Preparation method of fluoroelastomer / Al / CL-20 high-energy aluminum-containing explosive composite

Abstract

This invention discloses a method for preparing a high-energy aluminum-containing explosive composite of fluororubber / Al / CL-20, comprising: coating and modifying nano-Al powder with functional materials to obtain modified nano-Al powder; dissolving fluororubber in solvent A and allowing it to stand to obtain a fluororubber solution; adding hexanitrohexaazaisowulzane explosive CL-20 to the fluororubber solution, dissolving it, adding the modified nano-Al powder, and sonicating to prepare spherical liquid fluororubber / Al / CL-20, then adding deionized water and sonicating to obtain an emulsion; and extracting or freeze-drying the emulsion to obtain a solid spherical fluororubber / Al / CL-20 composite. This invention is based on the Pickering emulsion method, using modified nano-Al particles as an interface stabilizer to form a stable emulsion, resulting in a micron-sized composite containing modified nano-Al powder, fluororubber, and CL-20. This allows for close contact between CL-20 and nano-Al powder, and the high-energy composite explosive retains the unique properties of each material, combines multiple functions, and improves the performance of the composite material.

Description

Technical Field

[0001] This invention belongs to the field of energetic material composite technology, specifically the preparation method of a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite. Background Technology

[0002] Aluminum-containing explosives are mixed explosives composed of explosives and aluminum powder, also known as aluminized explosives. In aluminum-containing explosives, the aluminum powder can undergo a secondary reaction with the detonation products to form aluminum oxide, releasing a large amount of heat. This significantly increases the heat of explosion and work capacity, prolongs the detonation time, expands the blast radius, raises the fragmentation temperature, and promotes the expansion and pressurization of bubbles in water. The most significant characteristic of aluminum-containing explosives is their high heat of explosion and work capacity, giving them promising application prospects.

[0003] Hexanitrohexaazaisowrtzane (CL-20) is currently the highest-energy and most powerful non-nuclear elemental explosive known, with broad application prospects in weaponry and propellants. Aluminum powder of different sizes has been widely used in CL-20-based explosives, but problems such as incomplete combustion and long ignition delay times still exist, resulting in insufficient energy release. To improve the molding and pressing mixing performance of CL-20-based aluminum-containing explosives, some insensitive polymers or insensitive agents are used as binders. Although these have a good insensitive coating effect, they do not significantly improve the detonation heat and combustion reaction of CL-20-based aluminum-containing explosives. Compared with inert binders, the fluorine element in fluororubber can undergo an exothermic chemical reaction with aluminum, and using fluororubber as a binder can significantly improve the detonation heat of aluminum-containing explosives. Commonly used fluororubbers include the F23 and F26 series, which have good high-temperature resistance, aging resistance, and good physical and mechanical properties. These fluororubbers can be used as binders for the molding and pressing of CL-20-based aluminum-containing explosives. Li Jinxin et al. (Li Jinxin, Gou Li, Zhang Zhengzheng et al. Research on CL-20-based high explosive heat aluminum-containing press-fit mixed explosive [J]. Explosive Materials, 2020, 49(03):33-36+42.) improved the binder system and optimized the preparation process and pressing process. The optimal process conditions for mechanical dry mixing were determined to be: mixing temperature 70~85℃, mixing time 20~30min. The optimal process conditions for pressing were determined to be: pressing temperature 85℃, specific pressure 3300 kg / cm³. 2 The holding time is 60 minutes. The maximum pressure density of the new formulation is 2.041 g / cm³. 3It is 6.25% higher than the original formula and has good thermal stability and explosive performance. However, the process conditions are 70~85℃, which poses a certain risk factor in the production process. On the other hand, MACook (Cook MA, Filler A S, Keyes RT, et al. Aluminized explosives[J]. Journal of Physical Chemistry,1957, 61(2):189-196.) believes that when aluminum-containing explosives are detonated, aluminum powder does not participate in the chemical reaction before the CJ plane. Even if aluminum powder participates in the chemical reaction, it is far from fully reacted when it reaches the CJ plane, because the reaction of aluminum powder only begins and gradually completes when the detonation products expand. Hu Hongwei et al. (Hu Hongwei, Yan Jiajia, Chen Lang et al. Effects of aluminum powder content and particle size on the underwater explosion reaction characteristics of CL-20 aluminum explosive [J]. Explosion and Shock, 2017, 37(01):157-161.) Based on MACook, they studied the energy release characteristics of underwater explosion of CL-20-based aluminum explosive by utilizing the pulsation of underwater explosion shock wave and high-pressure gas mass. They tested the shock wave, secondary pressure wave and bubble parameters of its underwater explosion, and studied the effects of aluminum powder content and particle size on the explosion reaction of CL-20-based aluminum explosive. The conclusion was that smaller aluminum powder is more likely to react with the detonation products of the explosive, resulting in a faster reaction rate of the secondary reaction. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite. The core of this invention is to use the Pickering emulsion method to composite CL-20 with nano-Al powder using fluororubber, thereby improving explosive performance, reducing sensitivity, enhancing safety performance, and improving the overall performance of CL-20-based aluminum-containing explosives.

