High-quality hmx@htpe-wpu coated spherical explosive

Abstract

This invention discloses a high-quality HMX@HTPE-WPU-coated spherical propellant, comprising the following raw materials: high-quality octogen, polyethylene glycol-polytetrahydrofuran block copolymer ether-waterborne polyurethane. This invention solves the problems of high mechanical sensitivity and poor safety in existing high-quality HMX propellants; the impact sensitivity of the high-quality HMX@HTPE-WPU-coated spherical propellant of this invention is reduced to 56%, with good thermal stability, significantly improving the intrinsic safety of cast modified double-base propellants.

Description

Technical Field

[0001] This invention relates to a high-quality HMX@HTPE-WPU coated spherical propellant, mainly used in the manufacture of cast modified double-base propellants. Background Technology

[0002] HMX is a high-performance nitramine explosive with advantages such as high energy, high density, and high detonation velocity. It is widely used as a high-energy-density material in cast modified double-base propellant formulations. However, increasing the HMX content and decreasing the binder content in the propellant formulation to improve the energy level of cast modified double-base propellants inevitably leads to a decrease in the propellant's mechanical properties. Furthermore, as a non-reinforcing filler, HMX exhibits poor interfacial bonding between its particle surface and the binder, easily resulting in a "dewetting" phenomenon, which is a weak point in the propellant's mechanical properties. Therefore, enhancing the interfacial bonding strength between solid filler particles and the binder is one of the technical approaches to improving the mechanical properties of cast modified double-base propellants.

[0003] HMX is usually modified and coated to reduce its mechanical sensitivity. The paper "Research on Coating Modification of HMX with Polyacrylate" (Pyrotechnics, 2015, 167(6):40-43) discloses a method using a solution-water suspension method with polyacrylate or fluororubber as the coating agent to modify HMX, reducing the impact sensitivity H of a 2% fluororubber-HMX coated ball. 50 Impact sensitivity H of a 40.2cm, 2% polyacrylate-HMX coated ball 50 The length is 53.5 cm. "Coating of HMX with TEX to Reduce Sensitivity" Journal of Explosives and Pyrotechnics, 2018, 14(4):394-398. It reports a solution-water suspension coating method using 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0] 5,9 .0 3,11 The method of reducing the sensitivity of HMX by coating it with TEX and fluororubber was reported. The impact sensitivity of HMX coated with 3% fluororubber was 92% and the friction sensitivity was 100%. "Frictional properties of HMX coated with different binders" Science Technology and Engineering, 2018, 18(29):206-210. It reported the method of reducing the sensitivity of HMX by coating it with TEX and fluororubber. The impact sensitivity of HMX coated with 3% fluororubber was 92% and the friction sensitivity was 100%. # Methods for coating HMX with wax. However, no research has been published on reducing the mechanical sensitivity of high-quality HMX by coating it with polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane (HTPE-WPU). Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a high-quality HMX@HTPE-WPU-coated spherical propellant, solving problems such as poor bonding between the particle surface and the binder interface of HMX as a non-reinforcing filler in existing propellant formulations, which easily leads to phenomena similar to "dehydration". The present invention can reduce its mechanical sensitivity and improve the inherent safety of cast modified dual propellants.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A high-quality HMX@HTPE-WPU-coated spherical drug comprises the following raw materials: high-quality octogen, polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane.

[0007] The present invention also includes the following technical features:

[0008] Specifically, by weight percentage, it includes the following raw materials: 98.0% to 99.0% high-quality octogen, and 1.0% to 2.0% polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane.

[0009] Specifically, by weight percentage, it includes the following raw materials: 98.5% high-quality octogen and 1.5% polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane.

[0010] The method for preparing the high-quality HMX@HTPE-WPU-coated spherical drug includes the following steps:

[0011] Step 1, Preparation of demulsifier: Mix polyacrylamide with deionized water and stir until the polyacrylamide is completely dissolved to obtain an aqueous solution of polyacrylamide; mix the above aqueous solution of polyacrylamide with an aqueous solution of polyethyleneimine and stir to obtain a mixed demulsifier;

[0012] Step 2, Demulsification method for high-quality octogen: Weigh high-quality octogen, weigh polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane emulsion and dilute with deionized water. Stir the high-quality octogen and diluted polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane at room temperature to form suspension A. Raise the temperature of suspension A from room temperature to 45°C, slowly add the mixed demulsifier solution, and continue stirring after the addition is complete to form suspension B. Filter suspension B and wash with deionized water to avoid demulsifier residue. Place the filtered product in a water bath oven and dry to constant weight to obtain high-quality HMX@HTPE-WPU.

