Gem-dinitro ester energetic compound and synthesis method thereof

Abstract

The invention discloses a gem-dinitro ester energetic compound and a synthesis method thereof. According to the method, 2, 2-dinitro-1-propanol (DNPOH) and carboxylic acid are taken as raw materials, N, N '-dicyclohexylcarbodiimide (DCC) is taken as a condensing agent and a dehydrating agent, and 4-dimethylaminopyridine (DMAP) is taken as a catalyst to promote an esterification reaction, so that the gem-dinitro ester compound is obtained. The post-treatment method is relatively simple, column chromatography separation is not needed, the product purity is high, and the yield is high. The compound can be used as an energetic plasticizer or a melt-cast explosive carrier, and the method is a one-pot method and has the advantages of simple synthesis, mild reaction conditions, safe process, stable reaction, high yield and the like.

Description

Technical Field

[0001] The invention relates to a method for synthesizing geminal dinitroester energetic compounds, belonging to the technical field of energetic materials. Background Art

[0002] Solid propellants and polymer bonded explosives are important components of modern weapons and ammunition. The improvement of their energy is related to the improvement of the "long-range launch" and "high-efficiency destruction" capabilities of weapons and ammunition. With the development of strategic missiles and aerospace technology, higher requirements are placed on the performance of solid propellants and polymer bonded explosives. On the one hand, high energy must be guaranteed, and on the other hand, good mechanical properties must be achieved. As an important component of solid propellants and polymer bonded explosives, the increase in heat release of the binder system is conducive to the improvement of the overall energy. Studies have found that gradually making the binder system energetic is a feasible route. In the energetic binder system, energetic plasticizers are one of the important components. They play a role in plasticizing and stabilizing energetic polymers, affecting the energy, safety, mechanical properties and processing technology of the formula.

[0003] Since geminal dinitro groups have high energy, long-lasting stability, and excellent plasticizing properties, and ester groups are also good flexible groups, the development of geminal dinitro ester compounds with excellent comprehensive properties has become one of the hot topics in the field of energetic materials research. The existing methods for synthesizing geminal dinitro ester energetic compounds are mainly Fisher-Speier esterification methods such as the classic toluene reflux. However, for carboxylic acids with large steric hindrance, the Fisher-Speier esterification method is difficult to synthesize. Therefore, it is urgent to develop new methods for synthesizing geminal dinitro ester energetic compounds. Summary of the invention

[0004] The invention overcomes the shortcomings of the prior art and provides a method for preparing geminal dinitroester energetic compounds as potential energetic plasticizers or melt-cast explosive carriers. The one-step synthesis method is adopted to prepare geminal dinitroester compounds safely, efficiently and mildly.

[0005] Technical solution to achieve the purpose of the present invention:

[0006] In a first aspect, the present invention provides a geminal dinitroester compound having the following structure:

[0007]

[0008] in,

[0009]

[0010] In a second aspect, the present invention provides a method for preparing the geminal dinitroester compound according to the first aspect, comprising the following steps:

[0011] Step 1: At room temperature, carboxylic acid, 2,2-dinitro-1-propanol (DNPOH) and 4-dimethylaminopyridine (DMAP) are added to dichloromethane (DCM) in sequence, the temperature of the reaction system is controlled, N,N'-dicyclohexylcarboximide (DCC) is added under stirring conditions, and the mixture is stirred for a certain period of time and then warmed to room temperature and reacted for a period of time.

[0012]

[0013] Step 2: After the reaction is completed, stand at -20°C for 3 to 7 hours, filter while cold, wash the filtrate with dilute hydrochloric acid, sodium bicarbonate solution, and saturated brine in sequence, dry over anhydrous magnesium sulfate, and remove the solvent under reduced pressure to obtain a crude product;

[0014] Step 3: Dissolve the crude product in ethyl acetate, let stand at -20°C for 3 to 10 hours, filter while cold, and distill the filtrate under reduced pressure to obtain the crude product. Repeat this step twice to obtain the product.

