Implementation method of high-burning-rate compound

Abstract

The invention relates to the field of energetic materials, in particular to an implementation method of a high-burning-rate compound. The molecular formula of the high-burning-rate compound is C6H16N2 (NH4) (ClO4) 3, compared with DAP-4, the distance between C-O and N-O of the high-burning-rate compound is shorter, and the reduction of the spacing between atoms can aggravate the redox reaction between HDX-1 atoms, so that the burning reaction process is more violent, and the burning rate of the molecular perovskite energetic material is improved. The preparation process is mild in condition, safe, environmentally friendly and easy to amplify, and has a good application prospect in the field of high-burning-rate propellants.

Description

A method for realizing a high-burning-rate compound Technical Field

[0001] This invention relates to the field of energetic materials, and more specifically, to a method for realizing a high-burning-rate compound. Background Technology

[0002] Solid propellants are the power source for various solid rocket motors used in missiles, weapons, and spacecraft launches. The energy performance of the propellant determines its effective range and deterrent capability. High-burning-rate solid propellants can generate significant thrust instantaneously without requiring complex propellant grain combustion surface structures, meeting the requirements of high maneuverability, high precision, and high reaction speed in missiles. Therefore, the development and application of high-burning-rate solid propellants has always been a key focus of propellant development. In the field of four-component propellants, the commonly used high-energy components, namely HMX and RDX, are characterized by relatively slow combustion rates. Multiple technical approaches are needed to effectively increase the burning rate of solid propellants, including composite catalytic systems, ferrocene derivatives, hydrogen storage fuels, ultrafine ammonium perchlorate (AP), and nano-metal powders. However, these methods often introduce significant risks of spontaneous combustion and pose considerable safety problems.

[0003] Molecular perovskite energetic materials are densely packed ternary compounds crystallized within an ABX3 perovskite structure. In these compounds, the A, B, and X sites are substituted by molecules or ions, allowing for precise tuning of the material's composition and properties. A series of molecular perovskite energetic materials with high detonation performance and high specific impulse have been obtained through ion self-assembly. Among molecular perovskite energetic compounds, ClO4 is generally considered to be... - As an X-bridge site and NH4 + Compounds with B-sites exhibit higher average molecular weight and specific impulse of gaseous products. DAP-4 has a detonation velocity of 8806 m / s and a detonation pressure of 35.2 GPa, and its oxygen balance is highly compatible with that of conventional solid propellants, making it a promising high-burning-rate component for use in solid propellants. The A-site in DAP-4 is H2dabco. 2+ This spherical structure will contain NH4 + ClO4 - and H2dabco 2+ The tight bonding results in high thermal stability and a high ignition threshold. However, its application is limited by the need for a catalyst to catalyze combustion. Summary of the Invention

[0004] To address the aforementioned technical problems, the first aspect of this invention provides a high-burning-rate compound with a perovskite structure having the structural formula ABX3, wherein the A-site building unit is N,N'-dimethylpiperazine (dmpz).

[0005] This application innovatively uses the active intermediate dmpz generated from the pyrolysis of DAP-4 directly as the A-site building block, successfully developing a novel molecular perovskite energetic material, HDX-1 (i.e., a high-burning-rate compound). This design fundamentally bypasses the initial endothermic step, enabling the material to rapidly trigger a vigorous redox reaction upon heating, significantly enhancing the mass and heat transfer efficiency of the solid-state reaction.

[0006] In some embodiments, the molecular formula is C6H 16 N2(NH4)(ClO4)3.

[0007] The high-burning-rate compound of this invention is a novel molecular perovskite energetic material, different from the structure of DAP-4 in the prior art. Its combustion reaction process is more intense, and its burning rate is higher.

[0008] In some embodiments, B is an alkali metal ion, N2H5 + NH3OH + or NH4 + At least one of them.

[0009] In some embodiments, the alkali metal ion is Na⁺, K⁺, Rb⁺, or Cs. + At least one of them.

[0010] In some embodiments, X is at least one energetic anion.

[0011] In some embodiments, X is at least one monovalent energetic anion.

[0012] In some embodiments, X is at least one halogen-containing energetic anion.

