Al / polypeptide / AP biological composite energetic material and preparation method thereof
By forming a strong interaction with the polypeptide with Al powder and AP, the problem of easy agglomeration and uneven mixing of Al powder is solved, and the combustion efficiency and stability of the solid propellant is significantly improved.
Patent Information
- Application Number
- CN202510355807.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2025-06-27
AI Technical Summary
Al powder is prone to agglomeration in the solid propellant and the mixture with AP is uneven, resulting in a degradation of combustion performance.
The polypeptide is used to form a strong interaction with Al powder and AP, and the binding force of the polypeptide with Al powder is enhanced through chemical bonds and hydrogen bonds, and hydrogen bonds are formed with AP to improve interface contact.
The structural stability and combustion efficiency of composite materials are significantly improved, the mechanical and thermal properties of propellants are enhanced, and the energy utilization rate is improved.
Smart Images
Figure CN120208739A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of energetic materials, and particularly relates to an Al / polypeptide / AP biological composite energetic material and a preparation method thereof. Background Art
[0002] Aluminum powder has characteristics such as high combustion calorific value, high density, and low cost, and is commonly used as a metal fuel in solid propellants; AP has high oxygen content, strong oxidizing property, and good chemical stability, and all of its thermal decomposition products can be converted into stable gas products. Therefore, in solid propellants, Al powder is often compounded with the oxidizer AP to prepare Al / AP composites as a reducing agent. However, due to the presence of a dense oxide film on the surface of Al powder and easy agglomeration during the combustion process, the problems of low combustion efficiency, high ignition delay, and easy agglomeration of metal Al powder will lead to a decline in the combustion performance of the propellant.
[0003] Researchers have carried out a series of research works. For example, patents CN117843422A and CN115947640B propose to modify aluminum powder with fluoropolymers to improve the dispersibility and combustion performance of Al powder. In addition, by compounding the modified Al powder with AP, the prepared composite energetic material can improve the contact interface between Al powder and AP, thereby enhancing the safety of the composite material.
[0004] However, there are still some problems in the existing technologies. For example, uneven mixing: The uneven mixing of the oxidizer and the reducing agent results in a small contact area between the two, unable to fully exert their respective performances, leading to a decline in the overall performance of the propellant. Limited modification effect: Although fluoropolymers are used to modify aluminum powder, this modification method may not completely solve the problems of the oxide film on aluminum powder and agglomeration, and the improvement effect on combustion performance is limited. Insufficient interface improvement: Although the composite energetic material can improve the contact interface between aluminum powder and the oxidizer, the existing technologies may still not achieve ideal interface contact and reaction, and further optimization of the composite process and material properties is required. Complex composite process: The process of compounding the modified aluminum powder with the oxidizer may be relatively complex, requiring precise control of various parameters, with high operation difficulty and cost, which is not conducive to large-scale production and application. Summary of the Invention
[0005] Object of the Invention: Aiming at the problems of easy agglomeration of Al powder and uneven mixing of Al powder and AP, the present invention provides an Al / polypeptide / AP biological composite energetic material and a preparation method thereof.
[0006] Technical solution: The present invention provides an Al / polypeptide / AP bio - composite energetic material. The Al / polypeptide / AP bio - composite energetic material has a core - shell structure with Al / polypeptide as the core and AP as the shell; the particle size of the bio - composite energetic material is 5μm - 300μm; its content by mass percentage is: aluminum powder is 20% - 45%, polypeptide is 0 - 5%, AP is 50% - 75%, and the polypeptide content is not 0%.
[0007] Preferably, the polypeptide is a long - chain polypeptide and contains functional groups such as hydroxyl, carboxyl, nitro, etc.
[0008] The present invention has found through research that polypeptides contain rich functional groups and can form various chemical bonds with the surface of Al powder, thus significantly enhancing the binding force between the polypeptide and Al powder. This strong binding force makes the structure of the composite material more stable, and the Al powder is not prone to agglomeration and is evenly distributed in the composite material. Further research has found that the carboxyl group in the polypeptide can form an electrostatic interaction with the aluminum ions on the surface of the Al powder, and this electrostatic attraction further enhances the binding between the polypeptide and Al powder. At the same time, it can form strong hydrogen bonds with AP. As a relatively strong intermolecular force, hydrogen bonds can effectively enhance the interaction between the polypeptide and AP, thereby further improving the structural stability of the composite material.
