Use of graphene oxide to reduce sensitivity of ammonium dinitramide

Abstract

The application discloses application of graphene oxide in reducing sensitivity of ammonium dinitramide, and the graphene oxide is used as raw material, and through reasonable process treatment, impact sensitivity and friction sensitivity of ADN are reduced, thermal stability of ADN is improved, and thermal decomposition performance is improved. Further, the prepared graphene oxide / ADN composite solid has a block structure, edges and corners are relatively smooth, and particles are small and uniform, the composite can reduce impact sensitivity and friction sensitivity of ADN, and can improve thermal performance of ADN and improve mass loss.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of energetic materials, and particularly relates to the application of graphene oxide for reducing the sensitivity of ammonium dinitramide. BACKGROUND

[0002] ADN (chemical name: ammonium dinitramide) is a novel high-energy green oxidant composed of ammonium cation and dinitramide anion, and has the advantages of high density (1.82 g / cm 3 , high oxygen coefficient (2.0), clean combustion gas (free of halogen), etc. Compared with the common oxidant ammonium perchlorate (AP), ADN has higher enthalpy of formation (ADN: -1208 kJ / kg, AP: -2782 kJ / kg), smaller average relative molecular mass of combustion gas (ADN: 26, AP: 31), and higher theoretical specific impulse of ADN-based solid propellant than that of AP-based solid propellant by 3s-10s per unit mass. However, the application of ADN is limited due to its low sensitivity. SUMMARY

[0003] In view of the defects or deficiencies of the prior art, the present application provides the application of graphene oxide for reducing the impact sensitivity and friction sensitivity of ammonium dinitramide or / and improving the thermal stability and mass loss of ammonium dinitramide.

[0004] The present application also provides a preparation method of graphene oxide / ammonium dinitramide composite, and the preparation method comprises the following steps:

[0005] Step 1, uniformly mix a gamma-butyrolactone solution of graphene oxide and a gamma-butyrolactone solution of ADN under the condition of 20-35℃ to obtain a mixed solution;

[0006] Step 2, drop the mixed solution obtained in Step 1 into an organic solvent under the condition of 20-40℃; and collect the precipitate after drying at room temperature to obtain the graphene oxide / ammonium dinitramide composite; the organic solvent is selected from one or more than two kinds of mixture of dichloromethane, toluene, cyclohexane and trichloromethane.

[0007] Alternatively, the graphene oxide is added into gamma-butyrolactone to prepare a gamma-butyrolactone solution of graphene oxide by ultrasonic dispersion under the condition of 20-35℃.

[0008] Alternatively, the ammonium dinitramide is added into gamma-butyrolactone to prepare a gamma-butyrolactone solution of ADN by stirring uniformly under the condition of 20-35℃.

[0009] Alternatively, the gamma-butyrolactone solution of graphene oxide is added into the gamma-butyrolactone solution of ADN to prepare the mixed solution of Step 1 by stirring and then ultrasonic dispersion under the condition of 20-35℃.

[0010] Optionally, the ratio of the amount of graphene oxide to gamma-butyrolactone in the gamma-butyrolactone solution of graphene oxide is 0.3 mg to 60 mg, and the ratio of the amount of ADN to gamma-butyrolactone in the gamma-butyrolactone solution of ADN is 0.3 g to 3.0 g. The amount of the organic solvent is 500 g to 1500 g.

[0011] The graphene oxide used in the present application can reduce the sensitivity of ADN, improve the thermal stability of ADN, and improve the thermal decomposition performance.

[0012] Compared with ADN, the graphene / ADN composite solid of the present application has a block structure, smooth edges and corners, and small and uniform particles. The impact sensitivity is reduced from 9.3 J to 12.0 J to 15.0 J, and the friction sensitivity is reduced from 72% to 50% to 55%. In addition, the thermal performance of ADN can be improved, the thermal decomposition temperature of ADN is delayed by 0.05 ℃ to 3.08 ℃, thereby improving the thermal stability of ADN, thereby improving the stability of the propellant formula. In addition, the mass loss of ADN is increased by 6.54% to 7.10%, thereby promoting the complete decomposition of ADN, so that it can burn more fully in the propellant formula. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the SEM image of ADN used in the embodiment of the present application.

