Stable high-energy explosive-based composite energetic material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of energetic material compounding, and discloses a stable high-energy explosive-based composite energetic material and a preparation method and application thereof, the stable high-energy explosive-based composite energetic material comprises 93-96% of an energetic matrix CL-20, 3-6% of a composite sensitizer, and 1-1.5% of a surface modifier; the composite sensitizer is a mixture of g-C3N4, HO-CNT and GO, the surface modifier is obtained by mixing PDA and PEI, the preparation method comprises the steps of preparing g-C3N4 powder, preparing the three-dimensional composite sensitizer, performing PDA / PEI composite modification on CL-20 and performing electrostatic self-assembly coating, and the stable high-energy explosive-based composite energetic material is obtained through two-step in-situ coating and electrostatic self-assembly. According to the stable high-energy explosive-based composite energetic material disclosed by the invention, high energy of CL-20 is reserved, and meanwhile, efficient sensitivity reduction can be realized.

Description

Technical Field

[0001] This invention relates to the field of energetic material composite technology, and more specifically, to a stable high-energy explosive-based composite energetic material, its preparation method, and its application. Background Technology

[0002] Existing technologies have disclosed the use of g-C3N4-based composite energetic materials. For example, CN112898103A provides a method for preparing g-C3N4-based composite energetic materials. However, the energetic composite materials still have three major limitations: 1) The desensitizer is a two-dimensional structure of g-C3N4 / GO, which is insufficient for the integrity of the explosive crystal coating and is easy to fall off under mechanical stimulation; 2) The energy density of the base explosive (such as HMX) (about 7.8 kJ / g) is relatively low, which is difficult to meet the requirements of high-end weapons and equipment; 3) The surface modifier PEI has limited adhesion, the interface bonding between the desensitizer and the explosive is weak, and the long-term storage stability is poor.

[0003] Currently, CL-20, as the single-element explosive with the highest energy density (theoretical energy density 8.5kJ / g), is difficult to apply directly due to its extremely high mechanical sensitivity (impact sensitivity 2.8J, friction sensitivity 80N).

[0004] Therefore, developing a new composite system that can achieve efficient sensitivity reduction while retaining the high energy of CL-20 is of great practical significance. Summary of the Invention

[0005] In view of this, the present invention proposes a stable high-energy explosive-based composite energetic material, its preparation method and application, aiming to solve the problems of incomplete coating of explosive crystals, low energy density and poor long-term storage performance in the current explosive-based composite energetic materials.

[0006] This invention proposes a stable high-energy explosive-based composite energetic material, which comprises the following components by mass fraction: Energetic matrix CL-20 93-96%, composite desensitizer 3-6%, surface modifier 1-1.5%.

[0007] Furthermore, the composite desensitizer is a mixture of g-C3N4, HO-CNT, and GO, wherein the mass ratio of g-C3N4, HO-CNT, and GO is 2:1:4-4:3:6, and the HO-CNT has a tube diameter of 10-20 nm, a length of 1-5 μm, and a hydroxyl content of ≥5 wt%.

[0008] Furthermore, the surface modifier is obtained by mixing PDA and PEI at a mass ratio of 1:0.8-1:1.2.

[0009] A method for preparing a stable high-energy explosive-based composite energetic material includes the following steps: (1) Preparation of g-C3N4 powder: After grinding urea evenly, it was heated and kept warm, and then naturally cooled to room temperature. The resulting powder was light yellow g-C3N4 powder. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water, ultrasonically dispersed and then hydrazine hydrate was added. The mixture was stirred in an oil bath at 100℃, filtered and washed with deionized water, and vacuum dried to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, ultrasonically dispersed, PDA and PEI were added, and stirred at room temperature to obtain modified CL-20 dispersion; (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer of step (2) is added to the modified CL-20 dispersion of step (3) and ultrasonically dispersed. The mixture is stirred at room temperature, filtered, rinsed with deionized water, and then vacuum dried to obtain the stable high-energy explosive-based composite energetic material.

[0010] Furthermore, the amount of urea used in step (1) is 20g; the heating is carried out at a heating rate of 1.5-2.5℃ / min to 540-560℃; the holding time is 3.5-4.5h; and the particle size of the g-C3N4 powder is 50-100nm.