[0005] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0006] To achieve these objectives and other advantages according to the present invention, a method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite is provided, comprising the following steps:

[0007] Step 1: Modify the nano-Al powder by coating it with functional materials to obtain modified nano-Al powder;

[0008] Step 2: Dissolve fluororubber in solvent A, let it stand, and obtain a fluororubber solution;

[0009] Step 3: Add hexanitrosazaisowulzane explosive CL-20 to the fluororubber solution, dissolve it, add modified nano-Al powder, and sonicate to prepare spherical liquid fluororubber / Al / CL-20. Then add deionized water and sonicate again to obtain an emulsion.

[0010] Step 4: Extract or freeze-dry the emulsion to obtain a solid spherical fluororubber / Al / CL-20 composite.

[0011] Preferably, in step one, the size of the nano-Al powder is 20-500 nanometers, and the morphology is spherical or other irregular shape.

[0012] Preferably, the process in step one is as follows: dissolve the functional material in solvent B, then add nano-Al powder, stir at room temperature, slowly add cyclohexane, react for 0.5 to 2 hours, filter, and vacuum dry to obtain modified nano-Al powder.

[0013] Preferably, the solvent B is ethyl acetate or ethanol; the mass-to-volume ratio of the functional material to solvent B is 0.01~0.3g:100mL; and the mass-to-volume ratio of the nano-Al powder to cyclohexane is 3~8g:1000mL.

[0014] Preferably, in step one, the functional material is any one of stearic acid, palmitic acid, perfluorooctanoic acid, perfluoroheptanoic acid, perfluorohexanoic acid, perfluoropentanoic acid, perfluorobutyric acid, perfluorododecanoic acid, and perfluorotridecanoic acid, and the amount of the functional material is 0.01% to 5% of the mass of the nano-Al powder.

[0015] Preferably, in step two, solvent A is one or more of ethyl acetate, butyl acetate, isoamyl acetate, acetone, n-butyl ketone, methyl isobutyl ketone, cyclohexane, n-butane, cyclohexanone, toluenecyclohexanone, methyl butyl ketone, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, carbon tetrachloride, benzene, toluene, xylene, dimethyl sulfoxide, N,N-dimethylformamide, diethyl ether, petroleum ether, propylene oxide, ethylene glycol ether, and acetonitrile; the mass-to-volume ratio of the fluororubber to solvent A is 0.015~0.05g:2mL; and the standing time is 2~5 hours.

[0016] Preferably, in step two, the fluororubber is any one of the following: a binary copolymer of hexafluoropropylene and vinylidene fluoride; a ternary copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride; a ternary copolymer of tetrafluoroethylene, fluorinated vinyl ether, and vinylidene fluoride; a ternary copolymer of tetrafluoroethylene, propylene, and vinylidene fluoride; or a pentadienomer of tetrafluoroethylene, hexafluoropropylene, ethylene, fluorinated vinyl ether, and vinylidene fluoride.

