High-quality HMX-coated EWPU coated spherical medicine

Abstract

The invention discloses a high-quality HMX-coated EWPU (Ethylene Wolfram Polyurethane) coated spherical drug. The high-quality HMX-coated EWPU coated spherical drug is prepared from the following raw materials: 98.0 percent to 99.0 percent of high-quality HMX and 1.0 percent to 2.0 percent of glycidyl azide polymer waterborne polyurethane. The impact sensitivity of the high-quality HMX-coated EWPU coated spherical powder is reduced to 40%, the intrinsic safety of a casting modified double-base propellant is remarkably improved, and the high-quality HMX-coated EWPU coated spherical powder is suitable for preparing the casting modified double-base propellant.

Description

Technical Field

[0001] The invention relates to an Octogen (HMX) coated ball, which is mainly used for manufacturing a casting modified double-base propellant. Background Art

[0002] HMX is a nitramine explosive with excellent comprehensive performance. It has the advantages of high energy, high density, and high detonation velocity. As a high energy density material, it is widely used in the formulation of cast modified double-base propellants. However, in order to improve the energy level of cast modified double-base propellants, increasing the HMX content and reducing the binder content in the propellant formula will inevitably lead to a decrease in the mechanical properties of the propellant. At the same time, as a non-reinforcing filler, HMX has a poor interface bonding effect between the particle surface and the binder, and is prone to similar "dehumidification" phenomena, which is a weak link in the mechanical properties of the propellant. Therefore, enhancing the interfacial bonding strength between the solid filler particles and the binder is one of the technical approaches to improve the mechanical properties of cast modified double-base propellants.

[0003] HMX is usually surface modified and coated to reduce its mechanical sensitivity. "Study on in-situ coating of HMX with TATB" Energetic Materials, 2006, 14(5): 330-332. A method for in-situ generation of TATB-coated HMX using sonochemical synthesis is proposed. When the TATB content is 9.5%, compared with the sample prepared by the blending method, the impact sensitivity of the in-situ coated HMX@TATB is reduced from 64% to 24%, and the friction sensitivity is reduced from 8% to 0%, showing a good desensitization effect. "Study on the Desensitization of NTO-coated HMX" Journal of Explosives and Propellants, 2014, 37(1): 61-65. A strategy of coating HMX with 3-nitro-1,2,4-triazol-5-one (NTO) by solution recrystallization is reported. Compared with HMX, the friction sensitivity of 20% NTO-coated HMX is reduced from 100% to 50%, and the impact sensitivity is reduced from 100% to 50%. 50 From 22.4cm to 37.2cm. "Study on the coating modification of HMX by polyacrylate" Initiators, 2015, 167(6): 40-43. A solution-water suspension method was reported to use polyacrylate or fluororubber as the coating agent to achieve the coating modification of HMX. 2% fluororubber-HMX coated ball impact sensitivity H 50 40.2cm, 2% polyacrylate-HMX coated ball impact sensitivity H 50 The coating of HMX with TEX was 53.5 cm. Journal of Explosives and Propellants, 2018, 14(4): 394-398. A solution-water suspension coating method was reported using 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0 5,9 .0 3,11](TEX) and fluororubber coated HMX desensitization method. The impact sensitivity of 3% fluororubber coated HMX is 92%, and the friction sensitivity is 100%. "Friction properties of HMX coated with different adhesives" Science, Technology and Engineering, 2018, 18(29): 206-210. It is reported that the direct method was used to reduce the sensitivity of 6 adhesives (fluororubber, 202 rubber, butadiene rubber, GAP-ETPE, EVA, 68 # However, there is no public report on the research of coating high-quality HMX with polyazide glycidyl waterborne polyurethane (EWPU) to reduce its mechanical sensitivity. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high-quality HMX@EWPU coated spherical propellant to solve the problems of high mechanical sensitivity and poor safety of high-quality HMX in the prior art; to reduce its mechanical sensitivity and improve the intrinsic safety of the cast modified bipropellant.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] A high-quality HMX@EWPU coated spherical medicine comprises the following raw materials: high-quality octogen and polyazide glycidyl waterborne polyurethane.

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

[0008] Specifically, the raw materials include, by mass percentage, 98.0% to 99.0% of high-quality Octogen and 1.0% to 2.0% of polyazide glycidyl waterborne polyurethane.

[0009] Specifically, the raw materials include the following by mass percentage: 98.5% of high-quality Octogen and 1.5% of polyazide glycidyl waterborne polyurethane.