[0015] Preferably, in step 1, the molar ratio of DNPOH to carboxylic acid is 1:1-1.2; the molar ratio of DNPOH to DMAP is 1:0.1-0.2; and the molar ratio of DNPOH to DCC is 1:1.0-2.0.

[0016] Preferably, in step 1, room temperature refers to 20-30°C; and the temperature of the reaction system is less than 10°C.

[0017] Preferably, in step 1, DCC is added, stirred for 10 to 30 minutes, and then warmed to room temperature for reaction for 3 to 15 hours.

[0018] Preferably, in step 2, the concentration of dilute hydrochloric acid is 1M, the amount used each time is 1 / 3 to 1 / 2 of the volume of dichloromethane, and the number of washings is 3 to 5 times; the concentration of the sodium bicarbonate aqueous solution is 10% to 30wt%, the amount used each time is 1 / 3 to 1 / 2 of the volume of dichloromethane, and the number of washings is 3 to 5 times; the amount of saturated salt water used each time is 1 / 2 to 2 / 3 of the volume of dichloromethane, and the number of washings is 3 to 5 times.

[0019] Preferably, in step 3, the mass ratio of the volume of ethyl acetate to the crude product is 10-30 mL:1 g.

[0020] In a third aspect, the present invention further provides a use of the geminal dinitroester compound described in the first aspect as an energetic plasticizer or a carrier for melt-cast explosives.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The DCC preparation method of geminal dinitroester compounds of the present invention has only one step, simple steps, mild reaction conditions, no need for high temperature reflux, and avoids the use of highly corrosive concentrated sulfuric acid.

[0023] (2) The DCC preparation method of geminal dinitroester compounds of the present invention has strong applicability and can be used for the esterification of carboxylic acids with large steric hindrance and 2,2-dinitro-1-propanol, thus making up for the defects of the Fisher-Speier esterification method.

[0024] (3) The post-treatment method of the present invention is relatively simple, does not require column chromatography separation, and has high product purity and high yield.

[0025] (4) The geminal dinitroester compounds of the present invention can effectively reduce the viscosity of the adhesive GAP and increase its solid content. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the H NMR spectrum of (2,2-dinitropropyl)-3,5-difluorobenzoate in Example 1 of the present invention.

[0027] Figure 2 This is the carbon NMR spectrum of (2,2-dinitropropyl)-3,5-difluorobenzoate in Example 1 of the present invention.

[0028] Figure 3 This is the infrared spectrum of (2,2-dinitropropyl)-3,5-difluorobenzoate in Example 1 of the present invention.

[0029] Figure 4 This is the H NMR spectrum of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 of the present invention.

[0030] Figure 5 This is the carbon NMR spectrum of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 of the present invention.

[0031] Figure 6 This is the infrared spectrum of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 of the present invention.

[0032] Figure 7 This is the H NMR spectrum of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate in Example 3 of the present invention.

[0033] Figure 8 This is the carbon NMR spectrum of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate in Example 3 of the present invention.

[0034] Fig. 9This is the infrared spectrum of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate in Example 3 of the present invention.

[0035] Fig.10 This is the H NMR spectrum of (2,2-dinitropropyl)-3-nitro-5-trifluoromethyl benzoate in Example 4 of the present invention.

[0036] Fig.11 This is the carbon NMR spectrum of (2,2-dinitropropyl)-3-nitro-5-trifluoromethyl benzoate in Example 4 of the present invention.

[0037] Fig.12 This is the infrared spectrum of (2,2-dinitropropyl)-3-nitro-5-trifluoromethyl benzoate in Example 4 of the present invention.

[0038] Fig.13 This is the H NMR spectrum of (2,2-dinitropropyl)-6-trifluoromethyl nicotinate in Example 5 of the present invention.

