A method for degrading composite solid propellants

Abstract

This invention discloses a method for degrading composite solid propellants: the composite solid propellant to be degraded is immersed in a degradation solvent, during which it is degraded. The degradation solvent includes an effective component and a reinforcing component. The effective component is a nitramine compound, specifically N-butylnitrooxyethylnitramine. The reinforcing component is one of an ethanol / water mixture, ethyl acetate, or dichloromethane, to address the disposal problem of spent composite solid propellants. This invention degrades and breaks down the long-chain macromolecules of spent composite solid propellants using a degradation solvent. The operation is simple, the reaction conditions are mild, and it can degrade various propellants, effectively solving the post-treatment problem of waste composite solid propellants.

Description

Technical Field

[0001] This invention relates to the field of treatment technology for failed composite solid propellants, and discloses a method for degrading composite solid propellants. Background Technology

[0002] Composite solid propellant materials are a type of propellant composed of a binder macromolecule as the matrix, mixed with solid powdered oxidizer, powdered metallic fuel, and other components. A key role of the binder in the propellant is to bind heterogeneous particles such as the oxidizer and metallic fuel, providing a continuous binder phase that acts as the elastomer of the propellant. Currently used composite solid propellants can be classified according to their binders into CTPB propellants, HTPB propellants, polyether propellants, and azide polyether propellants, among others. During use and storage, the performance of composite solid propellants deteriorates over time, sometimes failing to meet operational requirements. Furthermore, this performance degradation affects the safety, reliability, and lifespan of solid rocket motors. Moreover, the preparation of composite solid propellants generates a large amount of waste propellant. These failed propellants occupy significant space and pose safety hazards; therefore, failed composite solid propellants must be disposed of safely and effectively.

[0003] Methods for treating composite solid propellants include deep burial, high seas dumping, open-air incineration, and explosion. However, these methods easily cause environmental pollution. Therefore, with technological advancements, researchers have developed relatively cleaner methods such as high-pressure water or eddy water jet cleaning. However, these methods are prone to explosion hazards during the process. Therefore, adopting a relatively safe, green, and low-cost dissolution and degradation method for treating composite solid propellants is one direction for the treatment of depleted composite solid propellants. Currently, there are methods for treating hydroxyl-terminated polybutadiene (HTPB) composite solid propellants using degradation solvents, but the operation is relatively complex, and methods for degrading other composite solid propellants are lacking. Summary of the Invention

[0004] The purpose of this invention is to provide a universal method for degrading composite solid propellants, which is applicable to a variety of composite solid propellants. It degrades and breaks down the long-chain macromolecules of the failed composite solid propellant using a degradation solvent. The method is simple to operate, has mild reaction conditions, and can degrade a variety of propellants, effectively solving the problem of reprocessing waste composite solid propellants.

[0005] The technical solution of the present invention is a method for degrading composite solid propellants, wherein the composite solid propellant to be degraded is immersed in a degradation solvent, and the composite solid propellant is degraded during the dissolution process; the degradation solvent includes an effective component, wherein the effective component is a nitramine compound.

[0006] Furthermore, the aforementioned active ingredient is N-butylnitroethylnitrosamine.

[0007] Furthermore, the degradation solvent also includes a reinforcing component, which is one of an alcohol / water mixture, an ester compound, or an alkane compound.

[0008] Furthermore, the reinforcing component is one of ethanol / water mixture, ethyl acetate, and dichloromethane.

[0009] Furthermore, the effective component accounts for 10% to 100% of the mass fraction of the degradation solvent.

[0010] Furthermore, the reinforcing component accounts for 90% to 0% of the mass fraction of the degradation solvent.

[0011] Furthermore, the composite solid propellant is an AP-containing propellant.

[0012] Furthermore, the AP-containing propellant is one of CTPB composite solid propellant, HTPB composite solid propellant, polyether composite solid propellant, or azide polyether composite solid propellant.