[0013] Specifically, step one includes:

[0014] Step 1.1: Mix polyacrylamide with deionized water and stir at 50°C until the polyacrylamide is completely dissolved;

[0015] Step 1.2: Mix the prepared polyacrylamide aqueous solution with the polyethyleneimine aqueous solution, and stir continuously at 300 r / min for 20 min at 50°C to obtain a mixed demulsifier.

[0016] Specifically, in step 1.1, polyacrylamide and deionized water are mixed at a mass ratio of 1:1000.

[0017] Specifically, in step 1.2, the polyacrylamide aqueous solution and the polyethyleneimine aqueous solution are mixed at a mass ratio of W(PEI):W(PAM) = 5:3.

[0018] Specifically, step two includes:

[0019] Step 2.1: Weigh high-quality octogen according to the formula amount, then weigh polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane emulsion and dilute it with deionized water. Stir the high-quality octogen and the diluted polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane at room temperature for 1 hour to form suspension A.

[0020] Step 2.2: Raise the temperature of suspension A from room temperature to 45°C, slowly add the mixed demulsifier solution, and continue stirring at a stirring rate of 300 r / min for 1 h after the addition is completed to avoid incomplete demulsification, so as to form suspension B;

[0021] Step 2.3: Filter the suspension B and wash it 5 times with deionized water to avoid demulsifier residue;

[0022] Step 2.4: Place the product obtained by vacuum filtration in a 50℃ water bath oven and dry it to constant weight to obtain high-quality HMX@HTPE-WPU.

[0023] Specifically, in step 2.1, 10g of high-quality octogen is weighed, and 0.5g of polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane emulsion is weighed and diluted with 100mL of deionized water.

[0024] Specifically, in step 2.2, 75g of mixed demulsifier solution is slowly added at a rate of 1 drop / s.

[0025] Compared with the prior art, the present invention has the following technical effects:

[0026] The coating material used in this invention for surface modification of high-quality octogen particles is polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane. The prepared coated spherical propellant has good insensitivity and thermal stability. Compared with ordinary HMX and high-quality HMX, the impact sensitivity of high-quality HMX@HTPE-WPU is reduced by 56%, and the thermal stability is better, which improves the intrinsic safety of cast modified double-base propellants. Attached Figure Description

[0027] Figure 1 High-quality scanning electron microscope images of HMX-1@HTPE-WPU.

[0028] Figure 2 High-quality scanning electron microscope images of HMX-2@HTPE-WPU.

[0029] Figure 3 This is a TG image of a high-quality HMX-1.

[0030] Figure 4 This is a TG image of a high-quality HMX-2.

[0031] Figure 5 For high-quality HMX-1@HTPE-WPU.

[0032] Figure 6 For high-quality HMX-2@HTPE-WPU. Detailed Implementation

[0033] This invention provides a high-quality HMX@HTPE-WPU-coated spherical propellant. Based on the insensitive properties of HTPE-WPU, it is used as a coating layer to reduce the mechanical sensitivity of the high-quality HMX. HMX, as a non-reinforcing filler, has high mechanical sensitivity, which is crucial to the mechanical and safety performance of cast modified dual-base propellants. Ordinary HMX has an irregular shape, and the adhesion between its edges and corners and the propellant binder matrix is ​​relatively weak, forming weak points in mechanical performance. Even small amounts of impurities and defects within the HMX itself inevitably have an adverse effect on mechanical properties. High-quality HMX is obtained by recrystallization and surface optimization treatment of ordinary HMX, and has the following advantages: ① regular morphology, near-spherical shape; ② controllable particle size, narrow distribution; ③ high purity, few impurities; ④ high crystal regularity, few internal crystal defects, high density, and high particle strength. Using HTPE-WPU to coat high-quality HMX significantly reduces its mechanical sensitivity and improves its thermal stability while maintaining energy levels. Introducing high-quality HMX coatings into cast modified double-base propellants can effectively avoid the mechanical and safety problems caused by ordinary HMX, and is an effective way to improve the microstructure integrity and mechanical properties of propellants.

[0034] This invention relates to a high-quality HMX@HTPE-WPU-coated spherical drug, comprising the following raw materials: high-quality octogen (HMX) and polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane (HTPE-WPU).

[0035] By weight percentage, it comprises the following raw materials: 98.0%–99.0% high-quality octogen and 1.0%–2.0% polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane. Preferably, it comprises 98.5% high-quality octogen and 1.5% polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane.

