Gas generating agent, its preparation method and application

Abstract

The application provides a gas generating agent and a preparation method and application thereof, and belongs to the technical field of composite solid propellant gas generating agents. The gas generating agent is prepared according to the adding proportion of 40-43% of a main gas generating agent, 17-18% of a secondary gas generating agent, 20-25% of an oxidant, 16-17% of a binder and 2% of a curing agent. The combustion temperature of the gas generating agent prepared by the application is far lower than 2000K of common gas generating agents under the pressure of 70atm; the average molecular weight of the combustion product is lower than 20g / mol; the gas production is higher than 1000L / kg; there is no corrosive gas such as HCl and HF in the combustion product, and there is a large amount of H2, N2 and CO; the specific impulse, characteristic velocity and other performances are higher than those of the currently used double-base type and composite propellant type gas generating agents. Moreover, the cost of raw materials is very low, the preparation process is simple, and there is a basis for large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite solid propellant gas generating agent, and particularly relates to a gas generating agent and a preparation method and application thereof. BACKGROUND

[0002] When a liquid rocket (missile) is launched, an initial power is needed to start the oxidizer pump and fuel pump of the liquid rocket (missile), and the power is usually from the high-speed, low-temperature and low-residue gas sprayed by the combustion of the gas generating agent in the gas generator in the rocket engine. In order to effectively protect the oxidizer pump and fuel pump, the gas generated by the combustion of the gas generating agent needs to have the characteristics of low temperature, large output and non-corrosive. In addition, the solid product generated by the combustion of the gas generating agent must be less than 10 mol%, otherwise the nozzle will be blocked. In addition, too much gas with high molecular weight will cause the average molecular weight of the gaseous product to increase, resulting in insufficient gas production; the generation of too much CO2 will cause the heat release of combustion to increase sharply, resulting in too high combustion temperature; and the generation of a large amount of HCl or HF will cause serious corrosion of the oxidizer pump and fuel pump of the rocket. When the formula is designed, it is necessary to ensure that small molecular weight gases such as CH4, CO, H2, N2 and H2O are generated more during the combustion of the gas generating agent; high molecular weight gases such as CO2 are generated as little as possible; corrosive gases such as HCl and HF are not generated; and solid carbon is generated as little as possible.

[0003] However, the currently used double-base type gas generating agent and composite propellant type gas generating agent have the problem of large CO2 and HCl production during combustion, resulting in high combustion temperature, small gas production and corrosive gas, and therefore further adjustment of the formula is needed.

[0004] Azotetrazole triaminoguanidine salt (TAGZT) and triaminoguanidine nitrate (TAGN) are two low-cost, high-burning rate, low-burning temperature, high-nitrogen content and halogen-free energetic compounds. They are not hygroscopic and do not contain crystal water, and are two excellent organic energetic compounds. In particular, the main gas generating agent TAGZT used in the present application was first synthesized in 1998, but since then, TAGZT has been rarely concerned and reported as explosives, and the main reason is that the precursor 5-amino tetrazole of TAGZT has not been industrialized before. In recent years, with the mass production of 5-amino tetrazole, the preparation cost of TAGZT has also been greatly reduced. The chemical formula of TAGZT is C4H 18 N 22, the relative molecular mass is 374.3g / mol, the enthalpy of formation is 1106kJ / mol, the nitrogen content reaches 82.3wt.%, the hydrogen content is 4.81wt.%, the oxygen balance is -72.7%, the thermal decomposition temperature is 200 DEG C, the theoretical detonation velocity is as high as 9441m / s, and the explosion gas generation amount is 939.4L / kg. The high nitrogen content and the large gas generation amount result in that the combustion temperature of TAGZT is very low, and the average molecular weight of the combustion product is also low. Therefore, TAGZT is extremely promising in the application in the high-performance gas generating agent. There is no report about the application of TAGZT and TAGN in the field of gas generating agent in the existing literature and patents. SUMMARY

[0005] The present application aims at providing a gas generating agent and a preparation method and application thereof, which has the characteristics of low combustion temperature, large gas generation amount, and no corrosive gas such as HCl and HF.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] The present application provides a gas generating agent, which comprises the following raw materials in mass percentage:

[0008] The main gas generating agent is 40-43%;

[0009] The auxiliary gas generating agent is 17-18%;

[0010] The oxidizing agent is 20-25%;

[0011] The binder is 16-17%;

[0012] The curing agent is 2%, and the sum of the weight percentages of the components is 100%.

