Preparation method of thermite

Abstract

The invention provides a preparation method of a thermite, which comprises the following steps: taking CuN (CN) 2 and aluminum powder as raw materials, adding an organic solvent, mixing, and carrying out vacuum drying to obtain the thermite, the mass ratio of the CuN (CN) 2 to the aluminum powder is (1: 1)-(1: 4). According to the method for preparing the thermite through CuN (CN) 2, a new thought for applying other oxides to an energetic material of the thermite is provided, the thermite can provide the heat of 1528.9 J / g and the gas production pressure of 50 KPa, and it is detected that a high-temperature-resistant material aluminum nitride is generated in a product obtained after combustion.

Description

Technical Field

[0001] The present invention relates to the technical field of thermite, and in particular to a preparation method of thermite. Background Art

[0002] Thermite is an energetic composite material composed of a metal reducing agent (usually aluminum powder) and a metal oxide (such as Fe2O3, CuO, MoO3, etc.), which releases a large amount of heat through a violent redox reaction. Current research focuses on the following aspects: (1) Energy density improvement: using high-energy oxidants (such as Bi2O3, WO3, Pb3O4) to increase the reaction enthalpy, but some materials are limited due to toxicity or high cost. (2) Combustion rate regulation: optimizing reaction kinetics through nano-aluminum powder (nAl), additives (such as PTFE, carbon nanotubes) or microstructure design (core-shell structure). (3) Multifunctionalization: combining with gas generating agents (such as nitrates, perchlorates) to achieve a combustion-gas coupling effect, which is used in propellants, pyrotechnics, etc.

[0003] Current issues include: (1) Energy bottlenecks with traditional oxidants (Fe2O3, CuO): The reaction relies solely on metal-oxygen exchange, resulting in limited heat release and gas generation. (2) Environmental and safety issues with perchlorate oxidants: They are hygroscopic and their decomposition products (HCl) are highly corrosive. (3) Insufficient combustion controllability: Some thermites burn too quickly or too slowly, making it difficult to balance energy release with engineering application requirements.

[0004] Metal dicyandiamide materials are composed of metal ions (such as Fe 2+ 、Co 2+ 、Ni 2+ 、Cu 2+ and Cu + transition metal ions) and dicyandiamide anion (chemical formula C2N3 -) coordination compounds or metal-organic frameworks (MOFs) formed through coordination bonds. Metallodicyandiamide materials, through the coordination of metal ions with dicyandiamide ligands, form diverse structures that combine magnetic properties, electrical conductivity, porosity, and catalytic activity, showing broad application prospects in fields such as energy, environment, and materials science. The dicyandiamide ligands in their structures are linear (N≡C—N—C≡N), and the anions are nitrogen-rich. Decomposition at high temperatures produces large amounts of nitrogen gas and energetic intermediates, providing a highly oxidizing environment, resulting in high nitrogen content and oxidizing capacity. Furthermore, the metal-nitrogen (MN) bond energy in transition metal dicyandiamide salts is typically lower than that of the metal-oxygen (MO) bond, resulting in lower thermodynamic stability but higher chemical activity. Furthermore, the decomposition of the dicyandiamide anion is accompanied by heat release (e.g., CN bond cleavage and N2 generation), which can create an energetic synergistic effect with the thermite reaction, increasing the overall reaction enthalpy. However, there are currently no reports on the use of metal dicyandiamide materials in the preparation of thermites. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to prepare thermite by using metal dicyandiamide material.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] The invention provides a preparation method of thermite. CuN(CN)2 and aluminum powder are used as raw materials, an organic solvent is added to the mixture, and then vacuum drying is performed to prepare the thermite. The mass ratio of CuN(CN)2 to aluminum powder is 1:1-1:4.

[0008] Beneficial effects: The method of preparing thermite through CuN(CN)2 in the present invention provides a new idea for applying other types of oxides to thermite energetic materials. The thermite of the present invention can provide 1528.9 J / g of heat, and the gas production pressure is 50 KPa. The product detection after combustion shows the formation of high-temperature resistant material aluminum nitride.

[0009] Preferably, the organic solvent is at least one of anhydrous ethanol, isopropanol, cyclohexane or n-butanol.

[0010] Preferably, the mixing is performed by ultrasound, and the ultrasound time is 10-15 min.

[0011] Preferably, the temperature of ultrasound is room temperature.

[0012] Preferably, the vacuum drying temperature is 40-60°C.

[0013] Preferably, the vacuum drying time is 10-14 hours.

[0014] Preferably, the preparation method of CuN(CN)2 is as follows: a soluble copper salt solution is added with a reducing agent to react to obtain a cuprous solution; the cuprous solution is added with N(CN)2 - The soluble salt undergoes precipitation reaction to obtain CuN(CN)2.

[0015] Preferably, the soluble copper salt solution is obtained by dissolving a soluble copper salt in deionized water, and the soluble copper salt includes at least one of nitrate, halide or acetate.

[0016] Preferably, the reducing agent is K2S2O5 or Na2S2O5.

[0017] Preferably, N(CN)2 - The soluble salt is NaN(CN)2.

[0018] Preferably, Cu 2+ The molar ratio of the reducing agent is 1:(1.1-2).

[0019] Preferably, Cu + With N(CN)2 - The molar ratio is 1:(1.5-2).

