Application method of high-efficiency desensitization of micro-nano high-energy explosive

Abstract

The application belongs to the technical field of energetic materials, and particularly relates to a micro-nano high-energy explosive high-efficiency desensitization application method. High-energy explosives CL-20, HMX and NC are used as raw materials, and a solvent-non-solvent method is adopted. After micro-nano particle size CL-20 / HMX eutectic explosive is prepared, the modified eutectic explosive is prepared through NC coating modification. The modified eutectic explosive prepared by the application has uniform particle size, good coating effect, relatively narrow particle size distribution, and significantly reduced mechanical sensitivity, and presents high-energy and insensitive characteristics. The application has simple process, convenient operation, safety and reliability, high yield, and is easy to industrialize. The application can effectively improve the dispersion uniformity of micro-nano particles, and prepare micro-nano eutectic explosive with better performance.

Description

Technical Field

[0001] This invention belongs to the technical field of energetic materials, specifically relating to an application method for efficiently reducing the sensitivity of micro-nano high-energy explosives. Background Technology

[0002] Micro- and nano-energetic materials possess both excellent energy density and safety performance, making them core energetic components for enhancing the overall performance of weapon systems. However, limited by their high specific surface area and strong interfacial interactions, these micro- and nano-particles are prone to aggregation and difficult to disperse in applications, reducing the processability of weapon systems. Surface modification technology can effectively improve the interfacial compatibility of micro- and nano-energetic materials, overcoming the defect of excessively high sensitivity in primary explosives and optimizing their performance. This provides a new path to resolving the contradiction between energy and safety in energetic materials, and is of great significance for improving the overall performance of explosives. Among these technologies, the co-crystallization of high- and low-sensitivity energetic materials holds promise for producing low-sensitivity energetic materials while ensuring the expected performance.

[0003] Surface coating modification is considered the most widely used and preferred solution due to its strong process controllability, high operational safety, and significant cost-effectiveness. For different application scenarios, there is a variety of coating agents and preparation methods for energetic materials. The choice of coating agent directly determines the coating effect, modification efficiency, and final application performance of the material. Polymers are the most widely used coating agents in the coating and modification of micro- and nano energetic materials. However, most of these coating agents are inert components, and their extensive use can lead to a decrease in the energy output of the energetic system, resulting in a certain energy loss and limiting their application in high-energy demand scenarios. Inorganic nanomaterial coating agents occupy an important position in the coating and modification of micro- and nano energetic materials due to their excellent thermal stability. However, these coating agents have obvious defects. The interfacial compatibility between inorganic particles and organic energetic matrices is poor, which can easily lead to interfacial separation and defects. In addition, the inorganic particles themselves have poor dispersibility and are prone to agglomeration, making it difficult to control the coating uniformity. Composite coating agents have a complex preparation process, requiring multiple steps of synergistic reaction. They have high requirements for the controllability of process parameters, and the preparation cost is significantly higher than that of single coating agents, which is not conducive to industrial-scale production. Furthermore, the relationship between their structure and performance is complex, and related theoretical research still needs to be further deepened. Metal / metal compound coating agents are mainly used to regulate the reactivity of micro- and nano energetic materials. However, these coating agents have the problem of poor stability. Metal nanoparticles are easily oxidized, which affects the coating effect and the storage stability of the material. In addition, the preparation cost is high. Furthermore, the coating process is complex and it is difficult to achieve uniform coating on the surface of micro- and nano energetic materials, which limits their large-scale application. Summary of the Invention

[0004] The purpose of this invention is to design an efficient desensitization method for micro / nano high-energy explosives, and to prepare nitrocellulose (NC) coated and modified micro / nano CL-20 / HMX, wherein 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowrutzane (CL-20) and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) are high-energy desensitization eutectic explosives, aiming to achieve effects such as narrow particle size distribution, smooth surface, uniform particle size, and significantly improved mechanical sensitivity, providing a new method for the modification research of energetic materials.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A highly efficient desensitization method for micro / nano high-energy explosives is proposed, which uses a solvent-non-solvent method to prepare high-energy desensitization NC-coated modified micro / nano CL-20 / HMX eutectic explosives.