[0009] Due to the closer binding between the polypeptide and Al powder and AP, this strong interaction has significant mechanical and thermal advantages in solid propellants. First, the strong interaction between the polypeptide and Al powder and AP can better disperse stress. When the propellant is subjected to external forces, these interactions can effectively disperse the stress, prevent the fracture and deformation of the material, and thus significantly improve the mechanical properties of the propellant. Second, under high - temperature conditions, these interactions can resist the destruction of the material structure by thermal motion, thereby improving the thermal stability of the propellant.
[0010] In addition, as an important metal fuel in solid propellants, Al powder has a high combustion calorific value, low price, rich sources, and high combustion efficiency. Through the close binding of the polypeptide and Al powder, the combustion efficiency of Al powder can be further improved, thereby increasing the characteristic velocity and specific impulse of the propellant. At the same time, the strong interaction between the polypeptide and AP can improve the combustion performance of the propellant, reduce the incomplete combustion phenomenon during the combustion process, and improve the energy utilization rate of the propellant.
[0011] The present invention also provides a method for preparing an Al / polypeptide / AP bio - composite energetic material, including the following steps:
[0012] Step (1), adding an organic solvent to the Al powder, placing it in a constant - temperature water bath, adding a magnetic stirrer and stirring; then adding the polypeptide to the above - mentioned solution, and ending the reaction; after centrifugation, washing, and vacuum drying, Al / polypeptide composite particles are obtained;
[0013] Step (2): Completely disperse the Al / polypeptide composite particles in a low-temperature saturated AP solution, then dropwise add a high-temperature saturated AP solution thereto. After the addition is completed, carry out aging, and obtain the Al / polypeptide / AP bioenergetic material after filtration and drying.
[0014] Preferably, in step (1), the organic solvent is one of cyclohexane, acetone, toluene, ethanol, ether, hydrofluoroether, or dichloromethane.
[0015] Preferably, in step (1), the particle size of the Al powder is 10 nm to 200 nm.
[0016] Preferably, in step (1), the magnetic stirring speed is 100 to 2000 rpm.
[0017] Preferably, in step (1), the centrifugation time is 3 to 10 min, the rotation speed is 2000 to 5000 rpm, and the organic solvent for washing is one of cyclohexane, acetone, toluene, ethanol, ether, hydrofluoroether, or dichloromethane.
[0018] Preferably, in step (2), the temperature of the low-temperature saturated AP solution is 0 to 20 °C, and the temperature of the high-temperature saturated AP solution is 60 to 100 °C.
[0019] Preferably, in step (2), the dropping rate is 1 to 20 mL / min, and the aging and crystal cultivation time is 1 to 12 h.
[0020] The present invention adopts a cooling crystallization method and simultaneously optimizes the reaction conditions to control the particle size and morphology of the Al / polypeptide / AP bio-composite energetic material. During the preparation process, controlling the particle size of the Al powder to be 10 nm to 200 nm can ensure its uniform dispersion in the polypeptide and AP, avoid agglomeration, and improve the mechanical properties and stability of the material; if the particle size of the Al powder is too large, the Al particles in the composite material cannot be evenly distributed, affecting the overall performance of the composite material; in addition, selecting aluminum powder on the nanoscale enables the assembly of the polypeptide to be controlled at the nanoscale dimension, and the smaller particle size of the Al powder has a larger specific surface area, which can provide more reactive sites, thereby improving the reactivity of the composite material and enhancing the conductivity and catalytic performance of the composite material.
