Application of graphene oxide for reducing sensitivity of ammonium dinitramide

Abstract

The invention discloses an application of graphene oxide in reducing the sensitivity of ammonium dinitramide, the graphene oxide is used as a raw material, the impact sensitivity and friction sensitivity of ADN (ammonium dinitramide) are reduced through reasonable process treatment, and the thermal stability and thermal decomposition performance of the ADN are also improved. Furthermore, the prepared graphene oxide / ADN compound solid is of a blocky structure, corners are smooth, particles are small and uniform, the impact sensitivity and friction sensitivity of the ADN can be reduced through the compound, the thermal performance of the ADN can be improved, and the mass loss can be improved.

Description

Technical Field

[0001] The invention belongs to the field of energetic materials, and in particular relates to the application of graphene oxide in reducing the sensitivity of ammonium dinitramide. Background Art

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

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

[0004] The present invention also provides a method for preparing a graphene oxide / ammonium dinitramide composite, and the provided preparation method comprises the following steps:

[0005] Step 1, at 20-35° C., mixing a γ-butyrolactone solution of graphene oxide and a γ-butyrolactone solution of ADN to obtain a mixed solution;

[0006] Step 2, under the condition of 20-40° C., the mixed solution obtained in step 1 is added dropwise to an organic solvent; after the addition is completed, the precipitate is collected and dried at room temperature to obtain a graphene oxide / ammonium dinitramide complex; the organic solvent is selected from one or a mixture of two or more of dichloromethane, toluene, cyclohexane and chloroform.

[0007] An optional solution is to add graphene oxide to γ-butyrolactone and perform ultrasonic dispersion at a temperature of 20 to 35° C. to obtain a γ-butyrolactone solution of graphene oxide.

[0008] An optional solution is to add ammonium dinitramide to γ-butyrolactone and stir the mixture evenly at a temperature of 20 to 35° C. to obtain a γ-butyrolactone solution of ADN.

[0009] An optional solution is to add the γ-butyrolactone solution of graphene oxide to the γ-butyrolactone solution of ADN, stir at 20-35° C., and then perform ultrasonic dispersion to obtain the mixed solution obtained in step 1.

[0010] An optional solution is that the ratio of graphene oxide to γ-butyrolactone in the γ-butyrolactone solution of graphene oxide is 0.3mg-60mg:20g-100g, and the ratio of ADN to γ-butyrolactone in the γ-butyrolactone solution of ADN is 0.3g-3.0g:10g-50g. The amount of organic solvent used is 500g-1500g.

[0011] The present invention adopts graphene oxide to reduce ADN sensitivity, improve ADN thermal stability, and enhance thermal decomposition performance.

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

[0013] Figure 1 is a SEM image of ADN used in the embodiments of the present invention.

[0014] Figure 2 The thermal decomposition DSC graph (a) and TG graph (b) of ADN used in the examples of the present invention are shown.

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

[0016] Figure 4 The thermal decomposition DSC graph (a) and TG graph (b) of the graphene oxide / ADN composite prepared in Example 1 of the present invention are shown.

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

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

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

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

[0021] Fig. 9 It is a SEM picture of the carbon nanotube / ADN composite prepared in Comparative Example 3 of the present invention.

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

[0023] Fig.11 is a SEM image of the composite prepared in Comparative Example 4 of the present invention.

[0024] Fig.12 is a SEM image of the composite prepared in Comparative Example 5 of the present invention.

[0025] Fig.13 is a SEM image of the composite prepared in Comparative Example 6 of the present invention.

[0026] Fig.14 is a SEM image of the composite prepared in Comparative Example 7 of the present invention. DETAILED DESCRIPTION

[0027] Unless otherwise specified, the scientific and technical terms used herein are understood according to the knowledge of ordinary technicians in the relevant fields.

[0028] The graphene oxide, graphene, reduced graphene oxide and carbon nanotubes used in the following examples were purchased from the distributor Beijing Bailingwei Technology Co., Ltd. Ammonium dinitramide (ADN) was provided by Xi'an Modern Chemistry Research Institute, 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. Figure 1 and Figure 2 They are the electron microscope image, thermal decomposition DSC image (a) and thermal analysis TG image (b) of ADN.

