Low-smoke medicament based on mesoporous silica adsorption and preparation method thereof

Abstract

The invention discloses a low-smoke medicament based on mesoporous silica adsorption and a preparation method thereof, and belongs to the technical field of firework medicament composite materials. The preparation process of the low-smoke medicament comprises the following steps: synthesizing a mesoporous silica material, carrying out amination modification on the surface of the mesoporous silica material, introducing the mesoporous silica material into a high-molecular fluoride-active metal medicament system, and compounding with an energetic material RDX to obtain the mesoporous silica adsorbed low-smoke medicament, the concentration rho PM10 of PM10 generated by explosion of the obtained low-smoke medicament is less than or equal to 63mu g / m < 3 >, and the concentration rho PM10 is less than or equal to 63mu g / m < 3 >. And the PM2.5 concentration rho PM2.5 is less than or equal to 35 [mu] g.m < 3 >, and a good low-smoke effect is shown. Compared with the prior art, the aminated mesoporous silica in the obtained pyrotechnic composition can adsorb smoke screen particles generated by explosion, can capture CO2, can reduce the smoke amount in the firework setting-off process and improve the ornamental value of fireworks, has the advantages of being safe, environmentally friendly and green, and has good application value in the field of fireworks and crackers.

Description

Technical Field

[0001] The invention relates to a low-smoke agent based on mesoporous silica adsorption and a preparation method thereof, belonging to the technical field of firework agent composite materials. Background Art

[0002] Traditional fireworks are mostly made of black powder, which contains sulfur. Burning black powder will produce a large amount of sulfur dioxide and sulfide, which can easily cause acid rain, leading to the death of plants and animals and corrosion of buildings. Its main gas product K 2 S. SO 2 , CO, NO 2 It is highly corrosive and irritating to the eyes, nose, throat and skin, and can easily induce sneezing, coughing, laryngitis and respiratory diseases. When black powder is not burned completely, it will produce a lot of black smoke, which not only affects the effect of fireworks, but also the carbon powder particles in the residue will cause PM 2.5 The value increases, causing air pollution, and the remaining solid residues will also pollute the soil environment; black powder will also cause a certain degree of noise pollution when it reacts violently and explodes. Therefore, safe and environmentally friendly products such as sulfur-free, low-smoke propellants and fuses are widely researched and applied, accelerating the replacement of black powder with safe and environmentally friendly propellants, and improving the safety and green level of products.

[0003] Active metals such as aluminum have the advantages of high energy density and low cost. As the main component of energetic materials, they are widely used in military and civilian fields such as explosives, aerospace propulsion, unmanned weapons, space exploration, and pyrotechnics. The energetic material system composed of active metal powder and polymer fluoropolymer as the main components shows obvious insensitivity when subjected to mechanical shock and thermal action, so it is highly safe and has low accident risk during production, storage, transportation and use. However, its combustion kinetics and reaction heat are limited by slow mass diffusion and incomplete reaction, and smoke is generated during combustion and explosion. Porous materials have good adsorption properties, so adding high-energy explosives to the polymer fluoropolymer-active metal system to increase the reaction heat, and introducing porous materials to reduce the smoke emission of pyrotechnics, and obtaining low-smoke agents has not been publicly reported. Summary of the invention

[0004] The present invention relates to a low-smoke agent based on mesoporous silica adsorption and a preparation method thereof. Active metal-polymer fluoride is compounded with energetic material cyclotrimethylene trinitramine (RDX), and surface amino-modified mesoporous silica is introduced to obtain a novel pyrotechnic agent, which realizes high energy, environmental protection and low smoke of the pyrotechnic agent and has good application prospects in the field of fireworks and firecrackers.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention first discloses a method for preparing a low-smoke agent based on mesoporous silica adsorption, comprising:

[0007] Amination of mesoporous silica, recrystallization of cyclotrimethylene trinitramine (RDX), and compression of pyrotechnic propellant columns.