[0013] In some embodiments, X is ClO4. - .

[0014] In some embodiments, the distance between COs is smaller than the distance between COs in DAP-4.

[0015] In some embodiments, the distance between COs is less than 3 Å.

[0016] In some embodiments, the distance between NOs is smaller than the distance between NOs in DAP-4.

[0017] In some embodiments, the distance between NOs is less than 2.85 Å.

[0018] Compared to DAP-4, the novel molecular perovskite energetic material (high-burning-rate compound) has a shorter distance between CO and NO atoms. This reduced interatomic spacing intensifies the redox reaction between HDX-1 atoms, thereby making the combustion process more intense and increasing the burning rate of the molecular perovskite energetic material. The preparation process involved in this invention is mild, safe, environmentally friendly, and easy to scale up, showing promising application prospects in the field of high-burning-rate propellants.

[0019] In some embodiments, the 2θ values ​​in X-ray diffraction measurements using Cu Kα lines were 11.8°±0.3°, 13.2°±0.3°, 16.8°±0.3°, 17.9°±0.3°, 20.7°±0.3°, 21.5°±0.3°, 23.9°±0.3°, 24.2°±0.3°, 24.4°±0.3°, 24.7°±0.3°, and 26.6°±0.3°. Peaks are observed at the positions of 0.3°, 29.6°±0.3°, 32.5°±0.3°, 33.0°±0.3°, 34.9°±0.3°, 35.1°±0.3°, 37.9°±0.3°, 38.6°±0.3°, 40.8°±0.3°, 44.0°±0.3°, 45.8°±0.3°, and 48.0°±0.3°.

[0020] It should be noted that 11.8°±0.3° refers to the range of (11.8°-0.3°)-(11.8°+0.3°), that is, the range of 11.5°-12.1°. Other degrees have the same meaning.

[0021] This application is the first to synthesize a high-burning-rate compound with the above-mentioned XRD characteristic peaks. The high-burning-rate compound has a burning rate greater than 20 mm / s, which is 199% higher than that of DAP-4.

[0022] In some embodiments, the heat of explosion of the novel molecular perovskite energetic material is greater than or equal to 7 kJ•g. -1 .

[0023] In some embodiments, the enthalpy of formation is greater than or equal to 330 kJ•mol. -1 .

[0024] On the other hand, a method for preparing a high-burning-rate compound is provided, comprising:

[0025] An aqueous solution of N,N'-dimethylpiperazine was mixed with a solution containing B and a solution containing X to obtain the high-burning-rate compound, the high-burning-rate compound having the structural formula ABX3.

[0026] In some embodiments, B is an alkali metal ion, N2H5 + NH3OH + or NH4+ At least one of them.

[0027] In some embodiments, the alkali metal ion is Na⁺, K⁺, Rb⁺, or Cs. + At least one of them.

[0028] In some embodiments, X is at least one energetic anion.

[0029] In some embodiments, X is at least one monovalent energetic anion.

[0030] In some embodiments, X is at least one halogen-containing energetic anion.

[0031] In some embodiments, X is ClO4. - .

[0032] In some embodiments, mixing an aqueous solution of N,N'-dimethylpiperazine with a solution containing B and a solution containing X includes:

[0033] Acidification of ammonium perchlorate aqueous solution yields acidified ammonium perchlorate aqueous solution;

[0034] An aqueous solution of N,N'-dimethylpiperazine was added dropwise to the acidified ammonium perchlorate aqueous solution. The mixture was first heated and stirred, then cooled and stirred, and filtered to obtain the high-burning-rate compound.

[0035] The molar ratio of N,N'-dimethylpiperazine to ammonium perchlorate is 1:(1-1.5).

[0036] This invention uses N,N'-dimethylpiperazine and ammonium perchlorate (AP) as raw materials. The raw materials exist in ionic form in the solution system, and HDX-1 is obtained by growth and crystallization using ion self-assembly. The high-burning-rate compound HDX-1 provided by this invention has the characteristics of high combustion rate, which is more than 150% higher than that of DAP-4 and PAP-M4 compounds. At the same time, HDX-1 also has high enthalpy of formation and high detonation performance.