[0011] Furthermore, in step (2), the solid-liquid ratio of g-C3N4, HO-CNT, and GO added to deionized water is 1g:80-120mL; the mass fraction of hydrazine hydrate is 85-90%; the amount of hydrazine hydrate used is 0.08-0.12mL per 100mL suspension; the ultrasonic parameters are: power 280-320W, frequency 38-42KHz, time 50-70min; the stirring parameters are: rotation speed 420-450r / min, time 1.5-2.5h; the vacuum drying parameters are: temperature 55-65℃, time 7-9h.

[0012] Furthermore, in step (3), the solid-liquid ratio of CL-20 added to deionized water is 1g:4-6mL; the ultrasonic parameters are: power 280-320W, time 80-100min; the stirring parameters are: speed 420-450r / min, time 1.5-2.5h.

[0013] Furthermore, the ultrasonic parameters in step (4) are: power 280-320W, time 40-50min; the stirring parameters are: rotation speed 420-450r / min, time 2.5-3.5h; and the vacuum drying parameters are: temperature 55-65℃, time 9-11h.

[0014] Furthermore, the deionized water rinsing operation in steps (2) and (4) is to use 50 mL of deionized water each time, and repeat 3 times.

[0015] This invention also provides applications of the stable high-energy explosive-based composite energetic materials described in the above technical solutions. Specifically, these applications include the preparation of missile warhead explosives, torpedo explosives, or solid propellants for deep space exploration; and the preparation of explosives for deep well blasting in mines or for perforating projectiles in oil and gas wells.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses g-C3N4 / HO-CNT / GO to form an interwoven three-dimensional structure, which improves the integrity of CL-20 coating and reduces the shedding rate under mechanical stimulation.

[0017] The PDA / PEI composite modification of this invention enhances the interfacial bonding force through hydrogen bonding (PDA hydroxyl group and CL-20 nitro group) and conjugation (PDA benzene ring and carbon material). The stable high-energy explosive-based composite energetic material prepared by this invention exhibits a reduced performance degradation rate after being stored at 50°C for 6 months.

[0018] Compared with traditional technologies, the stable high-energy explosive-based composite energetic material prepared by this invention has achieved a breakthrough in balancing high energy and low sensitivity. The impact sensitivity and friction sensitivity of the product are improved, while the thermal decomposition temperature and energy density still maintain the excellent performance of CL-20.

[0019] This invention uses water as the solvent throughout the process and contains no organic reagents, which can be extended to the modification of other ammonium nitrate explosives such as RDX and BCHMX, thus expanding the application of the technology. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0021] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0022] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0023] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This specification and embodiments are merely exemplary.

[0024] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0025] This invention proposes a stable high-energy explosive-based composite energetic material, which comprises the following components by mass fraction: Energetic matrix CL-20 93-96%, composite desensitizer 3-6%, surface modifier 1-1.5%.

[0026] In this invention, the stable high-energy explosive-based composite energetic material is further preferably composed of the following components by mass fraction: Energetic matrix CL-20 94-96%, composite desensitizer 3-5%, surface modifier 1-1.3%.

[0027] The composite desensitizer described in this invention is a mixture of g-C3N4, HO-CNT, and GO. The preferred mass ratio of g-C3N4, HO-CNT, and GO is 2:1:4-4:3:6, and more preferably 3:2:5-4:3:6. The HO-CNT has a tube diameter of 10-20 nm, a length of 1-5 μm, and a hydroxyl content of ≥5 wt%.

[0028] In this invention, HO-CNT is selectively added to the stable high-energy explosive-based composite energetic material. The HO-CNT, along with g-C3N4 and GO, forms a three-dimensional composite desensitization system. The tubular structure can disperse the local stress generated by impact / friction along the tube axis to the entire three-dimensional network, avoiding stress concentration that could cause CL-20 crystal breakage. This improves the integrity of the coating and disperses mechanical stress. The hydroxyl groups on the surface of the HO-CNT can form a weak electrostatic interaction with the nitro groups (-NO2) in the CL-20 molecule, reducing the voids at the interface between the desensitizer and the explosive, lowering the escape rate of thermal decomposition gases, increasing the thermal decomposition temperature of CL-20, and the HO-CNT in the three-dimensional network can serve as a conduction channel for the detonation wave, allowing the detonation wave to propagate uniformly along the network and avoiding detonation pressure fluctuations caused by local energy unevenness.

