Three-dimensional lamellar tatb mesogen and method for preparing the same

Abstract

The present application relates to a kind of three-dimensional layered TATB mesogen and its preparation method.Mesogen is layered by multiple lamellar crystal, and the particle size of mesogen is 50 μm-90 μm.The preparation method of three-dimensional layered TATB mesogen includes the following steps: (1) the preparation of primary lamellar nano-TATB particles, TATB is added to good solvent containing additives, completely dissolved at 60-130 DEG C, to obtain TATB saturated solution, then the saturated solution is dropped to room temperature under fast stirring, to obtain the suspension containing primary lamellar nano-TATB particles.(2) the oriented attachment of primary lamellar nano-TATB particles, the suspension containing primary lamellar nano-TATB particles is slowly stirred at room temperature for a certain time, so that primary lamellar nano-TATB particles occur oriented attachment in layer-layer stacking mode, filter, wash and dry, to obtain the three-dimensional layered TATB mesogen.The process flow of the present application is simple, and the three-dimensional layered TATB mesogen prepared has obvious micro-nano multi-level structure, good dispersibility, and the bulk density of mesogen is much higher than lamellar crystal, which can be used for casting charge and significantly improve the solid content of charge.

Description

Technical Field

[0001] This invention belongs to the field of energetic materials, specifically relating to a three-dimensional layered TATB mesocrystalline material and its preparation method. This invention has good application prospects in insensitive munitions. Background Technology

[0002] 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB) is currently the only single-element explosive that fully meets the standards for insensitive high-energy (IHE) explosives. It is highly insensitive to external stimuli such as heat, light, shock waves, friction, and mechanical impact, making it highly favored in military applications requiring insensitive explosives. Currently, TATB used in explosive charges is generally directly synthesized, with particle sizes ranging from 5 μm to 20 μm, and mostly in flake form. Due to its small particle size, it is mainly used for press-fitted PBXs. Its use in cast explosives suffers from poor flowability and low solid content, thus its application in cast explosives is very limited.

[0003] Large-particle TATB crystals possess good flowability and high bulk density, making them suitable for casting. Currently, the most practical method for preparing large-particle TATB is high-pressure synthesis. However, high-temperature and high-pressure operations not only pose significant safety risks but also severely limit the scale of production, falling far short of current application requirements. Recrystallization is one of the effective methods for controlling the particle size of explosive crystals; however, due to the strong intramolecular and intermolecular multiple hydrogen bonds in TATB, conventional recrystallization methods mostly yield one-dimensional plate-like crystals, making it difficult to obtain three-dimensional large-particle crystals. Therefore, developing a three-dimensional large-particle TATB preparation technology with milder process conditions is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a three-dimensional layered TATB mesocrystalline structure and its preparation method, in order to solve the technical problems existing in the background art.

[0005] The three-dimensional layered TATB mesocrystalline material prepared by this invention is composed of multiple plate-like crystals stacked in layers. The crystal particle size ranges from 50μm to 90μm. The flowability and bulk density of the crystal are much higher than those of the plate-like crystals. It can be used for casting explosives and significantly improves the solid content of the explosive.

[0006] To achieve the above-mentioned technical effects, the present invention provides a method for preparing three-dimensional layered TATB mesocrystalline material, comprising the following steps:

[0007] (1) Preparation of primary sheet-like nano-TATB particles: TATB is added to a good solvent containing additives and completely dissolved at 60℃~130℃ to obtain a saturated TATB solution. Then, the saturated solution is rapidly stirred and cooled to room temperature to obtain a suspension containing primary sheet-like nano-TATB particles.

[0008] (2) Oriented Attachment of Primary Sheet-like Nano TATB Particles: The suspension containing primary sheet-like nano TATB particles is slowly stirred at room temperature for a certain period of time to allow the primary sheet-like nano TATB particles to be orientedly attached in a layer-to-layer stacking manner. After filtration, washing and drying, the three-dimensional layered TATB mesocrystalline material is obtained.

