Application of polyphenol compound in nitrate-based energetic material

Abstract

The invention relates to the technical field of nitrate-based energetic materials, and discloses an application of a polyphenol compound in a nitrate-based energetic material. The application of the polyphenol compound in the nitrate-based energetic material is specifically the application of the polyphenol compound as a stabilizing agent in the nitrate-based energetic material. The polyphenol compound provided by the invention has the advantages of low price, no toxicity, easiness in synthesis and structure optimization, better nitrogen oxide free radical scavenging rate and stability, better effect than the traditional aniline and phenylurea stabilizers, and wide application prospect in the aspect of nitrate ester-based energetic material stabilizers.

Description

Technical Field

[0001] The present invention relates to the technical field of nitrate-based energetic materials, and in particular to the application of polyphenol compounds in nitrate-based energetic materials. Background Art

[0002] Nitrate-based energetic materials are a class of compounds containing nitrate functional groups, which are widely used in the fields of construction and mining blasting, gunpowder, missiles, propellants, and aerospace. However, during long-term storage, the nitrate functional groups of nitrate-based energetic materials will slowly decompose to produce nitrogen oxides and acidic substances (NO, NO2, HNO2 and HNO3, etc.), and these nitrate functional group decomposition products will further catalyze the decomposition of the nitrate functional groups, thereby causing degradation in many aspects such as the service life and performance of the nitrate-based energetic materials, and even causing the combustion and explosion of the nitrate-based energetic materials. In order to solve this problem, the existing technology usually adopts the method of adding a stabilizer, through the competitive reaction between the stabilizer and the decomposition products of the nitrate functional groups, to alleviate or inhibit the accelerated catalytic effect caused by the decomposition products, so as to solve the stability problem of the nitrate-based energetic materials.

[0003] For example, Tang et al. [Journal of Hazardous Materials. 2017, 187-196] synthesized a series of MNA-type stabilizers by changing the carbon chain on the nitrogen atom of MNA in order to improve the performance of the traditional stabilizer N-methyl-p-nitroaniline (MNA). They found that the growth of the carbon chain improved the compatibility of the stabilizer with nitroglycerin, but the high-temperature stability was not significantly improved. Shehata et al. [Polymer Degradation and Stability, 2002, 77, 355-37] found that the C=O bond in the structure of acrylamide polymer is an electron-withdrawing group, which reduces the activity of the compound in saponification reaction with the nitrate group, making the combination of acrylamide polymer and nitrocellulose more stable. Zayed et al. [Journal of Hazardous Materials, 2000, 73, 237-24] further verified the stabilizing effect of the amide group in their study on malonamide stabilizers, but their stabilizing performance was lower than that of traditional stabilizers. The literature [Arabian Journal of Chemistry, 2017, 10, 573-581] reported the potential possibility of using zeolite as a stabilizer; the surface of zeolite has a loose porous structure, which can adsorb nitrogen oxide gas products through cationic interactions and form a stable double-layer structure. Patent [CN202110504864.7] discloses the application of CAU-1 metal organic framework materials as stabilizers for nitrate compounds. The CAU-1 series of metal organic framework materials are low-toxic non-amine compounds, which are safer and more environmentally friendly and have broad application prospects. Niu Jiaxin et al. [Energetic Materials, 2012, 20 (5), 614-617] combined dimethyl diphenylurea (C2) and diphenylamine (DPA), resorcinol and 2-NDPA, 2-NDPA and 4-NDPA and other stabilizers in different proportions to obtain compound stabilizers. Studies have shown that the compound stabilizers have good chemical stability. The literature [Thermochimica Acta, 2019, 673, 78-91] reported a two-component compound stabilizer of DPA and N-(2-methoxyethyl)-p-nitroaniline (MENA), which not only has better performance than any single-component stabilizer, but also can minimize the toxic secondary derivatives produced by DPA; studies have shown that the secondary component in the compound stabilizer will weaken the consumption of the primary component and delay the thermal decomposition of nitrate compounds. The two components cooperate with each other to enhance the stabilizing effect of the stabilizer.

[0004] It can be found that the current mainstream research direction of stabilizers is alkaline aromatic stabilizers, but this type of stabilizer has performance defects to varying degrees, especially the amino groups therein are prone to produce toxic secondary derivatives, causing economic and human health losses; in order to solve the above problems, phenol ether compounds with free radical scavenging ability have gradually become the research focus of technicians in this field.

