustion chain, realizes cyclic flame retardation. And SiO2 can form a Si-O-Br crosslinking network with the coke layer formed by the decomposition of tris(tribromophenoxy) triazine, improve the compactness of the carbon layer, block heat and oxygen, and improve the extinguishing efficiency.

[0014] The vaporization endothermic of perfluorohexanone can quickly reduce the temperature of the fire scene, and its high steam density can quickly dilute oxygen, which helps the fire extinguishing agent to play a role in extinguishing the fire. Combined with the perfluoropolyether-based surfactant, it can reduce the surface tension of the liquid droplets, promote the penetration of the fire extinguishing agent into the combustible material, and further block the combustion. Seven fluoropropane is gaseous at room temperature, as the main body of the fire extinguishing agent, it can quickly spread in the fire scene, thereby effectively reducing the oxygen concentration, and it can form a gas-liquid two-phase fire extinguishing system with perfluorohexanone, expand the action range of the fire extinguishing agent, and inhibit the reignition.

[0015] Preferably, the preparation of ZIF-8 comprises the following steps: dissolving 2-methylimidazole in methanol, mixing uniformly to obtain solution A; dissolving zinc nitrate in methanol, slowly adding solution A, passing nitrogen, water bath heating reaction, centrifugation, washing, drying to obtain ZIF-8.

[0016] ZIF-8 is synthesized by solvothermal method using 2-methylimidazole and zinc nitrate in methanol, and the metal node (Zn 2+ ) has Lewis acidity, which can catalyze the decomposition of nitrogen / sulfur-containing toxic gas into harmless small molecules, reducing pollution.

[0017] Preferably, the temperature of the heating reaction is 55-65℃, and the time is 5-7h.

[0018] Preferably, in the step S2, the particle size of the crushed tris(tribromophenoxy) triazine is 3-5μm; the mass ratio of tris(tribromophenoxy) triazine to fumed nano-silicon dioxide is (9-12):1.

[0019] Fumed nano-silicon dioxide can improve the viscosity and inhibit the occurrence of droplet phenomenon during the fire extinguishing process.

[0020] Preferably, in the step S3, the preparation of modified nano-SiO2 comprises the following steps: dispersing nano-SiO2 in hexamethyldisilazane, heating and stirring, filtering, washing, drying to obtain modified nano-SiO2.

[0021] After hydrophobic modification, the surface energy of nano-SiO2 is reduced, which can avoid its aggregation in non-polar solvents and ensure uniform dispersion of nano-particles.

[0022] Preferably, the temperature of the heating and stirring is 55-65℃, and the time is 4-6h.

[0023] Preferably, the temperature of the drying is 60-70℃, and the time is 10-14h.

[0024] Preferably, in the step S3, the speed of continuous stirring is 150-250rpm.

[0025] Preferably, in the step S3, the modified nano-SiO2 and the ZIF-8 loaded with calcium fluoride are sequentially added with zinc borate and ultrasonic dispersion.

[0026] The zinc borate can be decomposed to form a B2O3 glass body at high temperature, which covers the surface of the combustible material, insulates oxygen, blocks combustion, and the released crystallization water can absorb heat and reduce temperature, and the water vapor can dilute the oxygen concentration, thereby enhancing the fire extinguishing effect of the fire extinguishing agent.

[0027] To achieve the above object, the application further provides a heptafluoropropane extinguishing agent prepared by the preparation method of the heptafluoropropane extinguishing agent, characterized by comprising the following components in weight percentage:

[0028] perfluorohexanone 15-20 parts, perfluoropolyether-based surfactant 0.05-0.1 parts, modified nano-SiO2 0.3-0.8 parts, ZIF-8 loaded with calcium fluoride 2-3 parts, composite powder 0.5-1.5 parts, and heptafluoropropane 70-80 parts.

[0029] The components in the above weight percentage can make the heptafluoropropane extinguishing agent achieve efficient fire extinguishing and reduce pollution.