[0007] A method for efficiently reducing the sensitivity of micro / nano high-energy explosives includes:

[0008] Step (1): Add CL-20 and HMX to an organic solvent in the specified molar ratio, dissolve by sonication, and filter to obtain a CL-20 / HMX mixed solution;

[0009] Step (2): Prepare a certain volume of non-solvent methanol-water solution in a flat-bottomed open-jacketed glass reactor;

[0010] Step (3): Turn on the magnetic stirrer and constant temperature water bath. After the water temperature is constant, add the CL-20 / HMX mixed solution from step (1) to the non-solvent solution from step (2), start timing immediately and continue stirring for 3 hours.

[0011] Step (4): The suspension obtained in step (3) is centrifuged, filtered and dried to obtain micro-nano CL-20 / HMX eutectic explosive;

[0012] Step (5): Dissolve NC in methanol and add dispersant cyclohexane;

[0013] Step (6): Add the micro / nano CL-20 / HMX eutectic explosive obtained in step (4) to the mixed solution obtained in step (5) and place it in a constant temperature water bath, then turn on the stirring.

[0014] Step (7): Pump the cyclohexane solution of n-octanol into the mixture obtained in step (6) using a peristaltic pump;

[0015] Step (8): Wash the precipitate obtained in step (7) with n-heptane, dry it, and obtain NC-coated modified micro / nano CL-20 / HMX eutectic explosive.

[0016] Furthermore,

[0017] In step (1), the molar ratio of CL-20 and HMX is 2:1, the organic solvent is DMSO, the sonication time is 5 min, and the solution concentration is 50 mg·ml-1.

[0018] In step (2), the volume ratio of methanol and deionized water is 1:1, and the volume of the prepared non-solvent solution is 40~160ml.

[0019] The water bath temperature in step (3) is -10 ~ -30℃, and the stirring speed is 0 ~ 600rpm.

[0020] In step (4), the centrifugation rate is 5000 ~ 6500 rpm, the duration is 10 ~ 20 min, the filter membrane used for vacuum filtration is 0.03 ~ 0.05 μm, and the freeze drying is carried out at a temperature of -50 ~ -60℃ for 8 h.

[0021] In step (5), the concentration of the methanol solution of NC is 0.05 ~ 0.1 g·ml-1; the dispersant is cyclohexane, and the volume ratio of methanol to cyclohexane is 1:2.

[0022] The stirring rate in step (6) is 500 ~ 650 rpm and the water bath temperature is -5 ~ 5℃.

[0023] The peristaltic rate in step (7) is 0.5 ~ 1 ml / min, the volume ratio of n-octanol to cyclohexane is 1:1, and the volume ratio of the cyclohexane solution of n-octanol to the methanol solution of NC is 2:1.

[0024] Compared with the prior art, the significant advantages of this invention are:

[0025] (1) This method significantly reduces the mechanical sensitivity of CL-20 by using HMX eutectic method and one-step coating with energetic material.

[0026] (2) The NC-coated desensitizing particles prepared by this method further reduce the sensitivity of energetic materials and exhibit the characteristics of high-energy insensitivity. Attached Figure Description

[0027] Figure 1 Scanning electron microscope (SEM) images of the micro / nano eutectic particles before and after NC coating modification.

[0028] Figure 2 DSC test curves of micro / nano eutectic particles before and after NC coating modification.

[0029] Figure 3 The TG test curves are shown for the micro / nano eutectic particles before and after NC coating modification.

[0030] Figure 4 XRD patterns of micro / nano eutectic particles before and after NC coating modification. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] The preparation of an NC-coated modified micro / nano CL-20 / HMX eutectic explosive according to the present invention includes the following steps:

[0033] Step (1): Add CL-20 and HMX to an organic solvent in the specified molar ratio, dissolve by sonication, and filter to obtain a CL-20 / HMX mixed solution;

[0034] Step (2): Prepare a certain volume of non-solvent methanol-water solution in a flat-bottomed open-jacketed glass reactor;

[0035] Step (3): Turn on the magnetic stirrer and constant temperature water bath. After the water temperature is constant, add the CL-20 / HMX mixed solution from step (1) to the non-solvent solution from step (2), start timing immediately and continue stirring for 3 hours.

[0036] Step (4): The suspension obtained in step (3) is centrifuged, filtered and dried to obtain micro-nano CL-20 / HMX eutectic explosive;

[0037] Step (5): Dissolve NC in methanol and add dispersant cyclohexane;

[0038] Step (6): Add the micro / nano CL-20 / HMX eutectic explosive obtained in step (4) to the mixed solution obtained in step (5) and place it in a constant temperature water bath, then turn on the stirring.

