CN113480385B

CN113480385B - NTO dissociation inhibitor and application thereof

Info

Publication number: CN113480385B
Application number: CN202110751324.9A
Authority: CN
Inventors: 王俊峰; 束庆海; 王满曼; 王子锋; 尚凤琴; 邹浩明; 马仙龙; 张哲�
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2021-07-02
Filing date: 2021-07-02
Publication date: 2022-04-12
Anticipated expiration: 2041-07-02
Also published as: CN113480385A

Abstract

The invention relates to an NTO dissociation inhibitor and application thereof, belonging to the field of energetic materials. The invention aims to solve the problems of low yield and large pollution of the existing method. The method comprises the steps of firstly preparing the NTO dissociation inhibitor by taking citric acid, malic acid, glycolic acid, tartaric acid, succinic acid, ethanol and propionic acid as raw materials, then uniformly mixing deionized water and the NTO dissociation inhibitor, and adding NTO. And (3) heating, then dropwise adding a binder system, stirring, dissolving, cooling and filtering to obtain the NTO-based mixed explosive molding powder. The waste liquid can be added into the water suspension for recycling. The NTO-based mixed explosive molding powder prepared by the invention is compact and smooth, has stable crystal form, and has little difference from the molding powder obtained by the existing method in mechanical sensitivity. Compared with the existing method, the method can greatly improve the yield of the NTO-based mixed explosive molding powder prepared by the water suspension method, reduce the NTO content in the waste liquid and reduce the pollution to the environment. Meanwhile, the method has the advantages of simple process, mild experimental conditions, low production cost and easy realization of large-scale production.

Description

NTO dissociation inhibitor and application thereof

Technical Field

The invention relates to an NTO dissociation inhibitor and application thereof, in particular to an NTO dissociation inhibitor and application thereof in a process of preparing NTO-based mixed explosive molding powder by a water suspension method, and belongs to the field of energetic materials.

Background

3-nitro-1, 2, 4-triazole-5-ketone (NTO) is a high-energy insensitive elementary explosive, the energy level of the high-energy insensitive elementary explosive is equivalent to RDX, and the theoretical detonation velocity and detonation pressure are 8550m/s and 34.9GPa respectively; the safety level of the explosive is equivalent to TATB which is commonly called as wood explosive, and the explosive has lower mechanical sensitivity, thermal sensitivity and shock wave sensitivity. In addition, the NTO also has the characteristics of simple synthesis process, low manufacturing cost and the like. Based on the above advantages, NTO has become one of the most promising elementary explosives in the present stage, and has received the general attention of domestic and foreign scholars. Currently, NTO has been used in a large number in the formulation of insensitive ammunition for Western multinational military and embodies excellent safety characteristics.

In order to meet the special requirements of explosive application or improve the comprehensive performance of the explosive in the use process, certain additives are often required to be added into the single-substance explosive and applied to weaponry in the form of mixed explosives. Research on NTO-based mixed explosives has begun early in Western countries, represented by the United states and the North convention, and research on formulations thereof is relatively mature, and a variety of NTO-based mixed explosive formulations mainly based on three types of charging, namely, press-fitting, melt-casting and pouring are formed. The mixed explosive for pressure loading has higher charging density and can obtain higher energy level, so the mixed explosive is commonly used in the parts of armor breaking and blasting combat and is a type of mixed explosive with wide requirements at present.

The pressed mixed explosive is formed by pressing explosive molding powder by adopting a pressing process. The composition of the explosive molding powder generally comprises a main explosive, a binder, a plasticizer and the like. The preparation method mostly adopts a solution water suspension method, because the water is used as a disperse phase and a heat transfer medium, the safety of the whole production process can be ensured. Meanwhile, the process conditions such as temperature, stirring speed and the like are convenient to control, and further smooth, compact and uniform-size molding powder particles can be obtained. Therefore, the solution water suspension method is the first choice preparation method of the NTO-based mixed explosive molding powder.

