CN109796291B

CN109796291B - Method for optimizing CL-20 decomposition reaction path and improving energy release efficiency thereof

Info

Publication number: CN109796291B
Application number: CN201910155726.5A
Authority: CN
Inventors: 李小东; 杨光成; 李�瑞; 黄兵; 谯志强; 刘有松
Original assignee: Institute of Chemical Material of CAEP
Current assignee: Institute of Chemical Material of CAEP
Priority date: 2019-03-01
Filing date: 2019-03-01
Publication date: 2021-04-09
Anticipated expiration: 2039-03-01
Also published as: CN109796291A

Abstract

The invention discloses a method for optimizing a CL-20 decomposition reaction path and improving the energy release efficiency thereof, belonging to the technical field of solid propellants, high explosives and the like. The method comprises the following steps: step one, adding an additive into CL-20 to form a composite material; and step two, performing initial decomposition and combustion reaction on the composite material obtained in the step one, wherein the additive has an accelerating effect on the initial decomposition and combustion reaction of the CL-20, a synergistic chemical reaction is generated between the additive and the CL-20, and a decomposition product of the CL-20 is also subjected to a chemical reaction with the additive and the decomposition product thereof. The method for improving the energy release efficiency is realized by optimizing the decomposition reaction path of the CL-20, the optimization of the decomposition reaction path of the CL-20 is realized by adding a proper additive into the CL-20 material, and a synergistic chemical reaction can be generated between the additive and the CL-20, wherein the synergistic chemical reaction is that the additive and the decomposition product of the CL-20 are subjected to a chemical reaction, so that the decomposition reaction path of the CL-20 is optimized, and the energy release efficiency is improved.

Description

Method for optimizing CL-20 decomposition reaction path and improving energy release efficiency thereof

Technical Field

The invention relates to the technical field of solid propellants, high explosives, primary explosives, propellant powder and the like, in particular to a method for optimizing a CL-20 decomposition reaction path and improving the energy release efficiency of the CL-20 decomposition reaction path.

Background

The energy density is a source of energy-containing materials, including explosives, propellants, pyrotechnic agents, and the like, for doing work. Further, it is an important subject of energetic material research to further increase the energy density to a large extent. In order to improve the energy density of energetic materials, the synthesis of new energetic molecules is the most important way. Over the years of development, functional energetic materials have gone through a history of energetic explosives ranging from trinitrotoluene (TNT) to hexogen (RDX), octogen (HMX), and CL-20. However, the energy density of the existing high-energy energetic materials approaches the limit of chemical energy release, so that the development speed of new energetic materials is extremely slow, and the energy increase amplitude is gradually slow. In addition, other properties such as safety are significantly reduced while obtaining high energy. Therefore, while developing new energetic materials and increasing their energy density, exploring how to utilize existing energetic materials is another way to achieve high performance weapons and propellants. For example, by adding catalysts, combustion promoters, etc., to improve the combustion and explosion performance of energetic materials.

CL-20 is a cage-shaped ammonium nitrate compound with high energy density, and is the single-substance explosive with the highest energy density at present. In addition to being a high explosive, CL-20 is a very potential oxidizer to replace the conventional oxidizer ammonium perchlorate in solid propellants. However, the decomposition or combustion reaction of CL-20 is not perfect and the products contain a high amount of NO₂And a solid C, H, O, N-containing particulate product that did not decompose to completion. These products are not the most thermodynamically stable products, meaning that their energy is not fully released. Therefore, optimizing the reaction channel of CL-20 by adding additives and improving the energy release amount are key scientific and technical problems for putting CL-20 into practical use. In response to this problem, existing approaches include the addition of nanocarbon catalysts, metal oxide catalysts, and the like. The addition of these catalysts can indeed improve the CL-20 reaction process and increase its energy release efficiency. However, these catalysts do not participate or participate only very little in the energy release reaction, resulting in a less pronounced increase in energy release. It is therefore desirable to explore new ways to improve the efficiency of CL-20 energy release, including the amount and rate of energy released.

