Method for inducing generation of beta-type HMX crystal based on microfluidic technology
By combining microfluidic technology with LLM-105, β-crystal HMX crystals were prepared, solving the problem of HMX desensitization and achieving a balance between high energy and high sensitivity of HMX, thus preparing HMX coparticles with excellent desensitization properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-07
AI Technical Summary
Existing technologies struggle to desensitize HMX while maintaining its high energy level, especially during the preparation of HMX crystal forms. The limitations of the traditional desensitizing component TATB mean that HMX mainly exists in the metastable α crystal form, and there is a lack of methods to directly generate the β crystal form.
By using microfluidic technology and LLM-105 as a crystal form inducer, the solvent and non-solvent phases of HMX were mixed in a microfluidic reactor by controlling the temperature and flow rate ratio, and β-crystal HMX crystals were prepared.
The insensitivity properties of HMX crystals were improved. The prepared β-crystal HMX coparticles have a uniform crystal morphology and narrow particle size distribution, which significantly reduces mechanical sensitivity.
Smart Images
Figure CN121800737A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of energetic materials technology and relates to a method for inducing the generation of β-type HMX crystals based on microfluidic technology. Background Technology
[0002] Octogen (HMX) is one of the highest-energy high explosives among single compounds currently used in large-scale engineering applications. It possesses excellent detonation velocity (approximately 9100 m / s) and heat of detonation, along with a high thermal decomposition temperature and good chemical stability, meeting the application requirements of various harsh environments. It is a key component in the preparation of high-performance hybrid explosives and propellants. However, HMX is relatively sensitive to external mechanical stimuli (such as impact and friction), and its impact sensitivity (H...) is... 50 HMX (typically below 30 cm) has significantly higher sensitivity than insensitive explosives such as TATB, posing significant safety risks during production, transportation, storage, and use. The contradiction between "high energy" and "high sensitivity" is the core bottleneck restricting its wider application. Therefore, insensitive modification of HMX while maintaining its high energy level as much as possible has become a crucial and urgent research goal in the field of energetic materials.
[0003] TATB is one of the most insensitive explosives known. Its combination with high-energy but sensitive HMX to form coparticles has been shown to significantly reduce the mechanical sensitivity of HMX while preserving its energy properties. Current literature largely focuses on the macroscopic performance output of the composite particles, such as the degree of sensitivity reduction, thermal decomposition behavior, and detonation performance, while generally neglecting a more fundamental and crucial scientific question in the coparticle formation process—the regulatory effect of the insensitive agent on the crystal structure of HMX itself. Although HMX exists in various crystal forms such as α, β, γ, and δ, and different crystal forms have significant differences in sensitivity, density, and stability, the two fundamental questions—which crystal form HMX exists in the coparticle and how the insensitive agent affects the crystal form selection of HMX—have been largely unresolved and unexplored in existing studies of other composite systems. Previous research by our group revealed that while microfluidic technology can continuously prepare TATB / HMX coparticles, HMX mainly exists in a metastable α-crystalline form. To obtain the β-crystalline form, additional post-processing steps such as mechanical stirring of the initial product are necessary (Zhang, 2023, Microfluidic Preparation of Micro / Nano TATB and TATB / HMX Composite Energetic Materials). This reveals the limitations of the traditional insensitive component TATB in inducing stable HMX crystal forms, and also highlights the urgent need to develop new insensitive components and processes that can directly generate β-HMX-based coparticles in one step. Summary of the Invention
[0004] The purpose of this invention is to provide a method for inducing the generation of β-type HMX crystals based on microfluidic technology. This method utilizes microfluidic technology and LLM-105 as a crystal form inducer to induce efficient crystal transformation of HMX in a composite system, thereby preparing HMX with a β-crystal structure.
[0005] The technical solution for achieving the objective of this invention is as follows:
[0006] A method for inducing the generation of β-type HMX crystals based on microfluidic technology includes the following steps:
[0007] The temperature of the microfluidic reactor was controlled at 30~50℃. The solvent phase and non-solvent phase containing LLM-105 and HMX were continuously pumped into the microfluidic reactor through a feed pump for mixing and crystallization. The effluent was then filtered, washed, and freeze-dried to obtain LLM-105 / HMX energetic coparticles with β-type HMX crystals.
[0008] Furthermore, the solvent phase containing LLM-105 and HMX is a solvent capable of dissolving LLM-105 and HMX, such as dimethyl sulfoxide (DMSO).
[0009] Furthermore, the non-solvent phase is a poor solvent for LLM-105 and HMX, such as water.