[0013] Further, the main gas generating agent is TAGZT, the auxiliary gas generating agent is TAGN, the oxidizing agent is PSAN, the binder is GAP or HTPB, and the curing agent is N-100 or TDI.

[0014] The present application further provides a preparation method of the gas generating agent, comprising the following steps:

[0015] The binder, the main gas generating agent, the auxiliary gas generating agent and the oxidizing agent are added in sequence and kneaded, then the curing agent is added and continuously kneaded until uniform, and then discharged, poured, and solidified.

[0016] Further, the air humidity in the two times of kneading is less than 20H2O / kg, the temperature in the kneading is less than 45 DEG C, and the time of each kneading is 0.5-1.5h.

[0017] Further, the vacuum degree before the two times of kneading needs to be controlled to be less than 0.004MPa.

[0018] Further, the temperature of the solidification is 60-80℃, and the time of the solidification is 8-12 days.

[0019] The application further provides the application of the above-mentioned gas generating agent in the liquid rocket launching process.

[0020] The application further provides the application of the above-mentioned gas generating agent in the liquid missile launching process.

[0021] The main and by-product gas agents, oxidizers and binders used in the application do not contain halogen, especially do not contain chlorine and fluorine elements. Therefore, no halogenated hydrogen (especially no HCl and HF) is generated in the gas, so that the gas is non-corrosive.

[0022] (1) The combustion temperature of the main and by-product gas agents used in the application is low, the average molecular weight of the combustion products is low, and the gas production is large, and the performance is higher than that of the currently used double-base type and composite propellant type gas generating agent.

[0023] (2) The cost of the raw materials involved in the application is very low, and the preparation process is simple, which has the basis for large-scale production.

[0024] (3) The gas generating agent of the application has wide application, and can be used in gas generators and other rapid gas generating devices.

[0025] (4) The combustion temperature of the gas generating agent of the application under 70atm pressure is far lower than 2000K of the ordinary gas generating agent; the average molecular weight of the combustion products is lower than 20g / mol; the gas production is higher than 1000L / kg. There is no corrosive gas such as HCl and HF in the combustion products, no solid carbon, a large amount of H2, N2 and CO. And the specific impulse is higher, reaching 2059N·s / kg, and the characteristic velocity reaches 1275m / s, which are higher than those of the traditional gas generating agent. DETAILED DESCRIPTION

[0026] The embodiments of the application are described in detail below, which are intended to explain the application, and cannot be understood as a limitation of the application. The specific techniques or conditions not mentioned in the embodiments are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be obtained by market purchase.

[0027] Example 1

[0028] Preparation of the gas generating agent:

[0029] The raw materials are weighed according to the formulation in Table 1, 170 g of GAP, 430 g of TAGZT, 180 g of TAGN, and 200 g of PSAN are slowly poured into a small kneader in sequence, the vacuum pump is started, and the vacuum degree is less than 0.004 MPa, then the kneader is started, and kneaded for 1 h, then the kneader is closed, and the vacuum pump is closed. Continue to add 20 g of N-100 to the kneader, then start the vacuum pump, and the vacuum degree is less than 0.004 MPa, then start the kneader, and knead for 1 h, then close the kneader, and pour the slurry into a product mold under vacuum conditions, close the vacuum pump, and place the poured product mold in a water bath oven at 70°C for solidification for 10 days, then obtain the gas generating agent product, and test the performance, and the results are shown in Tables 3 and 4.

[0030] Table 1: Formulation of the gas generating agent in Example 1

[0031]

[0032]

[0033] The performance of the gas generating agent prepared in Example 1 is shown in Table 3. It can be seen that the burning temperature under 70 atm pressure is only 1482 K, which is much lower than the 2000 K of ordinary gas generating agents; the average molecular weight of the combustion products is less than 20 g / mol; and the gas production is higher than 1000 L / kg. There is no corrosive gas such as HCl and HF in the combustion products, no solid carbon, a large amount of H2, N2 and CO, and a small amount of CH4 and H2O, which explains the reason why the gas generating agent has low burning temperature and high gas production. The interior ballistic performance of the gas generating agent prepared in Example 1 is shown in Table 4. It can be seen that the specific impulse of the gas generating agent in Example 1 is higher, reaching 2059 N·s / kg, and the characteristic velocity reaches 1275 m / s, both of which are higher than those of traditional gas generating agents. The thrust coefficient is larger, indicating that the gas expansion work is good. The burning rate under 70 atm pressure is 8.5 m / s, indicating that the burning rate is normal. The pressure index is slightly high, reaching 0.55, but is still within the usable range.