[0039] Fig.14 This is the carbon NMR spectrum of (2,2-dinitropropyl)-6-trifluoromethyl nicotinate in Example 5 of the present invention.

[0040] Fig.15 This is the infrared spectrum of (2,2-dinitropropyl)-6-trifluoromethyl nicotinate in Example 5 of the present invention.

[0041] Fig.16 It is the DSC chart of geminal dinitroester compounds in Examples 1 to 5 of the present invention.

[0042] Fig.17 This is a single crystal structure diagram of (2,2-dinitropropyl)-3,5-difluorobenzoate in Example 1 of the present invention.

[0043] Fig.18 This is a single crystal structure diagram of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 of the present invention. DETAILED DESCRIPTION

[0044] The following examples can enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0045] The present invention provides a method for preparing DCC of geminal dinitroester compounds as a potential energetic plasticizer or a carrier of melt-cast explosives, comprising:

[0046] Step 1: At room temperature, add carboxylic acid, 2,2-dinitro-1-propanol (DNPOH) and 4-dimethylaminopyridine (DMAP) to dichloromethane in sequence. Then, under external cooling (less than 10°C) and stirring, add N,N'-dicyclohexylcarbodiimide (DCC), stir for 10 to 30 minutes, then warm to room temperature 20 to 30°C and react for 3 to 15 hours.

[0047] Step 2: After the reaction is completed, stand at -20°C for 3 to 7 hours, filter while cold, wash the filtrate with 1M dilute hydrochloric acid 3 to 5 times, then wash with 10 to 30% sodium bicarbonate aqueous solution 3 to 5 times, and finally wash with saturated brine 3 to 5 times, dry over anhydrous magnesium sulfate, and remove the solvent under reduced pressure to obtain a crude product.

[0048] Step 3: Dissolve the crude product in an appropriate amount of ethyl acetate, let stand at -20°C for 3 to 10 hours, filter while cold, and distill the filtrate under reduced pressure to obtain the crude product. Repeat this step twice to obtain the product.

[0049]

[0050] Embodiment 1:

[0051] Preparation of (2,2-dinitropropyl)-3,5-difluorobenzoate

[0052]

[0053] At room temperature, 1.160g (7.34mmol) 3,5-difluorobenzoic acid, 1.000g (6.67mmol) 2,2-dinitro-1-propanol (DNPOH) and 0.108g (8.80mmol) 4-dimethylaminopyridine (DMAP) were added to 20mL of dichloromethane in sequence. Then, under stirring, the temperature of the reaction system was controlled to be less than 10°C, and 1.816g (8.80mmol) N,N'-dicyclohexylcarboximide (DCC) was added in batches. After stirring for 15min, the mixture was warmed to room temperature and reacted for 5h. After the reaction was completed, the mixture was allowed to stand at -20°C for 5h, and filtered while cold. The filtrate was first washed 3 times with 10mL 1M dilute hydrochloric acid solution, then washed 3 times with 10mL 20wt% sodium bicarbonate aqueous solution, and finally washed 3 times with 10mL saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was dissolved in 30 mL of ethyl acetate, allowed to stand at -20 °C for 4 h, filtered while cold, and the filtrate was distilled under reduced pressure to obtain a crude product. This step was repeated twice to obtain 1.563 g of (2,2-dinitropropyl)-3,5-difluorobenzoate, with a yield of 80.80%.

[0054] Embodiment 2:

[0055] Preparation of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate

[0056]