[0009] Furthermore, the good solvent in step (1) is selected from any one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), sulfolane, nitrobenzene, 1-ethyl-3-methylimidazolium nitrate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium bicarbonate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium bicarbonate, 1-allyl-3-ethylimidazolium tetrafluoroborate, and 1-vinyl-3-ethylimidazolium tetrafluoroborate.

[0010] Furthermore, the additive in step (1) is one or more of the following: hydroxypropyl methylcellulose, Tween 80, urea, polyacrylic acid, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polylactic acid, poly(4-vinylphenol), and polyvinyl acetate.

[0011] Furthermore, in step (1), the mass of the additive is 0.001% to 10% of the mass of TATB.

[0012] Furthermore, the stirring speed in step (1) is 800-1000 rpm.

[0013] Furthermore, the cooling rate in step (1) is 10℃ / min to 30℃ / min.

[0014] Furthermore, the stirring speed in step (2) is 50 to 200 rpm.

[0015] Furthermore, the stirring time in step (2) is 30 min to 200 min.

[0016] The beneficial effects of this application may include, but are not limited to, the following: The method for preparing three-dimensional layered TATB mesocrystalline crystals provided by this invention is inventive in that the process flow is simple and the process conditions are mild. The prepared crystal product is three-dimensional layered TATB mesocrystalline crystal with a particle size range of 50μm to 90μm, and the mesocrystalline crystal is composed of multiple layered stacked plate-like crystals. The formation of primary plate-like nanoparticles and their directional attachment in a layer-by-layer stacking manner are the key to the preparation of three-dimensional layered TATB mesocrystalline crystals by this invention. Among them, the synergistic regulation of additives, stirring speed, and cooling rate are the key factors for the formation of primary plate-like nanoparticles and their directional attachment in a layer-by-layer stacking manner.

[0017] The large-particle TATB prepared in this invention is a three-dimensional layered mesocrystalline structure. The preparation method involves first forming primary plate-like nanoparticles, and then, through the control of crystallization conditions, causing the obtained primary plate-like nanoparticles to undergo directional adhesion in a layer-to-layer stacking manner. The particle size range of the mesocrystalline structure is 50 μm to 90 μm. In contrast, the method described in "A Method for Preparing Large-Particle Triaminotrinitrobenzene by Cyclic Heating and Cooling (ZL 2016 1 0898225.2)" involves only partially dissolving the raw materials to form a suspension, and then preparing large-particle TATB with a particle size range of 50 μm to 200 μm through multiple heating and cooling processes. The method described in "A Method for Preparing Large-Particle Triaminotrinitrobenzene by Reaction Crystallization (ZL 2016 1 0898069.X)" uses a combination of chemical synthesis and crystallization, namely reaction crystallization. The TATB precursor compound is reacted with an amination reagent, and under the induction of TATB seed crystals, the crystals further grow to obtain large-particle TATB with a particle size range of 50 μm to 150 μm. Attached Figure Description

[0018] Figure 1 This is a SEM image of the three-dimensional layered TATB mesocrystalline material prepared according to the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] Conversely, this application covers any substitutions, modifications, equivalent methods, and schemes made within the spirit and scope of this application as defined in the claims. Furthermore, to provide the public with a better understanding of this application, certain specific details are described in detail below. However, this application can be fully understood by those skilled in the art even without these detailed descriptions.

[0021] The following will combine Figure 1This application provides a detailed description of a three-dimensional layered TATB mesocrystalline structure and its preparation method, as described in the embodiments. It is worth noting that the following embodiments are merely illustrative of this application and do not constitute a limitation thereof.

[0022] Example 1

[0023] At 100℃, 2g of solid TATB was added to 100g of 1-ethyl-3-methylimidazolium acetate containing 0.02g of hydroxypropyl methylcellulose and dissolved completely. The solution was then cooled to 25℃ at a rate of 20℃ / min while stirring at 900rpm. The stirring speed was then adjusted to 100rpm and stirred for 60min. The solution was then filtered, washed, and dried to obtain three-dimensional layered TATB mesocrystalline crystals of approximately 80μm. The SEM image is shown below. Figure 1 As shown.