[0037] In some embodiments, the acidification uses a perchloric acid solution. Its addition does not introduce new impurities, only providing H⁺. This acidification method does not alter the fundamental ionic composition of the system while allowing for precise pH control.

[0038] In some embodiments, the acidification of the ammonium perchlorate aqueous solution includes: adding a perchloric acid solution dropwise into the ammonium perchlorate aqueous solution, stirring, adding an aqueous solution and continuing stirring to obtain an acidified ammonium perchlorate aqueous solution. Dropwise addition allows for precise control of acidity, avoiding localized over-acidity or concentration fluctuations.

[0039] In some embodiments, the molar ratio of N,N'-dimethylpiperazine, ammonium perchlorate, and perchloric acid is 1:(1-1.5):2.

[0040] The molar ratios here are not strictly precise ratios; any ratio obtained by rounding is acceptable. For example, the molar ratios of N,N'-dimethylpiperazine, ammonium perchlorate, and perchloric acid of 1.05:(1-1.5):2.036 or 0.998:(1-1.5):1.99 are also included in this range.

[0041] In some embodiments, the preparation of an aqueous solution of N,N'-dimethylpiperazine includes mixing water with an N,N'-dimethylpiperazine solution to obtain an aqueous solution of dimethylpiperazine.

[0042] In some embodiments, mixing water with the N,N'-dimethylpiperazine solution includes adding N,N'-dimethylpiperazine to water, maintaining the temperature in an oil bath at 20-25°C, and stirring for 5-15 minutes.

[0043] In some embodiments, the mass fraction of dimethylpiperazine in the N,N' dimethylpiperazine aqueous solution is 30% to 40%.

[0044] In some embodiments, the preparation of an aqueous solution of ammonium perchlorate includes mixing ammonium perchlorate with water to obtain an aqueous solution of ammonium perchlorate.

[0045] In some embodiments, mixing ammonium perchlorate with water includes: adding ammonium perchlorate to water, maintaining the temperature in an oil bath at 25-30°C, and continuously stirring until the AP (ammonium perchlorate) is completely dissolved. Generally, stirring for 5-15 minutes is sufficient for dissolution.

[0046] In some embodiments, the concentration of ammonium perchlorate aqueous solution is 0.1-0.2 g / g.

[0047] In some embodiments, the perchloric acid solution contains 70% perchloric acid by mass.

[0048] In some embodiments, the aqueous solution is added dropwise after stirring.

[0049] In some embodiments, the drop rate of the aqueous solution is 1 mL / min.

[0050] In some embodiments, adding an aqueous solution after stirring and continuing to stir includes adding an aqueous solution and stirring continuously until the solution becomes clear.

[0051] Because adding perchloric acid to an ammonium perchlorate solution will cause perchlorate to precipitate, forming a white precipitate, it is necessary to add water again to dissolve the perchlorate. Clarity here means that there are no visible white insoluble substances, and the solution is transparent. Generally, when the amount of water added reaches 20% of the total solution volume (referring to the sum of the volumes of perchloric acid and water used to dissolve the ammonium perchlorate before adding water), the white precipitate will completely dissolve, achieving clarity.

[0052] In some embodiments, the temperature of the reaction system is maintained at 25-30°C when water is added.

[0053] In some embodiments, the dropping rate of the N,N'-dimethylpiperazine aqueous solution is 0.5 mL / min.

[0054] In some embodiments, the perchloric acid solution is added at a rate of 1-2 mL / min.

[0055] In some embodiments, the temperature increase is raised to 60°C.

[0056] In some embodiments, the cooling is initiated when stirring begins as soon as the temperature starts to drop.

[0057] In some embodiments, the stirring time during heating and stirring is 5-10 minutes.

[0058] In some embodiments, the cooling and stirring are performed until a white solid precipitates, thus forming a high-burning-rate compound.

[0059] In some embodiments, the cooling and stirring are performed until the temperature is cooled to below 10°C.

[0060] Normally, the reaction vessel is placed in a low-temperature environment, such as an ice bath at 0°C, and the reaction system begins to cool down while being continuously stirred. When the temperature of the reaction vessel drops to 10°C or below, a large amount of white solid will precipitate, at which point stirring can be stopped.