[0057] At room temperature, 1.292g (7.34mmol) 2,3,5-trifluorobenzoic acid, 1.000g (6.67mmol) 2,2-dinitro-1-propanol (DNPOH) and 0.108g (8.80mmol) 4-dimethylaminopyridine (DMAP) were added to 20mL of dichloromethane solution in sequence. Then, under stirring, the temperature of the reaction system was controlled to be less than 10°C, and 1.816g (8.80mmol) N,N'-dicyclohexylcarboximide (DCC) was added in batches. After stirring for 15min, the mixture was warmed to room temperature and reacted for 5h. After the reaction was completed, the mixture was allowed to stand at -20°C for 5h, and filtered while cold. The filtrate was first washed 3 times with 10mL 1M dilute hydrochloric acid, then washed 3 times with 10mL 20wt% sodium bicarbonate aqueous solution, and finally washed 3 times with 10mL saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was dissolved in 30 mL of ethyl acetate, allowed to stand at -20 °C for 5 h, filtered while cold, and the filtrate was distilled under reduced pressure to obtain a crude product. This step was repeated twice to obtain 1.567 g of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate, with a yield of 76.27%.

[0058] Embodiment 3:

[0059] Preparation of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate

[0060]

[0061] At room temperature, 1.358g (7.34mmol) 4-fluoro-3-nitrobenzoic acid, 1.000g (6.67mmol) 2,2-dinitro-1-propanol (DNPOH) and 0.108g (8.80mmol) 4-dimethylaminopyridine (DMAP) were added to 20mL of dichloromethane solution in sequence. Then, under stirring, the temperature of the reaction system was controlled to be less than 10°C, and 1.816g (8.80mmol) N,N'-dicyclohexylcarboximide (DCC) was added in batches. After stirring for 15min, the mixture was warmed to room temperature and reacted for 5h. After the reaction was completed, the mixture was allowed to stand at -20°C for 6h, and filtered while cold. The filtrate was first washed 3 times with 10mL 1M dilute hydrochloric acid, then washed 3 times with 10mL 20wt% sodium bicarbonate aqueous solution, and finally washed 3 times with 10mL saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was dissolved in 30 mL of ethyl acetate, allowed to stand at -20 °C for 7 h, filtered while cold, and the filtrate was distilled under reduced pressure to obtain a crude product. This step was repeated twice to obtain 1.648 g of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate, with a yield of 77.93%.

[0062] Embodiment 4:

[0063] Preparation of (2,2-dinitropropyl)-3-nitro-5-trifluoromethylbenzoate

[0064]

[0065] At room temperature, 1.725g (7.34mmol) 3-nitro-5-trifluoromethylbenzoic acid, 1.000g (6.67mmol) 2,2-dinitro-1-propanol (DNPOH) white solid and 0.108g (8.80mmol) 4-dimethylaminopyridine (DMAP) were added to 20mL of dichloromethane solution in sequence. Then, under stirring, the temperature of the reaction system was controlled to be less than 10°C, and 1.816g (8.80mmol) N,N'-dicyclohexylcarboximide (DCC) was added in batches. After stirring for 15min, the mixture was warmed to room temperature and reacted for 5h. After the reaction was completed, it was allowed to stand at -20°C for 5h, and filtered while cold. The filtrate was first washed 3 times with 10mL 1M dilute hydrochloric acid, then washed 3 times with 10mL 20wt% sodium bicarbonate aqueous solution, and finally washed 3 times with 10mL saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was dissolved in 40 mL of ethyl acetate, allowed to stand at -20 °C for 3 h, filtered while cold for 5 h, and the filtrate was distilled under reduced pressure to obtain a crude product. This step was repeated twice to obtain 1.951 g of (2,2-dinitropropyl)-3-nitro-5-trifluoromethylbenzoate, with a yield of 79.70%.

[0066] Embodiment 5:

[0067] Preparation of (2,2-dinitropropyl)-6-trifluoromethylnicotinate

[0068]