[0036] The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs according to the present invention includes:

[0037] (1) Preparation of demulsifier

[0038] ① Mix polyacrylamide (PAM) with deionized water at a mass ratio of 1:1000 and stir at 50°C until the polyacrylamide is completely dissolved;

[0039] ② The prepared polyacrylamide aqueous solution and polyethyleneimine (PEI) aqueous solution were mixed at a mass ratio of W(PEI):W(PAM) = 5:3, and stirred continuously at 300 r / min for 20 min at 50°C to obtain a mixed demulsifier.

[0040] (2) Demulsification method to encapsulate high-quality Octogen

[0041] ① Weigh out high-quality octogen (HMX) according to the formula, then weigh out polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane (HTPE-WPU) emulsion and add 100mL of deionized water to dilute it. Stir the high-quality octogen and the diluted polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane at room temperature for 1 hour to form suspension A.

[0042] ② Raise the temperature of suspension A from room temperature to 45℃, and slowly add 75g of mixed demulsifier solution at a rate of 1 drop / s. After the addition is completed, continue stirring at a stirring rate of 300r / min for 1h to avoid incomplete demulsification and form suspension B.

[0043] ③ Filter suspension B and wash it 5 times with deionized water to avoid demulsifier residue;

[0044] ④ Place the product obtained by vacuum filtration in a 50℃ water bath oven and dry it to constant weight to obtain high-quality HMX@HTPE-WPU.

[0045] The polyethylene glycol-tetrahydrofuran block copolymer ether-waterborne polyurethane (HTPE-WPU) emulsion (30% solid content) used in this invention was synthesized by Beijing Institute of Technology; high-quality octogen (HMX) was prepared by Xi'an Modern Chemistry Research Institute; and polyacrylamide (PAM) (cationic type) and polyethyleneimine (PEI) aqueous solution (nonionic type, 23.34% solid content) were provided by Ordnance Factory 845.

[0046] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0047] Example 1:

[0048] This embodiment provides a high-quality HMX@HTPE-WPU-coated spherical drug and its preparation method, including:

[0049] (1) Preparation of demulsifier

[0050] ① Mix PAM and deionized water at a mass ratio of 1:1000 and stir at 50°C until PAM is completely dissolved;

[0051] ② Mix the prepared PAM aqueous solution and PEI aqueous solution at a mass ratio of W(PEI):W(PAM) = 5:3, and stir continuously at 300 r / min for 20 min at 50℃ for later use.

[0052] (2) Demulsification method to encapsulate high-quality HMX-1

[0053] ① Weigh 10g of high-quality HMX-1, then weigh 0.5g of HTPE-WPU emulsion and add 100mL of deionized water to dilute it. Stir the high-quality HMX-1 and the diluted HTPE-WPU at room temperature for 1h to form suspension A.

[0054] Specifically, in this embodiment, HMX-1 has a regular shape, regular crystal size, a particle size distribution of 40μm-45μm, and an aspect ratio of 1.16;

[0055] ② Raise the temperature of suspension A from room temperature to 45℃, and slowly add 75g of mixed demulsifier solution at a rate of 1 drop / s. After the addition is completed, continue stirring at a stirring rate of 300r / min for 1h to avoid incomplete demulsification and form suspension B.

[0056] ③ Filter suspension B and wash it 5 times with deionized water to avoid demulsifier residue;

[0057] ④ Place the product obtained by vacuum filtration in a 50℃ water bath oven and dry it to constant weight to obtain high-quality HMX-1@HTPE-WPU.

[0058] Actual weight of HTPE-WPU = HTPE-WPU emulsion × solid content = 0.5g × 30% = 0.15g;

[0059] High-quality HMX percentage = 10 / (10+0.15)×100% = 98.5%;

[0060] HTPE-WPU mass percentage = 0.15 / (10+0.15)×100% = 1.5%.

[0061] Example 2:

[0062] This embodiment provides a high-quality HMX@HTPE-WPU-coated spherical drug and its preparation method. The preparation process of this embodiment is the same as that of Example 1, and high-quality HMX-2@HTPE-WPU is obtained. The difference is that the HMX-2 crystals in this embodiment are larger, more regular in shape, and have a uniform particle size than the HMX-1 crystals in Example 1. The particle size distribution is 60μm-75μm and the aspect ratio is 1.03.

[0063] To demonstrate the universality of HTPE-WPU coating with high-quality HMX, this invention uses two types of high-quality HMX from Examples 1 and 2 for verification; scanning electron microscope images of high-quality HMX-1@HTPE-WPU and high-quality HMX-2@HTPE-WPU are shown below. Figure 1 and 2 As shown, the rough surface of high-quality HMX particles indicates that the coating layer is evenly distributed on the surface of the high-quality HMX particles, and the coating effect is good.