[0029] The surface modifier described in this invention is preferably a mixture of PDA and PEI at a mass ratio of 1:0.8-1:1.2, and more preferably 1:1.

[0030] In this invention, a surface modifier is selectively added to the stable high-energy explosive-based composite energetic material. The surface modifier includes PDA and PEI. On the one hand, the amino (-NH2) and phenolic hydroxyl (-OH) groups of PDA can form strong bonds with the nitro groups on the surface of CL-20 crystals, and the amino (-NH2) groups of PDA can form hydrogen bonds with the hydroxyl groups in the desensitizer. The imino (-NH-) groups of PEI can form coordinate bonds with the hydroxyl groups in the desensitizer, thereby increasing the adsorption of the modifier on the HO-CNT surface and preventing the modified layer from falling off. On the other hand, when the material is subjected to impact / friction, the network structure of PDA can buffer local stress through chain segment deformation, preventing stress concentration from causing CL-20 crystal breakage. PDA contains about 15% nitrogen, which can participate in the reaction to generate N2 during detonation, avoiding energy loss caused by traditional inert modifiers. The PDA / PEI composite modification achieves strong bonding, low sensitivity, high energy retention, and long-term stability of the composite energetic material through the synergistic effect of PDA anchoring the interface and PEI regulating the charge.

[0031] A method for preparing a stable high-energy explosive-based composite energetic material includes the following steps: (1) Preparation of g-C3N4 powder: After grinding urea evenly, it was heated and kept warm, and then naturally cooled to room temperature. The resulting powder was light yellow g-C3N4 powder. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water, ultrasonically dispersed and then hydrazine hydrate was added. The mixture was stirred in an oil bath at 100℃, filtered and washed with deionized water, and vacuum dried to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, ultrasonically dispersed, PDA and PEI were added, and stirred at room temperature to obtain modified CL-20 dispersion; (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer of step (2) is added to the modified CL-20 dispersion of step (3) and ultrasonically dispersed. The mixture is stirred at room temperature, filtered, rinsed with deionized water, and then vacuum dried to obtain the stable high-energy explosive-based composite energetic material.

[0032] (1) Preparation of g-C3N4 powder: After grinding urea evenly, it was heated and kept warm, and then naturally cooled to room temperature. The resulting powder was light yellow g-C3N4 powder. In this invention, the amount of urea used in step (1) is 20g; the heating is preferably carried out at a heating rate of 1.5-2.5℃ / min to 540-560℃, more preferably at a heating rate of 2-2.5℃ / min to 550-560℃; the holding time is preferably 3.5-4.5h, more preferably 4-4.5h; the particle size of the g-C3N4 powder is preferably 50-100nm, more preferably 75-100nm.

[0033] (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water, ultrasonically dispersed and then hydrazine hydrate was added. The mixture was stirred in an oil bath at 100℃, filtered and washed with deionized water, and vacuum dried to obtain black three-dimensional composite desensitizing agent powder. In step (2) of this invention, the solid-liquid ratio of g-C3N4, HO-CNT, and GO added to deionized water is preferably 1g:80-120mL, more preferably 1g:100-120mL; the mass fraction of hydrazine hydrate is preferably 85-90%, more preferably 87-90%; the amount of hydrazine hydrate used is preferably 0.08-0.12mL per 100mL of suspension, more preferably 0.10-0.12mL per 100mL of suspension; the ultrasonic parameters are preferably: power 280- The preferred stirring parameters are: 320W power, 38-42KHz frequency, and 50-70min time; more preferably, 300-320W power, 40-42KHz frequency, and 60-70min time. The preferred stirring parameters are: 420-450r / min speed and 1.5-2.5h time; more preferably, 430-450r / min speed and 2-2.5h time. The preferred vacuum drying parameters are: 55-65℃ temperature and 7-9h time; more preferably, 60-65℃ temperature and 8-9h time.