[0069] At room temperature, 1.402g (7.34mmol) 6-trifluoromethylnicotinic acid, 1.000g (6.67mmol) 2,2-dinitro-1-propanol (DNPOH) and 0.108g (0.88mmol) 4-dimethylaminopyridine (DMAP) were added to 20mL of dichloromethane solution in sequence. Then, under stirring, the temperature of the reaction system was controlled to be less than 10°C, and 1.816g (8.80mmol) N,N'-dicyclohexylcarboximide (DCC) was added in batches. After stirring for 15min, the mixture was warmed to room temperature and reacted for 12h. After the reaction was completed, the mixture was allowed to stand at -20°C for 5h, and filtered while cold. The filtrate was first washed 3 times with 10mL 1M dilute hydrochloric acid, then washed 3 times with 10mL 20wt% sodium bicarbonate aqueous solution, and finally washed 3 times with 10mL saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was dissolved in 40 mL of ethyl acetate, allowed to stand at -20°C for 8 h, filtered while cold, and the filtrate was distilled under reduced pressure to obtain a crude product. This step was repeated twice to obtain 1.842 g of (2,2-dinitropropyl)-6-trifluoromethylnicotinate, with a yield of 85.49%.

[0070] The geminal dinitroester compounds obtained in Examples 1 to 5 were characterized.

[0071] First, the analysis results of (2,2-dinitropropyl)-3,5-difluorobenzoate in Example 1 are given:

[0072] like Figure 1 The H NMR spectrum shown, 1 H NMR (CDCl 3 ): δ=7.46, 7.09, 5.15, 2.28ppm.

[0073] like Figure 2 The NMR carbon spectrum shown, 13 C NMR (CDCl 3 ): δ=163.90,162.58,161.90,130.91,114.94,112.87,109.72,64.42,20.54ppm.

[0074] like Figure 3 Infrared spectrum shown, IR(ATR):

[0075] like Fig.16 The DSC graph shown has a melting point of 61.7°C and a thermal decomposition peak temperature of 264.9°C.

[0076] The analysis results of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2:

[0077] like Figure 4 The H NMR spectrum shown, 1 H NMR (CDCl 3 ): δ=7.39,7.21,5.17,2.31ppm.

[0078] like Figure 5 The NMR carbon spectrum shown, 13 C NMR (CDCl 3 ): δ=160.84,157.96,156.01,152.60,152.17,150.18,148.53,146.46,118.77,114.95,113.10,111.55,64.87,20.43ppm.

[0079] like Figure 6 Infrared spectrum shown, IR(ATR):

[0080] like Fig.16 The DSC graph shown has a melting point of 44.1°C and a thermal decomposition peak temperature of 265.1°C.

[0081] The analysis results of (2,2-dinitropropyl)-4-fluoro-3-nitrobenzoate in Example 3:

[0082] like Figure 7 The H NMR spectrum shown, 1 H NMR (CDCl 3 ): δ = 8.66, 8.23, 7.43, 5.18, 2.29ppm.

[0083] like Figure 8 The NMR carbon spectrum shown, 13 C NMR (CDCl 3 ): δ=161.84,159.72,157.54,136.61,128.20,125.05,119.44,114.95,64.47,20.52ppm.

[0084] like Fig. 9 Infrared spectrum shown, IR(ATR):

[0085] like Fig.16 The DSC graph shown has a melting point of 53.9°C and a thermal decomposition peak temperature of 254.2°C.

[0086] The analysis results of (2,2-dinitropropyl)-3-nitro-5-trifluoromethyl benzoate in Example 4:

[0087] like Fig.10 The H NMR spectrum shown, 1 H NMR (CDCl 3 ): δ = 8.94, 8.74, 8.52, 5.24, 2.32ppm.

[0088] like Fig.11 The NMR carbon spectrum shown, 13 C NMR (CDCl 3 ): δ=161.60,148.64,133.50,131.99,131.01,127.66,125.57,123.21,121.03,114.80,64.79,20.58ppm.

[0089] like Fig.12 Infrared spectrum shown, IR(ATR):

[0090] like Fig.16 The DSC graph shown has a melting point of 62.1°C and a thermal decomposition peak temperature of 265.3°C.

[0091] The analysis results of (2,2-dinitropropyl)-6-trifluoromethyl nicotinate in Example 5:

[0092] like Fig.13 The H NMR spectrum shown, 1 H NMR (CDCl 3 ): δ = 9.24, 8.42, 7.83, 5.20, 2.29ppm.