[0008] Furthermore, the amination of mesoporous silica comprises the following steps:

[0009] (1) dissolving hexadecyltrimethylammonium bromide (CTAB) in deionized water, adding ammonia water to adjust the pH value to 10-12, then slowly adding tetraalkoxysilane, and mechanically stirring at 60° C. under ultrasonic conditions for 5-6 hours to obtain a milky white mixed solution;

[0010] (2) filtering the milky white mixed solution, washing it with deionized water for 2 to 3 times, drying it at 60 to 80° C. to obtain a white powder, and then placing it in a muffle furnace at 300° C. to remove the template agent hexadecyltrimethylammonium bromide to obtain mesoporous silica;

[0011] (3) dissolving aminosilane in toluene solvent, adding mesoporous silica, heating and reacting at 80° C. under reflux for 18 to 24 hours to aminize the surface of the mesoporous silica, and drying the solvent to obtain aminized mesoporous silica.

[0012] Furthermore, in step (1), the mass ratio of hexadecyltrimethylammonium bromide to tetraalkoxysilane is 1:5-8;

[0013] The tetraalkoxysilane is selected from the group consisting of: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, or one or more combinations thereof.

[0014] Furthermore, in step (3), the mass ratio of aminosilane to mesoporous silica is 1:3-5;

[0015] The aminosilane is selected from: one or two of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0016] Further, the recrystallization of cyclotrimethylene trinitramine comprises the following steps:

[0017] (1) using a solvent-antisolvent method to recrystallize trimethylene trinitramine, dissolving trimethylene trinitramine in a dimethyl sulfoxide solution (DMSO) at room temperature to prepare a 1.0-1.5 mol / L trimethylene trinitramine solution;

[0018] (2) adding aminated mesoporous silica to the trimethylene trinitramine solution and soaking for 1 to 2 hours to completely wet the silica to obtain a mixed solution;

[0019] (3) quickly pouring the mixed solution into a sufficient amount of ionized water, and mechanically stirring at room temperature for 10 to 30 minutes to allow the trimethylene trinitramine to fully crystallize, thereby obtaining an aqueous suspension of trimethylene trinitramine and amino-modified mesoporous silica;

[0020] (4) filtering the suspension, washing the filtered product with deionized water for 2 to 3 times, and drying the product at 60 to 70° C. to a constant weight, thereby obtaining a composite of trimethylene trinitramine and mesoporous silica.

[0021] Furthermore, in step (2), the mass ratio of trimethylene trinitramine to amino-modified mesoporous silica is 5:1-2.

[0022] Furthermore, the pyrotechnic agent charge pressing comprises the following steps:

[0023] (1) 10 to 15 parts of magnesium powder, 20 to 35 parts of aluminum powder, 3 to 5 parts of boron powder, 10 to 15 parts of trimethylene trinitramine and a mesoporous silica composite are fully dried and fully mixed in a mixer, and then 30 to 40 parts of polytetrafluoroethylene are added to obtain a mixed powder;

[0024] (2) dissolving 5 to 10 parts of a binder in ethyl acetate, adding the mixed powder obtained in step (1) and mixing thoroughly to obtain a wet powder;

[0025] (3) The wet powder is pressed into a pharmaceutical column by a press and solidified at 150-180° C. to obtain a low-smoke agent based on mesoporous silica adsorption.

[0026] Furthermore, the binder in step (2) is one or more combinations of epoxy resin, polyvinyl alcohol, and phenolic resin.

[0027] The present invention also discloses a low-smoke medicine prepared according to any of the above-mentioned preparation methods.

[0028] Furthermore, the PM generated by the explosion of the low-smoke agent 10 Concentration PM10 ≤63 μg / m 3 , PM 2.5 Concentration PM2.5 ≤35 μg·m 3 .