[0039] Step (7): Pump the cyclohexane solution of n-octanol into the mixture obtained in step (6) using a peristaltic pump;

[0040] Step (8): Wash the precipitate obtained in step (7) with n-heptane, dry it, and obtain NC-coated modified micro / nano CL-20 / HMX eutectic explosive.

[0041] The present invention provides a specific implementation method in which the molar ratio of CL-20 and HMX in step (1) is 2:1, the organic solvent is DMSO, the ultrasonic time is 5 min, and the solution concentration is 50 mg·ml-1.

[0042] The present invention provides a specific implementation method in which the volume ratio of methanol and deionized water in step (2) is 1:1, and the volume of the non-solvent solution prepared is 40 ~ 160 ml.

[0043] The present invention provides a specific implementation method in which the water bath temperature in step (3) is -10 ~ -30℃ and the stirring rate is 0 ~ 600rpm.

[0044] The present invention provides a specific implementation method in which the centrifugation rate in step (4) is 5000 ~ 6500 rpm, the duration is 10 ~ 20 min, the filter membrane used for vacuum filtration is 0.03 ~ 0.05 μm, and the freeze drying is carried out at a temperature of -50 ~ -60℃ for 8 h.

[0045] The present invention provides a specific implementation method in which the concentration of methanol solution of NC in step (5) is 0.05 ~ 0.1 g·ml-1; the dispersant is cyclohexane, and the volume ratio of methanol to cyclohexane is 1:2.

[0046] The present invention provides a specific implementation method in which the stirring rate in step (6) is 500 ~ 650 rpm and the water bath temperature is -5 ~ 5℃.

[0047] The present invention provides a specific implementation method in which the peristaltic rate in step (7) is 0.5 ~ 1 ml / min, the volume ratio of n-octanol to cyclohexane is 1:1, and the volume ratio of the cyclohexane solution of n-octanol to the methanol solution of NC is 2:1.

[0048] like Figure 1 As shown, Figure 1 (a) is a scanning electron microscope image of the micro / nano eutectic particles before NC coating modification. Figure 1 (b) is a scanning electron microscope image of the micro / nano eutectic particles after NC coating modification. Before coating, the micro / nano CL-20 / HMX eutectic particles have a smooth and regular surface, exhibiting a rhombic shape and relatively dense packing. After coating, the micro / nano CL-20 / HMX eutectic particles show good coating effect, with obvious adhesion and film coating on the particle surface, and the particles are significantly more dispersed than before coating.

[0049] like Figure 2 As shown, the NC coating modification was performed at different heating rates (5, 10, 15, 20 °C·min). -1The DSC curves are shown in Figure (a). Before 200 ℃, the micro / nano eutectic explosives are very stable, with no exothermic or endothermic processes, indicating that there is no crystal transformation of CL-20 / HMX. After 230 ℃, a single exothermic peak appears, corresponding to the thermal decomposition of the micro / nano CL-20 / HMX eutectic. In Figure (b), the curve is stable before 180 ℃, with no small endothermic peak, proving that there is no crystal transformation during the heating process and the micro / nano eutectic after coating is stable. When the temperature rises to about 230 ℃, a clear decomposition exothermic peak appears. The exothermic peak belongs to the decomposition exothermic peak of the eutectic in the sample, and the decomposition peak temperature shifts towards higher temperatures with the increase of the heating rate.

[0050] like Figure 3 As shown in the TG curves of the micro-nano eutectic particles before and after NC coating modification, the thermal decomposition distribution of NC can be seen. Before 200℃, the NC-coated sample continuously loses weight, and the weight change is consistent with the NC coating situation, which also proves that NC coating is successful.

[0051] Depend on Figure 4 It is evident that the diffraction peak positions of the NC-coated modified sample are basically consistent with those of the raw material, indicating that after the in-situ polymerization reaction, the CL-20 / HMX eutectic in the modified sample still maintains the typical diffraction peaks of the original crystal, and the crystal structure remains unchanged. However, at the same time, it can be observed that the diffraction peak intensity of the NC-coated modified sample is significantly lower than that of the raw material. The reason for this may be that NC is amorphous, and after being coated on the surface of CL-20 / HMX, it interferes with the X-ray diffraction signal of the CL-20 / HMX crystal. This also indirectly demonstrates that CL-20 / HMX is effectively coated by NC.