Disclosure of Invention

Aiming at the defects of CL-20 in energy release processes such as decomposition and combustion and the like and the problems faced by the prior art that the energy release reaction process is improved by adding a catalyst, the invention aims to provide a method for optimizing a decomposition reaction path of CL-20 and improving the energy release efficiency of the CL-20, wherein the method for improving the energy release efficiency is realized by optimizing the decomposition reaction path of the CL-20, the optimization of the decomposition reaction path of the CL-20 is realized by adding a proper additive into a CL-20 material, a synergistic chemical reaction can be generated between the additive and the CL-20, the synergistic chemical reaction is characterized in that the additive and the decomposition product of the CL-20 are subjected to a chemical reaction, the decomposition reaction path of the CL-20 is optimized, and the energy release efficiency is improved; meanwhile, the decomposition product of the CL-20 also reacts with the additive and the decomposition product thereof, and the decomposition and energy release of the additive are promoted. Furthermore, a small amount of potassium salt is added on the basis of the addition of the additive to the CL-20, so that the synergistic chemical reaction between the CL-20 and the additive can be further promoted, and the decomposition reaction path of the additive can be further optimized. The method can remarkably improve the energy density level energy release rate of the CL-20 and the composite material thereof. The composite material has good application prospect in the fields of high-performance solid propellant, high explosive, primary explosive, propellant powder and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method of optimizing a CL-20 decomposition reaction pathway and increasing its energy release efficiency, comprising the steps of:

step one, adding an additive into CL-20 to form a composite material; the composite material has a greater amount of decomposition products than the gas products of its individual components, an increased amount of thermodynamically more stable products in the gas products, and a significant reduction in solid residues.

And step two, performing initial decomposition and combustion reaction on the composite material obtained in the step one, and performing a synergistic chemical reaction between the additive and the CL-20, wherein the synergistic chemical reaction is that the additive and a decomposition product of the CL-20 perform a chemical reaction, so that a decomposition reaction path of the CL-20 is optimized, and the energy release efficiency is improved. Meanwhile, the decomposition product of the CL-20 also reacts with the additive and the decomposition product thereof, and the decomposition and energy release of the additive are promoted. The synergistic chemical reaction is characterized in that the energy release amount or the energy release efficiency after the two components are compounded is obviously improved compared with that of the single component.

The mass percentage of the additive in the composite material is 0.001-50%.

The additive has certain reducibility and can react with the initial decomposition product NO of the CL-20 at high temperature₂Oxidation-reduction reaction to generate N₂O and CO, CO₂，H₂O and the like, which are more thermodynamically stable.

The additive simultaneously contains oxygen-containing functional groups, and can further perform chemical reaction with the intermediate product after CL-20 denitriding, so that the intermediate product is promoted to be decomposed into a more thorough gas product and a small amount of solid product. The additive simultaneously contains oxygen-containing functional groups such as hydroxyl, carbonyl and the like, can further perform chemical reaction with the intermediate product after the CL-20 denitrogenation, and promotes the intermediate product to be decomposed into more complete gas product and a small amount of solid product, such as CO₂，N₂，CO，H₂O，NO，N₂O, and the like.

The additive in the first step is Graphene Oxide (GO), or graphene quantum dots, or chemically modified single-walled carbon nanotubes, or chemically modified multi-walled carbon nanotubes, or fullerene.

The partial additive has a unique one-dimensional or two-dimensional structure, and is beneficial to forming a self-supporting composite material. The further addition of potassium salt in the composite material promotes the synergistic reaction between the two materials, so that the combustion reaction is more vigorous.

The mass ratio of the potassium salt in the self-supporting composite material is 0.01-2%.

The potassium salt is KOH or KNO₃Or KCL or KMnO₄。

Compared with the prior art, the invention has the beneficial effects that:

1. the method for improving the energy release efficiency is realized by optimizing a decomposition reaction path of the CL-20, the optimization of the decomposition reaction path of the CL-20 is realized by adding a proper additive into a CL-20 material, and a synergistic chemical reaction can be generated between the additive and the CL-20, wherein the synergistic chemical reaction is that the additive and a decomposition product of the CL-20 are subjected to a chemical reaction, and the decomposition reaction path of the CL-20 is optimized, so that the energy release efficiency is improved; meanwhile, the decomposition product of the CL-20 also reacts with the additive and the decomposition product thereof, and the decomposition and energy release of the additive are promoted. The method can remarkably improve the energy density level energy release rate of the CL-20 and the composite material thereof. The composite material has good application prospect in the fields of high-performance solid propellant, high explosive, primary explosive, propellant powder and the like.