[0029] The beneficial effects of the present invention are:

[0030] (1) The present invention achieves low smoke characteristics by adding surface amino-modified mesoporous silica to the pyrotechnic agent, thereby improving the viewing quality of fireworks. Mesoporous silica has the characteristics of large specific surface area and adjustable pore size, and its ordered pore structure is conducive to the adsorption and separation of tiny smoke particles. The amino-modified mesoporous silica can achieve the adsorption of smoke metal fluorides, gas separation and CO removal during the combustion of pyrotechnic agents. 2 Capture. Among them, the amino group, as a nucleophilic group, can obtain chelated amine ligands through nucleophilic reaction, which enhances the adhesion between mesoporous silica and smoke particles. In addition, the protonation of the amino group helps to adsorb metal ions through electrostatic action, further reducing the smoke products formed during the combustion of pyrotechnic agents. The PM generated by the explosion of the resulting low-smoke agent is 10 Concentration PM10 ≤63 μg / m 3 , PM 2.5 Concentration PM2.5 ≤35 μg·m 3 , with good low smoke effect.

[0031] (2) The present invention combines the energetic material RDX with mesoporous silica to obtain a high-energy composite material, which is then combined with a polymer fluoride-active metal system and pressed into a pyrotechnic column by an adhesive, which has the characteristics of high combustion heat and high safety. The energetic material RDX has a high sensitivity and there are certain safety risks during storage, transportation and use. The present invention recrystallizes RDX by a solvent-antisolvent method and combines it with surface amino-modified mesoporous silica to obtain an energetic composite material, which not only reduces the sensitivity of RDX, but also enhances the compatibility of the components of mesoporous silica and RDX-based pyrotechnic agents, thereby obtaining a pyrotechnic agent with stable performance.

[0032] (3) The present invention introduces a small amount of binder and uses a press to press and mold the pyrotechnic agent, which has the characteristics of high density and high filling volume. Compared with the extrusion granulation method in the prior art, the press molding method can greatly reduce the amount of adhesive used, which helps to improve the combustion and explosion performance of the pyrotechnic agent and increase the filling volume of the pyrotechnic agent in the fireworks. The increase in pressure helps to increase the burning time of the fireworks. In addition, reducing the use of polymer-based binders is conducive to reducing CO and CO during the fireworks burning process. 2 The production of gases such as chlorinated carbon dioxide helps protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a transmission electron microscope image of the mesoporous silica obtained in Example 1.

[0034] Figure 2 Based on the mesoporous SiO obtained in Example 3 2Scanning electron microscope image of / RDX composite energetic material. DETAILED DESCRIPTION

[0035] In order to have a clearer understanding of the technical features of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0036] Example 1

[0037] (1) 5 g of hexadecyltrimethylammonium bromide (CTAB) was dissolved in 50 mL of deionized water, and ammonia water was added to adjust the pH value to 12, and then 40 g of tetramethoxysilane was slowly added, and mechanical stirring was performed under ultrasonic conditions at 60° C. for 6 h to obtain a milky white mixed solution, which was filtered, washed, and dried to obtain a white powder, which was placed in a muffle furnace at 300° C. to remove the template CTAB to obtain mesoporous silica;

[0038] (2) dissolving 5 g of 3-aminopropyltrimethoxysilane in 50 mL of toluene solvent, adding 25 g of the mesoporous silica obtained in step (1), heating and reacting at 80° C. under reflux for 18 h, and drying the solvent to obtain amino-modified mesoporous silica;

[0039] (3) 5 g of RDX was dissolved in DMSO to prepare a 1.0 mol / L solution, 2 g of amino-modified mesoporous silica was added to the solution, and the solution was soaked for 1 h to completely wet it. Then, sufficient ionized water was quickly poured into the solution, and mechanical stirring was performed at room temperature for 10 min to obtain an aqueous suspension of RDX and amino-modified mesoporous silica. The mesoporous SiO 2 / RDX composite energetic materials;

[0040] (4) Mix 10 parts of magnesium powder, 20 parts of aluminum powder, 3 parts of boron powder, and 10 parts of mesoporous SiO 2 The / RDX composite energetic material is dried and fully mixed in a mixer, 40 parts of polytetrafluoroethylene are added to obtain a mixed powder, 5 parts of epoxy resin are dissolved in ethyl acetate and added to the mixed powder and fully mixed to obtain a wet powder;

[0041] (5) Pressing the wet powder obtained in step (4) into a medicine column by a press machine, and curing the obtained medicine column at 150° C. to obtain a pyrotechnic agent for fireworks.