[0034] In the preparation method of the high-energy explosive-based composite energetic material of the present invention, step (2) of preparing the three-dimensional composite desensitizer is selected by ultrasonication. The ultrasonication breaks up the interlayer stacking of g-C3N4, so that it is uniformly suspended in a few layers of sheets, which can then form a sheet-tube interweaving with the tubular structure of HO-CNT; it untangles and evenly distributes HO-CNT, so that it can serve as a three-dimensional skeleton in the desensitizer to connect g-C3N4 and GO, and avoid the local dense formation of agglomerates of HO-CNT; it breaks up the sheet aggregation of GO, so that it can fully contact g-C3N4 and HO-CNT, and after in-situ reduction to rGO, a three-dimensional conductive network of sheet-tube-sheet can be formed. The overall function is to achieve molecular-level interweaving and pre-dispersion of the three desensitizers.

[0035] In this invention, hydrazine hydrate is added to the preparation method of the high-energy explosive-based composite energetic material. Hydrazine hydrate is a core chemical reagent for achieving in-situ reduction of graphene oxide (GO), constructing a three-dimensional composite desensitizing network, and improving the energy and stability of the material. It can reduce GO to rGO (reduced graphene oxide) in situ, solving the performance defects of GO. The three-dimensional composite desensitizing agent (g-C3N4 / HO-CNT / GO) needs to form a stable interwoven structure through intermolecular forces. While reducing GO, hydrazine hydrate can also act as a "crosslinking agent" to strengthen the combination of the three components, promote the crosslinking and anchoring of the three-dimensional desensitizing network, and avoid structural collapse. The modified CL-20 (PDA / PEI coated, with a positively charged surface) needs to be combined with the three-dimensional desensitizing agent through electrostatic interaction. Hydrazine hydrate can regulate the surface charge state of the desensitizing agent through the reduction reaction.

[0036] (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, ultrasonically dispersed, PDA and PEI were added, and stirred at room temperature to obtain modified CL-20 dispersion; In step (3) of this invention, the solid-liquid ratio of CL-20 added to deionized water is preferably 1g:4-6mL, more preferably 1g:5-6mL; the ultrasonic parameters are preferably: power 280-320W, time 80-100min, more preferably power 300-320W, time 90-100min; the stirring parameters are preferably: rotation speed 420-450r / min, time 1.5-2.5h, more preferably rotation speed 430-450r / min, time 2-2.5h.

[0037] In the preparation method of the high-energy explosive-based composite energetic material of the present invention, step (3) of PDA / PEI composite modification of CL-20 is selected as an ultrasonic step. The ultrasonic step is to make the CL-20 particles uniformly suspended and surface activated, so as to ensure that the PDA / PEI forms a dense and uniform modified layer. The turbulent effect of the ultrasonic step can keep the CL-20 stable and suspended, avoid the bottom particles without a modified layer, and also break up the local aggregation of PDA / PEI molecules, ensuring that the modified layer is smooth and dense, and improving the interfacial bonding force.

[0038] (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer of step (2) is added to the modified CL-20 dispersion of step (3) and ultrasonically dispersed. The mixture is stirred at room temperature, filtered, rinsed with deionized water, and then vacuum dried to obtain the stable high-energy explosive-based composite energetic material.

[0039] In this invention, the preferred ultrasonic parameters in step (4) are: power 280-320W, time 40-50min, and more preferably power 300-320W, time 45-50min; the preferred stirring parameters are: rotation speed 420-450r / min, time 2.5-3.5h, and more preferably rotation speed 430-450r / min, time 3-3.5h; the preferred vacuum drying parameters are: temperature 55-65℃, time 9-11h, and more preferably temperature 60-65℃, time 10-11h.

[0040] In the preparation method of the high-energy explosive-based composite energetic material, the present invention selected an ultrasonic step in step (4) electrostatic self-assembly coating. The ultrasonic desensitizer particles are uniformly dispersed around the modified CL-20 to ensure that the electrostatic effect occurs fully and to avoid local areas without desensitizer protection. The uniform dispersion of the ultrasonic waves can prevent the desensitizer from being excessively accumulated on the surface of some CL-20 particles, ensuring that the desensitizer content deviation of each composite particle in the final product is <±0.2%, and the energy performance is uniform and stable.