[0013] Furthermore, the composite solid propellant is immersed in the degradation solvent at a temperature of 50℃ to 90℃.

[0014] Furthermore, the composite solid propellant is immersed in a degradation solvent and stirred simultaneously to improve the degradation rate.

[0015] The advantages and effects of this invention are:

[0016] 1. Ammonium perchlorate is the most important oxidant in composite solid propellants and is widely used in CTPB composite solid propellants, HTPB composite solid propellants, polyether composite solid propellants, and azide polyether composite solid propellants.

[0017] 2. The effective component N-butylnitroethylnitrosamine in the degradation solvent can interact with ammonium perchlorate, releasing heat. Since the energy provided by the exothermic reaction is greater than the ether bond energy in the propellant, the ether bond breaks, and the propellant degrades.

[0018] 3. The intermolecular forces between the reinforcing components in the degradation solvent and the propellant molecules are greater than the internal forces within the propellant molecules. Therefore, the reinforcing components can diffuse into the interior of the composite solid propellant, causing the solid propellant to swell and significantly increase its volume. This not only disrupts the cross-linking points but also increases the contact area between the effective component N-butylnitroethyl nitramine and the propellant, thereby achieving the degradation effect on the composite solid propellant.

[0019] This invention uses a degradation solvent to treat composite solid propellants, replacing the incineration method for treating waste composite solid propellants. This reduces environmental pollution and is beneficial to environmental protection. The degradation solvent has low toxicity and is less harmful to the human body. It can degrade a variety of propellants. The process is simple and easy to operate. Attached Figure Description

[0020] These and / or other aspects and advantages of the present invention will become clearer and more readily understood from the following detailed description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 This is the heat flow-time curve of N-butylnitroethyl nitramine and ammonium perchlorate at 90°C in an embodiment of the present invention.

[0022] Figure 2 The image shows the FTIR images of the CTPB composite solid propellant before and after degradation at 90°C using an N-butylnitroethylnitrosamine / ethanol / water degradation solution (mass ratio 2:1:2).

[0023] Figure 3 The FTIR images of the HTPB composite solid propellant in Example 2 of this invention before and after degradation at 90°C using an N-butylnitroethylnitrosamine / ethanol / water degradation solution (mass ratio 2:1:2).

[0024] Figure 4 The FTIR images of the polyether composite solid propellant before and after degradation at 90°C using an N-butylnitroethylnitramine / ethanol / water degradation solution (mass ratio 2:1:2) in Example 3 of this invention are shown.

[0025] Figure 5 The FTIR images of the azide polyether composite solid propellant before and after degradation at 90°C using an N-butylnitroethylnitramine / ethanol / water degradation solution (mass ratio 2:1:2) in Example 4 of this invention are shown. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. The described embodiments are only some, not all, of the embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings:

[0027] Example 1

[0028] A 5mm × 5mm × 5mm CTPB composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 90℃. After one day of degradation, the CTPB composite solid propellant was completely degraded into slag. FTIR analysis of the degradation products was performed (results are shown in [link to results]). Figure 2 This confirms the conclusion that the propellant molecular chain structure is destroyed during the degradation process.

[0029] Example 2

[0030] A 5mm × 5mm × 5mm HTPB composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 90℃. After one day of degradation, the HTPB composite solid propellant was completely degraded into slag. FTIR analysis of the degradation products was performed (results are shown in [link to results]). Figure 3 This confirms the conclusion that the propellant molecular chain structure is destroyed during the degradation process.

[0031] Example 3

[0032] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 90℃. After one day of degradation, the polyether composite solid propellant was completely degraded into residue. FTIR analysis of the degradation products was performed (results are shown in...). Figure 4 This confirms the conclusion that the propellant molecular chain structure is destroyed during the degradation process.

