CL-20 / NTO eutectic explosive as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of CL-20 / NTO eutectic explosive, and relates to the technical field of energetic materials, and the preparation method comprises the following steps: 1, respectively weighing CL-20 and NTO for later use; the molar ratio of CL-20 to NTO is (2-1): 1; step 2, dissolving CL-20 and NTO in a solvent, and stirring at room temperature for 30 minutes to obtain a uniformly mixed solution; step 3, carrying out spray drying on the solution in the step 2 to form a mixture of gas and CL-20 / NTO eutectic explosive particles; the gas is nitrogen; and step 4, collecting the CL-20 / NTO eutectic explosive particles prepared in the step 3. The spherical particles of the CL-20 / NTO eutectic explosive prepared by the preparation method disclosed by the invention are relatively lower in explosive sensitivity, more insensitive to outside stimulation, lower in friction sensitivity and impact sensitivity, better in safety and higher in preparation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of energetic materials, and in particular to a CL-20 / NTO eutectic explosive and a preparation method and application thereof. Background Art

[0002] A eutectic is a multicomponent molecular crystal formed by the interaction of two or more different molecules through non-chemical bonds such as hydrogen bonds, resulting in a unique structure and properties. As a novel modification technology, eutectic technology can effectively improve the oxygen balance and sensitivity of explosives, enhancing their detonation performance, workability, and safety, and holds broad research potential. 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) is one of the highest-energy explosives currently in use, but its high mechanical sensitivity limits its application. 3-Nitro-1,2,4-triazol-5-one (NTO) is a typical high-energy insensitive explosive. Its significant advantages include high power, high energy density, low mechanical sensitivity, and excellent thermal stability, making it a highly sought-after material in the high-energy explosives field. Forming a eutectic with the low-sensitivity explosive NTO promises to reduce its sensitivity while retaining its energy level, thereby broadening its application.

[0003] Currently, the methods commonly used to prepare eutectic explosives both domestically and internationally include solvent evaporation, spray drying, grinding, and solvent / non-solvent methods. Among these methods, the solvent evaporation method is currently the most widely used and effective method. The eutectic crystals prepared by this method are of high quality and relatively regular morphology, and single crystal X-ray diffraction experiments can be performed on them to obtain the corresponding lattice parameters. However, there are also a series of problems such as the time-consuming preparation process, low efficiency, difficulty in preparation, and low yield of eutectic samples, making large-scale production difficult. When preparing eutectic explosives using the grinding method, the raw materials are directly ground, which is somewhat dangerous and less than ideal in safety. When preparing eutectic explosives using the solvent / non-solvent method, the operation steps are numerous and the preparation process is complex. Compared with these methods, the spray drying method can improve the yield of eutectic explosives, is relatively simple to operate, has better safety, and is more efficient.

[0004] However, the CL-20 / HMX eutectic explosive prepared by the spray drying method has irregular crystal morphology and agglomeration, which results in low safety, insignificant sensitivity reduction effect, and low preparation efficiency. Summary of the Invention

[0005] In response to the above-mentioned problems, the present invention aims to provide a CL-20 / NTO eutectic explosive and a preparation method thereof. The spherical particles of the prepared CL-20 / NTO eutectic explosive have relatively lower explosive sensitivity, are more insensitive to external stimuli, have lower friction sensitivity and impact sensitivity, are safer, and have higher preparation efficiency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing a CL-20 / NTO eutectic explosive, characterized by comprising the following steps: Step 1: Weigh CL-20 and NTO separately and set aside; The molar ratio of CL-20 to NTO is 2-1:1; Step 2: Dissolve CL-20 and NTO in solvent and stir at room temperature for 30 minutes to obtain a uniformly mixed solution; Step 3: spray drying the solution in step 2 to form a mixture of gas and CL-20 / NTO eutectic explosive particles; The gas is nitrogen; Step 4: Collect the CL-20 / NTO eutectic explosive particles prepared in step 3.