[0005] Dejeaifve et al. [Propellants Explosives Pyrotechnics, 2020, 45, 1185-1193] screened more than 80 non-amine compounds and found that some phenol derivatives had no molecular toxicity and had a better stabilizing effect than the traditional stabilizer N'-methyl-N,N-diphenylurea (AKⅡ). Krumlinde et al. [Propellants Explosives Pyrotechnics, 2016, 42(1), 78-83] synthesized 5 electron-rich phenol ether stabilizers. The study confirmed that electron-rich phenol ether stabilizers have excellent stability and plasticizing properties, and will not combine with nitrogen oxides to form toxic secondary derivatives, and have less harm to the environment. Cherif et al. [International Journal of Biological Macromolecules, 2020, 164, 794-807; Thermochimica Acta, 2020, 692, 178732] extracted two types of lignin (OL and KL) from natural wood and confirmed that they have better stability than the traditional stabilizer DPA. Zhao et al. [Cellulose, 2020, 29, 9089-9104] confirmed that tea polyphenols have excellent nitroxide free radical scavenging ability and stability, and their high-temperature carbonization characteristics make them a potential carbon source for propellant combustion. Katoh et al. [Propellants Explosives Pyrotechnics, 2007, 32, 314-321] studied the potential possibility of hindered phenols as stabilizers and found that their stabilization mechanism is different from that of amine derivatives. Hindered phenols mainly absorb peroxide free radicals to inhibit the decomposition of nitrate compounds caused by acidity. Rodrigues et al. [Journal of Energetic Materials, 2022, 40(2), 218-241; Clean Technologies and Environmental Policy, 2022, 24(6), 1837-1849; Journal of Aerospace Technology and Management, 2019, 11] showed that curcumin and guaiacol both have certain stabilizing properties on nitrocellulose. Curcumin can react with NO2 and has no biological toxicity, but guaiacol has the potential to be carcinogenic and mutagenic.

[0006] It can be found that phenolic stabilizers can react with free radicals faster, have better thermal stability, and do not have the risk of saponification reaction and toxic secondary derivatives; however, they have poor high-temperature stability and are easily soluble in a variety of organic and inorganic solvents. During the thermal decomposition of nitrate compounds, they are prone to expansion and cause the drug column to rupture, which cannot meet the strategic needs of the development of nitrate-based energetic materials. In order to reduce the safety risks and environmental pollution during the storage of nitrate-based energetic materials, stable natural antioxidants or natural antioxidants with improved structural stabilization have potential application value.

[0007] The literature [Atmospheric Environment, 1995, 29 (23), 3423-3432] reported the reaction of isoquinoline alkaloids with gas-phase NO2. As the concentration of nitrogen oxide free radicals increases, indole can even be removed. Rosa A et al. [Journal of Agricultural and Food Chemistry, 2002, 50 (25), 7396-7401] showed that capsaicinoids have very obvious antioxidant activity against peroxyl free radicals. Orlo E et al. [Foods, 2021, 10 (8), 1807] showed through antioxidant experiments that eugenol has high free radical scavenging ability and anti-lipid peroxidation activity. Steven A et al. [Journal of Biological Chemistry, 1996, 271 (8), 3988-3994] explored the antioxidant properties of β-carotene. The study showed that β-carotene has a strong scavenging ability against a variety of free radicals, including nitric oxide free radicals, nitrogen dioxide free radicals, sulfacyl and sulfonyl free radicals. Among them, the nitrogen dioxide free radical scavenging rate constant reached 1.1±0.1×108mol-1dm3s-1. Zheng et al. [Journal of Molecular Modeling, 2018, 24, 1-8] used density functional theory (DFT) calculations to show that the 4'-OH group in luteolin is involved in its free radical scavenging process and has the most obvious effect on its antioxidant activity.

[0008] However, there is no public report on stabilized polyphenolic stabilizers and their structural optimization design. Therefore, providing an application of polyphenolic compounds in nitrate-based energetic materials has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0009] The purpose of the present invention is to provide an application of polyphenol compounds in nitrate-based energetic materials.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] Application of polyphenol compounds in nitrate-based energetic materials.

[0012] Furthermore, the application is specifically: the application of polyphenol compounds as stabilizers in nitrate-based energetic materials.

[0013] Furthermore, the polyphenol compound is a polyphenol compound containing multiple benzene rings and hydroxyl groups.

[0014] Furthermore, the polyphenol compounds containing multiple benzene rings and hydroxyl groups are quercetin, luteolin and baicalein extracted from natural products.

