A method for improving the performance of solid propellants using 5,10,15,20-tetrakis (4-siloxane phenyl) lead porphyrin compounds

Abstract

The present invention provides a method for improving the performance of a solid propellant. The method comprises adding a 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound to the solid propellant as a process aid to reduce the viscosity of the solid propellant and a catalyst to improve the combustion performance of the solid propellant. The 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound contains a catalytic lead porphyrin group and a dimethylsiloxane tail chain that acts as a process aid. The compound can improve the process performance during the propellant material molding process while regulating the combustion performance of a double-base or modified double-base propellant.

Description

Technical Field

[0001] The invention belongs to the technical field of solid propellants, relates to a combustion catalyst and a process aid for solid propellants, and particularly relates to a method for improving the performance of solid propellants by using a 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound. Background Art

[0002] Combustion catalysts can not only increase the burning rate of propellants and reduce the burning rate pressure index, but may also produce a "Maisu effect", thereby improving the combustion performance of double-base propellants or modified double-base propellants. Therefore, combustion catalysts with a content of only 1-5wt% are very important components in solid propellant formulations and are crucial to regulating the combustion performance of propellants. At present, double-base propellant and modified double-base propellant systems mostly regulate combustion performance by adding a certain amount of composite catalysts composed of lead salts, copper salts, and carbon black. In addition, adding process additives to double-base propellants and modified double-base propellants during the molding process can reduce the internal and external friction of the compression-molded double-base propellant, which is beneficial to compression-molding.

[0003] Currently, lead salicylate, lead stearate, lead oxide, and 2-ethyl lead acetate are commonly used burning rate catalysts in solid propellants, while vaseline and wax are commonly used process additives. However, with the continuous advancement of missile technology, existing single-function combustion catalysts and process additives are no longer able to meet the dual requirements of combustion performance and processability for new solid propellants. Summary of the Invention

[0004] In view of the defects and shortcomings of the existing technology, the purpose of the present invention is to provide a method for improving the performance of solid propellants by using 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compounds, thereby solving the technical problem that the existing technology lacks a compound that has the dual functions of solid propellant combustion catalyst and process aid.

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

[0006] A method for improving the performance of a solid propellant comprises adding a 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound into the solid propellant as a process aid for reducing the viscosity of the solid propellant.

[0007] A method for improving the performance of a solid propellant comprises adding a 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound into the solid propellant as a catalyst for improving the combustion performance of the solid propellant.

[0008] The present invention also has the following technical features:

[0009] Specifically, the chemical structure of the 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound is shown in Formula I:

[0010]

[0011] Specifically, the amount of the 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound added to the solid propellant is 1 wt% to 5 wt%.

[0012] Specifically, the preparation method of the 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound comprises the following steps:

[0013] Step 1: dissolving 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin in an organic solvent to prepare a 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin solution; dissolving a lead salt in an organic solvent, then adding the mixture to the 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin solution, and stirring to mix uniformly to prepare a mixed solution.

[0014] Step 2: Stir the mixed solution obtained in step 1 at a constant temperature of 70-80° C. for 2-4 hours, and then cool it to obtain a crude product.

[0015] Step 3: Extract the crude product obtained in step 2, then wash it with water, remove the solvent from the organic phase in a vacuum environment, perform column chromatography, and obtain 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound after drying.

[0016] Preferably, in step 1, the molar ratio of 5,10,15,20-tetrakis(4-silylphenyl)porphyrin to lead salt is 0.02:(0.01-0.03).

[0017] Preferably, the organic solvent is N,-N'-dimethylformamide.

[0018] Preferably, the lead salt is lead acetate.

[0019] Preferably, the solvent used for extraction is dichloromethane.

[0020] The beneficial technical effects of the present invention compared with the prior art are as follows:

[0021] (I) The 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound of the present invention contains a lead porphyrin group having a catalytic effect and a dimethylsiloxane tail chain having a process aid effect, and can simultaneously adjust the combustion performance of a double-base or modified double-base propellant and improve the process performance during the propellant material molding process.