[0061] In some embodiments, the white solid is filtered out after the system temperature drops below 10°C.

[0062] A third party also provides a high-burning-rate compound prepared by any of the above methods.

[0063] Fourthly, a solid propellant is also provided, comprising any of the high-burning-rate compounds described above.

[0064] Fifthly, a method for improving the burning rate of molecular perovskite energetic materials is also provided, comprising: using an active intermediate generated from the pyrolysis of the molecular perovskite energetic material as an A-site building unit.

[0065] In some embodiments, the intermediate is dmpz (N,N'-dimethylpiperazine).

[0066] Sixthly, a method for improving the burning rate of molecular perovskite energetic materials is also provided, including: shortening the interatomic distance between C–O and / or N–O in the structure of molecular perovskite energetic materials.

[0067] In some embodiments, the distance between COs is smaller than the distance between COs in DAP-4.

[0068] In some embodiments, the distance between COs is less than 3 Å.

[0069] In some embodiments, the distance between NOs is smaller than the distance between NOs in DAP-4.

[0070] In some embodiments, the distance between NOs is less than 2.85 Å.

[0071] This application addresses the issue of reducing the distance between the oxidant and organic molecules within the crystal lattice system (i.e., ClO4). − The distance between the atoms (C and N) is significantly reduced. This reduction in interatomic spacing intensifies the redox reactions between HDX-1 atoms, making them more susceptible to redox reactions. This, in turn, makes the combustion process more intense and increases the burning rate of the molecular perovskite energetic material.

[0072] The beneficial effects of this patent are:

[0073] 1. Compared with DAP-4 and PAP-M4 compounds, the product of this invention has a combustion rate that is more than 150% higher, while HDX-1 also has high enthalpy of formation and high detonation performance.

[0074] 2. The preparation process involved in this invention is mild, safe, environmentally friendly, and easy to scale up, and has good application prospects in the field of high-burning-rate propellants.

[0075] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, etc. Attached Figure Description

[0076] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0077] Figure 1 is a schematic diagram of the structure of a high-burning-rate compound;

[0078] Figure 2 is a SEM image of the product prepared in Example 1;

[0079] Figure 3 shows the XRD pattern of the product prepared in Example 1;

[0080] Figure 4 is a SEM image of the product prepared in Example 2;

[0081] Figure 5 is a SEM image of the product prepared in Example 3;

[0082] Figure 6 is a thermogravimetric diagram of the product prepared in Example 1;

[0083] Figure 7 shows the combustion performance test results of the product prepared in Example 1, DAP-4, and PAP-M4;

[0084] Figure 8 shows the crystal structures of the product prepared in Example 1, DAP-4, and PAP-M4. Detailed Implementation

[0085] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of specific embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0086] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, it is also expected that ranges of 60 to 110 and 80 to 120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise stated, the numerical range "a to b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 and 5" have been listed in this article; "0 to 5" is just a shortened representation of these numerical combinations. In addition, when a parameter is stated as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0087] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0088] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0089] In this application, "multiple" means two or more (including two).

[0090] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0091] Addressing the challenges posed by the significant spontaneous combustion risk and obvious safety issues often associated with existing high-energy components, this application focuses on ionic energetic materials with integrated oxygen and combustion within the crystal lattice, based on the intrinsic properties of the materials. Based on this mechanism, we infer that ionic energetic materials possess intrinsic combustion rates several orders of magnitude higher than molecular crystals; the difference in combustion rate is mainly determined by the characteristics of the initial decomposition stage, i.e., the earlier the exothermic reaction occurs in the solid-phase region and the higher the energy released, the faster the combustion rate. Among numerous candidate materials, molecular perovskite energetic materials show outstanding potential, with the DAP-4 compound being particularly prominent. It exhibits a detonation velocity of 8806 m / s and a detonation pressure of 35.2 GPa, demonstrating high oxygen balance and good energy release characteristics, showing promising application prospects as a functional component of high-burning-rate solid propellants.