[0014] Figure 2 is the thermal decomposition DSC graph (a) and TG graph (b) of ADN used in the embodiment of the present application.

[0015] Figure 3 is the SEM image of the graphene / ADN composite prepared in Example 1 of the present application.

[0016] Figure 4 is the thermal decomposition DSC graph (a) and TG graph (b) of the graphene / ADN composite prepared in Example 1 of the present application.

[0017] Figure 5 is the SEM image of the graphene / ADN composite prepared in Comparative Example 1 of the present application.

[0018] Figure 6 is the thermal decomposition DSC graph (a) and TG graph (b) of the graphene / ADN composite prepared in Comparative Example 1 of the present application.

[0019] Figure 7 is the SEM image of the reduced graphene oxide / ADN composite prepared in Comparative Example 2 of the present application.

[0020] Figure 8are the thermal decomposition DSC graph (a) and TG graph (b) of the reduced graphene oxide / ADN composite prepared in Comparative Example 2 of the present application.

[0021] Figure 9 is the SEM graph of the carbon nanotube / ADN composite prepared in Comparative Example 3 of the present application.

[0022] Figure 10 are the thermal decomposition DSC graph (a) and TG graph (b) of the carbon nanotube / ADN composite prepared in Comparative Example 3 of the present application.

[0023] Figure 11 is the SEM graph of the composite prepared in Comparative Example 4 of the present application.

[0024] Figure 12 is the SEM graph of the composite prepared in Comparative Example 5 of the present application.

[0025] Figure 13 is the SEM graph of the composite prepared in Comparative Example 6 of the present application.

[0026] Figure 14 is the SEM graph of the composite prepared in Comparative Example 7 of the present application. DETAILED DESCRIPTION

[0027] Unless otherwise defined, scientific and technical terms used in this text are understood according to the knowledge of the relevant person in the art.

[0028] The graphene oxide, graphene, reduced graphene oxide and carbon nanotubes used in the following examples are purchased through the distributor Beijing Bailingwei Technology Co., Ltd. Ammonium dinitramide (ADN) is provided by Xi'an Institute of Modern Chemistry, with an impact sensitivity of 9.3 J, a friction sensitivity (66°, 2.5 MPa) of 72%, a thermal decomposition temperature of 195.07°C, and a mass loss of 83.17% in TG test. Among them Figure 1 and Figure 2 are the electron micrograph, thermal decomposition DSC graph (a) and thermal analysis TG graph (b) of ADN, respectively.

[0029] The impact sensitivity in the following examples is tested by the impact sensitivity test method in GJB770A-97; the friction sensitivity is tested by the friction sensitivity test method in GJB770A-97.

[0030] Example 1:

[0031] Step 1, 4.5 mg of graphene oxide (GO) was added to 40 g of γ-butyrolactone and ultrasonically dispersed at 25°C for 1.5 h; 0.3 g of ADN was added to 10 g of γ-butyrolactone and stirred at 25°C for 15 min until the ADN was completely dissolved; the GO dispersion was poured into the ADN solution, and the system was stirred at 30°C for 1 h and ultrasonically dispersed for 10 min;

[0032] Step 2, the mixed solution of ADN and GO obtained in Step 1 was added dropwise into 500 g of dichloromethane under stirring at 30°C, and the solution was filtered to collect the precipitate, which was air-dried to constant weight to obtain 0.29 g of GO / ADN composite.