[0029] The impact sensitivity of the following examples was tested using the impact sensitivity test method in GJB770A-97; the friction sensitivity was tested using the friction sensitivity test method in GJB770A-97.

[0030] Embodiment 1:

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

[0032] Step 2, add the mixed solution of ADN and GO obtained in step 1 dropwise into 500 g of dichloromethane under stirring at 30° C. After the addition is complete, filter the solution to collect the precipitate, and dry it at room temperature to constant weight to obtain 0.29 g of GO / ADN composite.

[0033] After testing, the impact sensitivity of the GO / ADN composite prepared in this embodiment is 14.6 J, the friction sensitivity is 50%, the thermal decomposition temperature is 195.12 ° C, and the thermal decomposition mass loss is 90.27%. Figure 4 shown.

[0034] Scanning electron microscopy (SEM) analysis: see Figure 1 As shown, the ADN solid is a needle-shaped crystal and the particles are not uniform; in contrast, see Figure 3 As shown, the GO / ADN composite solid prepared in this example has a block structure, relatively smooth edges and corners, relatively uniform particles, and black GO can be faintly seen attached to the ADN solid.

[0035] Comparative Example 1:

[0036] The difference between this comparative example and Example 1 is that graphene oxide is replaced by graphene; the SEM analysis of the prepared composite is as follows Figure 5 As shown;

[0037] After testing, the composite prepared in this comparative example has an impact sensitivity of 9.5 J, a friction sensitivity of 72%, a thermal decomposition temperature of 195.75°C, and a thermal decomposition mass loss of 93.76%. Figure 6 shown.

[0038] Comparative Example 2:

[0039] The difference between this comparative example and Example 1 is that the graphene oxide is replaced by reduced graphene oxide; the SEM analysis of the prepared composite is as follows: Figure 7 As shown; after testing, the impact sensitivity of the composite prepared in this comparative example is 9J, the friction sensitivity is 68%, the thermal decomposition temperature is 189.28°C, and the thermal decomposition mass loss is 92.52%, see Figure 8 shown.

[0040] Comparative Example 3:

[0041] The difference between this comparative example and Example 1 is that the graphene oxide is replaced by carbon nanotubes; the SEM analysis of the prepared composite is as follows Fig. 9 As shown;

[0042] After testing, the composite prepared in this comparative example has an impact sensitivity of 8.0 J, a friction sensitivity of 64%, a thermal decomposition temperature of 194.55° C., and a thermal decomposition mass loss of 93.69%. Fig.10 (a) and (b) the thermal decomposition DSC graphs of the prepared carbon nanotubes / ADN.

[0043] Comparative Example 4:

[0044] The difference between this comparative example and Example 1 is that the γ-butyrolactone is replaced by tetrahydrofuran; the SEM analysis of the prepared composite is as follows: Fig.11 As shown;

[0045] According to tests, the composite prepared in this comparative example has an impact sensitivity of 7.4 J, a friction sensitivity of 55%, a thermal decomposition temperature of 195.08° C., and a thermal decomposition mass loss of 80.17%.

[0046] Comparative Example 5:

[0047] The difference between this comparative example and Example 1 is that γ-butyrolactone is replaced by N-methylpyrrolidone; the SEM analysis of the prepared composite is as follows: Fig.12 As shown;

[0048] After testing, the composite prepared in this comparative example has an impact sensitivity of 6.6 J, a friction sensitivity of 51%, a thermal decomposition temperature of 194.74° C., and a thermal decomposition mass loss of 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 0.3 g of ADN are added to 50 g of γ-butyrolactone and stirred at 25° C. for 1 hour and 155 min. The SEM analysis of the prepared composite is as follows: Fig.13 As shown;

[0051] According to tests, the composite prepared in this comparative example has an impact sensitivity of 5.9 J, a friction sensitivity of 61%, a thermal decomposition temperature of 195.01° C., and a thermal decomposition mass loss of 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 with 1,4-dioxane; the SEM analysis of the prepared composite is as follows: Fig.14 As shown;

[0054] According to tests, the composite prepared in this comparative example has an impact sensitivity of 9.4 J, a friction sensitivity of 73%, a thermal decomposition temperature of 195.04° C., and a thermal decomposition mass loss of 83.14%.