2. In addition, from the perspective of combustion applications, one of the additives in the present invention, GO, has a one-atom thick two-dimensional structure that provides support for the tessellation of CL-20 micron particles, while the interconnection between the GO two-dimensional materials forms a three-dimensional network structure. Since GO is in the presence of potassium salt (such as KOH, KNO)₃，KCL，KMnO₄Etc.) has good combustion propagation performance, therefore, in the composite material of the invention, the combustion of GO provides initial energy for the combustion reaction of CL-20, and provides relay for the combustion propagation among CL-20 particles, and a domino effect combustion propagation mode similar to relay competition is formed. This propagation mode is an innovative development of CL-20 applications with poor combustion performance.

Drawings

FIG. 1 is a scanning electron micrograph of the GO/CL-20 composite obtained from example 3;

FIG. 2a is a screenshot of the GO film burning under laser irradiation in example 3, 2b is a screenshot of the CL-20 powder burning under laser irradiation, 2c is a screenshot of the GO/CL-20 composite material burning video recording front under laser irradiation prepared in example 3, and 2d is a screenshot of the GO/CL-20 composite material burning video recording side under laser irradiation prepared in example 3;

FIG. 3 is a Differential Scanning Calorimetry (DSC) curve of various samples of example 3;

FIG. 4 is a comparison of the exotherms of the different samples of example 3;

FIG. 5 is a Fourier transform Infrared absorption Spectroscopy (FTIR) of the gaseous products generated during thermal decomposition of the different samples of example 3;

FIG. 6 is a graph of Fourier transform infrared absorption Spectroscopy (FTIR) absorption intensity as a function of thermal decomposition temperature for representative gaseous products generated during thermal decomposition for different samples of example 3;

FIG. 7 is a thermogravimetric comparison of different samples of example 3.

Detailed Description

The present invention will be further described with reference to the following examples, which are intended to illustrate only some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, other embodiments used by those skilled in the art without any creative effort belong to the protection scope of the present invention.

Example (b):

The mass percentage of the additive in the composite material is 0.001-50%.

The additive has certain reducibility and can react with the initial decomposition product NO of the CL-20 at high temperature₂Oxidation-reduction reaction is carried out to generate NO, N₂O and CO, CO₂，H₂O and the like, which are more thermodynamically stable.

The additive simultaneously contains oxygen-containing functional groups and can be further reacted with intermediate products after CL-20 denitrogenationThe biochemical reaction promotes the decomposition of the intermediate product into more complete gas products and a small amount of solid products. The additive simultaneously contains oxygen-containing functional groups such as hydroxyl, carbonyl and the like, can further perform chemical reaction with the intermediate product after the CL-20 denitrogenation, and promotes the intermediate product to be decomposed into more complete gas product and a small amount of solid product, such as CO₂，N₂，CO，H₂O，NO，N₂O, and the like.

The addition of potassium salt to the composite material promotes a synergistic reaction between the two, making the combustion reaction more vigorous.

The mass percentage of the additive in the self-supporting composite material is 0.01-2%.

The catalyst is a potassium salt. The potassium salt is KOH or KNO3 or KCL or KMnO 4.

The method for improving the energy release efficiency is realized by optimizing a decomposition reaction path of the CL-20, the optimization of the decomposition reaction path of the CL-20 is realized by adding a proper additive into a CL-20 material, and a synergistic chemical reaction can be generated between the additive and the CL-20, wherein the synergistic chemical reaction is that the additive and a decomposition product of the CL-20 are subjected to a chemical reaction, and the decomposition reaction path of the CL-20 is optimized, so that the energy release efficiency is improved; meanwhile, the decomposition product of the CL-20 also reacts with the additive and the decomposition product thereof, and the decomposition and energy release of the additive are promoted. The method can remarkably improve the energy density level energy release rate of the CL-20 and the composite material thereof. The composite material has good application prospect in the fields of high-performance solid propellant, high explosive, primary explosive, propellant powder and the like.