[0052] This invention provides a method for efficiently reducing the sensitivity of micro / nano high-energy explosives. The eutectic explosive prepared by this invention has a smooth surface, uniform particle size, significantly improved mechanical sensitivity, and exhibits high-energy desensitization characteristics. This invention features a simple process, convenient operation, safety, reliability, high yield, and is easily industrialized.

[0053] Although the invention has been described herein with reference to illustrative embodiments, these embodiments are merely preferred embodiments of the invention, and the implementation of the invention is not limited to these embodiments. It should be understood that those skilled in the art can devise many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the disclosure, drawings, and claims of this application, various modifications and improvements can be made to the components and / or layout of the main body assembly layout. Besides modifications and improvements to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A method for efficiently reducing the sensitivity of micro / nano high-energy explosives, characterized in that, The method includes: using high-energy explosives CL-20, HMX, and NC as raw materials, and employing a solvent-non-solvent method to prepare micro / nano-sized CL-20 / HMX eutectic explosives, followed by NC coating modification to obtain NC-modified CL-20 / HMX eutectic explosives.

2. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 1, characterized in that, The solvents for CL-20 and HMX are dimethyl sulfoxide and an aqueous solution of methanol, with a volume ratio of 1:1; the solvent for NC is methanol and the non-solvent is n-octanol; and the dispersant for the NC coating process is cyclohexane.

3. A method for efficiently reducing the sensitivity of micro / nano high-energy explosives, characterized in that, include: Step (1): Add CL-20 and HMX to an organic solvent in the specified molar ratio, dissolve by sonication, and filter to obtain a CL-20 / HMX mixed solution; Step (2): Prepare a certain volume of non-solvent methanol-water solution in a flat-bottomed open-jacketed glass reactor; Step (3): Turn on the magnetic stirrer and constant temperature water bath. After the water temperature is constant, add the CL-20 / HMX mixed solution from step (1) to the non-solvent solution from step (2), start timing immediately and continue stirring for 3 hours. Step (4): The suspension obtained in step (3) is centrifuged, filtered and dried to obtain micro-nano CL-20 / HMX eutectic explosive; Step (5): Dissolve NC in methanol and add dispersant cyclohexane; Step (6): Add the micro / nano CL-20 / HMX eutectic explosive obtained in step (4) to the mixed solution obtained in step (5) and place it in a constant temperature water bath, then turn on the stirring. Step (7): Pump the cyclohexane solution of n-octanol into the mixture obtained in step (6) using a peristaltic pump; Step (8): Wash the precipitate obtained in step (7) with n-heptane, dry it, and obtain NC-coated modified micro / nano CL-20 / HMX eutectic explosive.

4. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (1), the molar ratio of CL-20 to HMX is 2:1, the organic solvent used is DMSO, the sonication time is 5 min, and the solution concentration is 50 mg·ml. -1 .

5. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (2), the volume ratio of methanol and deionized water is 1:1, and the volume of the prepared non-solvent solution is 40 ~ 160 ml.

6. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (3), the water bath temperature is -10 ~ -30℃ and the stirring speed is 0 ~ 600rpm.

7. The method for efficient desensitization of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (4), the centrifugation rate is 5000 ~ 6500 rpm, the duration is 10 ~ 20 min, the filter membrane used for vacuum filtration is 0.03 ~ 0.05 μm, and the freeze drying is carried out at a temperature of -50 ~ -60℃ for 8 h.

8. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (5), the concentration of the methanol solution of NC is 0.05 ~ 0.1 g·ml. -1 The dispersant is cyclohexane, and the volume ratio of methanol to cyclohexane is 1:

2.

9. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (6), the stirring rate is 500 ~ 650 rpm and the water bath temperature is -5 ~ 5℃.

10. The method for efficiently reducing the sensitivity of micro / nano high-energy explosives as described in claim 3, characterized in that, In step (7), the peristaltic rate is 0.5 ~ 1 ml / min, the volume ratio of n-octanol to cyclohexane is 1:1, and the volume ratio of the cyclohexane solution of n-octanol to the methanol solution of NC is 2:1.

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