[0017] Preferably, the mass ratio of the fluororubber to the nano-Al powder is 0.1:1 to 1:10.

[0018] Preferably, the mass ratio of the fluororubber to CL-20 is 0.01:1 to 1:1.

[0019] Preferably, in step four, the extraction is performed by adding a non-solvent, and the amount of non-solvent is 0.01 to 100 times the mass of the solvent; the freeze-drying method is as follows: the emulsion is placed in a freezer at -50°C to rapidly solidify it, and then placed in a freeze dryer to dry for 12 to 36 hours.

[0020] Preferably, in step one, the nano-Al powder undergoes low-temperature plasma treatment, the process of which is as follows: the nano-Al powder is fed into an atmospheric pressure low-temperature plasma device, positioning the nano-Al powder 30-80 mm from the jet outlet of the atmospheric pressure low-temperature plasma. A gas medium is introduced into the atmospheric pressure low-temperature plasma device at a flow rate of 10-15 L / h, a working voltage is applied to form a plasma jet, and the moving speed of the jet outlet of the atmospheric pressure low-temperature plasma device is controlled at 10-15 mm / s, so that the plasma jet is sprayed onto the nano-Al powder, and the nano-Al powder is treated for 15-25 minutes. The working voltage is provided by a high-voltage AC power supply, the working voltage being 50-100 kV AC voltage with a frequency of 100-300 kHz; the gas medium is CF4 or CCl4.

[0021] This invention introduces the Pickering emulsion method, using nano-sized aluminum powder particles as an interface stabilizer. Under room temperature conditions, fluororubber and CL-20 are compounded with nano-Al powder in solution form to obtain a solid spherical fluororubber / Al / CL-20 composite. This allows the three components to be uniformly compounded at the microscale, enabling more stable energy release during combustion or detonation. At the same time, the spherical structure can reduce the sensitivity of CL-20 while improving flowability and packing density. This composite has broad application prospects in high-energy propellants and explosives.

[0022] The present invention has at least the following beneficial effects:

[0023] This invention is based on the Pickering emulsion method, using modified nano-Al particles as an interface stabilizer to form a stable emulsion, resulting in a micron-sized composite containing modified nano-Al powder, fluororubber, and CL-20. This allows for close contact between CL-20, nano-Al powder, and the composite material, and the high-energy composite explosive retains the unique properties of each material, combines multiple functions, and improves the performance of the composite material. This invention features a simple preparation process, low cost, and safe production process; the solid spherical fluororubber / Al / CL-20 composite obtained using this method has a particle size range of 30~50 μm.

[0024] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0025] Figure 1 The images shown are SEM, TEM, and EDS images of the nano-Al powder and modified nano-Al powder prepared in Example 1 of this invention. (a) is the SEM image of the nano-Al powder; (b) is the TEM image of the nano-Al powder; (c) and (d) are the TEM images of the modified nano-Al powder; and (e) is the EDS image of the modified nano-Al powder.

[0026] Figure 2 These are optical microscope images of the emulsion stability in Example 1 of this invention, wherein (a) is an emulsion prepared from nano-Al powder; (b) is a microscope image of the emulsion in Example 1; (c) is a microscope image of the emulsion in Example 2; and (d) is a microscope image of the emulsion in Example 3.

[0027] Figure 3 The images shown are SEM images of CL-20, nano-Al powder raw materials and the prepared composite in Example 1 of this invention, wherein (a) is an SEM image of CL-20 raw material; (b) is an SEM image of nano-Al powder raw material; (c) is an SEM image of fluororubber / Al / CL-20 composite; and (d) is an SEM image of the surface of fluororubber / Al / CL-20 composite. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0029] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not imply the presence or addition of one or more other elements or combinations thereof.