[0021] Beneficial effects: Compared with the prior art, the present invention has remarkable effects:
[0022] 1. In the Al / polypeptide / AP bio - composite energetic material of the present invention, the long - chain polypeptide molecules have abundant functional groups, which can form stable bonds with aluminum powder through chemical bonds or hydrogen bonds, effectively reducing the agglomeration of aluminum powder, promoting its uniform distribution in the composite material, contributing to improving the combustion efficiency and energy release of the propellant, and thus enhancing the overall performance of the propellant. The self - assembled film formed by polypeptide molecules on the surface of the energetic material can achieve the directional arrangement of Al, polypeptide, and AP at the nanoscale, ensuring the uniform mixing of the metal fuel and the oxidizer. This structural optimization significantly shortens the reaction diffusion distance, enhances the thermal stability, mechanical properties, and reaction activity of the propellant, enabling it to maintain good working conditions under high - temperature and high - pressure conditions.
[0023] 2. In the preparation method of the Al / polypeptide / AP bio - composite energetic material of the present invention, the cooling crystallization method is adopted and the reaction conditions are optimized, which can precisely control the morphology, size, and functionality of the Al / polypeptide / AP bio - composite energetic material. In addition, this method is easy to operate, the reaction conditions are mild, and the crystallization solvent can be recycled multiple times, meeting the concept of green environmental protection, having high economic benefits, and being suitable for large - scale industrial production. Brief Description of the Drawings
[0024] Figure 1 SEM image of the Al / polypeptide / AP composite energetic material prepared in Example 1 of the present invention;
[0025] Figure 2 XRD pattern of the Al / polypeptide / AP composite energetic material prepared in Example 1 of the present invention. Detailed Embodiments
[0026] The present invention will be further illustrated below in conjunction with the drawings and detailed embodiments. The materials, reagents, instruments, etc. used in the examples can be obtained from commercial channels without special instructions. It should be understood that the following detailed embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.
[0027] Example 1
[0028] A kind of Al / polypeptide / AP composite energetic material and its preparation method are prepared according to the following steps:
[0029] Preparation of Al / polypeptide: Add 0.6 g of aluminum powder with a diameter of 10 nm into a round - bottom flask, and add 60 ml of toluene as the solvent. Place the device in a constant - temperature water bath at 60 °C, add a magnetic stirrer and stir at a speed of 100 rpm. Then add 0.06 g of polypeptide into the above - mentioned solution and stir at 60 °C for 2 h. After that, centrifuge the solution for 3 min at a speed of 2000 rpm, wash three times, discard the supernatant, and vacuum - dry for 12 h to obtain Al / polypeptide composite particles.
[0030] Preparation of Al / Polypeptide / AP: Add AP to distilled water, place it in a water bath, heat and stir to obtain a high-temperature saturated solution at 60 °C. Take another container, add AP to distilled water, stir and disperse it, place it in an ice-water bath, and stir at a uniform speed. Then add 0.5125 g of Al / polypeptide composite particles to the solution to obtain a low-temperature saturated solution at 0 °C. Disperse the high-temperature saturated solution completely in the low-temperature saturated solution at a dropping rate of 1 mL / min, disperse for 5 min and then age. Finally, filter the mixed solution and freeze-dry it to obtain Al / polypeptide / AP composite particles.
[0031] Figure 1 The SEM image of the prepared Al / polypeptide / AP composite energetic material shows that the morphology of Al / polypeptide / AP is spherical-like, with a particle size of about 150 μm and uniform distribution. Al / polypeptide is wrapped inside AP, forming a core-shell structure with Al / polypeptide as the core and AP as the shell. Figure 2 The XRD pattern of the prepared Al / polypeptide / AP composite energetic material shows that there are only diffraction peaks of Al and AP in the figure, and no other peaks appear, indicating that the addition of polypeptide does not affect the crystal form of AP.
[0032] Example 2
[0033] A preparation method of an Al / polypeptide / AP composite energetic material is as follows:
[0034] Preparation of Al / Polypeptide: Add 1.3 g of Al powder with a diameter of 200 nm to a round-bottomed flask, and add 130 ml of ethanol as a solvent. Place the device in a constant-temperature water bath at 60 °C, add a magnetic stirrer and stir at a speed of 2000 rpm. Then add 0.13 g of polypeptide to the above solution and stir at 60 °C for 2 h. Then centrifuge the solution for 10 min at a speed of 5000 rpm, discard the supernatant, and vacuum-dry for 12 h to obtain Al / polypeptide composite particles.
