Preparation method of monodisperse micron rounded ammonium perchlorate cuboid with uniform particle size

Abstract

The invention discloses a preparation method of a monodisperse ammonium perchlorate micron rounded-corner cuboid with uniform particle size, which comprises the following steps: adding an ammonium perchlorate solution into a benzyl alcohol anti-solvent, and recrystallizing to prepare the monodisperse ammonium perchlorate micron rounded-corner cuboid with uniform particle size. The obtained micron rounded cuboid of ammonium perchlorate is about 25 microns, regular in morphology, good in dispersity and uniform in particle size. The preparation process is simple, operation is easy and convenient, the obtained product is good in stability, good in repeatability, high in yield and suitable for large-scale production, the morphology category of ammonium perchlorate is expanded, and the prepared monodisperse ammonium perchlorate micron rounded cuboid with the uniform particle size has wide application prospects in the field of propellants.

Description

Technical Field

[0001] The invention relates to a preparation method, in particular to a preparation method of monodispersed ammonium perchlorate micrometer rounded corner cuboids with uniform particle size. Background Art

[0002] Ammonium perchlorate is one of the most commonly used oxidizers in solid propellants, accounting for 60% to 80% of its mass fraction. The morphology of ammonium perchlorate has a significant impact on the performance of propellants, so the study of morphology control has attracted much attention. At present, researchers use liquid phase crystallization methods, including cooling crystallization, evaporation crystallization and anti-solvent crystallization, to prepare ammonium perchlorate with various morphologies. For example, M. Kohga (Adv. Powder Tech. 21 (2010) 443–447) prepared hexahedral ammonium perchlorate by cooling crystallization of a saturated solution of ammonium perchlorate in ethylene glycol. CN117285009A uses N,N-dimethylformamide / dimethyl sulfoxide as a mixed solvent, hexadecyltrimethylammonium bromide as a surfactant, and ethyl acetate as an anti-solvent to obtain one-dimensional needle-shaped ammonium perchlorate by anti-solvent crystallization. CN117285012A uses N,N-dimethylformamide as a solvent and ethyl acetate / oleic acid mixed solvent as an anti-solvent to obtain two-dimensional disk-shaped micron ammonium perchlorate by anti-solvent crystallization at room temperature. Ma Zhenye (CN102718187A) dissolved ammonium perchlorate in a mixed solvent of N, N-dimethylformamide / acetone to prepare a saturated solution, and then added it to the anti-solvent ethyl acetate to crystallize and obtain hollow cubic ammonium perchlorate. Liu Yang (Study on the Preparation of Ultrafine Ammonium Perchlorate in Mixed Solvent System, Master's Thesis, 2016) used N, N-dimethylacetamide and alcohol (methanol, ethanol, isopropanol, ethylene glycol) as a mixed solvent at room temperature, and ethyl acetate as an anti-solvent to crystallize and prepare ammonium perchlorate in which cubes and cuboids coexist. CN118637561A dissolved ammonium perchlorate in a mixed solution of methanol and triethanolamine, and then used the anti-solvent octane to precipitate to obtain ultrafine porous ammonium perchlorate.

[0003] As is known to all, ammonium perchlorate with regular morphology, good dispersibility and uniform particle size helps to improve the bulk density, mechanical properties and combustion stability of solid propellants, and thus has broad application prospects. However, the crystallization process of ammonium perchlorate is affected by the intrinsic structure and a variety of external factors, which makes it extremely difficult to regulate and obtain ammonium perchlorate materials with regular morphology, good dispersibility and uniform particle size, and there are few relevant literature reports at present. CN117285008A adds a high-temperature saturated solution of N,N-dimethylformamide dissolved in ammonium perchlorate to a low-temperature ethyl acetate anti-solvent, recrystallizes, and obtains a monodisperse, uniform particle size butterfly-shaped micron ammonium perchlorate. CN117285010A adds a high-temperature saturated solution of N,N-dimethylacetamide dissolved in ammonium perchlorate to a low-temperature ethyl formate anti-solvent, recrystallizes, and obtains a monodisperse, uniform particle size ammonium perchlorate micron cube. It can be seen that the existing technology can be used to prepare monodisperse ammonium perchlorate with uniform particle size in butterfly shape, cube shape, etc.; however, the existing technology still lacks a method for preparing ammonium perchlorate micrometer rounded corner cuboids.