[0042] Example 2

[0043] (1) Dissolve 5 g of hexadecyltrimethylammonium bromide (CTAB) in 50 mL of deionized water, add ammonia water to adjust the pH value to 10, then slowly add 25 g of tetramethoxysilane, and mechanically stir for 5 h under ultrasonic conditions at 60 ° C to obtain a milky white mixed solution, filter, wash, and dry to obtain a white powder, place it in a muffle furnace at 300 ° C to remove the template CTAB, and obtain mesoporous silica;

[0044] (2) dissolving 5 g of 3-aminopropyltrimethoxysilane in 50 mL of toluene solvent, adding 25 g of the mesoporous silica obtained in step (1), heating and reacting at 80° C. under reflux for 24 h, and drying the solvent to obtain amino-modified mesoporous silica;

[0045] (3) 5 g of RDX was dissolved in DMSO to prepare a 1.5 mol / L solution, 1 g of amino-modified mesoporous silica was added to the solution, and the solution was soaked for 2 h to completely wet it. Then, sufficient ionized water was quickly poured into the solution, and mechanical stirring was performed at room temperature for 30 min to obtain an aqueous suspension of RDX and amino-modified mesoporous silica. The mesoporous SiO 2 / RDX composite energetic materials;

[0046] (4) Mix 15 parts of magnesium powder, 35 parts of aluminum powder, 5 parts of boron powder, and 15 parts of mesoporous SiO 2 The / RDX composite energetic material is dried and fully mixed in a mixer, 30 parts of polytetrafluoroethylene is added to obtain a mixed powder, 10 parts of polyvinyl alcohol is dissolved in ethyl acetate and added to the mixed powder and fully mixed to obtain a wet powder;

[0047] (5) Pressing the wet powder obtained in step (4) into a medicine column by a press machine, and curing the obtained medicine column at 180° C. to obtain a pyrotechnic agent for fireworks.

[0048] Example 3

[0049] (1) 5 g of hexadecyltrimethylammonium bromide (CTAB) was dissolved in 50 mL of deionized water, and ammonia water was added to adjust the pH value to 11, and then 20 g of tetraethoxysilane was slowly added, and mechanical stirring was performed under ultrasonic conditions at 60° C. for 6 h to obtain a milky white mixed solution, which was filtered, washed, and dried to obtain a white powder, which was placed in a muffle furnace at 300° C. to remove the template CTAB to obtain mesoporous silica;

[0050] (2) dissolving 5 g of 3-aminopropyltrimethoxysilane in 50 mL of toluene solvent, adding 20 g of the mesoporous silica obtained in step (1), heating and reacting at 80° C. under reflux for 20 h, and drying the solvent to obtain amino-modified mesoporous silica;

[0051] (3) 5 g of RDX was dissolved in DMSO to prepare a 1.3 mol / L solution, 2 g of amino-modified mesoporous silica was added to the solution, and the solution was soaked for 2 h to completely wet it. Then, sufficient ionized water was quickly poured into the solution, and mechanical stirring was performed at room temperature for 20 min to obtain an aqueous suspension of RDX and amino-modified mesoporous silica. The mesoporous SiO 2 / RDX composite energetic materials;

[0052] (4) Mix 15 parts of magnesium powder, 30 parts of aluminum powder, 5 parts of boron powder, and 13 parts of mesoporous SiO 2 The / RDX composite energetic material is dried and fully mixed in a mixer, 35 parts of polytetrafluoroethylene are added to obtain a mixed powder, 5 parts of phenolic resin are dissolved in ethyl acetate and added to the mixed powder and fully mixed to obtain a wet powder;

[0053] (5) Pressing the wet powder obtained in step (4) into a medicine column by a press machine, and curing the obtained medicine column at 180° C. to obtain a pyrotechnic agent for fireworks.

