Method for coating pentazole hydroxylamine salt with copper alginate

Abstract

The invention discloses a method for coating pentazole hydroxylammonium salt with copper alginate, the pentazole hydroxylammonium salt is coated with a copper alginate gel network to form a composite material, the stirring rate and the dripping rate are strictly regulated and controlled by screening different mass ratios and drying modes, and the composite material is prepared. And an optimal experimental formula is screened out so as to achieve the purpose of reducing hygroscopicity and mechanical sensitivity. Compared with a pentazole hydroxylamine salt raw material synthesized in the early stage, the pentazole hydroxylamine-based composite energetic microsphere prepared by the preparation method disclosed by the invention is more regular in morphology, higher in sphericity degree, obviously reduced in sensitivity and hygroscopicity, easier to prepare medicines and capable of being popularized to preparation of composite microspheres of other energetic materials.

Description

Technical Field

[0001] This invention belongs to the field of high-energy energetic materials, specifically, it relates to a method for preparing pentazolyl hydroxylamine-based composite energetic microspheres. Background Technology

[0002] Energetic materials are essential destructive and propulsion energy materials for various weapon systems (including ballistic and cruise missiles), and are important components of explosives, propellants, and detonation products. Ultra-high-energy energetic materials refer to novel high-energy substances with energy at least an order of magnitude higher than conventional explosives. All-nitrogen materials, as a current focus of global research, are ultra-high-energy energetic materials with theoretically energies reaching 6-8 times the TNT equivalent, and their decomposition products are extremely stable nitrogen gas. Compared to traditional energetic materials, the energy released by all-nitrogen materials mainly comes from the large bond energy difference between N-N single bonds, N=N double bonds, and N≡N triple bonds in the molecule. Furthermore, due to nitrogen's electronegativity being second only to F and O, it can form strong chemical bonds; that is, all-nitrogen derivatives, composed entirely or partially of nitrogen, possess a certain degree of stability. Compared to traditional energetic materials, all-nitrogen materials have advantages such as ultra-high energy, low characteristic signals, and clean detonation products. As a typical representative of all-nitrogen materials, N5ˉ ions are considered the most promising all-nitrogen material for early application due to their mild preparation conditions. Therefore, conducting in-depth research on N5ˉ ions has significant theoretical implications and promising practical applications.

[0003] Since Nanjing University of Science and Technology synthesized the first stable N5ˉ ion salt (N5)6(H3O)3(NH4)4Cl [Science, 2017, 355, 374-376], the first hydrated N5ˉ ion metal salt Co(N5)2(H2O)4·4H2O [Angew. Chem. Int. Ed., 2017, 56, 4512-4514], and the first anhydrous N5ˉ ion metal salt AgN5, as well as more than thirty anhydrous N5ˉ ion nonmetallic salts, pentazolium chemistry has made groundbreaking progress. Among them, [NH3OH]... + N5ˉ、[N2H5] + N5ˉ and [NH4] + High-nitrogen-content, high-energy N5ˉ ionic salts, such as N5ˉ, possess advantages such as good stability and excellent detonation performance. Theoretical studies have shown that [NH3OH] + The theoretical detonation velocity and detonation temperature of N5ˉ reach 9930 m / s and 6283 kJ / kg, respectively, which exceeds the best-performing third-generation energetic material CL-20. It is currently the best-performing single-element energetic material in terms of overall explosive performance reported both domestically and internationally, and has significant potential application value in the fields of warhead, propellant, and propellant research.

[0004] But [NH3OH] +The high sensitivity and strong hygroscopicity of N5ˉ are mainly due to [NH3OH]. + N5ˉ crystals are mostly needle-like or rod-like, and the exposed N atoms on the crystal surface readily form hydrogen bonds with water molecules in the air, absorbing moisture from the air and thus limiting the [NH3OH] crystal structure. + Applications and development of N5ˉ in the field of energetic materials.