[0007] Furthermore, in step 3, the spray drying conditions are: inlet temperature of 70°C, outlet temperature of 50°C, feed rate of 2 mL / min, and pumping rate of 40 m / min. 3 / h.

[0008] The present invention also discloses a CL-20 / NTO eutectic explosive, characterized in that the explosive is prepared by the preparation method according to any one of claims 1 or 2.

[0009] The invention also discloses an application of a preparation method of CL-20 / NTO eutectic explosive in the field of high-energy explosives.

[0010] The beneficial effects of the present invention are: (1) CL-20 crystals are spindle-shaped with a particle size of about 100-150 μm; NTO crystals are irregular blocks with a particle size of about 100-200 μm; CL-20 / NTO eutectics are spherical with obvious agglomeration, and the individual particle size is about 1-5 μm. There are significant differences in the morphology and size of the CL-20 / NTO eutectic and the two single components. Spherical particles have relatively lower explosive sensitivity, are less sensitive to external stimuli, have lower friction sensitivity and impact sensitivity, and are safer. Therefore, the particle size of the CL-20 / NTO eutectic explosive is smaller than that of the raw materials CL-20 and NTO, and the crystals are spherical, with lower sensitivity than the raw materials and improved safety performance.

[0011] (2) X-ray powder diffraction and infrared spectroscopy characterization results showed that the spectrum of CL-20 / NTO cocrystal was not exactly the same as that of CL-20 and NTO. There were obvious shift differences and the generation of new peaks, which confirmed the formation of CL-20 / NTO cocrystal.

[0012] (3) CL-20 / NTO eutectic has good thermal stability. The explosion probability of CL-20 / NTO eutectic impact sensitivity is 36%, and the characteristic drop is high ( H 50 ) is 38.5cm, and the explosion probability of friction sensitivity is 44%, which is significantly lower than that of CL-20, and the safety is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The molecular models of CL-20 and NTO of the present invention, wherein (a) is CL-20 and (b) is NTO.

[0014] Figure 2 The morphologies of the CL-20, NTO and CL-20 / NTO eutectic explosives of the present invention are shown in Figure 1, where (a) is CL-20, (b) is NTO, and (c) is CL-20 / NTO eutectic explosive.

[0015] Figure 3 The powder X-ray diffraction patterns of CL-20, NTO and CL-20 / NTO co-crystal of the present invention are shown in FIG.

[0016] Figure 4 IR spectra of CL-20, NTO and CL-20 / NTO eutectic of the present invention.

[0017] Figure 5 The thermal performance curves of CL-20, NTO and CL-20 / NTO eutectic explosives of the present invention are shown in FIG. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0019] See also Figure 1-Figure 5 The present application discloses a method for preparing a CL-20 / NTO eutectic explosive, comprising the following steps: Step 1: Weigh CL-20 and NTO separately and set aside; The molar ratio of CL-20 to NTO is 2-1:1; It should be noted that when the ratio of CL-20 to NTO is 2:1 or 1:1, a CL-20 / NTO eutectic can be formed, which can maintain relatively good comprehensive performance. Simulation results show that the eutectic effect is best when the ratio is 1:1. In this application, when preparing CL-20 / NTO eutectic explosive, the molar ratio of CL-20 to NTO is required to be 1:1, because the molecular formula of CL-20 is C6H6O 12 N 12 , with a relative molecular mass of 438, and the molecular formula of NTO is C2H2O3N4, with a relative molecular mass of 130. Therefore, when preparing eutectic explosives, 0.01 mol of each of the two explosives is selected, so that the required weighed masses are 4.38 g and 1.30 g respectively.