[0034] Example 2

[0035] The raw materials were weighed according to the formulation in Table 2, 160 g of HTPB, 400 g of TAGZT, 170 g of TAGN, and 250 g of PSAN were slowly poured into a small kneader, the vacuum pump was started, and the vacuum degree was less than 0.004 MPa, then the kneader was started, and kneaded for 1 h, then the kneader was closed, and the vacuum pump was closed. 20 g of TDI was added to the kneader, and then the vacuum pump was started, and the vacuum degree was less than 0.004 MPa, then the kneader was started, and kneaded for 1 h, then the kneader was closed, and the vacuum pump was closed. The slurry was poured into the combustion chamber under vacuum, the vacuum pump was closed, and the poured product mold was placed in a water bath oven at 70°C for curing for 10 days to obtain the gas generating agent product, and the performance was tested, and the results are shown in Tables 3 and 4.

[0036] Table 2 Formulation of the gas generating agent in Example 2

[0037] Ingredient Substance Chemical Formula Oxygen Balance Mass Percent Primary Gas Generator TAGZT [C4H 18 N 22 ]]> -72.7％ 40％ By-product Gas Generator TAGN [C1H9N7O3] -33.5％ 17％ Oxidizer PSAN NH4NO3 +20.0％ 25％ Binder HTPB [C4H 6.052 O 0.052 ]]> -319.2％ 16％ Curing Agent TDI [C9H6N2O2] -174.7％ 2％

[0038] The performance of the gas generating agent prepared in Example 2 is shown in Table 3. It can be seen that the burning temperature under 70 atm pressure is only 1346 K, which is much lower than the 2000 K of ordinary gas generating agents; the average molecular weight of the combustion products is less than 20 g / mol; the gas production is higher than 1000 L / kg. There is no corrosive gas such as HCl and HF in the combustion products, there is a large amount of H2, N2 and CO, a small amount of CH4 and H2O, which explains the reason why the gas generating agent has low burning temperature and high gas production. But 5.7 mol% of solid carbon is generated in the combustion products, and since the amount of carbon generated is less than 10 mol%, it meets the requirements of the gas generating agent. The interior ballistic performance of the gas generating agent prepared in Example 2 is shown in Table 4. It can be seen that the specific impulse of the gas generating agent in Example 2 is higher, reaching 1985 N·s / kg, and the characteristic velocity reaches 1219 m / s, both higher than the data of traditional gas generating agents. The thrust coefficient is larger, indicating that the gas expansion work is good. The burning rate under 70 atm pressure is 4.6 m / s, indicating that the burning rate is normal. The pressure index is slightly high, reaching 0.61, but it is still within the usable range.

[0039] Table 3 Performance of the gas generating agent in Example 1 and Example 2

[0040]

[0041] Table 4 Interior ballistic performance of the gas generating agent in Example 1 and Example 2

[0042]

[0043] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. A gas generating agent, characterized by comprising: The raw materials include the following mass percentages: TAGZT: 40-43%; TAGN: 17-18%; PSAN: 20-25%; Binder: 16-17%; Curing agent: 2%, the sum of the weight percentages of the components being 100%; The binder is GAP or HTPB, and the curing agent is N-100 or TDI.

2. A method of producing the gas generating agent according to claim 1, characterized by, The method includes the following steps: The binder, TAGZT, TAGN and PSAN are sequentially kneaded, and then the curing agent is added and kneaded, after which the mixture is discharged, poured and cured; The binder is GAP or HTPB, and the curing agent is N-100 or TDI.

3. The preparation method according to claim 2, characterized in that, The air humidity during the two kneading processes is less than 20 H2O / kg, and the temperature is less than 45°C, and the time for each kneading process is 0.5-1.5 h.

4. The preparation method according to claim 3, characterized in that, The vacuum degree before the two kneading processes is controlled to be less than 0.004 MPa.

5. The preparation method according to claim 2, characterized in that, The curing temperature is 60-80°C, and the curing time is 8-12 days.

6. Use of the gas generating agent of claim 1 in the process of launching a liquid rocket.

7. Use of the gas generating agent of claim 1 in the process of launching a liquid missile.

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