[0010] The method for preparing the high-quality HMX@EWPU coated spherical medicine comprises the following steps:

[0011] Step 1, prepare demulsifier:

[0012] Step 1.1, polyacrylamide and deionized water are mixed at a mass ratio of 1:1000, and stirred at 50°C until the polyacrylamide is completely dissolved;

[0013] Step 1.2, the prepared polyacrylamide aqueous solution and the polyethyleneimine aqueous solution are mixed in a mass ratio of W(PEI):W(PAM)=5:3, and stirred at 50°C at a stirring rate of 300 r / min for 20 minutes to obtain a demulsifier;

[0014] Step 2: Demulsification method to coat high quality HMX:

[0015] Step 2.1, weighing high-quality octogen, weighing polyazido glycidyl waterborne polyurethane emulsion and adding 100 mL of deionized water to dilute, stirring the high-quality octogen and the diluted polyazido glycidyl waterborne polyurethane at room temperature for 1 hour to form a suspension A;

[0016] Step 2.2, raising the temperature of suspension A from room temperature to 45°C, slowly adding 75 g of demulsifier solution at a rate of 1 drop / s, and continuing stirring at a stirring rate of 300 r / min for 1 h to avoid incomplete demulsification, to form suspension B;

[0017] Step 2.3, the suspension B is filtered and washed with deionized water for 5 times to avoid residual demulsifier;

[0018] In step 2.4, the product obtained by filtration is placed in a 50°C water bath oven and dried to constant weight to obtain high-quality HMX@EWPU.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] The coating material used for surface modification of high-quality Octogen particles in the present invention is polyazide glycidyl waterborne polyurethane, and the prepared coated spherical propellant has a high energy level; compared with ordinary HMX and high-quality HMX, the impact sensitivity of high-quality HMX@EWPU is reduced to 40%, thereby improving the intrinsic safety of the cast modified double-base propellant. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a high-quality scanning electron microscope photo of HMX-1@EWPU.

[0022] Figure 2 This is a high-quality scanning electron microscope photo of HMX-2@EWPU. DETAILED DESCRIPTION

[0023] The present invention provides a high-quality HMX@EWPU coated spherical propellant. The inventive concept is that HMX, as a non-reinforcing filler, has high mechanical sensitivity and is crucial to the mechanical properties and safety performance of cast modified double-base propellants. Ordinary HMX has an irregular shape, and the edge corners are relatively weakly bonded to the propellant adhesive matrix, forming a weak point in mechanical performance. Its own small amount of impurities and defects will inevitably have an adverse effect on the mechanical properties. High-quality HMX is obtained by recrystallization and surface optimization treatment of ordinary HMX, and has the following advantages: ① Regular morphology, quasi-spherical; ② Controllable particle size, narrow distribution; ③ High purity, few impurities; ④ High crystal regularity, few internal defects of the crystal, high density, and high particle strength. Using EWPU ​​to coat high-quality HMX can greatly reduce the mechanical sensitivity of high-quality HMX while maintaining the energy level. Introducing coated high-quality HMX into cast modified double-base propellants can effectively avoid the problems of mechanical and safety characteristics brought by ordinary HMX, and is an effective way to improve the microstructural integrity and mechanical properties of propellants.

[0024] The high-quality HMX@EWPU provided by the present invention has the following mass percentage composition: 98.0% to 99.0% of high-quality octogenin and 1.0% to 2.0% of polyazide glycidyl waterborne polyurethane.

[0025] The preferred ratio is: 98.5% of high-quality Octogen and 1.5% of polyazide glycidyl waterborne polyurethane.

[0026] The preparation method of high-quality HMX@EWPU coated spherical medicine comprises the following steps:

[0027] Step 1, prepare demulsifier:

[0028] Step 1.1, polyacrylamide and deionized water are mixed at a mass ratio of 1:1000, and stirred at 50°C until the polyacrylamide is completely dissolved;

[0029] Step 1.2, the prepared polyacrylamide aqueous solution and the polyethyleneimine aqueous solution are mixed in a mass ratio of W(PEI):W(PAM)=5:3, and stirred at 50°C at a stirring rate of 300 r / min for 20 minutes to obtain a demulsifier;

[0030] Step 2: Demulsification method to coat high quality HMX:

[0031] Step 2.1, weighing high-quality octogen, weighing polyazido glycidyl waterborne polyurethane emulsion and adding 100 mL of deionized water to dilute, stirring the high-quality octogen and the diluted polyazido glycidyl waterborne polyurethane at room temperature for 1 hour to form a suspension A;

[0032] Step 2.2, raising the temperature of suspension A from room temperature to 45°C, slowly adding 75 g of demulsifier solution at a rate of 1 drop / s, and continuing stirring at a stirring rate of 300 r / min for 1 h to avoid incomplete demulsification, to form suspension B;

[0033] Step 2.3, the suspension B is filtered and washed with deionized water for 5 times to avoid residual demulsifier;

[0034] In step 2.4, the product obtained by filtration is placed in a 50°C water bath oven and dried to constant weight to obtain high-quality HMX@EWPU.

[0035] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0036] The polyazide glycidyl waterborne polyurethane (EWPU) (M n =24700 g·mol -1 , solid content of 30%, pH value 7.52) was synthesized by Beijing Institute of Technology; high-quality HMX was prepared by Xi'an Institute of Modern Chemistry; polyacrylamide (PAM) (cationic) and polyethyleneimine (PEI) aqueous solutions (non-ionic, solid content of 23.34%) were provided by Ordnance Factory 845.