[0020] Step 2: Dissolve CL-20 and NTO in 50 mL of solvent and stir at room temperature for 30 min to obtain a uniformly mixed solution; the solvent is acetone; Step 3: spray drying the solution in step 2 to form a mixture of gas and CL-20 / NTO eutectic explosive particles; Step 4: Separate the gas from step 3 from the mixture of CL-20 / NTO eutectic explosive particles using a vortex separator device, and collect the CL-20 / NTO eutectic explosive particles in a glass collector.

[0021] Specifically, the gas in step 3 is nitrogen.

[0022] The spray drying conditions of the spray drying device in step 3 are as follows: inlet temperature of 70°C, outlet temperature of 50°C, feed rate of 2 mL / min, and pumping rate of 40 m / min. 3 / h.

[0023] Example Reagents and instruments The reagents and main instruments required for the preparation of CL-20NTO eutectic explosive and its performance testing are shown in Tables 1 and 2, respectively.

[0024]

[0025] Preparation of CL-20 / NTO eutectic A eutectic explosive sample with a component ratio of 1:1 (CL-20:NTO) was prepared by spray drying. The specific preparation method is as follows: 4.38g (0.01mol) of CL-20 and 1.30g (0.01mol) of NTO were accurately weighed using an electronic balance. CL-20 and NTO were dissolved in 50mL of acetone and stirred at room temperature for 30min to obtain a uniform mixed solution. A spray drying apparatus was used under the following conditions: the inlet temperature was set to 70℃, the outlet temperature was set to 50℃, the feed rate was set to 2mL / min, and the pumping rate was set to 40m 3 / h; after spraying, a vortex separator device is used to separate the spray drying gas from the explosive particles, and the CL-20 / NTO eutectic explosive particles are collected in a glass collector.

[0026] The principle of spray drying is to inject a eutectic solution through a peristaltic pump and then atomize it into tiny droplets using a pressurized gas at a nozzle, increasing their surface area. As the solution comes into contact with the hot gas, the solvent evaporates, instantly achieving high supersaturation, shortening the crystal growth process and forming eutectic particles of controllable size.

[0027] Morphology observation The morphologies of the CL-20 / NTO eutectic explosive samples and the raw materials (CL-20, NTO) were measured using a Hitachi TM-1000 scanning electron microscope (SEM), with the SEM operating at an accelerating voltage of 20 kV.

[0028] Structural testing (1) Powder X-ray diffraction analysis of CL-20 / NTO eutectic The data were collected using a Bruker D8 Advance diffractometer with a Cu-Kα target ( λ =0.154056nm). The test voltage was 40kV, the current was 30mA, and the step scanning method was adopted with a step size of 0.05° and an angle of 5° to 90°.

[0029] (2) Infrared spectroscopy analysis of CL-20 / NTO eutectic Infrared spectrum test method: Take a sample of 3mg~5mg, press it with potassium bromide (KBr), add it to the sample cell, transmit it and collect data, the wavelength range is 500cm -1 ~4000cm -1 , with a resolution of 4cm -1 .

[0030] Thermal performance test Differential scanning calorimetry (DSC) was used to test the thermal properties of CL-20, NTO and CL-20 / NTO eutectic explosives, respectively. The mass of the raw material and eutectic explosive samples was selected to be 0.5 mg, and a nitrogen atmosphere was selected with a gas flow rate of 20 mL / min, a heating rate of 10°C / min, and a maximum heating temperature of 350°C.

[0031] Sensitivity test The impact sensitivity (explosion probability) of CL-20, NTO and CL-20 / NTO eutectic explosives was tested according to GJB772A-97 method 601.1, with a drop weight of 10 kg, a drop height of 25 cm and a charge of 50 mg. The characteristic drop height of eutectic explosives and raw materials was tested according to GJB772A-97 method 601.2. H 50 ), where the drop weight is 5 kg and the charge is 50 mg; the friction sensitivity (explosion probability) of the eutectic explosive and the raw material is tested separately in accordance with the provisions of GJB772A-97 method 602.1, where the gauge pressure is 3.92 MPa, the swing angle is 90°, and the charge is 20 mg.