[0092] Our analysis revealed that classic organic energetic materials are molecular crystals, exhibiting significant volatility during combustion. This volatility causes small molecules to escape into the gas phase before undergoing a redox energy release process involving the breaking and recombination of chemical bonds. Consequently, due to the difficulty of gas-solid phase thermal feedback, their burning rates are generally low. In contrast, molecular perovskite energetic materials are ionic crystals, characterized by intrinsically low volatility (i.e., low vapor pressure). Their decomposition reactions primarily occur in the solid phase, with the released small molecule components after lattice disruption re-entering the gas phase for redox reactions. Based on this mechanism, we hypothesize that: First, ionic energetic materials, especially molecular perovskite energetic materials which inherently assemble oxidants and reducing components within the same crystal lattice, possess intrinsic combustion rates several orders of magnitude higher than molecular crystals. The difference in burning rates among molecular perovskite energetic materials is primarily determined by the characteristics of the initial decomposition stage; that is, the earlier the exothermic reaction occurs in the solid phase and the higher the energy released, the faster the burning rate. Among them, DAP-4, a representative compound of molecular perovskite energetic materials, has been proven to have a high intrinsic burning rate: compared with HMX (burning rate of 0.35 mm / s at 0.1 MPa) and RDX (burning rate of 0.5 mm / s at 0.1 MPa), the intrinsic burning rate of DAP-4 powder is as high as 7.23 mm / s. It has been used to try to prepare high-burning-rate solid propellants, and the burning rate can reach 8.45 mm / s at 4 MPa. However, it is still far from reaching the level of high burning rate (≥25 mm / s at 6.86 MPa), and it still needs to be achieved through physicochemical means such as the addition of external catalysts.

[0093] Based on the above analysis and judgment, we propose for the first time a novel intermediate coupling strategy to construct high-burning-rate molecular perovskite energetic compounds (see Figure 1): by circumventing the key kinetic bottleneck in the decomposition process of DAP-4, where the C–C bond of the A-site cation dabco undergoes high-energy-barrier endothermic ring-opening to form a free radical, we find a method to rapidly increase the energy release rate in the early stage of the reaction. We innovatively use the active intermediate dmpz generated from the pyrolysis of DAP-4 directly as the A-site building block, successfully developing a novel molecular perovskite energetic material HDX-1 (i.e., the high-burning compound of this application).

[0094] This design fundamentally bypasses the initial endothermic step, enabling the material to rapidly trigger a vigorous redox reaction upon heating. Simultaneously, by shortening the C–O / N–O atomic spacing and increasing the solvent-accessible surface area, this design significantly enhances the mass and heat transfer efficiency of solid-state reactions.

[0095] This invention not only develops a class of molecular perovskite materials with excellent combustion performance, but also provides new ideas for the directional design of high-burning-rate energetic materials from the perspective of energy release pathway regulation.

[0096] This invention addresses the problem of high ignition thresholds in existing molecular perovskite energetic materials, which hinders their application in high-burning-rate solid propellants. It provides a novel molecular perovskite energetic compound (HDX-1) with a high combustion rate and its preparation method. This invention primarily improves the combustion rate of the molecular perovskite energetic material by reducing the distance between the oxidant and organic molecules within the crystal lattice system, thus facilitating redox reactions and resulting in a more intense combustion process. The preparation process is mild, safe, environmentally friendly, and easily scalable, showing promising application prospects in the field of high-burning-rate propellants.

[0097] The inventive concept of the preparation method of this invention is to use N,N'-dimethylpiperazine, AP and perchloric acid as raw materials. The three raw materials exist in ionic form in the solution system, and HDX-1 is obtained by growing and crystallizing using ion self-assembly.

[0098] The present application will be described in detail below through specific embodiments.

[0099] Example 1

[0100] A method for preparing a novel molecular perovskite energetic material HDX-1 with a high combustion rate includes the following process steps:

[0101] Dilution of N,N'-dimethylpiperazine: Weigh 0.571 g of N,N'-dimethylpiperazine and add it to 1 mL of deionized water. Keep the mixture in an oil bath at 25°C and stir for 10 min.

[0102] Dissolving AP: Weigh 0.587 g AP and add it to 4 mL of deionized water. Keep the oil bath at 25°C and stir continuously for 10 min until AP is completely dissolved.