[0005] Currently, coating methods are widely used in the field of energetic materials. By constructing composite materials, the mechanical sensitivity and hygroscopicity of explosives can be effectively reduced. Sodium alginate (SA) hydrogel, as a natural biomaterial, has attracted much attention due to its unique three-dimensional network structure and has been widely used for the coating protection and sustained release of drugs and protein molecules. Studies have shown that this technology is also applicable to the field of energetic materials, and can significantly improve the safety and stability of energetic compounds. SA is a dipolysaccharide composed of two monomers, β-D-mannuronic acid (M) and α-L-guluronic acid (G). The G unit in its molecular chain can be transported by divalent metal ions (such as Cu). 2+ Ionic cross-linking occurs, forming a three-dimensional network gel. The microstructure of this gel resembles a precise "cage," uniformly encapsulating drugs or energetic molecules for efficient loading and protection. After drying, the gel forms a mesoporous structure, which not only regulates the energy release rate of energetic materials but also reduces sensitivity through physical isolation. Based on these properties, alginate gels demonstrate significant application value in improving the thermal stability of explosives, inhibiting unintended decomposition, and enhancing safety. Summary of the Invention

[0006] To solve the problem of [NH3OH] in existing technologies + To address the issues of high sensitivity and high hygroscopicity of N5ˉ, this invention leverages the property of sodium alginate and metal ions to form a gel network through ion cross-linking. It utilizes sodium alginate, copper chloride, and [NH3OH]. + Using N5ˉ as raw material, pentazolyl hydroxylamine-based composite energetic microspheres are formed, thereby reducing their hygroscopicity and mechanical sensitivity.

[0007] A method for coating pentazolidinyl hydroxylamine salt with copper alginate (CA) includes the following steps:

[0008] (1) Add [NH3OH] to deionized water + N5ˉ(QA) and SA were ultrasonically mixed to obtain a QA / SA mixed hydrogel.

[0009] (2) While stirring, slowly drop the QA / SA mixed hydrogel into the liquid paraffin. After the addition is complete, continue stirring at the same speed for 30 minutes to obtain a uniform W / O emulsion.

[0010] (3) Add the isopropanol solution of CuCl2 dropwise into the above W / O emulsion and stir for 2 hours;

[0011] (4) Filter, wash with petroleum ether, freeze and dry under reduced pressure for 24 h to obtain QA / CA microspheres.

[0012] Furthermore, [NH3OH] + The mass ratio of N5ˉ to SA is 95:5.

[0013] Furthermore, the concentration of the QA / SA mixed hydrogel is 1.0 g / mL.

[0014] Furthermore, the volume ratio of the QA / SA mixed hydrogel to the liquid paraffin is 1:10.

[0015] Furthermore, in steps (2) and (3), the stirring speed is 300-1000 rpm, preferably 1000 rpm.

[0016] Furthermore, in step (3), the dropping rate is 0.5-2 mL / min, preferably 1 mL / min.

[0017] Furthermore, the concentration of isopropanol in CuCl2 is 0.05 g / mL.

[0018] Furthermore, the volume ratio of the CuCl2 isopropanol solution to the W / O emulsion is 1:11.

[0019] Furthermore, the vacuum drying temperature is 20-50℃, preferably 30℃.

[0020] Compared with existing technologies, this invention uses a copper alginate gel network to coat pentazolyl hydroxylamine salt to form a composite material. By screening different mass ratios and drying methods, and strictly controlling the stirring rate and dropping rate, the optimal experimental formulation is selected to reduce hygroscopicity and mechanical sensitivity. This process has the following advantages: (1) It is simple to operate and can continuously produce [NH3OH]. + (2) The coating material is non-toxic, biodegradable, green, environmentally friendly, safe and reliable; (3) It effectively enhances [NH3OH] + The safety performance of N5ˉ. The pentaazole hydroxylamine salt crystals prepared by this invention have a regular morphology and exhibit a spherical crystal structure. Compared with the crystals before treatment, the hygroscopicity and mechanical sensitivity are significantly reduced.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 It is a raw material [NH3OH] + Scanning electron microscope image of N5ˉ.