[0004] It should be noted that there are documents that use dimethyl sulfoxide and N,N-dimethylformamide as solvents and benzyl alcohol as anti-solvent to prepare irregular ammonium perchlorate microrods and irregular ammonium perchlorate cuboids (Adv. PowderTech. 35 (2024) 104447, J. Ind. Eng. Chem. 135 (2024) 513). However, there is no report in the existing literature on the preparation of monodisperse ammonium perchlorate micron-rounded cuboids with uniform particle size using benzyl alcohol as anti-solvent. Summary of the invention

[0005] The invention aims to provide a method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size. The method is simple to operate, has good product stability, good repeatability, high yield, and is suitable for large-scale production.

[0006] The technical solution of the present invention is: using benzyl alcohol as an anti-solvent, adding an ammonium perchlorate solution into the benzyl alcohol anti-solvent, and recrystallizing to prepare monodisperse ammonium perchlorate micrometer rounded corner cuboids with uniform particle size; the specific steps are as follows: (1) dissolving ammonium perchlorate in a solvent to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a certain temperature at a certain feeding rate for recrystallization; (3) The product is allowed to stand for separation, washed, and dried to obtain monodispersed ammonium perchlorate micrometer-rounded cuboids with uniform particle size.

[0007] In step (1), ammonium perchlorate is dissolved in a solvent at room temperature to form a saturated ammonium perchlorate solution.

[0008] In step (1), the solvent is one of N-methylpyrrolidone and pyridine.

[0009] In step (2), the certain feed rate is 1.5 to 6 mL / min; the certain temperature is 5 to 35 °C.

[0010] In step (2), the volume ratio of the saturated ammonium perchlorate solution to benzyl alcohol is controlled at 0.05-0.02, and the recrystallization process is carried out under stirring at 400-800 rpm.

[0011] In step (3), the product is washed with ethyl acetate for multiple times and dried at 60°C.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The ammonium perchlorate micrometer rounded cuboid prepared by the present invention expands the morphology category of ammonium perchlorate.

[0013] 2. The ammonium perchlorate micrometer rounded cuboid prepared by the present invention is about 25 micrometers in size, has a regular morphology, good dispersibility, and uniform particle size.

[0014] 3. Compared with ordinary cuboids, rounded cuboids have excellent dispersibility, low hygroscopicity, low sensitivity and high stability. They are used in the solid propellant molding process, with good fluidity, high filling density, strong mechanical properties and excellent safety performance.

[0015] 4. The raw materials for the preparation of the present invention are simple, involving only two reagents, N-methylpyrrolidone (or pyridine) and benzyl alcohol, and the production cost is low.

[0016] 5. The preparation process and production equipment of the present invention are simple and suitable for industrial production.

[0017] 6. The product of the present invention has good stability, good repeatability and high yield rate.

[0018] 7. The raw material ammonium perchlorate of the present invention is industrial ammonium perchlorate, which has no restrictions on particle size, morphology or crystal form. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Scanning electron microscope image of monodisperse, uniform particle size ammonium perchlorate micrometer rounded cuboids of Example 1; Figure 2 Scanning electron microscope image of monodisperse, uniform particle size ammonium perchlorate micrometer rounded cuboids of Example 2; Figure 3 Scanning electron microscope image of monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size in Example 3; Figure 4Scanning electron microscope image of monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size in Example 4; DETAILED DESCRIPTION

[0020] The following structural embodiments further illustrate the technical solution of the present invention, but should not be construed as limiting the technical solution. Adaptive improvements based on this embodiment all fall within the protection scope of the present invention.