[0037] Embodiment 1:

[0038] This embodiment provides a method for preparing high-quality HMX@EWPU coated spherical medicine, comprising:

[0039] (1) Preparation of demulsifier

[0040] ① Mix PAM and deionized water at a mass ratio of 1:1000 and stir at 50°C until PAM is completely dissolved;

[0041] ② The prepared PAM aqueous solution and PEI aqueous solution were mixed in a mass ratio of W(PEI):W(PAM)=5:3, and stirred at 50°C at a stirring rate of 300 r / min for 20 min for use.

[0042] (2) Demulsification method to coat high quality HMX-1

[0043] ① Weigh 10g of high-quality HMX-1, weigh 0.5g of EWPU ​​emulsion and add 100mL of deionized water to dilute it, stir the high-quality HMX-1 and the diluted EWPU ​​at room temperature for 1h to form a suspension A; wherein, the actual weighing value of EWPU ​​in 0.5g of EWPU ​​emulsion = EWPU ​​emulsion × solid content = 0.5g × 30% = 0.15g, and the corresponding mass percentage of 10g of high-quality HMX-1 is 98.5%, and the mass percentage of EWPU ​​is 1.5%;

[0044] ② Raise the temperature of suspension A from room temperature to 45°C, slowly add 75g of mixed demulsifier solution at a rate of 1 drop / s, and continue stirring at a stirring rate of 300r / min for 1h after the addition is completed to avoid incomplete demulsification, forming suspension B;

[0045] ③ Filter the suspension B and wash it with deionized water 5 times to avoid residual demulsifier;

[0046] ④ Place the product obtained by filtration in a 50°C water bath oven and dry to constant weight to obtain high-quality HMX-1@EWPU.

[0047] Embodiment 2:

[0048] This embodiment provides a method for preparing high-quality HMX@EWPU coated spherical medicine. This embodiment uses high-quality HMX-2, and the manufacturing method is the same as that of Example 1.

[0049] In order to prove the universality of EWPU ​​coated high-quality HMX, the present invention uses two high-quality HMX for verification:

[0050] HMX-1 has regular shape and regular crystal size, with a particle size distribution of 40μm-45μm and an aspect ratio of 1.16;

[0051] Compared with HMX-1, HMX-2 has larger crystal particles, regular shape, uniform particle size, particle size distribution in the range of 60μm-75μm, and aspect ratio of 1.03.

[0052] SEM photos of high-quality HMX-1@EWPU and high-quality HMX-2@EWPU are shown below: Figure 1 and 2 The surface of high-quality HMX particles is rough, indicating that the coating layer is evenly distributed on the surface of high-quality HMX particles and the coating effect is good.

[0053] The mechanical sensitivity of HMX, high-quality HMX and its coated samples were tested according to GJB 772A-97 method 601.1 (experimental conditions: 10 kg drop hammer, 250 mm drop height, 50 mg drug amount). The test results are shown in Table 1.

[0054] Table 1 Impact sensitivity test results

[0055] sample Impact sensitivity / % HMX 100 High quality HMX-1 92 High quality HMX-2 96 High quality HMX-1@EWPU 40 High quality HMX-2@EWPU 56

Claims

1. A high-quality HMX@EWPU coated spherical medicine, characterized in that: Includes the following raw materials: high-quality Octogen and polyazide glycidyl water-based polyurethane.

2. The high-quality HMX@EWPU coated spherical medicine according to claim 1, characterized in that: Calculated by mass percentage, the raw materials include: 98.0% to 99.0% of high-quality Octogen and 1.0% to 2.0% of polyazide glycidyl waterborne polyurethane.

3. The high-quality HMX@EWPU coated spherical medicine according to claim 1, characterized in that: Calculated by mass percentage, the raw materials include: 98.5% of high-quality Octogen and 1.5% of polyazide glycidyl waterborne polyurethane.

4. The method for preparing high-quality HMX@EWPU coated spherical medicine according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, prepare demulsifier: Step 1.1, polyacrylamide and deionized water are mixed at a mass ratio of 1:1000, and stirred at 50°C until the polyacrylamide is completely dissolved; Step 1.2, the prepared polyacrylamide aqueous solution and the polyethyleneimine aqueous solution are mixed in a mass ratio of W(PEI):W(PAM)=5:3, and stirred at 50°C at a stirring rate of 300 r / min for 20 minutes to obtain a demulsifier; Step 2: Demulsification method to coat high quality HMX: Step 2.1, weighing high-quality octogen, weighing polyazido glycidyl waterborne polyurethane emulsion and adding 100 mL of deionized water to dilute, stirring the high-quality octogen and the diluted polyazido glycidyl waterborne polyurethane at room temperature for 1 hour to form a suspension A; Step 2.2, raising the temperature of suspension A from room temperature to 45°C, slowly adding 75 g of demulsifier solution at a rate of 1 drop / s, and continuing stirring at a stirring rate of 300 r / min for 1 h to avoid incomplete demulsification, to form suspension B; Step 2.3, the suspension B is filtered and washed with deionized water for 5 times to avoid residual demulsifier; In step 2.4, the product obtained by filtration is placed in a 50°C water bath oven and dried to constant weight to obtain high-quality HMX@EWPU.

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