[0015] Furthermore, the polyphenol compound containing multiple benzene rings and hydroxyl groups is a modified hindered phenol compound bi-BHT.

[0016] Furthermore, the nitrate-based energetic material is nitrocellulose and / or nitroglycerin.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The polyphenol compounds provided by the present invention are cheap, non-toxic, easy to synthesize and have optimized structures, and have excellent nitrogen oxide free radical scavenging rate and stability performance, and are more effective than traditional aniline and phenylurea stabilizers, and have broad application prospects in nitrate-based energetic material stabilizers.

[0019] The polyphenol compound provided by the present invention contains hydroxyl groups, which can significantly improve its ability to scavenge nitroxide free radicals, thereby enhancing the stabilizing performance of the stabilizer on nitrate-based energetic materials;

[0020] The polyphenol compounds provided by the present invention do not contain amino groups, thus effectively avoiding the generation of toxic nitrosamine substances and being healthier and more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 Schematic diagram of the structures of quercetin, luteolin and baicalein of the present invention;

[0023] Figure 2 The graphs show the nitrogen oxide free radical scavenging rate curves of quercetin, luteolin and baicalein of the present invention. DETAILED DESCRIPTION

[0024] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0025] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0026] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0027] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0028] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0029] In the following examples, all the raw materials and reagents used were commercially available.

[0030] Example 1

[0031] Extraction of Quercetin

[0032] The rutin is dissolved in dilute sulfuric acid with a volume fraction of 2%, extracted at 80° C. for 4 hours, left to stand for 4 hours, and then the solvent is removed by vacuum filtration, washed, dried, and recrystallized to obtain the quercetin.

[0033] The structure of quercetin extracted in Example 1 is as follows Figure 1 shown.

[0034] Example 2

[0035] Extraction of Luteolin

[0036] The rutin was dissolved in an alkaline solution (NaOH solution) at pH=10, and 20 equivalents of a reducing agent consisting of thiourea dioxide, potassium chloride and potassium carbonate (the volume ratio of thiourea dioxide, potassium chloride and potassium carbonate was 1:2:2) were added, and the mixture was extracted at 60°C for 2h, and the solvent was removed by filtration under reduced pressure, and the mixture was washed, dried and recrystallized to obtain the luteolin.

[0037] The structure of luteolin extracted in Example 2 is as follows Figure 1 shown.

[0038] Example 3

[0039] Extraction of baicalin

[0040] The baicalin was dissolved in 10% by volume dilute sulfuric acid, and refluxed for extraction at 102° C. for 4 hours. After cooling to room temperature, the solvent was removed by filtration under reduced pressure, and the baicalin was obtained by washing, drying, and recrystallization.

[0041] The structure of baicalein extracted in Example 3 is as follows Figure 1 shown.

[0042] The polyphenol compounds extracted in Examples 1 to 3 were tested for their ability to eliminate nitrogen oxide free radicals using electron paramagnetic resonance detection. The test conditions for electron paramagnetic resonance detection are as follows:

[0043] (1) Using silver diethyldithiocarbamate as a capture agent;

[0044] (2) The central magnetic field is 3440.00G, the sweep width is 100.00G, the sweep time is 60.06s, the g value is 2.0, the microwave intensity is 2.000mW, and the microwave attenuation value is 8dB;

[0045] (3) Polyphenol compounds use ethanol as solvent;

[0046] (4) The source of nitroxide free radicals is sodium nitroprusside;

[0047] The calculation formula for the scavenging rate of polyphenols on nitrogen oxide free radicals is as follows:

[0048] η=(I0-I c ) / I0;

[0049] In the formula,

[0050] η-nitrogen oxide free radical scavenging rate;

[0051] I0- ESR signal intensity of nitrogen oxide free radicals in blank state;

[0052] I c - ESR signal intensity of nitroxide radicals after adding polyphenolic compounds;

[0053] The scavenging rates of the polyphenolic compounds extracted from Examples 1 to 3 on nitrogen oxide free radicals are as follows: Figure 2 As shown;

[0054] Depend on Figure 2 It can be seen that quercetin, luteolin and baicalein all have excellent scavenging rates of nitrogen oxide free radicals, among which the scavenging rate of quercetin for nitrogen oxide free radicals can reach 73.5%; the scavenging rate of luteolin for nitrogen oxide free radicals can reach 70.0%; and the scavenging rate of baicalein for nitrogen oxide free radicals can reach 67.5%.