[0041] In this invention, the deionized water rinsing operation in steps (2) and (4) is to use 50 mL of deionized water each time, and repeat 3 times.

[0042] In the preparation method of the stable high-energy explosive-based composite energetic material of the present invention, vacuum drying is selected. The vacuum drying is used to avoid high-temperature damage and to efficiently remove water and maintain purity. In step 2, the vacuum drying is used to protect the three-dimensional network skeleton of the composite desensitizer, to prevent structural collapse, to retain active groups and maintain cross-sectional binding ability, and to remove residual hydrazine hydrate to avoid interference from subsequent reactions. In step 4, the vacuum drying is used to protect the crystal structure of CL-20 in the composite energetic material product, to prevent energy loss, to ensure the compactness of the coating and improve mechanical stability, and to control the water content in the composite energetic material, ensuring storage safety. It also ensures that the product structure and performance are locked after coating, and avoids damage to the formed CL-20-modified layer-desensitizer interface due to improper drying.

[0043] This invention also provides applications of the stable high-energy explosive-based composite energetic materials described in the above technical solutions. Specifically, these applications include the preparation of missile warhead explosives, torpedo explosives, or solid propellants for deep space exploration; and the preparation of explosives for deep well blasting in mines or for perforating projectiles in oil and gas wells.

[0044] Example 1 Raw materials: The ratio of three-dimensional desensitizer g-C3N4:HO-CNT:GO=3:2:5, CL-20: composite desensitizer: surface modifier=94:5:1; Preparation method: (1) Preparation of g-C3N4 powder: 20g of urea was ground evenly and heated to 550℃ at a heating rate of 2℃ / min. After holding at the temperature for 4h, it was naturally cooled to room temperature and ground to obtain light yellow g-C3N4 powder with a particle size of 75nm. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water at a mass ratio of 3:2:5, wherein the solid-liquid ratio of g-C3N4, HO-CNT and GO added to deionized water was 1g:100mL. After dispersion by ultrasonication for 60min at a power of 300W and a frequency of 40KHz, hydrazine hydrate with a mass fraction of 87% was added. The mixture was stirred at a speed of 430r / min for 2h in an oil bath at 100℃. After filtration, the mixture was washed three times with 50mL of deionized water and dried under vacuum at 60℃ for 8h to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, and the solid-liquid ratio of CL-20 to deionized water was further preferably 1g:5mL. The mixture was ultrasonically dispersed for 90min under a power of 300W. PDA and PEI with a mass ratio of 1:1 were added, and the mixture was stirred at 430r / min for 2h at room temperature to obtain the modified CL-20 dispersion. (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer from step (2) was added to the modified CL-20 dispersion from step (3) and ultrasonically dispersed for 45 minutes at a power of 300W. The mixture was stirred at 430 r / min for 3 hours at room temperature. After filtration, it was washed three times with 50 mL of deionized water. After washing, it was vacuum dried at 60°C for 10 hours to obtain the stable high-energy explosive-based composite energetic material.

[0045] Example 2 Raw materials: The ratio of three-dimensional desensitizer g-C3N4:HO-CNT:GO = 4:3:6, CL-20: desensitizer: modifier = 95:4:1; Preparation method: (1) Preparation of g-C3N4 powder: 20g of urea was ground evenly and heated to 560℃ at a heating rate of 2.5℃ / min. After holding at the temperature for 4.5h, it was naturally cooled to room temperature and ground to obtain light yellow g-C3N4 powder with a particle size of 100nm. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water at a mass ratio of 4:3:6, wherein the solid-liquid ratio of g-C3N4, HO-CNT and GO added to deionized water was 1g:120mL. After dispersion by ultrasonication for 70min at a power of 320W and a frequency of 42KHz, hydrazine hydrate with a mass fraction of 90% was added. The mixture was stirred at a speed of 450r / min for 2.5h in an oil bath at 100℃. After filtration, the mixture was washed three times with 50mL of deionized water and dried under vacuum at 65℃ for 9h to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, and the solid-liquid ratio of CL-20 to deionized water was further preferably 1g:6mL. The mixture was dispersed by ultrasonication for 100min under a power of 300W. PDA and PEI with a mass ratio of 1:1 were added, and the mixture was stirred at 450r / min for 2.5h at room temperature to obtain the modified CL-20 dispersion. (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer from step (2) was added to the modified CL-20 dispersion from step (3) and ultrasonically dispersed for 50 min at a power of 320 W. The mixture was stirred at 450 r / min for 3.5 h at room temperature. After filtration, it was washed three times with 50 mL of deionized water. After washing, it was vacuum dried at 65 °C for 11 h to obtain the stable high-energy explosive-based composite energetic material.