[0030] Preferably, the following components in weight percentage are further included:

[0031] zinc borate 0.2-0.5 parts;

[0032] Preferably, the composite powder comprises the following components in weight percentage: tris(tribromophenoxy) triazine 9-18 parts and fumed nano-silicon dioxide 1-1.5 parts.

[0033] Preferably, the ZIF-8 loaded with calcium fluoride comprises the following components in weight percentage: calcium fluoride 2-4 parts and ZIF-8 8-16 parts.

[0034] The above technical solution of the application at least has the following beneficial effects:

[0035] (1) ZIF-8 has a zeolite imidazole ester framework structure and a high specific surface area, and its microporous structure can efficiently adsorb free radicals and toxic gases generated during combustion, reduce the flame chain reaction rate, and effectively improve the fire extinguishing efficiency of the extinguishing agent; after loading calcium fluoride, the pore structure of ZIF-8 can realize controlled release of fluoride ions, prolong the action time of the extinguishing agent, and Ca 2+ can combine with Cl - , SO4 2- and other corrosive ions in combustion products to reduce the emission of corrosive gases and pollution.

[0036] (2) The triazine structure in the composite powder decomposes at high temperature, releases bromine radicals, captures hydrogen radicals and hydroxyl radicals in the combustion chain, and achieves fire retardation and extinguishment. Nano-silicon dioxide can form a Si-O-Br crosslinking network with the coke layer formed by the decomposition of tris(tribromophenoxy) triazine, improve the compactness of the coke layer, block heat and oxygen, and further improve the fire extinguishing efficiency.

[0037] (3) Perfluorohexanone can quickly reduce the temperature of the fire scene, and its vapor density is high, forming a gas-liquid two-phase extinguishing system with heptafluoropropane, which can quickly dilute oxygen and help the extinguishing agent to play a role in extinguishing. In addition, perfluorohexanone combined with a perfluoropolyether-based surfactant can reduce the surface tension of liquid droplets, promote the penetration of the extinguishing agent into the combustible material, and further block the combustion. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. The described embodiments are part of the embodiments of the present application, and all other embodiments obtained by those skilled in the art based on the described embodiments of the present application belong to the scope of protection of the present application.

[0039] Embodiment 1

[0040] 12g of 2-methylimidazole was dissolved in 200mL of methanol, mixed uniformly to obtain solution A; 8g of zinc nitrate was dissolved in 200mL of methanol, slowly added to solution A, heated to 65℃ in a water bath, nitrogen was introduced, reacted for 5h, centrifuged, washed, and dried to obtain ZIF-8.

[0041] 4g of calcium fluoride nanoparticles was added to 200mL of anhydrous ethanol, dispersed to form a suspension, 16g of ZIF-8 was added, ultrasonic treatment was performed for 2h, and then the mixture was left to stand, filtered, and dried to obtain ZIF-8 loaded with calcium fluoride.

[0042] 9g of tris(tribromophenoxy) triazine was put into a pulverizer, pulverized to 3-5μm, 1g of fumed nano-silicon dioxide was added, and dry mixing was performed to obtain a composite powder.

[0043] 1g of nano-SiO2 was dispersed in a beaker containing 20mL of hexamethyldisilazane, the beaker was placed in a water bath, heated to 65℃, stirred for 4h, filtered, washed with anhydrous ethanol three times, and vacuum dried at 60℃ for 14h to obtain modified nano-SiO2.

[0044] Mix 18 g of perfluorohexanone with 0.08 g of perfluoropolyether-based surfactant, continuously stir, add 0.35 g of zinc borate, ultrasonic dispersion, then add 0.6 g of modified nano-SiO2 and 2 g of ZIF-8 loaded with calcium fluoride in sequence, high-speed shearing, add 1 g of composite powder, mix uniformly, then mix with 75 g of heptafluoropropane to obtain heptafluoropropane extinguishing agent.