[0033] It was detected that the impact sensitivity of the GO / ADN composite prepared in this example was 14.6 J, the friction sensitivity was 50%, the thermal decomposition temperature was 195.12°C, and the thermal decomposition mass loss was 90.27%, as shown in Table 1. Figure 4

[0034] Scanning electron microscope (SEM) analysis: as shown in FIG. 1, the ADN solid was needle-shaped crystal, and the particles were uneven; in contrast, as shown in FIG. 2, the GO / ADN composite solid prepared in this example had a block structure, the edges and corners were relatively smooth, the particles were relatively uniform, and the black GO could be seen attached to the ADN solid. Figure 1 Figure 3

[0035] Comparative Example 1:

[0036] The difference between this comparative example and Example 1 was that graphene oxide was replaced by graphene; the SEM analysis of the prepared composite is shown in FIG. 3. Figure 5

[0037] It was detected that the impact sensitivity of the composite prepared in this comparative example was 9.5 J, the friction sensitivity was 72%, the thermal decomposition temperature was 195.75°C, and the thermal decomposition mass loss was 93.76%, as shown in Table 1. Figure 6

[0038] Comparative Example 2:

[0039] The difference between this comparative example and Example 1 was that graphene oxide was replaced by reduced graphene oxide; the SEM analysis of the prepared composite is shown in FIG. 4. Figure 7 Figure 8

[0040] Comparative Example 3:

[0041] The difference between this comparative example and Example 1 was that graphene oxide was replaced by carbon nanotubes; the SEM analysis of the prepared composite is shown in FIG. 5. Figure 9

[0042] ​​​​​​​​The impact sensitivity of the compound prepared in the comparative example was 8.0 J, the friction sensitivity was 64%, the thermal decomposition temperature was 194.55°C, and the thermal decomposition mass loss was 93.69%. Among them Figure 10 The thermal decomposition DSC graph (a) and TG graph (b) of the carbon nanotube / ADN prepared are shown in the following figure.

[0043] Comparative Example 4:

[0044] The difference between this comparative example and Example 1 is that the γ-butyrolactone therein is replaced by tetrahydrofuran; the SEM analysis of the prepared compound is shown in the following figure. Figure 11

[0045] The impact sensitivity of the compound prepared in the comparative example was 7.4 J, the friction sensitivity was 55%, the thermal decomposition temperature was 195.08°C, and the thermal decomposition mass loss was 80.17%.

[0046] Comparative Example 5:

[0047] The difference between this comparative example and Example 1 is that the γ-butyrolactone therein is replaced by N-methylpyrrolidone; the SEM analysis of the prepared compound is shown in the following figure. Figure 12

[0048] The impact sensitivity of the compound prepared in the comparative example was 6.6 J, the friction sensitivity was 51%, the thermal decomposition temperature was 194.74°C, and the thermal decomposition mass loss was 80.56%.

[0049] Comparative Example 6:

[0050] The difference between this comparative example and Example 1 is that in step 1, 4.5 mg of graphene oxide (GO) and ADN 0.3 g are added to 50 g of γ-butyrolactone, and stirred at 25°C for 1 hour 155 min; the SEM analysis of the prepared compound is shown in the following figure. Figure 13

[0051] The impact sensitivity of the compound prepared in the comparative example was 5.9 J, the friction sensitivity was 61%, the thermal decomposition temperature was 195.01°C, and the thermal decomposition mass loss was 79.12%.

[0052] Comparative Example 7:

[0053] The difference between this comparative example and Example 1 is that the dichloromethane in step 2 is replaced by: 1,4-dioxane; the SEM analysis of the prepared compound is shown in the following figure. Figure 14

[0054] The impact sensitivity of the compound prepared in the comparative example was 9.4 J, the friction sensitivity was 73%, the thermal decomposition temperature was 195.04°C, and the thermal decomposition mass loss was 83.14%. ​​​​

[0055] Example 2:

[0056] The difference between this example and Example 1 is that the amount of each substance and the solution mixing parameters are different.

[0057] 60 mg of graphene oxide (GO) was added to 100 g of γ-butyrolactone, and ultrasonic dispersion was performed at 30°C for 2.0 h;

[0058] 3.0 g of ADN was added to 50 g of γ-butyrolactone, and stirring was performed at 35°C for 30 min until the ADN was completely dissolved;

[0059] The GO dispersion liquid was poured into the ADN solution, and stirring was performed on the system at 25°C for 0.75 h, and ultrasonic dispersion was performed for 30 min;

[0060] The mixed solution of ADN and GO was added dropwise to 1500 g of dichloromethane under stirring at 40°C, the solution was filtered after the dropwise addition was completed, and air-drying was performed at room temperature until the weight was constant, thereby obtaining 2.8 g of GO / ADN composite.