[0103] Formation of acidified AP: Measure 1.435 g of perchloric acid (70% by mass) and add it to the dissolved AP solution. After a white precipitate appears, continue to add 1 mL of deionized water (1 mL / min). Stir continuously at 25°C for 10 minutes to completely dissolve the AP.

[0104] The ionic self-assembly reaction process of HDX-1: N,N'-dimethylpiperazine solution was slowly added dropwise (0.5 mL / min) to acidified AP solution, with the dropping rate controlled at 0.5 mL / min. The mixture was kept in an oil bath at 60℃ and stirred for 10 min.

[0105] Crystallization of HDX-1: The above solution system at 60°C was placed in a 0°C ice-water bath and stirred continuously to precipitate a white solid product HDX-1.

[0106] Collection of HDX-1: After the above solution system is cooled to below 10℃, the obtained white solid product is filtered, washed 2-3 times with anhydrous ethanol, and then placed in a vacuum dryer and dried at 70℃ for 6 h to obtain HDX-1.

[0107] The HDX-1 prepared in Example 1 was analyzed by scanning electron microscopy. As shown in Figure 2, its crystal size is between 10-50 μm and the crystal morphology is a regular blocky crystal.

[0108] The HDX-1 prepared in Example 1 was subjected to XRD analysis, and its X-ray powder diffraction results were compared with those derived from its standard single-crystal structure, as shown in Figure 3. The intensity positions of the main XRD peaks are shown in Table 1. The test results showed no significant difference from the theoretical results, proving that the prepared HDX-1 phase has high purity.

[0109] Table 1. Results of X-ray powder diffraction peak positions in Example 1

[0111] Example 2

[0112] A method for preparing a novel molecular perovskite energetic material HDX-1 with a high combustion rate includes the following process steps:

[0113] Dilution of N,N'-dimethylpiperazine: Weigh 2.855 g of N,N'-dimethylpiperazine and add it to 5 mL of deionized water. Keep the mixture in an oil bath at 25°C and stir for 10 min.

[0114] Dissolving AP: Weigh 2.935 g AP and add it to 20 mL of deionized water. Keep the oil bath at 25°C and stir continuously for 10 min until AP is completely dissolved.

[0115] Formation of acidified AP: Measure 7.175 g of perchloric acid (70% by mass) and add it to the dissolved AP solution. After a white precipitate appears, continue to add 15 mL of deionized water. Stir continuously at 25°C for 10 minutes to completely dissolve the AP.

[0116] The ionic self-assembly reaction process of HDX-1: N,N'-dimethylpiperazine solution was slowly added dropwise to acidified AP solution at a rate of 0.5 mL / min, and the mixture was kept in an oil bath at 60℃ and stirred for 10 min.

[0117] Crystallization of HDX-1: The above solution system at 60°C was placed in a 0°C ice-water bath and stirred continuously to precipitate a white solid product HDX-1.

[0118] Collection of HDX-1: After the above solution system is cooled to below 10℃, the obtained white solid product is filtered, washed 2-3 times with anhydrous ethanol, and then placed in a vacuum dryer and dried at 70℃ for 6 h to obtain HDX-1.

[0119] The HDX-1 prepared in Example 2 was analyzed by scanning electron microscopy. As shown in Figure 4, its crystal size is between 10 and 50 μm, and the crystal morphology is a regular blocky crystal.

[0120] Example 3

[0121] A method for preparing a novel molecular perovskite energetic material HDX-1 with a high combustion rate includes the following process steps:

[0122] Dilution of N,N'-dimethylpiperazine: Weigh 5.710 g of N,N'-dimethylpiperazine and add it to 10 mL of deionized water. Keep the mixture in an oil bath at 25°C and stir for 10 min.

[0123] Dissolving AP: Weigh 5.870 g AP and add it to 40 mL of deionized water. Keep the oil bath at 25°C and stir continuously for 10 min until AP is completely dissolved.

[0124] Formation of acidified AP: Measure 14.350 g of perchloric acid (70% by mass) and add it to the dissolved AP solution. After a white precipitate appears, continue to add 30 mL of deionized water. Stir continuously at 25°C for 10 minutes to completely dissolve the AP.

