Preparation method of one-dimensional needle-shaped ammonium perchlorate

Abstract

The invention discloses a method for preparing one-dimensional needle-beam ammonium perchlorate. First, ammonium perchlorate and hexadecyltrimethylammonium bromide are simultaneously dissolved in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form a certain concentration of ammonium perchlorate solution; then, the ammonium perchlorate solution is heated to a certain temperature, and is added to an ethyl acetate anti-solvent at room temperature at a certain feed rate, and the ammonium perchlorate crystallizes due to supersaturation; after the crystallization is complete, the product is separated, washed, and dried to obtain a one-dimensional needle-beam ammonium perchlorate. The invention provides a method for preparing one-dimensional needle-beam ammonium perchlorate, which is simple to operate, has good stability, good repeatability, high yield, and is suitable for large-scale production of one-dimensional needle-beam ammonium perchlorate.

Description

Technical Field

[0001] The invention belongs to the technical field of energetic materials and relates to a preparation method, in particular to a preparation method of one-dimensional needle-beam ammonium perchlorate. Background Art

[0002] Ammonium perchlorate is a strong oxidant widely used in propellants, pyrotechnics, thermite and other fields. The morphology of ammonium perchlorate has a great influence on its sensitivity, charge density, and thermal decomposition performance. Therefore, the morphology control of ammonium perchlorate has always attracted much attention.

[0003] At present, researchers have used a variety of crystallization methods such as cooling crystallization and anti-solvent crystallization to prepare several different morphologies of ammonium perchlorate. 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 ethylene glycol. AA Vargeese (Crystal Growth Design, 8 (2008) 1060-1066) used water-soluble PVA as a surfactant to crystallize ammonium perchlorate to prepare wedge-shaped ammonium perchlorate. Ma Zhenye (CN102718187A) dissolved ammonium perchlorate in a mixed solvent of N,N-dimethylformamide / acetone to prepare a saturated solution, then added it to the anti-solvent ethyl acetate to crystallize and obtain hollow cubic ammonium perchlorate. Dong Qianqian (Study on the Preparation of Ultrafine Ammonium Perchlorate by Anti-Solvent Recrystallization, Master's Thesis, 2015) used N,N-dimethylformamide as the ammonium perchlorate solvent and ethyl acetate as the anti-solvent to prepare wedge-shaped ammonium perchlorate by crystallization at room temperature.

[0004] It can be seen that the existing technology can be used to prepare ammonium perchlorate with various morphologies such as hexahedron, wedge, hollow cube, etc.; however, in the existing technology, it is still impossible to obtain ammonium perchlorate with one-dimensional structural characteristics. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing one-dimensional needle-beam ammonium perchlorate. The method is simple to operate, has good stability, good repeatability and high yield, and realizes large-scale production of one-dimensional needle-beam ammonium perchlorate.

[0006] The technical solution of the present invention is: a method for preparing one-dimensional needle-shaped ammonium perchlorate, using N,N-dimethylformamide / dimethyl sulfoxide as a mixed solvent, hexadecyltrimethylammonium bromide as a surfactant, and ethyl acetate as an anti-solvent, and using an anti-solvent crystallization method to obtain one-dimensional needle-shaped ammonium perchlorate; the specific steps are as follows:

[0007] (1) dissolving ammonium perchlorate and hexadecyltrimethylammonium bromide simultaneously in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form an ammonium perchlorate solution of a certain concentration;

[0008] (2) heating the ammonium perchlorate solution in step 1 to a certain temperature, and adding it to the ethyl acetate anti-solvent at room temperature at a certain feeding rate, so that the ammonium perchlorate crystallizes due to supersaturation;

[0009] (3) After the crystallization is complete, the product is separated, washed, and dried to obtain one-dimensional needle-shaped ammonium perchlorate.

[0010] In step (1), the mass ratio of ammonium perchlorate to hexadecyltrimethylammonium bromide is 20-100.

[0011] In step (1), the volume ratio of N,N-dimethylformamide / dimethyl sulfoxide is 0.6 to 1.4.

[0012] In step (1), the concentration of the ammonium perchlorate solution is 0.5 to 1.5 mol / L.

[0013] In step (2), the temperature is raised to a certain temperature of 90 to 120 °C.

[0014] In step (2), the feed rate is set to be 1 to 5 mL / min.

[0015] In step (2), the volume ratio of the ammonium perchlorate solution to the ethyl acetate anti-solvent is 0.1 to 0.05.

[0016] In step (3), the product is washed with ethyl acetate for multiple times and dried at 60°C.

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

[0018] 1. The present invention is different from the traditional anti-solvent crystallization in that it adopts N,N-dimethylformamide / dimethyl sulfoxide mixed solvent, increases the temperature of the mixed solvent, and introduces hexadecyltrimethylammonium bromide surfactant into the mixed solvent to achieve the creation of one-dimensional needle-shaped ammonium perchlorate.

[0019] 2. The successful creation of needle-shaped ammonium perchlorate in the present invention realizes the regulation of the one-dimensional structure of the ammonium perchlorate material.

[0020] 3. The one-dimensional needle-shaped ammonium perchlorate prepared by the present invention has good product stability, good process repeatability and high yield.