However, NTO has high solubility in water, and its solubility in water at 19.8 deg.C can reach 1.28g/100 ml. Reports show that the NTO content in 1000L of wastewater generated in the preparation process of the NTO-based mixed explosive molding powder can reach 10-15 kg, and the numerical value is far higher than the content of TNT, RDX, HMX, NQ and other common explosives in the industrial wastewater. Therefore, although the water suspension method can ensure the safe preparation of the NTO-based mixed explosive molding powder and obtain high-quality molding powder particles, a large amount of NTO is lost in the preparation process, the yield of the NTO-based mixed explosive molding powder is seriously reduced, and the preparation cost is improved. In addition, high-concentration NTO in the wastewater is difficult to naturally degrade, and can produce toxic effects on animals and plants in the environment and cause great harm to the ecological environment. Therefore, how to improve the preparation yield of the NTO-based mixed explosive molding powder and reduce the pollution of the preparation of the NTO-based mixed explosive molding powder to the environment is always a key point of attention of scientific research personnel and production enterprises.

Disclosure of Invention

The invention provides an NTO dissociation inhibitor which can effectively inhibit the dissociation rate of NTO in an aqueous solution. The NTO dissociation inhibitor provided by the invention is applied to the water suspension method to prepare the NTO-based mixed explosive molding powder, and the yield of the molding powder can be greatly improved. Meanwhile, the NTO content in the waste liquid can be reduced, and the pollution to the environment is reduced.

The invention is realized by the following technical scheme:

preparation and application of an NTO dissociation inhibitor, which comprises the following steps:

step one, preparation of NTO dissociation inhibitor

Dissolving a certain amount of weak acid in absolute ethyl alcohol at room temperature, and then adding a proper amount of propionic acid into the ethanol solution to prepare the NTO dissociation inhibitor.

The weak acid in the NTO dissociation inhibitor is one or a mixture of citric acid, malic acid, glycolic acid, tartaric acid and succinic acid in any proportion, and the mass ratio of a system formed by the weak acid to the ethanol to the propionic acid is 1: 5-100: 0.5 to 2.

Step two, preparation of binder system solution

Putting a certain mass of the binder and the plasticizer into a conical flask, adding a proper amount of ethyl acetate, stirring at room temperature, and standing for a period of time to fully dissolve the binder and the plasticizer to prepare a binder system solution.

In the binder solution, Estane, cellulose acetate butyrate and fluororubber (F2311 or F2603) can be used as the binder, and 2, 2-dinitropropanol formal and bis 2, 2-dinitropropanol acetal 1:1 low-eutectic compound, diethyl phthalate or nitrooxyethyl nitramine can be used as the plasticizer. The ratio of the binder to the plasticizer to the ethyl acetate was 1 (mass): 0.5-2 (by mass): 15-25 (volume).

Step three, preparing molding powder by using water suspension method

And (2) adding the NTO dissociation inhibitor prepared in the step one into a beaker filled with deionized water at room temperature, stirring and fully mixing uniformly, then adding a certain mass of NTO into the mixed solution, and fully stirring to uniformly disperse the NTO to obtain the aqueous suspension of the NTO. And subsequently, heating the aqueous suspension of NTO, dropwise adding the binder system solution prepared in the step two into the aqueous suspension at a certain stirring rate, keeping the temperature for a period of time after the dropwise adding is finished, and heating the system to 60 ℃ to disperse the ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. Filtering, washing with ethanol, and drying to obtain NTO-based mixed explosive molding powder.

In the above step, the stirring speed is 350-450 r/min; the mass of the NTO dissociation inhibitor and the deionized water is 1: 10 to 100 parts; the mass ratio of the total mass of the ethanol, the propionic acid and the deionized water to the NTO is 1: 1.5-2.2.

Step four, recycling and reusing waste liquid

And adding the waste liquid obtained by filtering in the third step into the aqueous suspension, and allowing the waste liquid to participate in the preparation of the NTO-based mixed explosive molding powder again. The weak acid in the waste liquid can continuously inhibit the dissociation of NTO.

The NTO-based mixed explosive molding powder can be used for pressing mixed explosives and can be applied to armor-breaking, killing blasting and penetration blasting combat parts.