[0046] Example 3 Raw materials: The ratio of three-dimensional desensitizer g-C3N4:HO-CNT:GO=3:3:5, CL-20: desensitizer: modifier=96:3:1; Preparation method: (1) Preparation of g-C3N4 powder: 20g of urea was ground evenly and heated to 555℃ at a heating rate of 2℃ / min. After holding at the temperature for 4h, it was naturally cooled to room temperature and ground to obtain light yellow g-C3N4 powder with a particle size of 90nm. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water at a mass ratio of 3:3:5, wherein the solid-liquid ratio of g-C3N4, HO-CNT and GO added to deionized water was 1g:110mL. After dispersion by ultrasonication for 65min at a power of 310W and a frequency of 41KHz, hydrazine hydrate with a mass fraction of 88% was added. The mixture was stirred at a speed of 440r / min for 2h in an oil bath at 100℃. After filtration, it was washed three times with 50mL of deionized water and dried under vacuum at 63℃ for 8.5h to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, and the solid-liquid ratio of CL-20 to deionized water was further preferably 1g:5.5mL. The mixture was ultrasonically dispersed for 95min under a power of 310W. PDA and PEI with a mass ratio of 1:1 were added, and the mixture was stirred at 440r / min for 2h at room temperature to obtain the modified CL-20 dispersion. (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer from step (2) was added to the modified CL-20 dispersion from step (3) and ultrasonically dispersed for 48 minutes at a power of 310W. The mixture was stirred at 440 r / min for 3 hours at room temperature. After filtration, it was washed three times with 50 mL of deionized water. After washing, it was vacuum dried at 63°C for 10.5 hours to obtain the stable high-energy explosive-based composite energetic material.

[0047] Comparative Example Raw materials: CL-20 95%, two-dimensional desensitizer (g-C3N4:GO mass ratio 1:1) 4.5%, single PEI modifier 0.5%; Preparation method: (1) Preparation of g-C3N4 powder: Same as in Example 1 (20g urea, heating to 550℃ at 2℃ / min, holding for 4h), particle size 75nm; (2) Preparation of two-dimensional desensitizing agent: Take g-C3N4 and GO in a ratio of 5:5 and add them to deionized water. The solid-liquid ratio is 1g:70mL. Sonicate at 300W power for 60min. After direct filtration, vacuum dry at 60℃ for 8h. (3) CL-20 modified with PEI: Take 9.5g of CL-20 and add it to 50mL of deionized water, sonicate at 300W for 90min, add 0.05g of PEI, and stir at 350r / min for 2h; (4) Simple mixing and coating: Add 0.45g of two-dimensional desensitizer to the modified CL-20 dispersion, sonicate at 300W for 45min, stir at 350r / min for 3h, filter and vacuum dry at 60℃ for 10h.

[0048] Performance testing: The performance test results of Examples 1-3 and the comparative examples are shown in Table 1 below: Table 1 Performance test results of Examples 1-3 and Comparative Examples

[0049] In summary, compared to the comparative example, the addition of HO-CNT to the desensitizer in this invention can significantly improve the pile foundation sensitivity and friction sensitivity of the composite energetic material. Its thermal stability and activation energy are also improved to a certain extent. After being sealed at 50°C for 6 months, the impact sensitivity and friction sensitivity show little change. Furthermore, the detonation velocity of pure CL-20 in underwater explosion is 9300 m / s and the detonation pressure is 39 GPa, while the detonation velocity of this invention is 9150-9250 m / s and the detonation pressure is 37.5-38.3 GPa. The composite energetic material prepared by this invention can achieve efficient desensitization while retaining the high energy of CL-20.