[0022] (II) The 5,10,15,20-tetrakis(4-siloxanylphenyl)lead porphyrin compound of the present invention uses lead and its oxides, which are produced during decomposition during combustion, as catalytically active components. Furthermore, the combustion process also produces a large amount of carbonaceous material, which can serve as an auxiliary catalytic component to further enhance the catalytic effect. Furthermore, the metalloporphyrin portion of the 5,10,15,20-tetrakis(4-siloxanylphenyl)lead porphyrin compound before decomposition has an auxiliary catalytic effect on solid propellant combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a burning rate-pressure curve diagram of Example 4; Figure 1 Middle: The vertical axis u represents the burning rate (unit: mm·s -1 ), the horizontal axis P represents pressure (in MPa), curve a is the burning rate-pressure curve of the blank formula, and curve b is the burning rate-pressure curve of the formula with the addition of 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound.

[0024] Figure 2 This is a catalytic efficiency-pressure curve diagram of Example 4; Figure 2 In the figure, ηr on the ordinate represents the catalytic efficiency (dimensionless, specifically the ratio of the burning rate of the propellant sample with the catalyst added to the burning rate of the blank sample at the same pressure), P on the abscissa represents the pressure (in MPa), curve a is the catalytic efficiency-pressure curve of the blank formulation, and curve b is the catalytic efficiency-pressure curve of the formulation with the addition of 5,10,15,20-tetrakis(4-siloxanylphenyl)lead porphyrin compound.

[0025] Figure 3 is the rheological curve diagram of Example 4; Figure 3 In the middle: η on the vertical axis represents viscosity (unit: Pa·s), γ on the horizontal axis represents shear rate (unit: s -1 ), curve a is the rheological curve of the blank formula, and curve b is the rheological curve of the formula with the addition of 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound.

[0026] The technical solution of the present invention is further described below in conjunction with embodiments. DETAILED DESCRIPTION

[0027] It should be noted that all raw materials used in the present invention, unless otherwise specified, are raw materials known in the art, for example:

[0028] 5,10,15,20-Tetrakis(4-silyloxyphenyl)porphyrin is a compound known in the prior art, as described in the article "Sub-5 nm homeotropically aligned columnar structures of hybrids constructed by porphyrin and oligo(dimethylsiloxane) (CHEMICAL COMMUNICATIONS, 2021.11, DOI: https: / / doi.org / 10.1039 / D1CC05886J).

[0029] In accordance with the above technical solution, 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.

[0030] Example 1:

[0031] This embodiment provides a 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound, and the preparation method of the compound specifically comprises the following steps:

[0032] Step 1: Weigh 44.19 g (0.02 mol) of 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin and dissolve it in 150 mL of N,N'-dimethylformamide to prepare a 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution; weigh 9.76 g (0.03 mol) of lead acetate, prepare a solution with 50 mL of N,N'-dimethylformamide, add the solution to the 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution, stir and mix evenly to prepare a mixed solution.

[0033] Step 2: Stir the mixed solution obtained in step 1 at a constant temperature of 80° C. for 2 h, and then cool it to room temperature to obtain a crude product.

[0034] Step 3: The crude product obtained in step 2 was extracted with dichloromethane, and then washed with deionized water. The organic phase was then freed from the solvent in a vacuum environment and subjected to column chromatography. After drying, 46.22 g of a purple product was obtained with a yield of 95.7 wt%.

[0035] In this example, the purple product finally obtained was analyzed, and its characterization data are as follows:

[0036] H NMR spectrum: 1H NMR (400 MHz, CDCl3, δ, ppm): 8.54 (d, 16H), 8.13 (d, 8H), 7.87 (d, 8H), 7.15 (d, 8H), 4.09 (t, 8H), 1.91 (d, 8H), 0.72 (t, 8H), 0.21–0.04 (m, 84H). The above H NMR data correspond to H in the target compound.