[0023] Figure 2 It is a raw material [NH3OH] + Polarizing microscope image of N5ˉ.

[0024] Figure 3 The [NH3OH] obtained in Example 1 of this invention + Scanning electron microscope image of N5ˉ composite material. Detailed Implementation

[0025] The present application will be further described below with reference to specific embodiments.

[0026] It should be noted that terms such as "upper", "lower", "left", "right", and "middle" used in this specification are only for clarity of description and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0029] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0030] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0031] Example 1

[0032] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ (homemade) was added to 1 mL of deionized water and ultrasonically mixed at 50°C to obtain a 1.0 g / mL QA / SA mixed hydrogel, wherein the raw material [NH3OH] was added. + The morphology of N5ˉ is as follows Figure 1 As shown in the polarizing microscope image. Figure 2As shown. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin stirred magnetically at 1000 rpm, and stirred at the same speed for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was injected into the W / O emulsion at a dropping rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.582 g, and the yield was 58.2%. The scanning electron microscope image of the sample is shown below. Figure 3 As shown.

[0033] Example 2

[0034] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g of CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin with magnetic stirring at 1000 rpm, and stirred at the same speed for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was injected into the W / O emulsion at a dropping rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, and freeze-dried for 24 h to obtain QA / CA microspheres. The sample weight was 0.421 g, and the yield was 42.1%.

[0035] Example 3

[0036] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to a mixture of 10 mL of liquid paraffin and 0.05 g β-cyclodextrin stirred magnetically at 1000 rpm for 30 min, resulting in a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, and freeze-dried for 24 h to obtain QA / CA microspheres. The sample weight was 0.348 g, and the yield was 34.8%.

[0037] Example 4

[0038] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50 °C to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to a mixture of 10 mL of liquid paraffin and 0.05 g β-cyclodextrin stirred magnetically at 1000 rpm for 30 min, resulting in a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. The pale blue suspension was filtered, washed three times with petroleum ether, frozen, and then dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The crystal weight was 0.572 g, with a yield of 57.2%.

[0039] Example 5

[0040] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50 °C to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to a mixture of 10 mL of liquid paraffin and 0.05 g β-cyclodextrin stirred magnetically at 1000 rpm for 30 min, yielding a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. The pale blue suspension was filtered, washed three times with petroleum ether, washed three times with ethyl acetate, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The crystal weight was 0.608 g, with a yield of 60.8%.

[0041] Example 6

[0042] Weigh out 0.04g of sodium alginate and 0.96g of [NH3OH]. +N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g of CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin with magnetic stirring at 1000 rpm, and stirred at the same speed for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a dropping rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.436 g, and the yield was 43.6%.

[0043] Example 7

[0044] Weigh out 0.03g of sodium alginate and 0.97g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g of CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin stirred magnetically at 1000 rpm for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.237 g, and the yield was 23.7%.

[0045] Example 8

[0046] Weigh out 0.02g of sodium alginate and 0.98g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g of CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin stirred magnetically at 1000 rpm, and stirred at the same speed for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was injected into the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.127 g, and the yield was 12.7%. The low yield and low SA content made it difficult to form the hydrogel.

[0047] Example 9

[0048] Weigh out 0.01g of sodium alginate and 0.99g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g of CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to 10 mL of liquid paraffin at 1000 rpm with magnetic stirring, and stirred at the same speed for 30 min to obtain a homogeneous W / O emulsion. CuCl2 isopropanol solution was injected into the W / O emulsion at a drop rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.091 g, and the yield was 9.1%. The low yield and low SA content made it difficult to form the hydrogel.