[0030] Example 1:

[0031] A method for preparing a high-energy aluminum-containing explosive based on a fluororubber / Al / CL-20 composite includes the following steps:

[0032] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0033] Step 2: Take 0.0250g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0034] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0035] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0036] In this invention, the impact sensitivity characteristic drop height H50 of the raw material CL-20 is 13cm, and the friction sensitivity explosion probability is 100%; while the characteristic drop height H50 of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 1 is 22cm, and the explosion probability is 92%, which shows that the mechanical safety performance of the material is significantly improved.

[0037] The sample (raw material CL-20 or the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 1) was placed in a 2*2*2 mm aluminum trough, and then photographed with a camera to record the burning time and burning length. The burning rate of the raw material CL-20 was found to be 4.3 cm / s, while the burning rate of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 1 was increased by 80% compared with the raw material.

[0038] Example 2:

[0039] A method for preparing a high-energy aluminum-containing explosive based on a fluororubber / Al / CL-20 composite includes the following steps:

[0040] Step 1: Low-temperature plasma treatment of nano-Al powder. The process is as follows: Nano-Al powder is fed into an atmospheric pressure low-temperature plasma device, positioned 50 mm from the plasma jet outlet. A gas medium is introduced into the device at a flow rate of 10 L / h. A working voltage is applied to form a plasma jet. The moving speed of the plasma jet outlet is controlled at 15 mm / s, allowing the plasma jet to spray onto the nano-Al powder. The nano-Al powder is treated for 15 minutes. The working voltage is provided by a high-voltage AC power supply, specifically 100 kV AC voltage at a frequency of 300 kHz. The gas medium is CF4. Low-temperature plasma treatment alters the morphology of the nano-Al powder, increases its surface functional groups, and facilitates the coating and modification of the nano-Al powder by functional materials. This, in turn, improves the performance of the prepared fluororubber / Al / CL-20 composite high-energy aluminum-containing explosive.

[0041] 0.05 g of perfluorododecanoic acid was dissolved in 100 mL of ethyl acetate. 5 g of nano-Al powder treated with low-temperature plasma was dispersed in the above solution. The mixture was stirred at room temperature, and 1000 mL of cyclohexane was slowly added dropwise. The reaction was carried out for 1 h, filtered, and dried under vacuum to obtain the F-Al complex.

[0042] Step 2: Take 0.0250g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0043] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0044] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0045] In this invention, the impact sensitivity characteristic drop height H50 of the raw material CL-20 is 13cm, and the friction sensitivity explosion probability is 100%; while the characteristic drop height H50 of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 2 is 23cm, and the explosion probability is 90%, which shows that the mechanical safety performance of the material is significantly improved.

[0046] The sample (raw material CL-20 or the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 2) was placed in a 2*2*2 mm aluminum trough, and then photographed with a camera to record the burning time and burning length. The burning rate of the raw material CL-20 was found to be 4.3 cm / s, while the burning rate of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 2 was increased by 82% compared with the raw material.

[0047] Example 3:

[0048] A method for preparing a high-energy aluminum-containing explosive based on a fluororubber / Al / CL-20 composite includes the following steps:

[0049] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0050] Step 2: Add 0.0250g F2605 and 2 ml ethyl acetate to a supercritical carbon dioxide reactor, introduce carbon dioxide to form supercritical carbon dioxide for swelling treatment, depressurize, and obtain fluororubber solution; the pressure reached by introducing carbon dioxide is 15MPa, and the treatment is carried out at 40℃ for 90min, with a depressurization rate of 0.1MPa / min;

[0051] Step 3: Take 1.0004g of CL-20 and 0.025g of the modified nano-Al powder (F-Al composite) from Step 1 and add it to the above fluororubber solution. Then, introduce carbon dioxide again to form supercritical carbon dioxide for dispersion treatment. Depressurize, sonicate for 20 minutes, add 10 ml of deionized water, and sonicate for another 20 minutes to obtain a gray emulsion. The carbon dioxide pressure reached was 15MPa, and the treatment was carried out at 35℃ for 90 minutes, with a depressurization rate of 0.1MPa / min.