[0050] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is determined by the appended claims.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A stable high-energy explosive-based composite energetic material, characterized in that, The stabilized high-energy explosive-based composite energetic material comprises the following components by mass fraction: Energetic matrix CL-20 93-96%, composite desensitizer 3-6%, surface modifier 1-1.5%.

2. The stable high-energy explosive-based composite energetic material according to claim 1, characterized in that, The composite desensitizer is a mixture of g-C3N4, HO-CNT, and GO, with a mass ratio of g-C3N4, HO-CNT, and GO of 2:1:4-4:3:

6. The HO-CNT has a tube diameter of 10-20 nm, a length of 1-5 μm, and a hydroxyl content of ≥5 wt%.

3. The stable high-energy explosive-based composite energetic material according to claim 1, characterized in that, The surface modifier is obtained by mixing PDA and PEI at a mass ratio of 1:0.8-1:1.

2.

4. A method for preparing a stable high-energy explosive-based composite energetic material as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Preparation of g-C3N4 powder: After grinding urea evenly, it was heated and kept warm, and then naturally cooled to room temperature. The resulting powder was light yellow g-C3N4 powder. (2) Preparation of three-dimensional composite desensitizing agent: g-C3N4, HO-CNT and GO were added to deionized water, ultrasonically dispersed and then hydrazine hydrate was added. The mixture was stirred in an oil bath at 100℃, filtered and washed with deionized water, and vacuum dried to obtain black three-dimensional composite desensitizing agent powder. (3) PDA / PEI composite modified CL-20: CL-20 was added to deionized water, ultrasonically dispersed, PDA and PEI were added, and stirred at room temperature to obtain modified CL-20 dispersion; (4) Electrostatic self-assembly coating: The three-dimensional composite desensitizer of step (2) is added to the modified CL-20 dispersion of step (3) and ultrasonically dispersed. After stirring at room temperature, the mixture is filtered and rinsed with deionized water. After rinsing, it is vacuum dried to obtain the stable high-energy explosive-based composite energetic material.

5. The method for preparing the stable high-energy explosive-based composite energetic material according to claim 4, characterized in that, The amount of urea used in step (1) is 20g; the heating is carried out at a heating rate of 1.5-2.5℃ / min to 540-560℃; the holding time is 3.5-4.5h; and the particle size of the g-C3N4 powder is 50-100nm.

6. The method for preparing the stable high-energy explosive-based composite energetic material according to claim 4, characterized in that, In step (2), the solid-liquid ratio of g-C3N4, HO-CNT, and GO added to deionized water is 1g: 80-120mL; the mass fraction of hydrazine hydrate is 85-90%; the amount of hydrazine hydrate used is 0.08-0.12mL per 100mL suspension; the ultrasonic parameters are: power 280-320W, frequency 38-42KHz, time 50-70min; the stirring parameters are: rotation speed 420-450r / min, time 1.5-2.5h; the vacuum drying parameters are: temperature 55-65℃, time 7-9h.

7. The method for preparing the stable high-energy explosive-based composite energetic material according to claim 4, characterized in that, In step (3), the solid-liquid ratio of CL-20 to deionized water is 1g:4-6mL; the ultrasonic parameters are: power 280-320W, time 80-100min; the stirring parameters are: speed 420-450r / min, time 1.5-2.5h.

8. The method for preparing the stable high-energy explosive-based composite energetic material according to claim 4, characterized in that, The ultrasonic parameters for step (4) are: power 280-320W, time 40-50min; the stirring parameters are: rotation speed 420-450r / min, time 2.5-3.5h; and the vacuum drying parameters are: temperature 55-65℃, time 9-11h.

9. The method for preparing the stable high-energy explosive-based composite energetic material according to claim 4, characterized in that, The deionized water rinsing operation in steps (2) and (4) is to use 50 mL of deionized water each time, and repeat 3 times.

10. The application of a stable high-energy explosive-based composite energetic material according to any one of claims 1-3, characterized in that, include: Applications in the preparation of missile warhead explosives, torpedo explosives, or solid propellants for deep space exploration; Applications include the preparation of explosives for deep well blasting in mines or for perforation shells in oil and gas wells.

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