[0054] Example 4

[0055] (1) 5 g of hexadecyltrimethylammonium bromide (CTAB) was dissolved in 50 mL of deionized water, and ammonia water was added to adjust the pH value to 11, and then 20 g of tetraethoxysilane was slowly added, and mechanical stirring was performed under ultrasonic conditions at 60° C. for 6 h to obtain a milky white mixed solution, which was filtered, washed, and dried to obtain a white powder, which was placed in a muffle furnace at 300° C. to remove the template CTAB to obtain mesoporous silica;

[0056] (2) dissolving 5 g of 3-aminopropyltriethoxysilane in 50 mL of toluene solvent, adding 20 g of the mesoporous silica obtained in step (1), heating and reacting at 80° C. under reflux for 20 h, and drying the solvent to obtain amino-modified mesoporous silica;

[0057] (3) 5 g of RDX was dissolved in DMSO to prepare a 1.5 mol / L solution, 2 g of amino-modified mesoporous silica was added to the solution, and the solution was soaked for 2 h to completely wet it. Then, sufficient ionized water was quickly poured into the solution, and mechanical stirring was performed at room temperature for 20 min to obtain an aqueous suspension of RDX and amino-modified mesoporous silica. The mesoporous SiO 2 / RDX composite energetic materials;

[0058] (4) Mix 13 parts of magnesium powder, 35 parts of aluminum powder, 3 parts of boron powder, and 15 parts of mesoporous SiO 2 The / RDX composite energetic material is dried and fully mixed in a mixer, 35 parts of polytetrafluoroethylene are added to obtain a mixed powder, 5 parts of phenolic resin are dissolved in ethyl acetate and added to the mixed powder and fully mixed to obtain a wet powder;

[0059] (5) Pressing the wet powder obtained in step (4) into a medicine column by a press machine, and curing the obtained medicine column at 160° C. to obtain a pyrotechnic agent for fireworks.

[0060] Comparative Example 1

[0061] (1) Dissolve 5 g of RDX in DMSO to prepare a 1.3 mol / L solution, then quickly pour into sufficient ionized water, mechanically stir at room temperature for 20 min to obtain an aqueous suspension of RDX, and obtain recrystallized RDX by filtering, washing, and drying;

[0062] (2) 15 parts of magnesium powder, 30 parts of aluminum powder, 5 parts of boron powder, and 13 parts of recrystallized RDX are fully mixed in a mixer, 35 parts of polytetrafluoroethylene are added to obtain a mixed powder, 5 parts of phenolic resin are dissolved in ethyl acetate and added to the mixed powder and fully mixed to obtain a wet powder;

[0063] (3) Pressing the wet powder obtained in step (2) into a medicine column by a press machine, and curing the obtained medicine column at 180° C. to obtain a pyrotechnic agent for fireworks.

[0064] Table 1 PM generated during the combustion and explosion of pyrotechnic agents in Examples 1 to 4 10 Concentration and PM 2.5 Concentration parameters

[0065]

[0066] The transmission electron microscope image of the mesoporous silica obtained in Example 1 is as follows Figure 1 As shown in the figure, the mesoporous silica particles prepared in the present invention have a uniform channel structure; the mesoporous SiO 2 Scanning electron microscope images of / RDX composite energetic materials Figure 2 As shown, the picture shows mesoporous SiO 2 There is no phase separation with the recrystallized RDX, and the two have good adhesion.

[0067] PM generated during the combustion and explosion of the low-smoke agents obtained in Examples 1 to 4 10 Concentration and PM 2.5 The concentration parameters are listed in Table 1. The PM 10 The concentration parameters ranged from 59.8 to 62.5 μg / m 3 Between, PM 2.5 The concentration parameters ranged from 30.1 to 34.8 μg / m 3 Compared with the ρ of comparative example 1 PM10 and ρ PM2.5 It dropped significantly, indicating that the pyrotechnic agent based on mesoporous silica achieved low smoke generation in the combustion and explosion process.