[0035] Preparation of Al / Polypeptide / AP: Add AP to distilled water, place it in a water bath, heat and stir to obtain a high-temperature saturated solution at 100 °C. Take another container, add AP to distilled water, stir and disperse it, place it in an ice-water bath, and stir at a uniform speed. Then add 1.281 g of Al / polypeptide composite particles to the solution to obtain a low-temperature saturated solution at 20 °C. Disperse the high-temperature saturated solution completely in the low-temperature saturated solution at a dropping rate of 20 mL / min, disperse for 5 min, then age. Finally, filter the mixed solution and freeze-dry it to obtain Al / polypeptide / AP composite particles.
[0036] Example 3
[0037] An Al / polypeptide / AP composite energetic material and its preparation method are prepared according to the following steps:
[0038] Preparation of Al / polypeptide: Add 1.2 g of Al powder with a diameter of 100 nm to a round-bottomed flask, and add 120 ml of cyclohexane as the solvent. Place the device in a constant temperature water bath at 60 °C, add a magnetic stirrer and stir at a speed of 1000 rpm. Then add 0.12 g of polypeptide to the above solution and stir at 60 °C for 2 h. After that, centrifuge the solution for 5 min at a speed of 3000 rpm, wash three times, discard the supernatant, and vacuum dry for 12 h to obtain Al / polypeptide composite particles.
[0039] Preparation of Al / polypeptide / AP: Add AP to distilled water, place it in a water bath, heat and stir to obtain a high-temperature saturated solution at a temperature of 80 °C; take another container, add AP to distilled water and stir to disperse it, then place it in an ice-water bath and stir at a uniform speed. Then add 1.104 g of Al / polypeptide composite particles to the solution to obtain a low-temperature saturated solution at a temperature of 10 °C; disperse the high-temperature saturated solution completely in the low-temperature saturated solution at a dropping rate of 5 mL / min, disperse for 5 min and then age. Finally, filter the mixed solution and freeze-dry to obtain Al / polypeptide / AP composite particles.
Claims
1. An Al / polypeptide / AP biocomposite energetic material, characterized in that: A core-shell structure with Al / polypeptide as the core and AP as the shell; the particle size of the biocomposite energetic material is 5μm to 300μm; The content thereof is as follows by mass percentage: aluminum powder is 20% to 45%, polypeptide is 0 to 5%, AP is 50% to 75%, and the polypeptide content is not 0%.
2. The Al / polypeptide / AP biocomposite energetic material according to claim 1, characterized in that: The polypeptide is a long-chain polypeptide and contains hydroxyl, carboxyl and nitro functional groups.
3. A method for preparing an Al / polypeptide / AP biocomposite energetic material, comprising the following steps: Step (1), adding an organic solvent to Al powder, placing the mixture in a constant temperature water bath, and adding a magnetic stirrer for stirring; then adding the polypeptide to the solution, and the reaction is terminated; after centrifugation, washing, and vacuum drying, Al / polypeptide composite particles are obtained; Step (2), completely dispersing the Al / polypeptide composite particles in a low-temperature saturated AP solution, then dripping a high-temperature AP saturated solution therein, aging after the dripping is complete, filtering and drying to obtain the Al / polypeptide / AP bioenergetic material.
4. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (1), the organic solvent is one of cyclohexane, acetone, toluene, ethanol, ether, hydrofluoroether, or dichloromethane.
5. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (1), the particle size of the Al powder is 10 nm to 200 nm.
6. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (1), the magnetic stirring speed is 100 to 2000 rpm.
7. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (1), the centrifugation time is 3 to 10 minutes, the rotation speed is 2000 to 5000 rpm, and the washing organic solvent is one of cyclohexane, acetone, toluene, ethanol, ether, hydrofluoroether or dichloromethane.
8. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (2), the temperature of the low-temperature saturated AP solution is 0-20°C, and the temperature of the high-temperature saturated AP solution is 60-100°C.
9. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (2), the dropping rate is 1 to 20 mL / min.
10. The method for preparing the Al / polypeptide / AP biocomposite energetic material according to claim 3, characterized in that: In step (2), the aging and crystal growing time is 1 to 12 hours.