[0125] The ionic self-assembly reaction process of HDX-1: N,N'-dimethylpiperazine solution was slowly added dropwise to acidified AP solution at a rate of 0.5 mL / min, and the mixture was kept in an oil bath at 60℃ and stirred for 10 min.

[0126] Crystallization of HDX-1: The above solution system at 60°C was placed in a 0°C ice-water bath and stirred continuously to precipitate a white solid product HDX-1.

[0127] Collection of HDX-1: After the above solution system is cooled to below 10℃, the obtained white solid product is filtered, washed 2-3 times with anhydrous ethanol, and then placed in a vacuum dryer and dried at 70℃ for 6 h to obtain HDX-1.

[0128] The HDX-1 prepared in Example 3 was analyzed by scanning electron microscopy. As shown in Figure 5, its crystal size is between 10 and 50 μm, and the crystal morphology is a regular blocky crystal.

[0129] The HDX-1 prepared in Example 1 was analyzed by TG-DSC, and the results are shown in Figure 6. The initial decomposition temperature of HDX-1 was approximately 340 °C, and the decomposition termination temperature was approximately 368 °C. During the decomposition process, a prominent exothermic peak appeared, characterized by a peak temperature of 362 °C, which is higher than that of HMX (279 °C) and RDX (210 °C). The stable intramolecular covalent bonds and Coulomb interactions of the molecular perovskite energetic material make HDX-1 significantly more thermally stable than traditional energetic materials.

[0130] The HDX-1 prepared in Example 1 was subjected to density and heat of explosion analysis, and its detonation performance was calculated using EXPLO 5. The results are compared with those of DAP-4 and PAP-M4, as shown in Table 2. The energy performance of HDX-1 is comparable to that of DAP-4, but its enthalpy of formation is significantly higher than that of DAP-4.

[0131] Table 2 shows the test results of the examples and comparative examples.

[0132]

[0133] The HDX-1 prepared in Example 1 was subjected to combustion performance testing (multifunctional combustion diagnostics, high-speed camera imaging), and the test results are shown in Figure 7. The flame temperatures of HDX-1 and PAP-M4 were basically the same, both higher than those of DAP-4. At 0.1 MPa, the combustion rate of HDX-1 (21.64 mm / s) was 167% higher than that of PAP-M4 (8.11 mm / s) and 199% higher than that of DAP-4 (7.23 mm / s). Furthermore, HDX-1 had a combustion rate 60 times higher than that of commonly used propellant oxidizers HMX (0.35 mm / s at 0.1 MPa) and RDX (0.5 mm / s at 0.1 MPa).

[0134] The crystal structure of HDX-1 prepared in Example 1 was compared with that of DAP-4 and PAP-M4, and the results are shown in Figure 8 and Table 3. Compared with the distance observed in DAP-4, the symmetry and structural features of H2dabco and H2dmpz result in a shorter distance between CO and NO in HDX-1. The same conclusion was reached when comparing PAP-M4 with HDX-1. Therefore, in the perovskite structure of HDX-1, compared with DAP-4 and PAP-M4, ClO4... - The distance between the atoms and C and N is significantly reduced. This decrease in interatomic spacing intensifies redox reactions between HDX-1 atoms.

[0135] Table 3 Comparison of interatomic distances among three molecular perovskite energetic compounds

[0136]

[0137] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A high-burning-rate compound, characterized in that, The structure is a perovskite structure with the formula ABX3, wherein the A-site building unit is N,N'-dimethylpiperazine.

2. The high-burning-rate compound according to claim 1, characterized in that, B is an alkali metal ion, N2H5. + NH3OH + or NH4 + At least one of the following; preferably, the alkali metal ion is Na⁺, K⁺, Rb⁺ or Cs. + At least one of the following; and / or X is at least one energetic anion; preferably, X is at least one monovalent energetic anion; preferably, X is at least one halogen-containing energetic anion; more preferably, X is ClO4. - .

3. The high-burning-rate compound according to claim 1, characterized in that, The molecular formula is C6H 16 N2(NH4)(ClO4)3.