[0021] 4. The raw material ammonium perchlorate has no restrictions on particle size, morphology, or crystal form. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 1;

[0023] Figure 2This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 2;

[0024] Figure 3 This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 3. DETAILED DESCRIPTION

[0025] 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.

[0026] Example 1: Preparation of one-dimensional needle-shaped ammonium perchlorate according to the following steps

[0027] (1) dissolving ammonium perchlorate and hexadecyltrimethylammonium bromide simultaneously in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form a 0.5 mol / L ammonium perchlorate solution; wherein: the mass ratio of ammonium perchlorate to hexadecyltrimethylammonium bromide is 20, the volume ratio of N,N-dimethylformamide / dimethyl sulfoxide is 0.6, and the concentration of the ammonium perchlorate solution is 0.5 mol / L;

[0028] (2) heating the ammonium perchlorate solution of step 1 to 90° C. and adding it to the ethyl acetate anti-solvent at room temperature at a feeding rate of 1 mL / min, so that the ammonium perchlorate crystallizes due to supersaturation; wherein the volume ratio of the ammonium perchlorate solution to the ethyl acetate anti-solvent is 0.05;

[0029] (3) After the crystallization is complete, the product is separated, washed with ethyl acetate for multiple times, and dried at 60°C to obtain one-dimensional needle-shaped ammonium perchlorate.

[0030] Example 2: Preparation of one-dimensional needle-shaped ammonium perchlorate according to the following steps

[0031] (1) dissolving ammonium perchlorate and hexadecyltrimethylammonium bromide simultaneously in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form a 1.0 mol / L ammonium perchlorate solution; wherein: the mass ratio of ammonium perchlorate to hexadecyltrimethylammonium bromide is 60, the volume ratio of N,N-dimethylformamide / dimethyl sulfoxide is 1.0, and the concentration of the ammonium perchlorate solution is 1.0 mol / L;

[0032] (2) heating the ammonium perchlorate solution in step 1 to 105°C and adding it to the ethyl acetate anti-solvent at room temperature at a feeding rate of 3 mL / min, so that the ammonium perchlorate crystallizes due to supersaturation; wherein the volume ratio of the ammonium perchlorate solution to the ethyl acetate anti-solvent is 0.075;

[0033] (3) After the crystallization is complete, the product is separated, washed with ethyl acetate for multiple times, and dried at 60°C to obtain one-dimensional needle-shaped ammonium perchlorate.

[0034] Example 3: Preparation of one-dimensional needle-shaped ammonium perchlorate according to the following steps

[0035] (1) dissolving ammonium perchlorate and hexadecyltrimethylammonium bromide simultaneously in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form a 1.5 mol / L ammonium perchlorate solution; wherein: the mass ratio of ammonium perchlorate to hexadecyltrimethylammonium bromide is 100, the volume ratio of N,N-dimethylformamide / dimethyl sulfoxide is 1.4, and the concentration of the ammonium perchlorate solution is 1.5 mol / L;

[0036] (2) The ammonium perchlorate solution in step 1 is heated to 120°C and added to the ethyl acetate anti-solvent at room temperature at a feed rate of 5 mL / min, and the ammonium perchlorate crystallizes due to supersaturation; wherein the volume ratio of the ammonium perchlorate solution to the ethyl acetate anti-solvent is 0.1;

[0037] (3) After the crystallization is complete, the product is separated, washed with ethyl acetate for multiple times, and dried at 60°C to obtain one-dimensional needle-shaped ammonium perchlorate.

[0038] Figure 1 This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 1; Figure 2 This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 2; Figure 3 This is a scanning electron microscope image of the one-dimensional needle-shaped ammonium perchlorate of Example 3.

Claims

1. A method for preparing one-dimensional needle-beam ammonium perchlorate, characterized in that: Using N,N-dimethylformamide / dimethyl sulfoxide as a mixed solvent, hexadecyltrimethylammonium bromide as a surfactant, and ethyl acetate as an anti-solvent, a one-dimensional needle-shaped ammonium perchlorate is obtained by an anti-solvent crystallization method; the specific steps are as follows: (1) dissolving ammonium perchlorate and hexadecyltrimethylammonium bromide simultaneously in a N,N-dimethylformamide / dimethyl sulfoxide mixed solvent to form an ammonium perchlorate solution of a certain concentration; (2) heating the ammonium perchlorate solution in step 1 to a certain temperature, and adding it to the ethyl acetate anti-solvent at room temperature at a certain feeding rate, so that the ammonium perchlorate crystallizes due to supersaturation; (3) After the crystallization is complete, the product is separated, washed, and dried to obtain one-dimensional needle-shaped ammonium perchlorate; In step (1), the mass ratio of ammonium perchlorate to hexadecyltrimethylammonium bromide is 20 to 100; In step (1), the volume ratio of N,N-dimethylformamide / dimethyl sulfoxide is 0.6 to 1.4; In step (1), the concentration of ammonium perchlorate solution is 0.5 to 1.5 mol / L; In step (2), the temperature is raised to a certain temperature of 90 to 120°C; In step (2), the feed rate is 1 to 5 mL / min; In step (2), the volume ratio of the ammonium perchlorate solution to the ethyl acetate anti-solvent is 0.1 to 0.05; In step (3), the product is washed with ethyl acetate for multiple times and dried at 60°C.

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