[0045] Example 2

[0046] Dissolve 12 g of 2-methylimidazole in 200 mL of methanol, mix uniformly to obtain solution A; dissolve 8 g of zinc nitrate in 200 mL of methanol, slowly add to solution A, heat to 60℃ in a water bath, pass nitrogen, react for 6 h, centrifuge, wash, dry to obtain ZIF-8.

[0047] Add 3 g of calcium fluoride nanoparticles to 150 mL of anhydrous ethanol, disperse to form a suspension, add 12 g of ZIF-8, ultrasonic treatment for 2 h, stand, filter, dry to obtain ZIF-8 loaded with calcium fluoride.

[0048] Put 9 g of tris(tribromophenoxy)triazine into a pulverizer, pulverize to 3-5 μm, add 1 g of fumed nano-silicon dioxide, dry mix to obtain composite powder.

[0049] Disperse 1 g of nano-SiO2 in a beaker containing 20 mL of hexamethyldisilazane, place the beaker in a water bath, heat to 55℃, stir for 6 h, filter, wash with anhydrous ethanol three times, vacuum dry at 70℃ for 10 h to obtain modified nano-SiO2.

[0050] Mix 15 g of perfluorohexanone with 0.05 g of perfluoropolyether-based surfactant, continuously stir, add 0.5 g of zinc borate, ultrasonic dispersion, then add 0.3 g of modified nano-SiO2 and 3 g of ZIF-8 loaded with calcium fluoride in sequence, high-speed shearing, add 1.5 g of composite powder, mix uniformly, then mix with 70 g of heptafluoropropane to obtain heptafluoropropane extinguishing agent.

[0051] Example 3

[0052] Dissolve 12 g of 2-methylimidazole in 200 mL of methanol, mix uniformly to obtain solution A; dissolve 8 g of zinc nitrate in 200 mL of methanol, slowly add to solution A, heat to 55℃ in a water bath, pass nitrogen, react for 7 h, centrifuge, wash, dry to obtain ZIF-8.

[0053] Add 2 g of calcium fluoride nanoparticles to 100 mL of anhydrous ethanol, disperse to form a suspension, add 8 g of ZIF-8, ultrasonic treatment for 2 h, stand, filter, dry to obtain ZIF-8 loaded with calcium fluoride.

[0054] Put 18 g of tris (tribromophenoxy) triazine into a pulverizer, crush to 3-5 μm, add 1.5 g of fumed nano-silicon dioxide, dry mix to obtain a composite powder.

[0055] Put 1 g of nano-SiO2 into a beaker containing 20 mL of hexamethyldisilazane, place the beaker in a water bath, heat to 60℃, stir for 5 h, filter, wash three times with anhydrous ethanol, and vacuum dry at 65℃ for 12 h to obtain modified nano-SiO2.

[0056] Mix 20 g of perfluorohexanone with 0.1 g of perfluoropolyether-based surfactant, continuously stir, add 0.2 g of zinc borate, ultrasonic dispersion, then sequentially add 0.8 g of modified nano-SiO2 and 2.5 g of ZIF-8 loaded with calcium fluoride, high-speed shear, add 1 g of composite powder, mix uniformly, and then mix with 75 g of heptafluoropropane to obtain a heptafluoropropane extinguishing agent.

[0057] Example 4

[0058] Dissolve 12 g of 2-methylimidazole in 200 mL of methanol, mix uniformly to obtain solution A; dissolve 8 g of zinc nitrate in 200 mL of methanol, slowly add to solution A, water bath heating to 60℃, nitrogen inlet, reaction for 5.5 h, centrifugation, washing, drying to obtain ZIF-8.

[0059] Add 3 g of calcium fluoride nanoparticles to 150 mL of anhydrous ethanol, disperse to form a suspension, add 12 g of ZIF-8, ultrasonic treatment for 2 h, stand, filter, dry to obtain ZIF-8 loaded with calcium fluoride.