[0021] Example 1: Preparation of ammonium perchlorate micrometer rounded corner cuboids according to the following steps (1) Dissolving ammonium perchlorate in N-methylpyrrolidone at room temperature to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a temperature of 35° C. at a feeding rate of 1.5 mL / min for recrystallization; wherein the volume ratio of the saturated ammonium perchlorate solution to the benzyl alcohol is controlled at 0.05, and the recrystallization process is carried out under stirring at 400 rpm; (3) The product was allowed to stand for separation, washed with ethyl acetate several times, dried at 60°C, and scanned by electron microscope. Figure 1 As shown, monodispersed ammonium perchlorate micrometer rounded cuboids with uniform particle size were obtained.

[0022] Example 2: Preparation of ammonium perchlorate micrometer rounded corner cuboids according to the following steps (1) Dissolving ammonium perchlorate in N-methylpyrrolidone at room temperature to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a temperature of 20°C at a feeding rate of 3.75 mL / min for recrystallization; wherein the volume ratio of the saturated ammonium perchlorate solution to the benzyl alcohol is controlled at 0.035, and the recrystallization process is carried out under stirring at 600 rpm; (3) The product was allowed to stand for separation, washed with ethyl acetate several times, dried at 60°C, and scanned by electron microscope. Figure 2 As shown, monodispersed ammonium perchlorate micrometer rounded cuboids with uniform particle size were obtained.

[0023] Example 3: Preparation of ammonium perchlorate micrometer rounded corner cuboids according to the following steps (1) At room temperature, dissolving ammonium perchlorate in pyridine to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a temperature of 5°C at a feeding rate of 6 mL / min for recrystallization; wherein the volume ratio of the saturated ammonium perchlorate solution to the benzyl alcohol is controlled at 0.02, and the recrystallization process is carried out under stirring at 800 rpm; (3) The product was allowed to stand for separation, washed with ethyl acetate several times, dried at 60°C, and scanned by electron microscope. Figure 3 As shown, monodispersed ammonium perchlorate micrometer rounded cuboids with uniform particle size were obtained.

[0024] Example 4: Preparation of ammonium perchlorate micrometer rounded corner cuboids according to the following steps (1) At room temperature, dissolving ammonium perchlorate in pyridine to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a temperature of 20° C. at a feeding rate of 3.75 mL / min for recrystallization; wherein the volume ratio of the saturated ammonium perchlorate solution to the benzyl alcohol is controlled at 0.035, and the recrystallization process is carried out under stirring at 600 rpm; (3) The product was allowed to stand for separation, washed with ethyl acetate several times, dried at 60°C, and scanned by electron microscope. Figure 4 As shown, monodispersed ammonium perchlorate micrometer rounded cuboids with uniform particle size were obtained.

Claims

1. A method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size, characterized in that: The ammonium perchlorate solution is added to the benzyl alcohol anti-solvent for recrystallization to prepare monodisperse ammonium perchlorate micrometer rounded corner cuboids with uniform particle size; the specific steps are as follows: (1) dissolving ammonium perchlorate in a solvent to form a saturated ammonium perchlorate solution; (2) adding a saturated ammonium perchlorate solution to a benzyl alcohol anti-solvent at a certain temperature at a certain feeding rate for recrystallization; (3) The product is allowed to stand for separation, washed, and dried to obtain monodispersed ammonium perchlorate micrometer-rounded cuboids with uniform particle size.

2. The method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size according to claim 1, characterized in that: In step (1), ammonium perchlorate is dissolved in a solvent at room temperature to form a saturated ammonium perchlorate solution.

3. The method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size according to claim 1, characterized in that: In step (1), the solvent is one of N-methylpyrrolidone and pyridine.

4. The method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size according to claim 1, characterized in that: In step (2), the certain feed rate is 1.5 to 6 mL / min; the certain temperature is 5 to 35 °C.

5. The method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size according to claim 1, characterized in that: In step (2), the volume ratio of the saturated ammonium perchlorate solution to benzyl alcohol is controlled at 0.05-0.02, and the recrystallization process is carried out under stirring at 400-800 rpm.

6. The method for preparing monodisperse ammonium perchlorate micrometer rounded cuboids with uniform particle size according to claim 1, characterized in that: In step (3), the product is washed with ethyl acetate for multiple times and dried at 60°C.

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