[0064] The mechanical sensitivity of HMX, high-quality HMX and its coated samples was tested according to GJB 772A-97 method 601.1 (experimental conditions: 10kg drop weight, 250mm drop height, 50mg drug dosage). The test results are shown in Table 1.

[0065] Table 1 Impact Sensitivity Test Results

[0066] sample Impact sensitivity / % HMX 100 High-quality HMX-1 92 High-quality HMX-2 96 High-quality HMX-1@HTPE-WPU 56 High-quality HMX-2@HTPE-WPU 60

[0067] Thermal stability TG curves of high-quality HMX and high-quality HMX@HTPE-WPU are as follows: Figures 3 to 6 Compared with the thermal decomposition temperatures of high-quality HMX-1 and high-quality HMX-2 (291.4℃ and 291.5℃ respectively), high-quality HMX-1@HTPE-WPU and high-quality HMX-2@HTPE-WPU begin to lose weight at a higher temperature (291.8℃), indicating that the coating material effectively isolates the external heat source, slows down the thermal decomposition process, improves the thermal stability of high-quality HMX, and enhances safety.

Claims

1. A high-quality HMX@HTPE-WPU-coated spherical drug, characterized in that, By weight percentage, it includes the following raw materials: 98.0%~99.0% high-quality octogen, 1.0%~2.0% polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane; high-quality octogen is obtained by recrystallization and surface optimization treatment of ordinary HMX.

2. The high-quality HMX@HTPE-WPU-coated spherical drug as described in claim 1, characterized in that, By weight percentage, it includes the following raw materials: 98.5% high-quality Octogen, 1.5% polyethylene glycol polytetrahydrofuran block copolymer ether - waterborne polyurethane.

3. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs according to claim 1 or 2, characterized in that, Includes the following steps: Step 1, Preparation of demulsifier: Mix polyacrylamide with deionized water and stir until the polyacrylamide is completely dissolved to obtain an aqueous solution of polyacrylamide; mix the above aqueous solution of polyacrylamide with an aqueous solution of polyethyleneimine and stir to obtain a mixed demulsifier; Step 2, Demulsification method for high-quality octogen: Weigh high-quality octogen, weigh polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane emulsion and dilute with deionized water. Stir the high-quality octogen and diluted polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane at room temperature to form suspension A. Raise the temperature of suspension A from room temperature to 45°C, slowly add the mixed demulsifier solution, and continue stirring after the addition is complete to form suspension B. Filter suspension B and wash with deionized water to avoid demulsifier residue. Place the filtered product in a water bath oven and dry to constant weight to obtain high-quality HMX@HTPE-WPU.

4. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 3, characterized in that, Step one includes: Step 1.1: Mix polyacrylamide with deionized water and stir at 50°C until the polyacrylamide is completely dissolved; Step 1.2: Mix the prepared polyacrylamide aqueous solution with the polyethyleneimine aqueous solution, and stir continuously at 300 r / min for 20 min at 50°C to obtain a mixed demulsifier.

5. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 4, characterized in that, In step 1.1, polyacrylamide and deionized water are mixed at a mass ratio of 1:1000.

6. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 4, characterized in that, In step 1.2, the polyacrylamide aqueous solution and the polyethyleneimine aqueous solution are mixed at a mass ratio of W(PEI):W(PAM) = 5:

3.

7. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 3, characterized in that, Step two includes: Step 2.1: Weigh high-quality octogen according to the formula amount, then weigh polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane emulsion and dilute it with deionized water. Stir the high-quality octogen and the diluted polyethylene glycol polytetrahydrofuran block copolyether-waterborne polyurethane at room temperature for 1 hour to form suspension A. Step 2.2: Raise the temperature of suspension A from room temperature to 45°C, slowly add the mixed demulsifier solution, and continue stirring at a stirring rate of 300 r / min for 1 h after the addition is completed to avoid incomplete demulsification, so as to form suspension B; Step 2.3: Filter the suspension B and wash it 5 times with deionized water to avoid demulsifier residue; Step 2.4: Place the product obtained by vacuum filtration in a 50℃ water bath oven and dry it to constant weight to obtain high-quality HMX@HTPE-WPU.

8. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 7, characterized in that, In step 2.1, weigh 10g of high-quality octogen, weigh 0.5g of polyethylene glycol polytetrahydrofuran block copolymer ether-waterborne polyurethane emulsion and dilute it with 100mL of deionized water.

9. The method for preparing high-quality HMX@HTPE-WPU-coated spherical drugs as described in claim 7, characterized in that, In step 2.2, 75g of mixed demulsifier solution is slowly added at a rate of 1 drop / s.

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