[0033] Example 4

[0034] A 5mm × 5mm × 5mm azide polyether composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 90℃. After one day of degradation, the azide polyether composite solid propellant was completely degraded into residue. FTIR analysis of the degradation products was performed (results are shown in...). Figure 5 This confirms the conclusion that the propellant molecular chain structure is destroyed during the degradation process.

[0035] Example 5

[0036] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine and ethyl acetate mixed at a mass ratio of 1:1) and degraded at 90℃. After one day of degradation, the polyether composite solid propellant was completely degraded into slag.

[0037] Example 6

[0038] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine and dichloromethane mixed at a mass ratio of 1:1) and degraded at 90℃. After one day of degradation, the polyether composite solid propellant was completely degraded into slag.

[0039] Example 7

[0040] A 5mm × 5mm × 5mm azide polyether composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine) and degraded at 70℃. After 3 days of degradation, the azide polyether composite solid propellant was completely degraded into slag.

[0041] Example 8

[0042] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 70℃. After one day of degradation, the polyether composite solid propellant was completely degraded into residue.

[0043] Example 9

[0044] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded at 50°C. After 7 days of degradation, the polyether composite solid propellant was completely degraded into slag.

[0045] Example 10

[0046] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine, ethanol, and water mixed in a mass ratio of 1:8:1) and degraded at 70℃. After 4 days of degradation, the polyether composite solid propellant was completely degraded into slag.

[0047] Example 11

[0048] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitrooxyethyl nitramine, ethanol, and water mixed in a mass ratio of 1:1:8) and degraded at 70℃. After 4 days of degradation, the polyether composite solid propellant was completely degraded into slag.

[0049] Example 12

[0050] A 5mm × 5mm × 5mm polyether composite solid propellant was placed in a degradation solution (N-butylnitroethyl nitramine, ethanol, and water mixed in a mass ratio of 2:1:2) and degraded under stirring conditions at 50℃ and a stirring rate of 10 r / min. After 2 days of degradation, the polyether composite solid propellant was completely degraded into slag.

[0051] Figure 1The heat flow-time curve of N-butylnitroethyl nitramine and ammonium perchlorate at 90℃ is shown. Infrared analysis indicates that the curve is at 1083 cm⁻¹. -1 The peak at 1083 cm⁻¹ represents the stretching vibration of the CO bond in the ether. Comparing the infrared spectra of the composite solid propellant before and after degradation, the peak at 1083 cm⁻¹ was found to be the highest in the propellant. -1 The stretching vibration peaks of the ether-CO bond are significantly weakened, indicating that the structure is partially destroyed and the propellant has degraded.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made within the protection scope of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. A method for degrading composite solid propellants, characterized in that, The composite solid propellant to be degraded is immersed in a degradation solvent, and the composite solid propellant is degraded during the dissolution process; The degradation solvent includes an effective component, which is N-butylnitroethylnitramine. The composite solid propellant is an AP-containing propellant, and the AP-containing propellant is one of CTPB composite solid propellant, HTPB composite solid propellant, and polyether composite solid propellant.

2. The method for degrading composite solid propellants according to claim 1, characterized in that, The degradation solvent also includes a reinforcing component, which is one of an alcohol / water mixture, an ester compound, or an alkane compound.

3. The method for degrading composite solid propellants according to claim 2, characterized in that, The reinforcing component is one of ethanol / water mixture, ethyl acetate, and dichloromethane.

4. The method for degrading composite solid propellants according to claim 1, characterized in that, The effective component accounts for 10% to 100% of the mass fraction of the degradation solvent.

5. The method for degrading composite solid propellants according to claim 2, characterized in that, The reinforcing component accounts for 90% to 0% of the mass fraction of the degradation solvent.

6. The method for degrading composite solid propellants according to claim 1, characterized in that, The temperature at which the composite solid propellant is immersed in the degradation solvent is 50℃~90℃.

7. The method for degrading composite solid propellants according to claim 1, characterized in that, The composite solid propellant is immersed in a degradation solvent and stirred simultaneously to improve the degradation rate.

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