Advantageous effects

1. The NTO dissociation inhibitor consists of one or more organic weak acids, can ionize a large amount of H ions in aqueous solution and improve the concentration of the H ions in the aqueous solution. The presence of large amounts of H ions in the aqueous solution effectively inhibits dissociation of the NTO as a weak acid. Meanwhile, the ethanol is used as the solvent of the NTO dissociation inhibitor, so that the solubility of the NTO in the aqueous solution can be effectively reduced, and the NTO is more in the form of solid particles in the aqueous suspension. The two effects synergistically improve the content of solid NTO in the aqueous suspension, effectively improve the yield of NTO-based mixed explosive molding powder prepared by a water suspension method, and simultaneously reduce the preparation cost.

2. Citric acid, malic acid, glycolic acid, tartaric acid and succinic acid in the NTO dissociation inhibitor have higher solubility in water, and cannot be lost in the process of preparing the NTO-based mixed explosive molding powder by a water suspension method, so the NTO-based mixed explosive molding powder can be repeatedly utilized in the method.

3. Several organic acids such as citric acid, malic acid, glycolic acid, tartaric acid, succinic acid and the like used in the NTO dissociation inhibitor are compounds existing in nature, and have little harm to natural environment and organisms. Therefore, the use of the NTO dissociation inhibitor causes no pollution to the natural environment. Meanwhile, the method effectively reduces the NTO content in the waste liquid of the NTO-based mixed explosive molding powder prepared by the water suspension method, and reduces the pollution of nitrogen-rich compounds in the waste liquid to the natural environment.

4. The preparation method has the advantages of simple preparation process, simple and convenient operation, mild experimental conditions, low production cost and easy realization of large-scale production.

Drawings

FIG. 1 is a flow chart of the application of the NTO dissociation inhibitor, namely the preparation of the NTO-based mixed explosive molding powder, according to the invention;

FIG. 2 shows the NTO content in the waste liquid measured by high performance liquid chromatography; wherein, the graph a shows the NTO content in the waste liquid (not recycled) obtained in example 5; FIG. b shows the NTO content in the waste liquid obtained in example 6;

FIG. 3 is a scanning electron microscope image of the NTO-based mixed explosive molding powder;

FIG. 4 is an X-ray powder diffraction pattern of the NTO-based mixed explosive molding powder.

Detailed Description

In order to make the experimental technical scheme of the invention clearer, the invention is further described in detail by combining the attached drawings and examples.

Example 1

0.5g of citric acid was added to a 25mL beaker at room temperature, 10mL of ethanol was added to dissolve the solid, and 0.5mL of propionic acid was added to the ethanol solution to prepare an NTO dissociation inhibitor.

4g of Estane and 6g of nitrooxyethyl nitramine are put into a conical flask, 60mL of ethyl acetate is added, the mixture is stirred at room temperature and is placed for a period of time to be fully dissolved, and then a binder system solution is prepared.

Adding the prepared NTO dissociation inhibitor into a 500mL beaker filled with 150mL deionized water at room temperature, stirring and fully mixing uniformly, adding 90g NTO, and fully stirring to uniformly disperse the NTO to obtain an NTO aqueous suspension. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 350r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, 93.7g of NTO-based mixed explosive molding powder is obtained in total, and the yield is 93.7%.

Example 2

At room temperature, 0.5g of malic acid was added to a 25mL beaker, 25mL of ethanol was added to dissolve the solid, and then 1.0mL of propionic acid was added to the ethanol solution to prepare an NTO dissociation inhibitor.

2.4g of cellulose acetate butyrate and 3.6g of diethyl phthalate are put into a conical flask, 50mL of ethyl acetate is added, stirring is carried out at room temperature, and the mixture is placed for a period of time to be fully dissolved to prepare a binder system solution.

Adding the prepared NTO dissociation inhibitor into a 500mL beaker filled with 180mL deionized water at room temperature, stirring and fully mixing uniformly, adding 94g NTO, and fully stirring to uniformly disperse the NTO to obtain an NTO aqueous suspension. Then, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 380r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, 91.5g of NTO-based mixed explosive molding powder is obtained in total, and the yield is 91.5%.