[0055] The polyphenol compounds extracted from Examples 1 to 3 were tested for stability by using methyl violet test paper test, vacuum stability test (VST), constant temperature thermogravimetric test and adiabatic accelerated calorimetry test, using nitrocellulose as nitrate-based energetic material;

[0056] Among them, the methyl violet test paper test and vacuum stability test are tested in accordance with GJB 770B-2005 "Test Methods for Explosive Powder"; the test temperature of the constant temperature thermogravimetric test is 135°C and the test time is 6 hours; the test conditions of the adiabatic accelerated calorimetry test are as follows:

[0057] (1) The test procedure is the heat-search-wait (HSW) mode;

[0058] (2) The heating rate in the heating stage is 10°C / min, the search time is 30 min, and the heating threshold in the waiting stage is 1°C / min;

[0059] (3) The starting temperature is 100°C and the ending temperature is 300°C;

[0060] The results of the stability test of polyphenol compounds are shown in Table 1;

[0061] Table 1 Test results of stability of polyphenol compounds

[0062]

[0063]

[0064] From the data in Table 1, it can be seen that quercetin, luteolin and baicalein all have excellent stabilizing properties, which are better than the traditional stabilizers diphenylamine (DPA) and N,N'-dimethyl-N,N'-diphenylurea (C2).

[0065] Example 4

[0066] Preparation of Improved Hindered Phenol Compound bi-BHT

[0067] 1) Dissolve 2,6-di-tert-butyl-4-methylphenol (BHT) in tert-butyl alcohol and use Br2 as an oxidant to oxidize to generate intermediate 1;

[0068] 2) 0.017 mol of the intermediate product 1 obtained in step 1) was dissolved in 40 mL of anhydrous ethanol, and 0.02 mol of NaHCl and 0.02 mol of NaBH4 were added, and the mixture was reacted at 0°C for 2 h, and extracted with ether. The organic phases were combined, washed, dried, and filtered under reduced pressure to remove the solvent to obtain the intermediate product 2;

[0069] 3) 0.366 mmol of the intermediate product 2 obtained in step 2) and 260 mg of H-mont were added to 3 mL of CH2Cl2 and reacted at 25°C for 0.67 h to obtain the bi-BHT.

[0070] The preparation formula of Example 4 is as follows:

[0071]

[0072] The ability of bi-BHT prepared in Example 4 to eliminate nitrogen oxide free radicals was tested by electron paramagnetic resonance detection in the same manner as above. The test showed that the scavenging rate of bi-BHT (2 mM / L) for nitrogen oxide free radicals could reach 54.9%.

[0073] The bi-BHT prepared in Example 4 was tested for stability by using methyl violet paper and nitrocellulose as the nitrate-based energetic material. The testing method was the same as above. The test showed that the color change time of the methyl violet paper was 74 minutes, and the stability was better than that of BHT (62 minutes).

[0074] The melting point of the bi-BHT prepared in Example 4 was tested. The test showed that the melting point of bi-BHT was 155° C., which was significantly higher than that of BHT (70° C.), thus improving the easy sublimation property of hindered phenol.

[0075] A comprehensive comparison of the ability of polyphenols to eliminate nitrogen oxide free radicals and their stabilization performance on nitrate-based energetic material nitrocellulose shows that as the hydroxyl groups in the structures of baicalein, luteolin and quercetin increase in sequence, the scavenging rate of nitrogen oxide free radicals gradually increases, and the stabilization performance on nitrocellulose gradually increases, which indicates the enhancing effect of the hydroxyl functional group on the stabilization performance of polyphenol stabilizers.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does 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. Application of polyphenol compounds in nitrate-based energetic materials.

2. The use according to claim 1, characterized in that: The application is specifically: the application of polyphenol compounds as stabilizers in nitrate-based energetic materials.

3. The use according to claim 1, characterized in that: The polyphenol compound is a polyphenol compound containing multiple benzene rings and hydroxyl groups.

4. The use according to claim 3, characterized in that: The polyphenol compounds containing multiple benzene rings and hydroxyl groups are quercetin, luteolin and baicalein extracted from natural products.

5. The use according to claim 3, characterized in that: The polyphenol compound containing multiple benzene rings and hydroxyl groups is a modified hindered phenol compound bi-BHT.

6. The use according to claim 1, characterized in that: The nitrate-based energetic material is nitrocellulose and / or nitroglycerin.

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