[0010] Furthermore, the temperature of the microfluidic reactor is 40°C.
[0011] Furthermore, the flow rate ratio of the solvent phase containing LLM-105 and HMX to the non-solvent phase is 1:2~6, and the total flow rate is 30~50 mL / min.
[0012] Furthermore, the flow rate of the non-solvent phase is 5.7–16.7 mL / min, and the flow rate of the solvent phase is 20–34.3 mL / min.
[0013] Furthermore, the mass ratio of LLM-105 to HMX is 1:5 to 1:15, preferably 1:9.
[0014] Furthermore, in the solvent phase containing LLM-105 and HMX, the concentrations of LLM-105 and HMX are 4 g / mL.
[0015] Compared with the prior art, the present invention has the following advantages:
[0016] (1) The present invention uses a microfluidic platform to realize continuous preparation, safe preparation of small doses, easy adjustment of conditions, and greatly optimizes the efficiency of process development.
[0017] (2) This invention is the first to utilize microfluidic technology and use LLM-105 as a crystal form inducer to prepare LLM-105 / HMX energetic coparticles in which the HMX component exists in the β crystal form. These coparticles benefit from the instantaneous and uniform mixing in the microchannel, have the characteristics of uniform crystal morphology and narrow particle size distribution, and exhibit excellent insensitivity properties. Attached Figure Description
[0018] Figure 1 The images are SEM images of the LLM-105 / HMX coparticles in Example 1, where (a) is an LLM-105 / HMX coparticle and (b) is a magnified view of the LLM-105 / HMX coparticles.
[0019] Figure 2 The image shows the XRD pattern of the LLM-105 / HMX coparticles in Example 1.
[0020] Figure 3 The image shows the XRD pattern of the TATB / HMX coparticles in Comparative Example 1.
[0021] Figure 4 SEM images of LLM-105 / HMX for Comparative Examples 2(a), 3(b), 4(c), and 5(d). Detailed Implementation
[0022] The present invention will now be described in further detail with reference to its embodiments and accompanying drawings. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.
[0023] Example 1
[0024] (1) Preparation of precursor solution: Accurately weigh 0.2g of LLM-105 and 1.8g of HMX, dissolve them together in 50mL of DMSO, and sonicate in a 50℃ water bath until completely dissolved to obtain a clear and transparent precursor solution.
[0025] (2) System temperature control: Connect the microfluidic reactor to the high and low temperature circulation device and set the temperature of the reaction zone to 40℃.
[0026] (3) Set fluid parameters: Set the feed flow rate of the precursor solution to 13.3 mL / min and the feed flow rate of the deionized water to 26.7 mL / min, that is, the total flow rate is 40 mL / min and the flow rate ratio is 1:2.
[0027] (4) Continuous reaction and product collection: The two fluids mentioned above are steadily pumped into the microfluidic reactor through the feed pump. After the fluid at the outlet stabilizes, the reaction suspension is collected.
[0028] (5) Post-processing: The collected suspension was filtered, the filter cake was washed three times with deionized water, and then freeze-dried to obtain the final product LLM-105 / HMX coparticles.
[0029] Characterization of the product revealed the formation of uniform, spherical particles in its SEM images (see [link]). Figure 1 XRD patterns (see) Figure 2 This confirms that the HMX component in the LLM-105 / HMX coparticles exists in the β crystal form.
[0030] Example 2
[0031] This embodiment is largely the same as Example 1, except that in step (3), the flow rate of the precursor solution is 10 mL / min and the flow rate of the deionized water is 20 mL / min, that is, the total flow rate is 30 mL / min. The XRD pattern also confirms that its HMX is β crystal form.
[0032] Example 3
[0033] This embodiment is largely the same as Example 1, except that in step (3), the flow rate of the precursor solution is 16.7 mL / min and the flow rate of the deionized water is 33.3 mL / min, that is, the total flow rate is 50 mL / min. The XRD pattern also confirms that its HMX is β crystal form.
[0034] Example 4
[0035] This embodiment is largely the same as embodiment 1, except that: in step (3), the flow rate of the precursor solution is 8 mL / min and the flow rate of the deionized water is 32 mL / min, that is, the flow rate ratio is 1:4.
[0036] Example 5
[0037] This embodiment is largely the same as embodiment 1, except that: in step (3), the flow rate of the precursor solution is 5.7 mL / min and the flow rate of the deionized water is 34.3 mL / min, that is, the flow rate ratio is 1:6.
[0038] Example 6
[0039] This embodiment is largely the same as Embodiment 1, except that the temperature of the reaction zone is set to 30°C in step (2).