[0052] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0053] In this invention, the impact sensitivity characteristic drop height H50 of the raw material CL-20 is 13cm, and the friction sensitivity explosion probability is 100%; while the characteristic drop height H50 of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 3 is 24cm, and the explosion probability is 89%, which shows that the mechanical safety performance of the material is significantly improved.

[0054] The sample (raw material CL-20 or the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 3) was placed in a 2*2*2 mm aluminum trough, and then photographed with a camera to record the burning time and burning length. The burning rate of the raw material CL-20 was found to be 4.3 cm / s, while the burning rate of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 3 was increased by 83% compared with the raw material.

[0055] Example 4:

[0056] A method for preparing a high-energy aluminum-containing explosive based on a fluororubber / Al / CL-20 composite includes the following steps:

[0057] Step 1: Low-temperature plasma treatment of nano-Al powder. The process is as follows: Nano-Al powder is fed into an atmospheric pressure low-temperature plasma device, positioned 50 mm from the plasma jet outlet. A gas medium is introduced into the device at a flow rate of 10 L / h. A working voltage is applied to form a plasma jet. The moving speed of the plasma jet outlet is controlled at 15 mm / s, allowing the plasma jet to spray onto the nano-Al powder. The nano-Al powder is treated for 15 minutes. The working voltage is provided by a high-voltage AC power supply, specifically 100 kV AC voltage at a frequency of 300 kHz. The gas medium is CF4. Low-temperature plasma treatment alters the morphology of the nano-Al powder, increases its surface functional groups, and facilitates the coating and modification of the nano-Al powder by functional materials. This, in turn, improves the performance of the prepared fluororubber / Al / CL-20 composite high-energy aluminum-containing explosive.

[0058] Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and dry under vacuum to obtain F-Al complex;

[0059] Step 2: Add 0.0250g F2605 and 2 ml ethyl acetate to a supercritical carbon dioxide reactor, introduce carbon dioxide to form supercritical carbon dioxide for swelling treatment, depressurize, and obtain fluororubber solution; the pressure reached by introducing carbon dioxide is 15MPa, and the treatment is carried out at 40℃ for 90min, with a depressurization rate of 0.1MPa / min;

[0060] Step 3: Take 1.0004g of CL-20 and 0.025g of the modified nano-Al powder (F-Al composite) from Step 1 and add it to the above fluororubber solution. Then, introduce carbon dioxide again to form supercritical carbon dioxide for dispersion treatment. Depressurize, sonicate for 20 minutes, add 10 ml of deionized water, and sonicate for another 20 minutes to obtain a gray emulsion. The carbon dioxide pressure reached was 15MPa, and the treatment was carried out at 35℃ for 90 minutes, with a depressurization rate of 0.1MPa / min.

[0061] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0062] In this invention, the impact sensitivity characteristic drop height H50 of the raw material CL-20 is 13cm, and the friction sensitivity explosion probability is 100%; while the characteristic drop height H50 of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 4 is 28cm, and the explosion probability is 85%, which shows that the mechanical safety performance of the material is significantly improved.

[0063] The sample (raw material CL-20 or the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 4) was placed in a 2*2*2 mm aluminum trough, and then photographed with a camera to record the burning time and burning length. The burning rate of the raw material CL-20 was found to be 4.3 cm / s, while the burning rate of the fluororubber / Al / CL-20 composite high-energy aluminum explosive prepared in Example 4 was increased by 86% compared with the raw material.

[0064] Example 5:

[0065] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0066] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0067] Step 2: Take 0.0350g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0068] Step 3: Dissolve 1.4000g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.035g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0069] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0070] Example 6:

[0071] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0072] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0073] Step 2: Take 0.0250g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0074] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 30 min to obtain a gray emulsion.