[0060] Put 18 g of tris (tribromophenoxy) triazine into a pulverizer, crush to 3-5 μm, add 1 g of fumed nano-silicon dioxide, dry mix to obtain a composite powder.

[0061] Put 1 g of nano-SiO2 into a beaker containing 20 mL of hexamethyldisilazane, place the beaker in a water bath, heat to 55℃, stir for 6 h, filter, wash three times with anhydrous ethanol, and vacuum dry at 60℃ for 14 h to obtain modified nano-SiO2.

[0062] Mix 18 g of perfluorohexanone with 0.1 g of perfluoropolyether-based surfactant, continuously stir, add 0.4 g of zinc borate, ultrasonic dispersion, then sequentially add 0.5 g of modified nano-SiO2 and 2 g of ZIF-8 loaded with calcium fluoride, high-speed shear, add 0.5 g of composite powder, mix uniformly, and then mix with 80 g of heptafluoropropane to obtain a heptafluoropropane extinguishing agent.

[0063] Example 5

[0064] 12 g 2-methylimidazole was dissolved in 200 mL of methanol, mixed uniformly to obtain solution A; 8 g of zinc nitrate was dissolved in 200 mL of methanol, slowly added to solution A, heated to 55°C in a water bath, nitrogen was introduced, reacted for 6.5 h, centrifuged, washed, and dried to obtain ZIF-8.

[0065] 2 g of calcium fluoride nanoparticles were added to 100 mL of anhydrous ethanol, dispersed to form a suspension, 8 g of ZIF-8 was added, ultrasonic treatment was performed for 2 h, left to stand, filtered, and dried to obtain ZIF-8 loaded with calcium fluoride.

[0066] 18 g of tris (tribromophenoxy) triazine was put into a pulverizer and pulverized to 3-5 μm, 1.5 g of fumed nano-silicon dioxide was added, and dry mixing was performed to obtain a composite powder.

[0067] 1 g of nano-SiO2 was dispersed in a beaker containing 20 mL of hexamethyldisilazane, the beaker was placed in a water bath, heated to 50°C, stirred for 5.5 h, filtered, washed with anhydrous ethanol three times, and vacuum dried at 60°C for 11 h to obtain modified nano-SiO2.

[0068] 15 g of perfluorohexanone was mixed with 0.05 g of perfluoropolyether-based surfactant, continuously stirred, 0.5 g of zinc borate was added, ultrasonic dispersion was performed, then 0.6 g of modified nano-SiO2 and 2 g of ZIF-8 loaded with calcium fluoride were added in sequence, high-speed shearing was performed, 1 g of composite powder was added, mixed uniformly, and then mixed with 75 g of heptafluoropropane to obtain heptafluoropropane extinguishing agent.

[0069] Example 6

[0070] 12 g of 2-methylimidazole was dissolved in 200 mL of methanol, mixed uniformly to obtain solution A; 8 g of zinc nitrate was dissolved in 200 mL of methanol, slowly added to solution A, heated to 65°C in a water bath, nitrogen was introduced, reacted for 5.5 h, centrifuged, washed, and dried to obtain ZIF-8.

[0071] 4 g of calcium fluoride nanoparticles were added to 200 mL of anhydrous ethanol, dispersed to form a suspension, 16 g of ZIF-8 was added, ultrasonic treatment was performed for 2 h, left to stand, filtered, and dried to obtain ZIF-8 loaded with calcium fluoride.

[0072] 9 g of tris (tribromophenoxy) triazine was put into a pulverizer and pulverized to 3-5 μm, 1 g of fumed nano-silicon dioxide was added, and dry mixing was performed to obtain a composite powder.

[0073] 1 g of nano-SiO2 was dispersed in a beaker containing 20 mL of hexamethyldisilazane, the beaker was placed in a water bath, heated to 65°C, stirred for 4.5 h, filtered, washed with anhydrous ethanol three times, and vacuum dried at 65°C for 11 h to obtain modified nano-SiO2.