[0040] Example 7
[0041] This embodiment is largely the same as Embodiment 1, except that the temperature of the reaction zone is set to 50°C in step (2).
[0042] Comparative Example 1
[0043] This comparative example is largely the same as Example 1, except that the desensitizing agent LLM-105 is replaced with TATB in step (1).
[0044] The obtained TATB / HMX coparticles were subjected to XRD analysis, and their spectra (see [reference]). Figure 3 The results clearly show that the HMX component in the coparticles exists in the α-crystalline form. As can be seen from Example 1 and Comparative Example 1, under the same microfluidic conditions, different desensitizing agents have drastically different inducing effects on the HMX crystalline form.
[0045] Comparative Example 2
[0046] This comparative example is largely the same as Example 1, except that the total flow rate is 20 mL / min. Its SEM image (see [link to example]). Figure 4 a) Clearly, the morphology of LLM-105 / HMX is distinctly sheet-like.
[0047] Comparative Example 3
[0048] This comparative example is largely the same as Example 1, except that the total flow rate is 60 mL / min. Its SEM images are shown below. Figure 4 b.
[0049] Comparative Example 4
[0050] This comparative example is largely the same as Example 1, except that the temperature is 20°C. Its SEM image is shown below. Figure 4 c.
[0051] Comparative Example 5
[0052] This comparative example is largely the same as Example 1, except that the temperature is 60°C. Its SEM image is shown below. Figure 4 d.
[0053] Performance testing:
[0054] Impact sensitivity tests (characteristic drop height H) were performed on the products obtained in Examples 1-5 and Comparative Example 1. 50 The test results were summarized in Table 1, using raw material HMX as a reference.
[0055] Table 1
[0056] Serial Number Material Name Drop weight (kg) Sensitivity height (cm) 1 LLM-105 / HMX (Example 1) 5 55-60 2 LLM-105 / HMX (Example 2) 5 50-55 3 LLM-105 / HMX (Example 3) 5 45-50 4 LLM-105 / HMX (Example 4) 5 45-50 5 LLM-105 / HMX (Example 5) 5 50-55 6 LLM-105 / HMX (Example 6) 5 50-55 7 LLM-105 / HMX (Example 7) 5 50-55 8 TATB / HMX (Comparative Example 1) 5 60-65 9 LLM-105 / HMX (Comparative Example 2) 5 40-45 10 LLM-105 / HMX (Comparative Example 3) 5 40-45 11 LLM-105 / HMX (Comparative Example 4) 5 35-40 12 LLM-105 / HMX (Comparative Example 5) 5 40-45 13 HMX raw materials 5 15
[0057] As shown in Table 1, the impact sensitivity of the LLM-105 / HMX coparticles with β-type HMX prepared in Examples 1 to 5 is significantly lower than that of the raw material HMX, exhibiting excellent insensitivity characteristics. Although the TATB / HMX (α-type) cocrystal in Comparative Example 1 also achieved insensitivity, its sensitivity is significantly better than that of the LLM-105 / HMX coparticles with β-type HMX.
Claims
1. A method for inducing the generation of β-type HMX crystals based on microfluidic technology, characterized in that, Includes the following steps: The temperature of the microfluidic reactor was controlled at 30~50℃. The solvent phase and non-solvent phase containing LLM-105 and HMX were continuously pumped into the microfluidic reactor through a feed pump for mixing and crystallization. The effluent was then filtered, washed, and freeze-dried to obtain LLM-105 / HMX energetic coparticles with β-type HMX crystals.
2. The method according to claim 1, characterized in that, The solvent phase containing LLM-105 and HMX uses DMSO as the solvent, and the non-solvent phase is water.
3. The method according to claim 1, characterized in that, The temperature of the microfluidic reactor is 40℃.
4. The method according to claim 1, characterized in that, The flow rate ratio of the solvent phase to the non-solvent phase containing LLM-105 and HMX is 1:2~6, and the total flow rate is 30~50 mL / min.
5. The method according to claim 1, characterized in that, The flow rate of the non-solvent phase was 5.7–16.7 mL / min, and the flow rate of the solvent phase was 20–34.3 mL / min.
6. The method according to claim 1, characterized in that, The mass ratio of LLM-105 to HMX is 1:5 to 1:
15.
7. The method according to claim 1, characterized in that, The mass ratio of LLM-105 to HMX is 1:
9.
8. The method according to claim 1, characterized in that, In the solvent phase containing LLM-105 and HMX, the concentration of LLM-105 and HMX is 4 g / mL.