In addition, from the perspective of combustion applications, the additive GO in the present invention has a two-dimensional structure of single atom thickness that provides support for the intercalation of CL-20 micron particles, while the interconnection between the GO two-dimensional materials forms a three-dimensional network structure. Since GO is in the presence of potassium salt (such as KOH, KNO)₃，KCL，KMnO₄Etc.) has good combustion propagation performance, therefore, in the composite material of the invention, the combustion of GO provides initial energy for the combustion reaction of CL-20, and provides relay for the combustion propagation among CL-20 particles, and a domino effect combustion propagation mode similar to relay competition is formed. This propagation mode is an innovative development of CL-20 applications with poor combustion performance.

Graphene Oxide (GO) is taken as an example of the additive. The key point of the invention is to realize the uniform inlaying and dispersion of CL-20 micron particles in the GO three-dimensional network structure to form the composite material. To achieve this, the present invention utilizes solution processing techniques to disperse CL-20 in the GO colloidal aqueous dispersion. The CL-20 and GO can form hydrogen bonds in a water solvent, and the characteristic ensures the compatibility of CL-20 particles in GO water dispersion, thereby being beneficial to realizing stable GO/CL-20 colloidal water dispersion. The GO/CL-20 colloidal aqueous dispersion can be prepared into the GO/CL-20 composite material by utilizing various technologies. Comprises (1) coating method, such as coating on other materials with brush pen, brush, etc.; (2) printing on the substrate material by using a screen printing technology; (3) obtaining the GO/CL-20 composite material by a freeze drying method; (4) and obtaining the GO/CL-20 composite material by using a vacuum filtration method.

Soaking GO/CL-20 composite material obtained by the technical means in potassium salt (such as KOH and KNO) with certain concentration₃，KCL，KMnO₄Etc.) and the like. Because CL-20 and GO respectively have good dispersibility in a water solvent, GO and CL-20 in the obtained composite material are fully contacted, thereby ensuring the sufficiency of a synergistic reaction between the GO and the CL-20 during reactions such as combustion, decomposition, explosion and the like.

Example 1:

0.6g of CL-20 micron powder is added into 2mL of deionized water, stirred for 10min and then ultrasonically dispersed for 10 min. Adding 3g of GO hydrogel into the dispersion liquid, carrying out magnetic stirring for 12h, then carrying out freeze drying, and drying for 12h to obtain the GO/CL-20 composite material.

Example 2:

0.6g of CL-20 micron powder is added into 2mL of deionized water, stirred for 10min and then ultrasonically dispersed for 10 min. 3g of GO hydrogel is added into the dispersion liquid, and magnetic stirring is carried out for 12 hours. The mass fraction of GO in the GO hydrogel is 12%. And transferring the dispersion liquid obtained after stirring into a vacuum filtration container for filtration, carrying out freeze drying after the solvent is dried, and drying for 2h to obtain the self-supporting GO/CL-20 composite material.

Example 3:

0.6g of CL-20 micron powder is added into 2mL of deionized water, stirred for 10min and then ultrasonically dispersed for 10 min. 3g of GO hydrogel is added into the dispersion liquid, and magnetic stirring is carried out for 12 hours. The mass fraction of GO in the GO hydrogel is 12%. And transferring the dispersion obtained after stirring to a vacuum filtration container for filtration, adding 2mL of 0.2mol/L KOH solution after the solvent is drained, continuing filtration, pouring out the redundant KOH solution after 1h, freeze-drying, and drying for 2h to obtain the self-supporting GO/CL-20 composite material.

FIG. 1 is a scanning electron micrograph of the GO/CL-20 composite obtained from embodiment three. The combustion of the self-supporting GO/CL-20 composite, CL-20 powder and GO film in example 3 was triggered by a 1064nm laser beam. As shown in fig. 2a, 2b, 2c and 2d, wherein 2a is a screenshot of the burning process of GO thin film, 2b is a screenshot of the burning process of CL-20 powder under laser irradiation, and 2c and 2d are screenshots of burning video of GO/CL-20 composite material prepared by using the third embodiment. FIG. 2c is a front view, and FIG. 2d is a side view. The laser intensity triggering GO and GO/CL-20 composite materials is 2W, and the irradiation time is respectively 13ms and 15 ms. Laser intensity 8W triggering CL-20, time 520 ms. The combustion process shows that pure GO is slightly combusted, the CL-20 is locally combusted under the long-time irradiation of strong laser, but is extinguished along with the stop of the irradiation of the laser beam, and the GO/CL-20 composite material is violently combusted after the short-time irradiation of the laser.

