A method for characterizing eutectic content in CL-20 / HMX eutectic process
Determining the characteristic peak strength ratio of CL-20/HMX eutectic samples through FTIR technology, solving the problem of difficulty in quantitative characterization in the prior art, and achieving accurate analysis and simple operation of CL-20/HMX eutectic content, demonstrating that Features of wider applicability and lower complexity.
Patent Information
- Application Number
- CN202210392783.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-15
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2042-04-15
AI Technical Summary
Existing methods are difficult to accurately characterize the content of CL-20/HMX eutectics, especially in the analysis of the slight differences between its properties and monomers.
Using FTIR technology, the characteristic peak intensity ratio of CL-20/HMX eutectic samples was determined by the FTIR method through sample preparation, testing and data analysis steps, and the characteristic peak intensity of the CL-20/HMX eutectic samples were calculated, and quantitative analysis was performed based on the characteristic peak intensity of the internal standard.
The accurate characterization of the CL-20/HMX eutectic content is achieved, which is simple to operate and has a wider applicability and lower complexity compared with the XRD method.
Smart Images
Figure CN114778479B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of crystal content determination, and in particular to a method for characterizing eutectic content in a CL-20 / HMX eutectic process. Background Art
[0002] CL-20 / HMX eutectic (n CL-20 :n HMX =2:1) The density at room temperature is 1.945 g·cm -3 , oxygen balance is 7.97% higher than β-HMX, theoretical detonation velocity is 100m·s higher than β-HMX -1 The impact sensitivity is lower than ε-CL-20 and equivalent to β-HMX, and it is expected to become an effective substitute for CL-20 in the field of energetic materials.
[0003] There are many methods for preparing CL-20 / HMX eutectics, including solvent evaporation, solvent-antisolvent method, ball milling, acoustic resonance mixing method, etc. During the preparation process, the difference in properties between CL-20 / HMX eutectics and CL-20 and HMX can be used to qualitatively analyze whether CL-20 / HMX eutectics are formed.
[0004] At present, the commonly used analysis methods are: according to the different morphologies, SEM, microscope, etc. can clearly distinguish the morphology of CL-20 / HMX eutectic (rectangular shape) and CL-20 (spindle shape) and HMX (prismatic shape); according to the different crystal structures, XRD can be used to measure the characteristic peaks of CL-20 / HMX eutectic at 11.1°, 11.8°, and 13.5° that are obviously different from CL-20 and HMX; according to the different thermal properties, DSC can be used to measure that the thermal decomposition peak temperature of CL-20 / HMX eutectic is lower than the thermal decomposition peak temperature of CL-20 and HMX. Summary of the invention
[0005] One purpose of this project is to provide a method for characterizing the eutectic content in the CL-20 / HMX eutectic process.
[0006] To achieve the above objectives, this plan is as follows:
[0007] A method for quantitative characterization of eutectic in a CL-20 / HMX eutectic process, the method comprising the following steps:
[0008] 1. Sample preparation: ε-CL-20 and β-HMX were mixed evenly to prepare samples with different CL-20 / HMX eutectic contents;
[0009] 2. Test: FTIR test was performed on samples with different CL-20 / HMX eutectic contents;
[0010] 3. Data analysis: After removing the baseline, plot the peak intensity ratio versus time curve and calculate the CL-20 / HMX eutectic content.
[0011] Preferably, the internal standard is -NO2.
[0012] Preferably, the CL-20 / HMX eutectic content is calculated by the relative content of the FTIR characteristic peak intensities of the standard CL-20 / HMX eutectic and the internal standard itself and the content of the internal standard.
[0013] Preferably, the characteristic peak of CL-20 / HMX eutectic is at 718 cm -1 The characteristic peak of ε-CL-20 is at 723cm -1 The characteristic peak of the internal standard is at 1606cm -1 Place.
[0014] The beneficial effects of this program are as follows:
[0015] 1. Can be used to quantitatively characterize CL-20 / HMX eutectic;
[0016] 2. Easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the implementation of the present scheme, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present scheme. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 It is a flow chart of the characterization method operation in the embodiment;
[0019] Figure 2 FTIR test graphs of mixtures of different CL-20 / HMX eutectic mass fractions prepared in Example;
[0020] Figure 3 CL-20 / HMX eutectic (718 cm -1 ) / -NO2(1606cm -1 )、CL-20(718cm -1 ) / -NO2(1606cm -1 ) The ratio of characteristic peak intensity (normalized) varies with the mass fraction of CL-20 / HMX eutectic;
[0021] Figure 4 FTIR test graphs at different times during the preparation of CL-20 / HMX eutectic in the embodiment;
[0022] Figure 5CL-20 / HMX eutectic (718 cm) during eutectic preparation in Example -1 ) / -NO2(1606cm -1 ) The ratio of characteristic peak intensities (normalized) changes over time;
[0023] Figure 6 This is a graph showing the change in CL-20 / HMX eutectic content (normalized) over time during the eutectic preparation process in the example. DETAILED DESCRIPTION
[0024] The implementation method of this solution is further described in detail below. Obviously, the described embodiments are only part of the embodiments of this solution, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of this solution can be combined with each other without conflict.