[0020] Preferably, the precipitation reaction obtains a precipitate, and the precipitate is vacuum dried to obtain CuN(CN)2.

[0021] Preferably, the vacuum drying temperature is 100-140° C., and the vacuum drying time is 8-14 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the X-ray diffraction spectrum of CuN(CN)2 in the embodiment;

[0023] Figure 2 is a scanning electron microscope image of CuN(CN)2 in the embodiment;

[0024] Figure 3 is a DSC graph of the thermite in the embodiment;

[0025] Figure 4 1 is a diagram showing the combustion effect of thermite in the embodiment;

[0026] Figure 5 is the XRD pattern of the combustion product of thermite in the embodiment;

[0027] Figure 6 This is a diagram showing the combustion effect of thermite in the comparative example. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0030] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0031] Example 1

[0032] This embodiment provides a method for preparing thermite, which is as follows:

[0033] Preparation of S1 CuN(CN)2

[0034] Dissolve Cu(NO3)2﹒2.5H2O in deionized water, add excess K2S2O5 and stir thoroughly to obtain Cu(NO3)2﹒2.5H2O. + A solution having a concentration of about 0.1 mol / L of cuprous solution. Dissolve NaN(CN)2 in deionized water and stir thoroughly to obtain a NaN(CN)2 solution having a concentration of 0.1 mol / L.

[0035] At room temperature, 20 ml of cuprous solution was slowly added dropwise to 40 ml of NaN(CN)2 solution and allowed to stand for 24 h to allow Cu + With N(CN)2 - The reaction was completed, filtered, and a precipitate was obtained; the precipitate was heated at 100°C in vacuum for 12 hours to obtain CuN(CN)2. The X-ray diffraction spectrum and scanning electron microscopy of the CuN(CN)2 are shown in FIG. Figure 1-2 shown.

[0036] Preparation of S2 thermite

[0037] 0.05 g of CuN(CN)2 and 0.05 g of aluminum powder were placed in a beaker, and 5 ml of anhydrous ethanol was added thereto. The mixture was ultrasonically mixed at room temperature for 10 min, and then vacuum dried at 50°C for 12 h to obtain thermite.

[0038] Performance test of S3 thermite

[0039] 1. Heat detection: 5.09g of thermite was placed in a TG-DSC device to study the exothermic performance. The device was heated at a rate of 10K / min in an argon atmosphere. The results are as follows: Figure 3 As shown, according to the peak area integration in the figure, the heat release energy of thermite is 1528.9 J / g.

[0040] 2. Combustion detection: Place 50mg of thermite in the air and trigger the ignition of the thermite through a heating resistor. The current of the heating resistor is 3A and the voltage is 5V. At the same time, a high-speed camera is used to record the combustion process and take pictures to collect the results. Figure 4 As shown, according to Figure 4 It can be seen that the combustion flame of thermite is intense and the height of the combustion flame is high; the combustion products are detected as follows Figure 5 As shown, the combustion products of thermite include the formation of high-temperature resistant material aluminum nitride.

[0041] Example 2

[0042] This embodiment provides a method for preparing thermite. Compared with Example 1, this embodiment differs in that the mass ratio of CuN(CN)2 to aluminum powder is 1:3, and all other aspects are the same.

[0043] In the thermite combustion detection of this embodiment, the combustion flame is intense and the combustion flame height is high; the combustion product of the thermite includes the formation of high-temperature resistant material aluminum nitride.

[0044] Comparative Example 1

[0045] This comparative example provides a method for preparing thermite. Compared with Example 1, this comparative example differs in that CuN(CN)2 and aluminum powder are mixed in a molar ratio of 1:1, and the rest are the same as Example 1 to prepare thermite.

[0046] In the combustion test of thermite in this comparative example, due to insufficient aluminum powder as fuel, the thermite does not burn, and only the heating resistance wire turns red. Figure 6 shown.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing thermite, characterized in that: Thermite is prepared by adding an organic solvent into the mixture of CuN(CN)2 and aluminum powder as raw materials and then drying in vacuum; the mass ratio of CuN(CN)2 to aluminum powder is 1:1-1:

4.

2. The method for preparing thermite according to claim 1, characterized in that: The organic solvent is at least one of anhydrous ethanol, isopropanol, cyclohexane or n-butanol.

3. The method for preparing thermite according to claim 1, characterized in that: Mixing was performed by sonication for 10-15 min.

4. The method for preparing thermite according to claim 3, characterized in that: The temperature of ultrasound was room temperature.

5. The method for preparing thermite according to claim 1, characterized in that: The vacuum drying temperature is 40-60°C.

6. The method for preparing thermite according to claim 5, characterized in that: The vacuum drying time is 10-14h.

7. The method for preparing the thermite according to any one of claims 1 to 6, characterized in that: The preparation method of CuN(CN)2 is as follows: Soluble copper salt solution is added with reducing agent to react to obtain cuprous solution; the cuprous solution is added with N(CN)2 - The soluble salt undergoes precipitation reaction to obtain CuN(CN)2.

8. The method for preparing thermite according to claim 7, characterized in that: The reducing agent is K2S2O5 or Na2S2O5.

9. The method for preparing thermite according to claim 7, characterized in that: Cu 2+ The molar ratio of the reducing agent is 1:(1.1-2).

10. The method for preparing thermite according to claim 7, characterized in that: Cu + With N(CN)2 - The molar ratio is 1:(1.5-2).

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