[0093] like Fig.14 The NMR carbon spectrum shown, 13 C NMR (CDCl 3 ): δ=161.28,151.15,150.08,138.11,125.57,120.95,119.52,118.77,113.91,63.49,19.58ppm.

[0094] like Fig.15 Infrared spectrum shown, IR(ATR):

[0095]

[0096] like Fig.16 The DSC graph shown has a melting point of 92.9°C and a thermal decomposition peak temperature of 263.6°C.

[0097] The (2,2-dinitropropyl)-3,5-difluorobenzoate obtained in Example 1 was dissolved in dichloromethane and slowly evaporated at room temperature to obtain a single crystal thereof. The single crystal cultured from the sample in Example 1 was subjected to an X-ray single crystal diffraction test, and its crystal structure was as follows: Fig.17 Its unit cell parameters are shown below:

[0098] Crystal system: monoclinic;

[0099] Point group: P 2 1 / c;

[0100] Unit cell parameters: α=γ=90°, β=100.759(3)°;

[0101] Unit cell volume:

[0102] Z = 4;

[0103] Density: 1.581 g cm -3 (296K).

[0104] The (2,2-dinitropropyl)-2,3,5-trifluorobenzoate obtained in Example 2 was dissolved in dichloromethane and slowly evaporated at room temperature to obtain a single crystal thereof. The single crystal cultured from the sample described in Example 1 was subjected to an X-ray single crystal diffraction test, and its crystal structure was as follows: Fig.18 Its unit cell parameters are shown below:

[0105] Crystal system: triclinic;

[0106] Point group: P-1;

[0107] Unit cell parameters: α=112.467(7)°, β=95.309(7)°; γ=96.550(8)°

[0108] Unit cell volume:

[0109] Z = 2;

[0110] Density: 1.643 g cm -3 (296K).

[0111] The density of the geminal dinitroester compounds of Examples 1-5 was measured at 25°C using a Micromeritics AccuPycII 1345 gas displacement pycnometer. The oxygen balance was measured using a gas pycnometer with a composition of C a H b F c N d O eThe result was calculated by using the modified equation 1600(e+0.5c-2a-0.5b) / M (M is the molecular weight) of the CHFNO-based compound. At the same time, the heat of formation of Examples 1-5 was calculated by Gaussian software using the density functional theory B3LYP / 6-31G(d,p) method; the impact sensitivity of Examples 1-5 was determined by the BAM method; and the temperature was measured using a differential scanning calorimeter (DSC) at 10°C·min -1 The melting points and decomposition temperatures of Examples 1-5 were measured at a heating rate of . In addition, the detonation velocity, detonation pressure, specific impulse of Examples 1-5 and the specific impulse of the propellant formulations formed by Examples 1-5 were calculated by EXPLO5 v6.05.04. The propellant formulation mainly uses the geminal dinitroester compound or DOS prepared by the present invention as a plasticizer (10% by mass), fine HMX as an energetic component (38% by mass), GAP as a binder (8% by mass), ferrocene as a combustion rate catalyst (2% by mass), aluminum powder as a combustion rate regulator (15% by mass), and ammonium perchlorate (AP) as an oxidant (27% by mass).

[0112] The performance test results of Examples 1-5 are shown in Table 1 below.