[0037] C NMR spectrum: 13 C NMR (100 MHz, CDCl3, δ, ppm): 163.82, 162.47, 150.11, 137.34, 134.12, 131.37, 120.73, 120.03, 118.91, 113.54, 77.16, 76.97, 76.53, 70.45, 22.82, 14.32, 2.11, 1.97, 1.39, 0.32. The above C NMR data correspond to the C in the target compound.

[0038] Elemental analysis showed that the measured values of each element (wt%) were: C, 55.42; H, 6.09; N, 2.23, while the theoretical calculated content of each element in the target compound was (wt%): C, 55.71; H, 6.18; N, 2.32. The above data showed that the molecular formula of the target compound was consistent with C 112 H 148 N4O 20 PbSi 12 consistent.

[0039] The measured value of metal by X-ray fluorescence spectrometry is (wt%): 8.39, while the theoretical value of metal content in the target compound is (wt%): 8.58. The above data show that the molecular formula of the target compound is consistent with C 112 H 148 N4O 20 PbSi 12 consistent.

[0040] Based on the above characterization data, it can be inferred that the chemical structure of the purple product (i.e., 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound) is as shown in Formula I:

[0041]

[0042] Example 2:

[0043] This embodiment provides a method for preparing a 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound, which specifically comprises the following steps:

[0044] Step 1: Weigh 44.19 g (0.02 mol) of 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin and dissolve it in 150 mL of N,N'-dimethylformamide to prepare a 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution; weigh 9.76 g (0.03 mol) of lead acetate, prepare a solution with 50 mL of N,N'-dimethylformamide, add the solution to the 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution, stir and mix evenly to prepare a mixed solution.

[0045] Step 2: Stir the mixed solution obtained in step 1 at a constant temperature of 75° C. for 4 hours, and then cool it to room temperature to obtain a crude product.

[0046] Step 3: The crude product obtained in step 2 was extracted with dichloromethane, and then washed with deionized water. The organic phase was then freed from the solvent in a vacuum environment and subjected to column chromatography. After drying, 44.14 g of a purple product was obtained with a yield of 91.4 wt%.

[0047] In this example, the characterization data of the purple product are known to those of Example 1, that is, the product is a 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound.

[0048] Example 3:

[0049] This embodiment provides a method for preparing a 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound, which specifically comprises the following steps:

[0050] Step 1: Weigh 44.19 g (0.02 mol) of 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin and dissolve it in 150 mL of N,N'-dimethylformamide to prepare a 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution; weigh 8.115 g (0.01 mol) of lead acetate, prepare a solution with 50 mL of N,N'-dimethylformamide, add the solution to the 5,10,15,20-tetrakis(4-siloxane phenyl)porphyrin solution, stir and mix evenly to prepare a mixed solution.

[0051] Step 2: Stir the mixed solution obtained in step 1 at a constant temperature of 70° C. for 3 h, and then cool it to room temperature to obtain a crude product.

[0052] Step 3: The crude product obtained in step 2 was extracted with dichloromethane, and then washed with deionized water. The organic phase was then freed from the solvent in a vacuum environment and subjected to column chromatography. After drying, 44.96 g of a purple product was obtained with a yield of 93.1 wt%.

[0053] In this example, the characterization data of the purple product are known to those of Example 1, that is, the product is a 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound.

[0054] Example 4:

[0055] This example provides a method for improving the performance of a solid propellant using the 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound of Examples 1 to 3. The method specifically comprises: adding 3 wt % of the 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound to the solid propellant.

[0056] In this embodiment, the solid propellant is a solid propellant known in the prior art, and its basic formula is: a double-base adhesive (composed of nitrocellulose and nitroglycerin) is 60wt%, RDX is 37wt%, other additives (including No. 2 neutralizing agent, vaseline, etc.) are 3wt%, and the dosage is 500g.