Example 3

0.5g of malic acid and 0.5g of glycolic acid were added to a 25mL beaker at room temperature, and 15mL of ethanol was further added to dissolve the solid, followed by addition of 2.0mL of propionic acid to the ethanol solution to prepare an NTO dissociation inhibitor.

3.0g of fluororubber F2311 and 5.0g of diethyl phthalate are placed in a conical flask, 50mL of ethyl acetate is added, stirring is carried out at room temperature, and the mixture is placed for a period of time to be fully dissolved to prepare a binder system solution.

Adding the prepared NTO dissociation inhibitor into a 500mL beaker filled with 180mL deionized water at room temperature, stirring and fully mixing uniformly, adding 92g NTO, and fully stirring to uniformly disperse the NTO to obtain an NTO aqueous suspension. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 450r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, the NTO-based mixed explosive molding powder is obtained, the total amount is 94.3, and the yield is 94.3%.

Example 4

0.5g each of citric acid, tartaric acid and succinic acid was added to a 50mL beaker at room temperature, and 40mL of ethanol was added to dissolve the solid, followed by 2.0mL of propionic acid to the ethanol solution to prepare an NTO dissociation inhibitor.

8.0g of fluororubber F2603 and 12.0g of 2, 2-dinitropropanol formal and bis 2, 2-dinitropropanol acetal 1:1 were put into a conical flask, 80mL of ethyl acetate was added, stirred at room temperature, and left for a while to be sufficiently dissolved, thereby preparing a binder system solution.

Adding the prepared NTO dissociation inhibitor into a 1L beaker filled with 350mL of deionized water at room temperature, stirring and fully mixing uniformly, adding 180g of NTO, and fully stirring to uniformly disperse the NTO to obtain an aqueous suspension of the NTO. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 400r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, 178.7g of NTO-based mixed explosive molding powder is obtained in total, and the yield is 89.4%.

Example 5

0.5g each of citric acid, malic acid and glycolic acid was added to a 50mL beaker at room temperature, and 30mL of ethanol was further added to dissolve the solid, followed by addition of 2.0mL of propionic acid to the ethanol solution to prepare an NTO dissociation inhibitor.

5.0g of fluororubber F2311 and 8.0g of 2, 2-dinitropropanol formal and bis 2, 2-dinitropropanol acetal 1:1 low co-dissolved matter are put into a conical flask, 80mL of ethyl acetate is added, stirring is carried out at room temperature, and the mixture is placed for a period of time to be fully dissolved, so as to prepare a binder system solution.

At room temperature, the prepared NTO dissociation inhibitor is added into a 500mL beaker filled with 200mL deionized water, and after the mixture is stirred and mixed fully and uniformly, 135g NTO is added and stirred fully to disperse the mixture uniformly, so that aqueous suspension of NTO is obtained. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 400r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, the NTO-based mixed explosive molding powder is obtained, the total amount is 137.7g, and the yield is 93.0%. The NTO content of the obtained waste liquid was 69.70% as shown in FIG. 2(a) by HPLC.

The waste liquid obtained by filtering can be repeatedly used in the preparation process of NTO molding powder. 150mL of the waste solution of this example was added to a 1000mL beaker containing an aqueous suspension of NTO, and sufficiently stirred to disperse the solution uniformly. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the binder system solution of this example was added dropwise thereto at a stirring rate of 400r/min, and after 20 minutes of incubation, the system was heated to 60 ℃ to drive off the ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, 139.5g of NTO-based mixed explosive molding powder is obtained in total, and the yield is 94.5%.

Example 6

To prove that the method disclosed by the patent improves the yield of the preparation of the NTO-based mixed explosive molding powder, the example uses the original method to prepare the NTO-based mixed explosive molding powder for comparison with the method disclosed by the patent.

5.0g of Estane and 8.0g of a low co-solvent of 2, 2-dinitropropanol formal and bis 2, 2-dinitropropanol acetal 1:1 are put into a conical flask, 80mL of ethyl acetate is added, stirred at room temperature and placed for a period of time to be fully dissolved, and a binder system solution is prepared.