[0068] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a low-smoke agent based on mesoporous silica adsorption, comprising: Amination of mesoporous silica, recrystallization of cyclotrimethylene trinitramine, and compression of pyrotechnic propellant columns.

2. The preparation method according to claim 1, wherein: The amination of mesoporous silica comprises the following steps: (1) dissolving hexadecyltrimethylammonium bromide in deionized water, adding ammonia water to adjust the pH value to 10-12, then slowly adding tetraalkoxysilane, and mechanically stirring at 60° C. under ultrasonic conditions for 5-6 hours to obtain a milky white mixed solution; (2) filtering the milky white mixed solution, washing it with deionized water for 2 to 3 times, drying it at 60 to 80° C. to obtain a white powder, and then placing it in a muffle furnace at 300° C. to remove the template agent hexadecyltrimethylammonium bromide to obtain mesoporous silica; (3) dissolving aminosilane in toluene solvent, adding mesoporous silica, heating and reacting at 80° C. under reflux for 18 to 24 hours to aminize the surface of the mesoporous silica, and drying the solvent to obtain aminized mesoporous silica.

3. The preparation method according to claim 2, wherein: The mass ratio of hexadecyltrimethylammonium bromide to tetraalkoxysilane in step (1) is 1:5-8; The tetraalkoxysilane is selected from the group consisting of: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, or one or more combinations thereof.

4. The preparation method according to claim 2, wherein: The mass ratio of the aminosilane to the mesoporous silica in step (3) is 1:3-5; The aminosilane is selected from: one or two of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

5. The preparation method according to claim 1, wherein: The cyclotrimethylene trinitramine recrystallization comprises the following steps: (1) using a solvent-antisolvent method to recrystallize trimethylene trinitramine, dissolving trimethylene trinitramine in a dimethyl sulfoxide solution at room temperature to prepare a 1.0-1.5 mol / L trimethylene trinitramine solution; (2) adding aminated mesoporous silica to the trimethylene trinitramine solution and soaking for 1 to 2 hours to completely wet the silica to obtain a mixed solution; (3) quickly pouring the mixed solution into a sufficient amount of ionized water, and mechanically stirring at room temperature for 10 to 30 minutes to allow the trimethylene trinitramine to fully crystallize, thereby obtaining an aqueous suspension of trimethylene trinitramine and amino-modified mesoporous silica; (4) filtering the suspension, washing the filtered product with deionized water for 2 to 3 times, and drying the product at 60 to 70° C. to a constant weight, thereby obtaining a composite of trimethylene trinitramine and mesoporous silica.

6. The preparation method according to claim 5, wherein: In step (2), the mass ratio of trimethylene trinitramine to amino-modified mesoporous silica is 5:1-2.

7. The preparation method according to claim 1, wherein: The pyrotechnic agent charge pressing comprises the following steps: (1) 10 to 15 parts of magnesium powder, 20 to 35 parts of aluminum powder, 3 to 5 parts of boron powder, 10 to 15 parts of trimethylene trinitramine and a mesoporous silica composite are fully dried and fully mixed in a mixer, and then 30 to 40 parts of polytetrafluoroethylene are added to obtain a mixed powder; (2) dissolving 5 to 10 parts of a binder in ethyl acetate, adding the mixed powder obtained in step (1) and mixing thoroughly to obtain a wet powder; (3) The wet powder is pressed into a pharmaceutical column by a press and solidified at 150-180° C. to obtain a low-smoke agent based on mesoporous silica adsorption.

8. The preparation method according to claim 5, wherein: The binder in step (2) is one or more combinations of epoxy resin, polyvinyl alcohol, and phenolic resin.

9. A low-smoke medicine prepared according to the preparation method according to any one of claims 1 to 8.

10. The low smoke agent according to claim 9, wherein: The PM generated by the explosion of low-smoke agent 10 Concentration PM10 ≤63 μg / m 3 , PM 2.5 Concentration PM2.5 ≤35 μg·m 3 .

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