[0074] Mix 18 g of perfluorohexanone with 0.1 g of perfluoropolyether-based surfactant, continuously stir, add 0.3 g of zinc borate, ultrasonic dispersion, then add 0.5 g of modified nano-SiO2 and 3 g of ZIF-8 loaded with calcium fluoride in sequence, high-speed shearing, add 1.5 g of composite powder, mix uniformly, and then mix with 80 g of heptafluoropropane to obtain heptafluoropropane extinguishing agent.

[0075] Example 7

[0076] Dissolve 12 g of 2-methylimidazole in 200 mL of methanol, mix uniformly to obtain solution A; dissolve 8 g of zinc nitrate in 200 mL of methanol, slowly add solution A, heat to 65 DEG C in a water bath, pass nitrogen, react for 5.5 h, centrifuge, wash, and dry to obtain ZIF-8.

[0077] Add 4 g of calcium fluoride nanoparticles to 200 mL of anhydrous ethanol, disperse to form a suspension, add 16 g of ZIF-8, ultrasonic treatment for 2 h, stand, filter, and dry to obtain ZIF-8 loaded with calcium fluoride.

[0078] Put 9 g of tris(tribromophenoxy)triazine into a pulverizer, pulverize to 3-5 μm, add 1 g of fumed nano-silicon dioxide, dry mix to obtain composite powder.

[0079] Disperse 1 g of nano-SiO2 in a beaker containing 20 mL of hexamethyldisilazane, place the beaker in a water bath, heat to 65 DEG C, stir for 4 h, filter, wash with anhydrous ethanol for three times, and vacuum dry at 60 DEG C for 13 h to obtain modified nano-SiO2.

[0080] Mix 18 g of perfluorohexanone with 0.1 g of perfluoropolyether-based surfactant, continuously stir, add 0.3 g of zinc borate, ultrasonic dispersion, then add 0.5 g of modified nano-SiO2 and 3 g of ZIF-8 loaded with calcium fluoride in sequence, high-speed shearing, add 1.5 g of composite powder, mix uniformly, and then mix with 80 g of heptafluoropropane to obtain heptafluoropropane extinguishing agent.

[0081] The present application also carries out comparative examples and related tests.

[0082] Comparative Example 1

[0083] Comparative Example 1 and Example 1 only differ in that the preparation of ZIF-8 loaded with calcium fluoride is not carried out in Comparative Example 1, only calcium fluoride is used, and other compositions and preparation methods are the same as those of Example 1, and heptafluoropropane extinguishing agent is prepared.

[0084] Comparative Example 2

[0085] The difference between Comparative Example 2 and Example 1 is that the preparation of the composite powder is not carried out in Comparative Example 2, and the other compositions and preparation methods are the same as those in Example 1, and heptafluoropropane extinguishing agent is prepared.

[0086] Comparative Example 3

[0087] The difference between Comparative Example 3 and Example 1 is that perfluorohexanone is not added in Comparative Example 3, and the other compositions and preparation methods are the same as those in Example 1, and heptafluoropropane extinguishing agent is prepared.