[0113] Table 1

[0114]

[0115] As shown in Table 1, the density and oxygen balance of Examples 1-5 are higher than those of DOS and DNAN, and close to those of TNT. On the other hand, thermal stability is an important characteristic of energetic materials. The trends of the DSC curves of these compounds are consistent, and they are all composed of a lower melting point peak and an exothermic peak (e.g. Fig.16 ). Its melting point peak ranges from 40 to 100°C, and its thermal decomposition peak temperature is higher than 250°C, indicating that these geminal dinitroester compounds have good thermal stability, and there are significant differences in melting point and thermal decomposition temperature. At the same time, the impact sensitivity of these compounds is higher than 40J, indicating that they have the characteristics of insensitive energetic materials. The detonation velocity and detonation pressure of Examples 3 and 4 are higher than DNAN, but slightly inferior to TNT, indicating that they may become potential carriers of melt-cast explosives. In addition, the specific impulse of these compounds is higher than that of the current DOS, and the specific impulse of the formulations with Examples 1-5 as energetic plasticizers is higher than the specific impulse with DOS as the plasticizer, so these compounds may be used as potential insensitive solid energetic plasticizers.

[0116] The (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 having a lower melting point was mixed with GAP, and the viscosity of GAP and the mixture thereof was tested using a viscometer. The results are shown in Table 2 below.

[0117] Table 2

[0118]

[0119] 2 / GAP refers to a mixture of (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 and GAP in a mass ratio of 1:10.

[0120] It can be seen from Table 2 that simply adding (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in a mass ratio of 1:10 to the binder GAP can effectively reduce the viscosity of GAP. Therefore, (2,2-dinitropropyl)-2,3,5-trifluorobenzoate in Example 2 has the application potential of becoming an insensitive energetic plasticizer.

Claims

1. A geminal dinitroester compound, characterized in that: It has the following structure: in, 2. A method for preparing a geminal dinitroester compound as claimed in claim 1, characterized in that: The following steps are included: Step 1: At room temperature, carboxylic acid, 2,2-dinitro-1-propanol and 4-dimethylaminopyridine are added to dichloromethane in sequence, the temperature of the reaction system is controlled, and N,N'-dicyclohexylcarboximide is added under stirring conditions. After stirring for a certain period of time, the mixture is heated to room temperature and reacted for a period of time. Step 2: After the reaction is completed, stand at -20°C for 3 to 7 hours, filter while cold, wash the filtrate with dilute hydrochloric acid, sodium bicarbonate solution, and saturated brine in sequence, dry over anhydrous magnesium sulfate, and remove the solvent under reduced pressure to obtain a crude product; Step 3: Dissolve the crude product in ethyl acetate, let stand at -20°C for 3 to 10 hours, filter while cold, and distill the filtrate under reduced pressure to obtain the crude product. Repeat this step twice to obtain the product.

3. The method according to claim 2, characterized in that In step 1, the molar ratio of 2,2-dinitro-1-propanol to carboxylic acid is 1:1-1.2; the molar ratio of 2,2-dinitro-1-propanol to 4-dimethylaminopyridine is 1:0.1-0.2; and the molar ratio of 2,2-dinitro-1-propanol to N,N'-dicyclohexylcarboximide is 1:1.0-2.

0.

4. The method according to claim 2, characterized in that In step 1, room temperature refers to 20-30°C; the temperature of the reaction system is less than 10°C.

5. The method according to claim 2, characterized in that In step 1, N,N'-dicyclohexylcarboximide is added, stirred for 10 to 30 minutes, and then warmed to room temperature for reaction for 3 to 15 hours.

6. The method according to claim 2, characterized in that In step 2, the concentration of dilute hydrochloric acid is 1M, and the amount used each time is 1 / 3 to 1 / 2 of the volume of dichloromethane, and the washing number is 3 to 5 times; the concentration of the sodium bicarbonate aqueous solution is 10% to 30wt%, and the amount used each time is 1 / 3 to 1 / 2 of the volume of dichloromethane, and the washing number is 3 to 5 times; the amount of saturated salt water used each time is 1 / 2 to 2 / 3 of the volume of dichloromethane, and the washing number is 3 to 5 times.

7. The method according to claim 2, characterized in that In step 3, the mass ratio of the volume of ethyl acetate to the crude product is 10-30 mL:1 g.

8. Use of the gem-dinitroester compound as claimed in claim 1 as an energetic plasticizer or a carrier for melt-cast explosives.

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