[0075] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0076] Example 7:

[0077] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0078] Step 1: Dissolve 0.25 g palmitic acid in 100 mL ethanol, disperse 5 g nano Al powder in the above solution, stir at room temperature, slowly add 1000 mL cyclohexane, react for 1 h, filter and vacuum dry to obtain modified nano Al powder;

[0079] Step 2: Take 0.0500g of F2601 and swell it in 2 ml of ethyl acetate, then let it stand for 3 hours;

[0080] Step 3: Dissolve 2.0000g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0500g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 14 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0081] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water, heat to 75~80℃, wait for the ethyl acetate to completely evaporate, dry and filter to obtain the complex.

[0082] Example 8:

[0083] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0084] Step 2: Take 0.0250g of F2311 and swell it in 2 ml of ethyl acetate, then let it stand for 3 hours;

[0085] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0250g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0086] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0087] Example 9:

[0088] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0089] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0090] Step 2: Take 0.0450g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0091] Step 3: Dissolve 0.1800g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0450g of the modified nano-Al powder from Step 1 and sonicate for 30 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0092] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0093] Example 10:

[0094] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0095] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0096] Step 2: Take 0.0250g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0097] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0098] Step 4: Immediately place the emulsion obtained in Step 3 into a freezer at -50°C to allow it to solidify rapidly, and then place it in a freeze dryer to dry for 24 hours to obtain the complex.

[0099] Example 11:

[0100] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0101] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0102] Step 2: Take 0.0250g of F2605, swell it in 2 ml of dichloroethane, and let it stand for 3 hours;

[0103] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0104] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash away the dichloroethane, dry and filter to obtain the complex.

[0105] Example 12:

[0106] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0107] Step 1: Dissolve 0.05 g of perfluoroheptanoic acid in 100 mL of ethanol, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0108] Step 2: Take 0.0150g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0109] Step 3: Dissolve 0.0600g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0150g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0110] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0111] Example 13:

[0112] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0113] Step 1: Dissolve 0.05 g of perfluorododecanoic acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0114] Step 2: Take 0.0150g of F2311 and swell it in 2 ml of ethyl acetate, then let it stand for 3 hours;

[0115] Step 3: Dissolve 0.0600g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0150g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 10 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0116] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0117] Example 14:

[0118] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0119] Step 1: Dissolve 0.05 g of stearic acid in 100 mL of ethanol, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain nano-Al powder with adjusted lipophilicity and hydrophilicity.

[0120] Step 2: Take 0.0250g of F2605, swell it in 2 ml of ethyl acetate, and let it stand for 3 hours;

[0121] Step 3: Dissolve 1.0004g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.0250g of the modified nano-Al powder from Step 1 and sonicate for 20 minutes. After the modified nano-Al powder is dispersed in the solution, add 10ml of deionized water and sonicate for 20 minutes to obtain a gray emulsion.

[0122] Step 4: Pour the emulsion obtained in Step 3 into 500 ml of deionized water for extraction. Wait for the complex to precipitate to the bottom of the cup, discard the supernatant, wash with deionized water 2-3 times, wash with ethyl acetate, dry and filter to obtain the complex.

[0123] Example 15:

[0124] A method for preparing a fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite includes the following steps:

[0125] Step 1: Dissolve 0.05 g of perfluorobutyric acid in 100 mL of ethyl acetate, disperse 5 g of nano-Al powder in the above solution, stir at room temperature, slowly add 1000 mL of cyclohexane, react for 1 h, filter and vacuum dry to obtain F-Al complex;

[0126] Step 2: Take 0.0250g of F2601 and swell it in 2 ml of ethyl acetate, then let it stand for 3 hours;

[0127] Step 3: Dissolve 1.0000g of CL-20 in the above solution and wait for it to completely dissolve. Then add 0.025g of the modified nano-Al powder from Step 1 and sonicate for 20 min. After the modified nano-Al powder is dispersed in the solution, add 14 ml of deionized water and sonicate for 20 min to obtain a gray emulsion.