[0057] Effect verification of Example 4:

[0058] (A) In order to verify the effect of 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound on the combustion performance of modified double-base propellant, the present invention designed the following experiment: using the basic formula of the above-mentioned solid propellant as a blank control sample, and using the above-mentioned solid propellant with an additional 3wt% of 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound added as an experimental sample, a combustion performance test was carried out. The specific process of the test refers to the target line method given in the "Standard of the Ministry of Aerospace Industry of the People's Republic of China" Q915-1985. The side of the treated 5mm×5mm×120mm small strip was coated with polyvinyl alcohol solution 6 times and dried, and then the burning rate was tested in a burning rate meter. The test temperature was 20°C and the pressure range was 4MPa~15MPa. The test results are as follows Figure 1 and Figure 2 shown.

[0059] from Figure 1 and Figure 2 As can be seen in the figure, adding 3wt% of 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin to a modified double-base propellant significantly increases its burning rate. Within the pressure range of 4MPa to 12MPa, the catalytic efficiency is above 1.3, and particularly within the 4MPa to 10MPa range, the catalytic efficiency reaches above 1.5. Furthermore, the pressure exponent is significantly reduced in the medium- and high-pressure ranges. Within the pressure range of 8MPa to 15MPa, the burning rate pressure exponent, n, reaches 0.26, exhibiting platform combustion.

[0060] (B) To verify the effect of 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound on the rheological properties of modified double-base propellants, the present invention designed the following experiment: using the above solid propellant basic formula as a blank control sample and the above solid propellant with an additional 3wt% of 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound as an experimental sample, rheological properties were tested. The test used a rotational rheometer to measure the rheological data of the sample using dynamic rheology. During the test, the gap was 1mm, the test temperature was 90°C, and the shear rate range was 0.01-100s. -1 The test results are as follows. Figure 3 shown.

[0061] from Figure 3 It can be seen that in 0.01~100s -1 Within the shear rate range, the viscosity of the blank control sample is always higher than that of the experimental sample. This result shows that adding 3wt% of 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound to the modified double-base propellant can reduce the viscosity of the material and improve the molding process performance.

Claims

1. A method for improving the performance of solid propellant, characterized in that: The method comprises adding a 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound to a solid propellant as a process aid for reducing the viscosity of the solid propellant; the chemical structure of the 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound is shown in Formula I:

2. A method for improving the performance of solid propellant, characterized in that: The method comprises adding a 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound into a solid propellant as a catalyst for improving the combustion performance of the solid propellant; the chemical structure of the 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound is shown in Formula I:

3. The method for improving the performance of solid propellant according to claim 1 or 2, characterized in that: The amount of the 5,10,15,20-tetrakis(4-siloxane phenyl) lead porphyrin compound added to the solid propellant is 1wt% to 5wt%.

4. The method for improving the performance of solid propellant according to claim 1 or 2, characterized in that: The preparation method of the 5,10,15,20-tetrakis(4-siloxanephenyl)lead porphyrin compound specifically comprises the following steps: Step 1: dissolving 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin in an organic solvent to prepare a 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin solution; dissolving a lead salt in an organic solvent, then adding the mixture to the 5,10,15,20-tetrakis(4-siloxanylphenyl)porphyrin solution, and stirring to mix uniformly to prepare a mixed solution; Step 2: stirring the mixed solution obtained in step 1 at a constant temperature of 70-80° C. for 2-4 hours, and then cooling to obtain a crude product; Step 3: Extract the crude product obtained in step 2, then wash it with water, remove the solvent from the organic phase in a vacuum environment, perform column chromatography, and obtain 5,10,15,20-tetrakis(4-silylphenyl)lead porphyrin compound after drying.

5. The method for improving the performance of solid propellant according to claim 4, wherein: In step 1, the molar ratio of 5,10,15,20-tetrakis(4-silylphenyl)porphyrin to lead salt is 0.02:(0.01-0.03).

6. The method for improving the performance of solid propellant according to claim 4, wherein: In step 1, the organic solvent is N,-N'-dimethylformamide.

7. The method for improving the performance of solid propellant according to claim 4, wherein: In step 1, the lead salt is lead acetate.

8. The method for improving the performance of solid propellant according to claim 4, wherein: In step 3, the solvent used for extraction is dichloromethane.

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