135g NTO was added to a 500mL beaker containing 230mL of deionized water at room temperature and stirred well to disperse it uniformly to give an aqueous suspension of NTO. Subsequently, the aqueous suspension of NTO was heated to 50 ℃ and the prepared binder system solution was added dropwise thereto at a stirring rate of 400r/min, and after the addition was completed and the temperature was maintained for 20 minutes, the system was heated to 60 ℃ to disperse ethyl acetate. After the ethyl acetate was removed, the suspension was cooled to below 20 ℃. After filtering, washing with ethanol and drying, 119.8g of NTO-based mixed explosive molding powder is obtained in total, and the yield is 81.0%.

The content of NTO in the waste liquid obtained in example 6 was measured by a high performance liquid chromatography, and the result is shown in FIG. 2 (b). As can be seen from the figure, the NTO content in the waste liquid obtained by the prior method is 99.83%. The NTO content in the waste liquid obtained by the method is only 69.70%, and is reduced by about 30%. The results show that the NTO content in the waste liquid obtained by preparing the NTO-based mixed explosive molding powder by using the method disclosed by the patent is greatly reduced compared with that of the waste liquid obtained by using the original method. Therefore, the method is a relatively green and environment-friendly preparation method of the NTO-based mixed explosive molding powder.

The structure of the NTO-based mixed explosive molding powder obtained in the above example was characterized by using a scanning electron microscope and XRD powder diffraction.

FIG. 3 is a scanning electron microscope image of the NTO-based mixed explosive molding powder obtained in example 5. As can be seen from figure 3, the molding powder is in a round spherical shape, the surface is compact and smooth, the additive is clearly visible on the crystal surface and in gaps among crystals, the NTO crystal outline is blurred, and the characteristics show that the main explosive NTO is well coated by the binder system. Fig. 4 is an x-ray powder diffraction pattern of the NTO-based mixed explosive molding powder and the NTO simple substance obtained in example 1, example 3 and example 5. In the figure, the shape characteristic peak of NTO is not shifted, and the surface has no crystal transformation of NTO, which proves that the method used in the patent is stable to the crystal form of NTO.

The impact sensitivity and the friction sensitivity of the molding powders of examples 1 to 6 were measured by the percentage explosion method in GJB772A-79, and the results are shown in Table 1. The result shows that the NTO-based mixed explosive modeling powder prepared by the method has small difference between the mechanical sensitivity and the modeling powder obtained by the common method, has good safety characteristics, and can be applied to the armor-breaking and blasting warheads and the penetration warheads with strict requirements on safety performance.

Meanwhile, the yield of the embodiment 1-6 is also shown in table 1, and the result shows that the yield of the molding powder can be effectively improved by using the NTO-based mixed explosive molding powder prepared by the method provided by the invention, and the yield can be improved by at least 10% in six embodiments.

TABLE 1 yield and mechanical sensitivity of NTO-based mixed explosive molding powders

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. Use of an inhibitor of NTO dissociation, characterized by: the method for preparing the NTO-based mixed explosive molding powder by using the inhibitor in a water suspension method comprises the following steps: adding an inhibitor into deionized water, and adding NTO into the mixed solution to obtain an aqueous suspension; heating the aqueous suspension, and adding a binder system solution to prepare high-yield NTO-based mixed explosive molding powder and recyclable waste liquid;

the NTO dissociation inhibitor is prepared by dissolving one or more solid weak acids in a mixed solution of ethanol;

adding propionic acid to the mixed solution;

the solid weak acid comprises: citric, malic, glycolic, tartaric, and succinic acids;

the mass of the ethanol is 5-100 times of that of the solid weak acid;

the mass of the propionic acid is 0.5-2 times of that of the solid weak acid.

2. The use of an inhibitor of NTO dissociation according to claim 1, wherein: the method for utilizing the recyclable waste liquid comprises the following steps: adding the filtered waste liquid into the aqueous suspension to enable the waste liquid to participate in the preparation of the NTO-based mixed explosive molding powder again; the weak acid in the waste liquid continues to inhibit the dissociation of NTO.