The specific experimental data are as follows:

FIG. 3 is a Differential Scanning Calorimetry (DSC) curve of various samples. The GO/CL-20 composite material exhibits an additional exotherm between 150 degrees Celsius and 140 degrees Celsius compared to CL-20 and GO.

FIG. 4 compares the heat release of different samples. The heat release of GO/CL-20 composites is significantly increased compared to both CL-20 and GO.

FIG. 5 is a Fourier transform infrared absorption spectrum (FTIR) of gaseous products generated during thermal decomposition of different samples. Comparison by FTIR showed decomposition of pure CL-20 with NO₂Mainly GO is decomposed by small amount of CO₂And H₂And (C) O. And NO in the decomposition product of GO/CL-20 composite material₂With significantly reduced amounts of gaseous products of higher thermodynamic stability, such as N₂O，NO，H₂O，CO₂Etc. are significantly increased. Proves that NO is generated between GO and CL-20₂The related synergistic reaction ensures that the decomposition reaction is more complete and the energy release is more.

FIG. 6 is a graph of Fourier transform Infrared absorption Spectroscopy (FTIR) absorption intensity as a function of thermal decomposition temperature for representative gaseous products generated during thermal decomposition for different samples. FTIR intensity changes showed that pure representative decomposition products of CL-20 all appeared in a narrow temperature range of 228 to 250 degrees Celsius, with the products being in NO₂Mainly contains a small amount of N₂O，NO，H₂O and CO₂. While the decomposition products of GO/CL-20 appear in a wide temperature range of 150 to 250 ℃, and the products are N₂O and NO are the main. The differences in the amount of nitrogen oxides in the CL-20 and GO/CL-20 decomposition products indicate that GO addition is facilitated in combination with NO₂The related secondary chemical reaction ensures that the CL-20 reaction is more complete and is beneficial to releasing more energy. In addition, the gas products with the highest thermodynamic stability among the GO/CL-20 decomposition products, such as H₂O and CO₂The amount of the catalyst is far higher than that of pure CL-20 and GO, which shows that the decomposition reaction of GO/CL-20 composite products is more complete, and the decomposition reaction channel is optimized, which means higher energy release.

FIG. 7 is a thermogravimetric curve comparison of different samples. The GO/CL-20 has the least decomposition residual mass, which shows that the decomposition reaction channel is optimized, the composite material is decomposed more completely, and the energy is released more completely.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A method for optimizing a CL-20 decomposition reaction pathway and increasing its energy release efficiency, comprising: the method comprises the following steps:

step one, adding an additive into CL-20 to form a composite material; the additive has certain reducibility and can react with the initial decomposition product NO of the CL-20 at high temperature₂Carrying out oxidation-reduction reaction; the additive simultaneously contains oxygen-containing functional groups, and can further perform chemical reaction with the intermediate product after the CL-20 denitriding to promote the intermediate product to be decomposed into more thorough gas products and a small amount of solid products;

the additive in the first step is graphene oxide; the mass percentage of the additive in the composite material is 0.001-50%;

the additive has a one-dimensional or two-dimensional structure and forms a self-supporting composite material with CL-20;

and step two, performing initial decomposition and combustion reaction on the composite material obtained in the step one, wherein the additive has an accelerating effect on the initial decomposition and combustion reaction of the CL-20, a synergistic chemical reaction is generated between the additive and the CL-20, and meanwhile, a decomposition product of the CL-20 is also subjected to a chemical reaction with the additive and the decomposition product thereof.

2. The method of claim 1, wherein the energy release efficiency of the CL-20 decomposition reaction pathway is increased by: in step two, the potassium salt is added to the composite material for initial decomposition and combustion reactions.

3. The method of claim 2, wherein the energy release efficiency of the CL-20 decomposition reaction pathway is increased by: the mass ratio of the potassium salt in the composite material is 0.01-2%.

4. The method of claim 2 for optimizing the CL-20 decomposition reaction pathway and increasing its energy release efficiencyThe method is characterized in that: the potassium salt is KNO₃Or KCL or KMnO₄。