[0049] Example 10

[0050] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. + N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to a mixture of 10 mL of liquid paraffin and 0.05 g Span 80 stirred magnetically at 1000 rpm for 30 min, resulting in a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. Finally, the pale blue suspension was filtered, washed three times with petroleum ether, frozen, and dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.271 g, and the yield was 27.1%.

[0051] Example 11

[0052] Weigh out 0.05g of sodium alginate and 0.95g of [NH3OH]. +N5ˉ was added to 1 mL of deionized water and ultrasonically mixed at 50℃ to obtain a 1.0 g / mL QA / SA mixed hydrogel. 0.05 g CuCl2 was dissolved in 1 mL of isopropanol solution with ultrasonic assistance. 1 mL of the QA / SA mixed hydrogel was slowly added dropwise to a mixture of 10 mL of liquid paraffin and 0.05 g Tween 80 stirred magnetically at 1000 rpm for 30 min, resulting in a homogeneous W / O emulsion. CuCl2 isopropanol solution was added to the W / O emulsion at a rate of 1 mL / min using a peristaltic pump, and stirred for 2 h after the addition was complete. The pale blue suspension was filtered, washed three times with petroleum ether, frozen, and then dried under reduced pressure at room temperature for 24 h to obtain QA / CA microspheres. The sample weight was 0.169 g, and the yield was 16.9%.

[0053] Based on the BAM sensitivity test and hygroscopicity test, the sensitivity test data and hygroscopicity test data corresponding to different formulation ratios of pentazolidinyl hydroxylamine salt in the embodiments of the present invention are listed in Table 1 and Table 2, respectively.

[0054] Table 1 Examples and Raw Materials [NH3OH] + Impact and friction sensitivity results for N5ˉ

[0055]

[0056] Example 9: The sample size was too small to perform mechanical sensitivity testing.

[0057] Table 2 Examples and Raw Materials [NH3OH] + The hygroscopic results of N5ˉ

[0058]

[0059]

[0060] Examples 7, 8, 9, 10, and 11 had too small sample quantities to perform hygroscopicity tests.

[0061] The above embodiments are merely preferred embodiments of the present invention, but the implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, or combinations made without departing from the spirit and principle of the present invention, such as various combinations of solutions in the embodiments, should be considered equivalent replacements and are all within the protection scope of the present invention.

Claims

1. A method for coating pentazolidinyl hydroxylamine salt with copper alginate, characterized in that, Includes the following steps: (1) Add [NH3OH] to deionized water. + N5ˉ and sodium alginate were ultrasonically mixed to obtain a QA / SA mixed hydrogel. (2) While stirring, slowly drop the QA / SA mixed hydrogel into the liquid paraffin. After the addition is complete, continue stirring at the same speed for 30 min to obtain a uniform W / O emulsion. (3) Add the isopropanol solution of CuCl2 dropwise into the above W / O emulsion and stir for 2 h; (4) Filter, wash with petroleum ether, freeze and dry under reduced pressure for 24 h to obtain QA / CA microspheres.

2. The method as described in claim 1, characterized in that, [NH3OH] + The mass ratio of N5ˉ to sodium alginate is 95:

5.

3. The method as described in claim 1, characterized in that, The concentration of the QA / SA mixed hydrogel is 1.0 g / mL.

4. The method as described in claim 1, characterized in that, The volume ratio of QA / SA mixed hydrogel to liquid paraffin is 1:

10.

5. The method as described in claim 1, characterized in that, In steps (2) and (3), the stirring speed is 300-1000 rpm, preferably 1000 rpm.

6. The method as described in claim 1, characterized in that, In step (3), the dropping rate is 0.5-2 mL / min, preferably 1 mL / min.

7. The method as described in claim 1, characterized in that, The concentration of isopropanol in CuCl2 is 0.05 g / mL.

8. The method as described in claim 1, characterized in that, The volume ratio of the CuCl2 isopropanol solution to the W / O emulsion is 1:

11.

9. The method as described in claim 1, characterized in that, The vacuum drying temperature is 20-50 ℃, preferably 30 ℃.

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