[0088] Performance detection test

[0089] The heptafluoropropane extinguishing agents prepared in Examples 1-7 and Comparative Examples 1-3 are respectively used for extinguishing experiments, and the extinguishing object is n-heptane; n-heptane is injected into the combustion disc in the closed combustion chamber, and after ignition, when the flame height is stable, the heptafluoropropane extinguishing agent is sprayed, and the time for the flame to be completely extinguished is recorded, whether there is a reignition phenomenon within 5 minutes after extinguishing is monitored, and the concentrations of HF and CO in the gas after combustion are detected, and the results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from Table 1 above, compared with Example 1, the HF content in the gas after the heptafluoropropane extinguishing agent prepared in Comparative Example 1 is significantly increased, indicating that the ZIF-8 loaded with calcium fluoride can effectively adsorb harmful gases generated during combustion and reduce pollution; after the heptafluoropropane extinguishing agent prepared in Comparative Example 2 is extinguished, reignition occurs, and the extinguishing time is also longer, indicating that the heptafluoropropane extinguishing agent prepared in Comparative Example 2 has a large gap in extinguishing performance compared with Example 1, indicating that the tris(tribromophenoxy)triazine and nano silicon dioxide in the composite powder can effectively improve the extinguishing ability of the heptafluoropropane extinguishing agent and inhibit reignition; the heptafluoropropane extinguishing agent prepared in Comparative Example 3 has a certain degree of decline in extinguishing ability compared with Example 1, indicating that the gas-liquid two-phase system formed by perfluorohexane and heptafluoropropane can promote the heptafluoropropane extinguishing agent to play a better role.

[0093] Example 7 and Example 6, the heptafluoropropane extinguishing agent prepared in Example 7 does not use zinc borate, so the extinguishing time is longer, indicating that the addition of zinc borate can improve the fire-retardant and oxygen-blocking ability of the extinguishing agent, thereby enhancing the extinguishing ability of the extinguishing agent.

[0094] The above is a preferred embodiment of the present application, and those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A process for the preparation of heptafluoropropane fire extinguishant, characterized in that, It comprises the following steps: Step S1, calcium fluoride nanoparticles are added to anhydrous ethanol, after complete dispersion, ZIF-8 is added, ultrasonic treatment, standing, filtration, drying, to obtain ZIF-8 loaded with calcium fluoride; Step S2, tris (tribromophenoxy) triazine is put into a pulverizer for crushing, then fumed nano-silicon dioxide is added for dry mixing, to obtain a composite powder; Step S3, 15-20 parts of perfluorohexanone are mixed with 0.05-0.1 parts of perfluoropolyether surfactant, continuous stirring is performed, 0.2-0.5 parts of zinc borate is added and ultrasonic dispersion is performed, then 0.3-0.8 parts of modified nano-SiO2 and 2-3 parts of ZIF-8 loaded with calcium fluoride are sequentially added, high-speed shearing is performed, and finally 0.5-1.5 parts of the composite powder is added, mixed uniformly, and mixed with 70-80 parts of heptafluoropropane to obtain heptafluoropropane extinguishing agent; The preparation of the modified nano-SiO2 comprises the following steps: nano-SiO2 is dispersed in hexamethyldisilazane, heated and stirred, filtered, washed, and dried to obtain modified nano-SiO2; the temperature of the heating and stirring is 55-65℃, and the time is 4-6h.

2. A process for the preparation of heptafluoropropane fire extinguishant according to claim 1, characterized in that, In the step S1, the preparation of ZIF-8 comprises the following steps: 2-methylimidazole is dissolved in methanol, mixed uniformly to obtain solution A; zinc nitrate is dissolved in methanol, slowly added to solution A, nitrogen is introduced, water bath heating reaction is performed, centrifugation, washing, and drying to obtain ZIF-8.

3. A process for the preparation of heptafluoropropane fire extinguishant according to claim 2, characterized in that, The temperature of the heating reaction is 55-65℃, and the time is 5-7h.

4. A process for the preparation of heptafluoropropane fire extinguishant according to claim 1, characterized in that, In the step S2, the particle size of the crushed tris (tribromophenoxy) triazine is 3-5μm; the mass ratio of tris (tribromophenoxy) triazine to fumed nano-silicon dioxide is (9-12):

1.

5. A process for the preparation of heptafluoropropane fire extinguishant according to claim 1, characterized in that, The temperature of the drying is 60-70℃, and the time is 10-14h.

6. A process for the preparation of heptafluoropropane fire extinguishant according to claim 1, characterized in that, In the step S3, the speed of the continuous stirring is 150-250rpm.

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