[0024] Example 2

[0025] At 120℃, 0.2g of solid TATB was added to 200g of DMSO containing 0.003g of urea and dissolved completely. Then, the temperature was reduced to 25℃ at a stirring speed of 850rpm and a cooling rate of 30℃ / min. The stirring speed was then adjusted to 50rpm and stirred for 150min. After filtration, washing, and drying, three-dimensional layered TATB mesocrystalline crystals of about 75μm were obtained.

[0026] Example 3

[0027] At 100℃, 5g of solid TATB was added to 100g of DMSO containing 0.01g of polyvinylpyrrolidone and 100g of 1-ethyl-3-methylimidazolium bicarbonate and dissolved completely. Then, the temperature was reduced to 25℃ at a stirring speed of 1000rpm and a cooling rate of 15℃ / min. The stirring speed was then adjusted to 200rpm and stirred for 100min. After stirring, the mixture was filtered, washed, and dried to obtain three-dimensional layered TATB mesocrystalline crystals of about 85μm.

[0028] Example 4

[0029] At 100℃, 1g of solid TATB was added to 200g of DMF containing 0.01g of polyethyleneimine and 100g of 1-butyl-3-methylimidazolium bicarbonate and completely dissolved. Then, the temperature was reduced to 25℃ at a stirring speed of 950rpm and a cooling rate of 20℃ / min. The stirring speed was then adjusted to 100rpm and stirred for 90min. After stirring, the mixture was filtered, washed, and dried to obtain three-dimensional layered TATB mesocrystalline crystals of about 50μm.

[0030] Example 5

[0031] At 90℃, 0.5g of solid TATB was added to 100g of 1-ethyl-3-methylimidazolium bicarbonate containing 0.005g of polyvinyl alcohol and completely dissolved. Then, the temperature was reduced to 25℃ at a stirring speed of 800rpm and a cooling rate of 25℃ / min. The stirring speed was then adjusted to 150rpm and stirred for 60min. After stirring, the mixture was filtered, washed, and dried to obtain three-dimensional layered TATB mesocrystalline crystals of about 60μm.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a three-dimensional lamellar TATB mesogen, characterized in that, Includes the following steps: (1) Preparation of primary sheet-like nano-TATB particles: TATB is added to a good solvent containing additives and completely dissolved at 60℃~130℃ to obtain a saturated TATB solution. Then, the saturated solution is rapidly stirred and cooled to room temperature to obtain a suspension containing primary sheet-like nano-TATB particles. (2) Directional attachment of primary sheet-like nano-TATB particles: The suspension containing primary sheet-like nano-TATB particles is slowly stirred at room temperature for a certain period of time to allow the primary sheet-like nano-TATB particles to be directionally attached in a layer-by-layer stacking manner. After filtration, washing and drying, the three-dimensional layered TATB mesocrystalline material is obtained. The stirring speed in step (1) is 800-1000 rpm, and the cooling rate is 10℃ / min-30℃ / min; The additive in step (1) is one or more of the following: hydroxypropyl methylcellulose, Tween 80, urea, polyacrylic acid, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polylactic acid, poly(4-vinylphenol), and polyvinyl acetate.

2. The method as described in claim 1, characterized in that, The good solvent in step (1) is selected from any one or more of dimethyl sulfoxide, N,N-dimethylformamide, sulfolane, nitrobenzene, 1-ethyl-3-methylimidazolium nitrate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium bicarbonate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium bicarbonate, 1-allyl-3-ethylimidazolium tetrafluoroborate, and 1-vinyl-3-ethylimidazolium tetrafluoroborate.

3. The method as described in claim 1, characterized in that, In step (1), the mass of the additive is 0.001% to 10% of the mass of TATB.

4. The method as described in claim 1, characterized in that, The stirring speed in step (2) is 50 to 200 rpm.

5. The method as described in claim 1, characterized in that, The stirring time in step (2) is 30 min to 200 min.

6. A three-dimensional layered TATB mesocrystalline material, prepared by the method described in any one of claims 1 to 5, characterized in that: Mesocrystalline crystals are formed by the stacking of multiple plate-like crystals, and the particle size ranges from 50 μm to 90 μm.

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