4. The high-burning-rate compound according to claim 1, characterized in that, The 2θ values ​​obtained using X-ray diffraction with Cu Kα lines were 11.8°±0.3°, 13.2°±0.3°, 16.8°±0.3°, 17.9°±0.3°, 20.7°±0.3°, 21.5°±0.3°, 23.9°±0.3°, 24.2°±0.3°, 24.4°±0.3°, 24.7°±0.3°, and 26.6°± Peaks are observed at the positions of 0.3°, 29.6°±0.3°, 32.5°±0.3°, 33.0°±0.3°, 34.9°±0.3°, 35.1°±0.3°, 37.9°±0.3°, 38.6°±0.3°, 40.8°±0.3°, 44.0°±0.3°, 45.8°±0.3°, and 48.0°±0.3°.

5. A method for preparing a high-burning-rate compound, characterized in that, include: An aqueous solution of N,N'-dimethylpiperazine is mixed with a solution containing B and a solution containing X to obtain the high-burning-rate compound, the high-burning-rate compound having the structural formula ABX3; preferably, B is an alkali metal ion or N2H5. + NH3OH + or NH4 + At least one of the following; preferably, the alkali metal ion is Na⁺, K⁺, Rb⁺ or Cs. + At least one of the following: preferably, X is at least one energetic anion; preferably, X is at least one monovalent energetic anion; preferably, X is at least one halogen-containing energetic anion; more preferably, X is ClO4. - .

6. The preparation method according to claim 5, characterized in that, The mixing of the N,N'-dimethylpiperazine aqueous solution with the solutions containing B and X comprises: acidifying the ammonium perchlorate aqueous solution to obtain an acidified ammonium perchlorate aqueous solution; adding the N,N'-dimethylpiperazine aqueous solution dropwise into the acidified ammonium perchlorate aqueous solution, first heating and stirring, then cooling and stirring, and filtering to obtain the high-burning-rate compound; wherein the molar ratio of N,N'-dimethylpiperazine to ammonium perchlorate is 1:1-1.

5.

7. The preparation method according to claim 5, characterized in that, The acidification of the ammonium perchlorate aqueous solution includes: acidification using a perchloric acid solution; preferably, the perchloric acid solution is added dropwise to the ammonium perchlorate aqueous solution, and after stirring, an aqueous solution is added and stirring is continued to obtain an acidified ammonium perchlorate aqueous solution; wherein, the molar ratio of N,N'-dimethylpiperazine, ammonium perchlorate and perchloric acid is 1:1-1.5:

2.

8. The preparation method according to claim 6, characterized in that, The mass fraction of the N,N'-dimethylpiperazine aqueous solution is 30%~40%; and / or the mass fraction of the perchloric acid solution is 70%; and / or the concentration of the ammonium perchlorate aqueous solution is 0.1-0.2 g / g.

9. The preparation method according to claim 6, characterized in that, The aqueous solution is added dropwise after stirring; preferably, the dropping rate is 1-2 mL / min; and / or the dropping rate of the N,N'-dimethylpiperazine aqueous solution is 0.5-1 mL / min; and / or the dropping rate of the perchloric acid solution is 1-2 mL / min; and / or the heating is raised to 50-60°C.

10. The preparation method according to claim 5, characterized in that, The addition of an aqueous solution after stirring and continued stirring includes: adding an aqueous solution and stirring continuously until the solution is clear; and / or the stirring time for heating and stirring is 5-10 minutes; and / or the cooling and stirring is carried out until the temperature is cooled to below 10°C.

11. A solid propellant, characterized in that, Includes the high-burning-rate compound as described in any one of claims 1-4.

12. A method for increasing the burning rate of molecular perovskite energetic materials, comprising: The active intermediate generated by the pyrolysis of molecular perovskite energetic materials is used as the A-site building unit; preferably, the active intermediate is N,N'-dimethylpiperazine.

13. A method for increasing the burning rate of molecular perovskite energetic materials, comprising: Shorten the interatomic distances of C–O and / or N–O in the molecular perovskite energetic material structure; preferably, the distance between CO atoms is smaller than the distance between CO atoms in DAP-4; preferably, the distance between CO atoms is less than 3 Å; preferably, the distance between NO atoms is smaller than the distance between NO atoms in DAP-4; preferably, the distance between NO atoms is less than 2.85 Å.

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