[0061] It was detected that the impact sensitivity of the GO / ADN composite prepared in this example was 15.0 J, the friction sensitivity was 55%, the thermal decomposition temperature was 198.15°C, and the thermal decomposition mass loss was 88.71%.

[0062] Example 3:

[0063] The difference between this example and Example 1 is that the amount of each substance and the solution mixing parameters are different.

[0064] 0.3 mg of graphene oxide (GO) was added to 20 g of γ-butyrolactone, and ultrasonic dispersion was performed at 35°C for 1.5 h;

[0065] 0.4 g of ADN was added to 25 g of γ-butyrolactone, and stirring was performed at 28°C for 15 min until the ADN was completely dissolved;

[0066] The GO dispersion liquid was poured into the ADN solution, and stirring was performed on the system at 40°C for 0.5 h, and ultrasonic dispersion was performed for 12 min;

[0067] The mixed solution of ADN and GO was added dropwise to 600 g of dichloromethane under stirring at 25°C, the solution was filtered after the dropwise addition was completed, and air-drying was performed at room temperature until the weight was constant, thereby obtaining 0.37 g of GO / ADN composite.

[0068] It was detected that the impact sensitivity of the GO / ADN composite prepared in this example was 12.0 J, the friction sensitivity was 50%, the thermal decomposition temperature was 195.12°C, and the thermal decomposition mass loss was 89.47%.

[0069] The detection results of the products prepared in the above examples and comparative examples are shown in Table 1.

[0070] Table 1

[0071]

[0072]

Claims

1. A method for preparing a graphene oxide / diammonium nitroxyl complex, characterized by, The method comprises the following steps: Step 1, under the condition of 20-35 DEG C, mix the gamma-butyrolactone solution of graphene oxide with the gamma-butyrolactone solution of ADN uniformly to obtain a mixed solution; Step 2, under the condition of 20-40 DEG C, drop the mixed solution obtained in step 1 into an organic solvent; after the dropping is completed, collect the precipitate, dry at room temperature to obtain a graphene oxide / ammonium dinitramide composite; the organic solvent is selected from one or more than two kinds of mixture of dichloromethane, toluene, cyclohexane and chloroform.

2. The method for preparing a graphene oxide / diammonium nitroxyl complex according to claim 1, characterized in that, The graphene oxide is added into gamma-butyrolactone, ultrasonic dispersion is carried out under the temperature condition of 20-35 DEG C to obtain a gamma-butyrolactone solution of graphene oxide.

3. The method for preparing a graphene oxide / diammonium nitroxyl complex according to claim 1, characterized in that, The ammonium dinitramide is added into gamma-butyrolactone, stirring is carried out uniformly under the temperature condition of 20-35 DEG C to obtain a gamma-butyrolactone solution of ADN.

4. The method for preparing a graphene oxide / diammonium nitroxyl complex according to claim 1, characterized by, The gamma-butyrolactone solution of graphene oxide is added into the gamma-butyrolactone solution of ADN, stirring is carried out under 20-35 DEG C, then ultrasonic dispersion is carried out to obtain the mixed solution obtained in step 1.

5. The method for preparing a graphene oxide / diammonium nitroxyl complex according to claim 1, characterized in that, The dosage ratio of graphene oxide and gamma-butyrolactone in the gamma-butyrolactone solution of graphene oxide is 0.3 mg-60 mg: 20 g-100 g; the dosage ratio of ADN and gamma-butyrolactone in the gamma-butyrolactone solution of ADN is 0.3 g-3.0 g: 10 g-50 g.

6. The method of claim 5, wherein the graphene oxide / ammonium dinitramide composite is prepared by the steps of: (a) mixing graphene oxide and ammonium dinitramide in a solvent; (b) drying the mixture; and (c) heating the dried mixture. The dosage of the organic solvent is 500 g-1500 g.

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