[0128] Step 4: Immediately place the emulsion obtained in Step 3 into a freezer at -50°C to allow it to solidify rapidly, and then place it in a freeze dryer to dry for 24 hours to obtain the complex.

[0129] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a fluoroelastomer / Al / CL-20 high energy aluminized explosive composite, characterized in that, It comprises the following steps: Step one, the functional material is used to coat and modify the nano Al powder, and the modified nano Al powder is obtained; Step two, the fluororubber and solvent A are added into the supercritical carbon dioxide reactor, carbon dioxide is introduced to form supercritical carbon dioxide for swelling treatment, pressure relief, and fluororubber solution is obtained; the solvent A is one or more of ethyl acetate, butyl acetate, isoamyl acetate, acetone, n-butanone, methyl isobutyl ketone, cyclohexane, n-butane, cyclohexanone, toluene cyclohexanone, methyl butanone, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, carbon tetrachloride, benzene, toluene, xylene, dimethyl sulfoxide, N,N dimethylformamide, diethyl ether, petroleum ether, propylene oxide, ethylene glycol ether, acetonitrile; Step three, the hexanitrohexaazaisowurtzitane explosive CL-20 and the modified nano Al powder are added into the fluororubber solution, supercritical carbon dioxide is introduced again for dispersion treatment, pressure relief, ultrasonic treatment, and then deionized water is added and ultrasonic treatment is performed; an emulsion is obtained; the pressure reached by introducing carbon dioxide is 10-15 MPa, and the treatment is performed at a temperature of 35-40℃, and the pressure relief speed is 0.1-0.5 MPa / min; Step four, the emulsion is extracted or freeze-dried to obtain a solid spherical fluororubber / Al / CL-20 composite.

2. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, In step one, the size of the nano Al powder is 20-500 nanometers, and the morphology is spherical or other irregular shapes.

3. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, In step one, the process is as follows: the functional material is dissolved in solvent B, then the nano Al powder is added, stirring is performed at room temperature, cyclohexane is slowly added dropwise, reaction is performed for 0.5-2 hours, filtration is performed, and vacuum drying is performed to obtain the modified nano Al powder; the solvent B is ethyl acetate or ethanol.

4. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 3, characterized in that, The mass-volume ratio of the functional material to solvent B is 0.01-0.3 g:100 mL; the mass-volume ratio of the nano Al powder to cyclohexane is 3-8 g:1000 mL.

5. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1 or 3, characterized in that, In step one, the functional material is any one of stearic acid, palmitic acid, perfluorooctanoic acid, perfluoroheptanoic acid, perfluorohexanoic acid, perfluoropentanoic acid, perfluorobutyric acid, perfluorododecanoic acid, and perfluorotridecanoic acid, and the amount of the functional material is 0.01%-5% of the mass of the nano Al powder.

6. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, In step two, the mass-volume ratio of the fluororubber to solvent A is 0.015-0.05 g:2 mL.

7. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, In step two, the fluororubber is any one of a binary copolymer of hexafluoropropylene and vinylidene fluoride, a ternary copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride, a ternary copolymer of tetrafluoroethylene, fluorine-containing vinyl ether, and vinylidene fluoride, a ternary copolymer of tetrafluoroethylene, propylene, and vinylidene fluoride, and a quinary copolymer of tetrafluoroethylene, hexafluoropropylene, ethylene, fluorine-containing vinyl ether, and vinylidene fluoride.

8. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, The mass ratio of the fluororubber to the nano Al powder is 0.1:1-1:10; the mass ratio of the fluororubber to CL-20 is 0.01:1-1:

1.

9. The preparation method of the fluororubber / Al / CL-20 high-energy aluminum-containing explosive composite as described in claim 1, characterized in that, The extraction in the fourth step adopts a method of adding non-solvent, and the amount of non-solvent is 0.01-100 times of the mass of solvent; the freeze-drying method is: the emulsion is placed in a freezer at-50℃ to make it freeze quickly, and then is placed in a freeze dryer to dry for 12-36h.

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