[0032] Morphological observation results The morphologies of CL-20, NTO and CL-20 / NTO eutectic explosives were observed under a scanning electron microscope. Figure 2 shown.

[0033] from Figure 2 The CL-20 crystals are spindle-shaped with a particle size of approximately 100-150 μm; the NTO crystals are irregular and blocky with a particle size of approximately 100-200 μm; and the CL-20 / NTO eutectic is spherical with significant agglomeration, with individual particles approximately 1-5 μm in size. The CL-20 / NTO eutectic exhibits significant differences in morphology and size from the two individual components.

[0034] Structural test results (1) Powder X-ray diffraction test results The powder X-ray diffraction patterns of CL-20, NTO and CL-20 / NTO eutectic explosives are shown in Figure 2. Figure 3 shown.

[0035] from Figure 3It can be seen that the main diffraction peaks of CL-20 appear at 12.72°, 13.92°, and 30.30°; the main diffraction peaks of NTO appear at 13.15°, 16.56°, 17.88°, and 29.35°. After the formation of the CL-20 / NTO eutectic, its main diffraction peaks are 13.43°, 24.03°, and 28.40°, while the diffraction peaks of the raw materials have weakened or even disappeared. This indicates that the diffraction pattern of the CL-20 / NTO eutectic is significantly different from that of CL-20 and NTO, and the positions of the diffraction peaks have changed significantly. Some diffraction peaks of the raw materials (CL-20 and NTO) have disappeared, while new diffraction peaks have appeared in the CL-20 / NTO eutectic explosive. From a theoretical analysis perspective, if the two components are simply physically mixed, their respective diffraction peaks should remain unchanged. This indicates that the crystals prepared by the spray drying method in the experiment are not a simple physical mixture of CL-20 and NTO, but a new substance. Moreover, the formation of the eutectic has a great influence on the arrangement of molecules inside the crystal, thus causing a significant change in the diffraction peaks. Figure 3 The powder X-ray diffraction results confirmed that a eutectic was formed between CL-20 and NTO.

[0036] (2) Infrared spectrum test results The infrared spectra of CL-20, NTO and CL-20 / NTO eutectic explosives are shown in Figure 2. Figure 4 shown.

[0037] from Figure 4 It can be seen that the CL-20 / NTO eutectic explosive has a peak at 3030 cm -1 A peak appears at 3040 cm, which corresponds to the stretching vibration peak of C—H in CL-20 / NTO eutectic explosive. For single substance CL-20, the position of C—H stretching vibration peak in its molecule is 3040 cm -1 In addition, the CL-20 / NTO eutectic has a peak at 1610 cm -1 and 1575cm -1 There is a peak at 1610 cm-1, which corresponds to the symmetrical stretching vibration peak of -NO2; while the corresponding vibration peaks of single substance CL-20 and NTO appear at 1610 cm-1, respectively. -1 and 1595cm -1 Based on this, it can be seen that most of the infrared absorption peaks of the CL-20 / NTO eutectic are 5 cm-1 higher than those of the two raw materials (CL-20 and NTO). -1 ~10cm -1 The changes further confirmed the formation of eutectic.

[0038] Thermal performance test results The thermal performance test results of CL-20, NTO and CL-20 / NTO eutectic explosives are as follows: Figure 5 shown.

[0039] from Figure 5 It can be seen that the thermal performance curve of the pure component CL-20 has only one exothermic peak at 252.0℃, which corresponds to the thermal decomposition temperature of CL-20; the thermal performance curve of the pure component NTO has one endothermic peak and one exothermic peak, corresponding to temperatures of 205.5℃ and 243.1℃, respectively. The endothermic peak at 205.5℃ corresponds to the melting point of NTO, and the exothermic peak at 243.1℃ corresponds to the thermal decomposition temperature of NTO; the DSC curve of the CL-20 / NTO eutectic has two endothermic peaks and one exothermic peak, at 165.6℃, 203.0℃, and 223.5℃, respectively. There is a small endothermic peak at 165.6℃, which is speculated to be the crystallization transition peak of the CL-20 / NTO eutectic. There is an endothermic peak at 203.0℃, which corresponds to the melting peak of the eutectic, and a wider exothermic peak at 223.5℃, which corresponds to the thermal decomposition temperature of the eutectic.