[0055] Embodiment 2:

[0056] This embodiment is different from embodiment 1 in that the amounts of the substances used and the solution mixing parameters are different:

[0057] 60 mg of graphene oxide (GO) was added to 100 g of γ-butyrolactone and ultrasonically dispersed at 30 °C for 2.0 h.

[0058] Add 3.0 g of ADN to 50 g of γ-butyrolactone and stir at 35 °C for 30 min until ADN is completely dissolved;

[0059] Pour the GO dispersion into the ADN solution, stir the system for 0.75 h at 25 °C, and ultrasonically disperse for 30 min;

[0060] The mixed solution of ADN and GO was added dropwise to 1500 g of dichloromethane under stirring at 40° C. After the addition was complete, the solution was filtered and dried at room temperature to constant weight to obtain 2.8 g of GO / ADN composite.

[0061] According to the test, the GO / ADN composite prepared in this example has an impact sensitivity of 15.0 J, a friction sensitivity of 55%, a thermal decomposition temperature of 198.15° C., and a thermal decomposition mass loss of 88.71%.

[0062] Embodiment 3:

[0063] This embodiment is different from embodiment 1 in that the amounts of the substances used and the solution mixing parameters are different:

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

[0065] Add 0.4 g ADN to 25 g γ-butyrolactone and stir at 28 °C for 15 min until ADN is completely dissolved;

[0066] Pour the GO dispersion into the ADN solution, stir the system at 40 °C for 0.5 h, and ultrasonically disperse for 12 min;

[0067] The mixed solution of ADN and GO was added dropwise to 600 g of dichloromethane under stirring at 25° C. After the addition was complete, the solution was filtered and dried at room temperature to constant weight to obtain 0.37 g of GO / ADN composite.

[0068] According to the test, the GO / ADN composite prepared in this example has an impact sensitivity of 12.0 J, a friction sensitivity of 50%, a thermal decomposition temperature of 195.12° C., and a thermal decomposition mass loss of 89.47%.

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

[0070] Table 1

[0071]

[0072]

Claims

1. 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.

2. A method for preparing a graphene oxide / ammonium dinitramide composite, characterized in that: The method comprises the following steps: Step 1, at 20-35° C., mixing a γ-butyrolactone solution of graphene oxide and a γ-butyrolactone solution of ADN to obtain a mixed solution; Step 2, under the condition of 20-40° C., the mixed solution obtained in step 1 is added dropwise to an organic solvent; after the addition is completed, the precipitate is collected and dried at room temperature to obtain a graphene oxide / ammonium dinitramide complex; the organic solvent is selected from one or a mixture of two or more of dichloromethane, toluene, cyclohexane and chloroform.

3. The method for preparing the graphene oxide / ammonium dinitramide composite according to claim 2, characterized in that: Graphene oxide is added into gamma-butyrolactone, and ultrasonic dispersion is performed at a temperature of 20 to 35° C. to obtain a gamma-butyrolactone solution of graphene oxide.

4. The method for preparing the graphene oxide / ammonium dinitramide composite according to claim 2, characterized in that: Add ammonium dinitramide to γ-butyrolactone, and stir evenly at a temperature of 20-35° C. to prepare a γ-butyrolactone solution of ADN.

5. The method for preparing the graphene oxide / ammonium dinitramide composite according to claim 2, characterized in that: The γ-butyrolactone solution of graphene oxide is added to the γ-butyrolactone solution of ADN, and the mixture is dispersed by ultrasonic after stirring at 20-35° C. to obtain the mixed solution obtained in step 1.

6. The method for preparing the graphene oxide / ammonium dinitramide composite according to claim 2, characterized in that: The usage ratio of graphene oxide to γ-butyrolactone in the γ-butyrolactone solution of graphene oxide is 0.3mg-60mg:20g-100g; the usage ratio of ADN to γ-butyrolactone in the γ-butyrolactone solution of ADN is 0.3g-3.0g:10g-50g.

7. The method for preparing the graphene oxide / ammonium dinitramide composite according to claim 6, characterized in that: The amount of organic solvent used is 500g to 1500g.

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