[0025] The inventors of the present application have found that the strong characteristic of the absorption peak in the fingerprint region of infrared spectroscopy can distinguish the slight differences in the structures of different compounds. In the CL-20 / HMX eutectic, CL-20 and HMX have intermolecular interactions such as hydrogen bonds, and the molecular structures of CL-20 and HMX are different from those of ε-CL-20 and β-HMX. Therefore, the difference in the absorption peak in the fingerprint region of CL-20 / HMX eutectic relative to CL-20 and HMX can be measured using the FTIR method.
[0026] Compared with the XRD method, the FTIR method has the following advantages:
[0027] 1. Low difficulty. Rietveld refinement of XRD data requires a relatively accurate initial model, and requires the selection of appropriate peak shape parameters, instrument parameters, and background functions. The calculation process is complicated. The FTIR method only requires the removal of the baseline and the calculation of the peak intensity.
[0028] 2. Wide application range. Rietveld refinement of XRD data requires a relatively simple system. A complex system with multiple phases will greatly increase the difficulty of refinement, increase the refinement time, and reduce the accuracy. In the FTIR method, other phases have no effect on the key characteristic peaks, and have no significant effect on the calculation process and results.
[0029] The inventors of the present application provide a method for characterizing the eutectic content in a CL-20 / HMX eutectic process, comprising the following steps:
[0030] 1. Sample preparation: ε-CL-20 and β-HMX were mixed evenly to prepare samples with different CL-20 / HMX eutectic contents;
[0031] 2. Test: FTIR test was performed on samples with different CL-20 / HMX eutectic contents;
[0032] 3. Data analysis: After removing the baseline, plot the peak intensity ratio versus time curve and calculate the CL-20 / HMX eutectic content.
[0033] The present application is described below through specific embodiments.
[0034] This example is described using a sample containing CL-20 / HMX eutectic.
[0035] like Figure 1 As shown, a method for characterizing the eutectic content in a CL-20 / HMX eutectic process comprises the following steps:
[0036] 1. Standard CL-20 / HMX eutectic, ε-CL-20, β-HMX (n CL-20 :n HMX =2:1) and mixed evenly to prepare a sample with a CL-20 / HMX eutectic mass fraction of 0% to 100%;
[0037] 2. Take out the CL-20 / HMX eutectic sample and perform FTIR test. The test results are as follows: Figure 2 and Figure 4 As shown;
[0038] 3. Draw the CL-20 / HMX eutectic (718cm -1 ) / -NO2(1606cm -1 )、CL-20(723cm -1 ) / -NO2(1606cm -1 ) The characteristic peak intensity ratio varies with the CL-20 / HMX eutectic content standard curve. The standard curve is as follows: Figure 3 As shown,
[0039] The CL-20 / HMX eutectic (718 cm -1 ) / -NO2(1606cm -1 ) Relationship curve between the ratio of characteristic peak intensity y1 and the CL-20 / HMX eutectic content x:
[0040] y1=0.0046x+0.55, r=0.99, CL-20(723cm -1 ) / -NO2(1606cm -1 )
[0041] CL-20 / HMX eutectic (718cm -1 ) / -NO2(1606cm -1 ) Relationship curve between the ratio of characteristic peak intensity y2 and the CL-20 / HMX eutectic content x:
[0042] y2=-0.0052x+1.06, r=-0.98,
[0043] That is, the peak intensity ratio is linearly related to the CL-20 / HMX eutectic content, such as Figure 5 As shown, the peak intensity ratio can be used to determine the CL-20 / HMX eutectic content. Figure 6 .
[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.
Claims
1. A method for characterizing eutectic content in a CL-20 / HMX eutectic process, characterized in that the method comprises the following steps:
1. Sample preparation: ε-CL-20 and β-HMX were mixed evenly to prepare samples with different CL-20 / HMX eutectic contents; 2. Test: FTIR test was performed on samples with different CL-20 / HMX eutectic contents; 3. Data analysis: After removing the baseline, plot the peak intensity ratio versus time curve and calculate the CL-20 / HMX eutectic content, including: Drawing of CL-20 / HMX eutectic (718cm -1 ) / -NO2(1606cm -1 ) characteristic peak intensity ratio with CL-20 / HMX eutectic content standard curve, and obtain CL-20 / HMX eutectic (718cm -1 ) / -NO2(1606cm -1 ) Relationship curve between the ratio of characteristic peak intensity y2 and the CL-20 / HMX eutectic content x: y2=0.0046x+0.55,r=0.99; Furthermore, a curve of the change of CL-20 / HMX eutectic content x with reaction time t was plotted: x=0.19t-1.14, r=0.
99.
2. The method for characterizing eutectic content in the CL-20 / HMX eutectic process according to claim 1, characterized in that: The internal standard is -NO2.
3. The method for characterizing eutectic content in the CL-20 / HMX eutectic process according to claim 1, characterized in that: The CL-20 / HMX eutectic content was calculated by the relative content of the FTIR characteristic peak intensities of the standard CL-20 / HMX eutectic and the internal standard itself and the content of the internal standard.
4. The method for characterizing eutectic content in the CL-20 / HMX eutectic process according to claim 1, characterized in that: The characteristic peak of CL-20 / HMX eutectic is at 718 cm -1 The characteristic peak of ε-CL-20 is at 723cm -1 The characteristic peak of the internal standard is at 1606cm -1 Place.