[0040] By comparing the DSC curves of CL-20, NTO and CL-20 / NTO eutectic explosives, it can be seen that the thermal properties of the CL-20 / NTO eutectic explosive are quite different from those of the raw materials (CL-20, NTO). Its thermal decomposition temperature is about 30°C lower than that of CL-20 and about 20°C lower than that of NTO, indicating that the formation of eutectic has a significant impact on the thermal properties of the explosive.

[0041] Sensitivity test results Impact sensitivity of CL-20, NTO and CL-20 / NTO eutectic explosives (explosion probability and characteristic drop height) H 50 The experimental results of ) and friction sensitivity (explosion probability) are shown in Table 3.

[0042]

[0043] As shown in Table 3, the impact sensitivity, characteristic drop height, and friction sensitivity of the pure CL-20 explosive are 100%, 11 cm, and 100%, respectively. The corresponding sensitivities of the pure NTO explosive are 34%, 45 cm, and 40%, respectively. The sensitivity test results for the CL-20 / NTO eutectic explosive are 36%, 38.5 cm, and 44%, respectively. Compared with CL-20, the eutectic explosive has a 64% lower impact sensitivity, a 27.5 cm higher characteristic drop height, and a 56% lower friction sensitivity. Therefore, the sensitivity of the CL-20 / NTO eutectic explosive is significantly lower than that of CL-20, effectively enhancing safety.

[0044] In summary, CL-20 crystals are spindle-shaped with a particle size of approximately 100-150 μm; NTO crystals are irregular blocks with a particle size of approximately 100-200 μm; and the CL-20 / NTO eutectic is spherical with significant agglomeration, with individual particles approximately 1-5 μm in size. The CL-20 / NTO eutectic exhibits significant differences in morphology and size from the two individual components.

[0045] The results of X-ray powder diffraction and infrared spectroscopy characterization showed that the spectrum of CL-20 / NTO cocrystal was not exactly the same as those of CL-20 and NTO. There were obvious shift differences and the generation of new peaks, confirming the formation of CL-20 / NTO cocrystal.

[0046] CL-20 / NTO eutectic has good thermal stability. The explosion probability of CL-20 / NTO eutectic impact sensitivity is 36%, and the characteristic drop is high ( H 50 ) is 38.5cm, and the explosion probability of friction sensitivity is 44%, which is significantly lower than that of CL-20.

[0047] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing CL-20 / NTO eutectic explosive, characterized in that: The following steps are involved: Step 1: Weigh CL-20 and NTO separately and set aside; The molar ratio of CL-20 to NTO is 2-1:1; Step 2: Dissolve CL-20 and NTO in solvent and stir at room temperature for 30 minutes to obtain a uniformly mixed solution; Step 3: spray drying the solution in step 2 to form a mixture of gas and CL-20 / NTO eutectic explosive particles; The gas is nitrogen; Step 4: Collect the CL-20 / NTO eutectic explosive particles prepared in step 3.

2. The method for preparing a CL-20 / NTO eutectic explosive according to claim 1, wherein: In step 3, the spray drying conditions are: inlet temperature of 70°C, outlet temperature of 50°C, feed rate of 2 mL / min, and pumping rate of 40 m / min. 3 / h.

3. A CL-20 / NTO eutectic explosive, characterized by: The explosive is prepared by the preparation method according to any one of claims 1 or 2.

4. Use of the preparation method of the CL-20 / NTO eutectic explosive according to any one of claims 1 or 2 in the field of high-energy explosives.

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