Nitrate energetic plasticizer as well as synthesis method and application thereof

Abstract

The invention discloses a nitrate energetic plasticizer as well as a synthesis method and application thereof, and the synthesis method comprises the following steps: dispersing a compound 3-alkoxy-1, 2-diol propane in an organic solvent containing concentrated sulfuric acid in an ice bath, slowly dropwise adding a nitration reagent, slowly heating to a reaction temperature after dropwise adding, and reacting for 2 hours; after the reaction, pouring ice water for quenching, stirring for 30 minutes to separate an organic phase, extracting a water phase with dichloromethane, and combining the extracted organic phases; and respectively washing the organic phase with a saturated potassium bicarbonate solution and pure water for several times, removing residual moisture by using anhydrous magnesium sulfate, and carrying out reduced pressure distillation to remove dichloromethane, thereby obtaining the nitrate energetic plasticizer. The synthesis method of the aliphatic energetic plasticizer is simple, the energetic nitrate group is introduced on the basis that the aliphatic compound contains the flexible ether group, the novel aliphatic energetic plasticizer is obtained, and the aliphatic energetic plasticizer has the advantages of being low in viscosity, good in thermal stability, low in glass transition temperature and the like and is a potential application type energetic plasticizer.

Description

Technical Field

[0001] The present invention relates to the field of energetic material synthesis, in particular to a nitrate energetic plasticizer and a synthesis method and application thereof. Background Art

[0002] As the energy source of weapon systems, formulated explosives or propellants must have high energy and good mechanical properties, while also being able to reduce vulnerability during storage and transportation. Plasticizers, as indispensable components of formulated explosives and propellants, play an important role in improving their overall performance. Plasticizers can reduce the viscosity and glass transition temperature of adhesives, improve the flexibility and processing properties of formulated explosives and solid propellants, and have a significant impact on their sensitivity, mechanical properties, and detonation performance. With the expansion of propellant applications, increasingly demanding usage scenarios have also placed higher demands on the energy and environmental adaptability of propellants. As an important component of regulating performance, energetic plasticizers need to have a combination of energy and adaptability to achieve good overall performance.

[0003] The nitrate ester (oxynitro) functional group (-ONO2) has a formation enthalpy of -66.2 kJ / mol, and its molecular weight and oxygen content are relatively high, at 62 g / mol and 77.4%, respectively. Furthermore, the nitrogen atoms in the -ONO2 functional group do not consume oxygen atoms, ultimately generating nitrogen gas. The remaining oxygen atoms are then available for ammunition combustion, resulting in a higher oxygen balance. Currently, NG, a commonly used nitrate plasticizer in high-energy propellant formulations, represents a class of nitrate plasticizers. These plasticizers offer numerous advantages, including high density, a relatively high oxygen balance and energy content, and a significant plasticizing effect on adhesives and explosives. Energetic plasticizers based on aliphatic compounds have relatively low molecular weights, are more likely to exist as liquids, and exhibit superior glass transition temperatures and viscosity properties. However, a simple and effective synthesis method for nitrate energetic plasticizers is currently lacking. Summary of the Invention

[0004] The present invention aims to provide a nitrate-based energetic plasticizer and a method for synthesizing the same. The plasticizer has the advantages of simple synthesis, low viscosity, good thermal stability, and low glass transition temperature.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] The present invention provides a method for synthesizing a nitrate ester energetic plasticizer. The synthesis method is carried out according to the following reaction formula:

[0007] Where R is CH3, Any one of .

[0008] The synthesis method of the present invention uses 3-alkoxy-1,2-diol propane of formula (I) as the starting material.

[0009] The compound of formula (I) is dispersed in a dichloromethane solution of nitric and sulfuric acid mixture to carry out nitration reaction to obtain the compound of formula (II) 3-alkoxy-1,2-dioxonitropropane.

[0010] The specific steps include:

[0011] Step S1, dispersing the compound 3-alkoxy-1,2-diol propane in an organic solvent containing 0.5-4 ml of concentrated sulfuric acid in an ice bath to obtain an organic solution system;

[0012] Step S2, slowly adding the nitrating agent dropwise to the organic solution system, and then slowly raising the temperature to the reaction temperature after the addition is completed, and reacting for 0.5-3 hours;

[0013] Step S3, pouring the mixed solution into ice water to quench, stirring for 10-40 minutes to separate the organic phase, extracting the aqueous phase with dichloromethane, and combining the extracted organic phases;

[0014] In step S4, the organic phase is washed several times with a saturated potassium bicarbonate solution and pure water, and residual water is removed with anhydrous magnesium sulfate. Dichloromethane is removed by vacuum distillation to obtain a liquid product II (yield of about 60-70%).

[0015]

[0016] As a preference of the present invention, the organic solvent in step S1 is one of dichloromethane and acetonitrile.

[0017] As a preferred embodiment of the present invention, the nitrating agent in step S2 is one of nitric and sulfuric acid, fuming nitric acid, and nitrogen pentoxide.

[0018] As a preference of the present invention, the volume ratio of the nitrating agent to the concentrated sulfuric acid is 1:(1-4).

[0019] As a preferred embodiment of the present invention, the molar ratio of 3-alkoxy-1,2-diol propane to the nitrating agent is 1:(3-10).

[0020] As a preference of the present invention, the reaction temperature in step S2 is room temperature or other temperatures between 25-40°C.

[0021] The present invention also provides a nitrate energetic plasticizer, Where R is CH3, Any one of .

[0022] The present invention also provides an application of a nitrate energetic plasticizer as a plasticizer in formulated explosives or propellants.

[0023] The beneficial effect of the present invention is that an energetic nitrate group is introduced into an aliphatic compound containing a flexible ether group to obtain a new aliphatic energetic plasticizer. The synthesis method of this type of plasticizer is simple, and it has the advantages of low viscosity, good thermal stability, low glass transition temperature, etc., and is a potential application-type energetic plasticizer. DETAILED DESCRIPTION

[0024] Example 1. Synthesis of the compound 3-tert-butoxy-1,2-dioxonitropropane (TDNP) of formula (II)

[0025]

[0026] Under ice bath, compound 3-(tert-butoxy)propane-1,2-diol (0.741 g, 5 mmol) was dispersed in a dichloromethane solution containing concentrated sulfuric acid (1 ml). Subsequently, fuming nitric acid (0.25 mL) was slowly added dropwise to the system. After the addition was completed, the temperature was slowly raised to room temperature. After reacting for 2 h, the mixed solution was poured into 15 mL of ice water and stirred for 30 min to separate the organic phase. The aqueous phase was extracted with dichloromethane, and the extracted organic phases were combined and washed several times with saturated potassium bicarbonate solution and pure water, respectively. Residual water was removed by anhydrous magnesium sulfate, and dichloromethane was removed by distillation under reduced pressure to obtain 0.91 g of a light yellow liquid (yield 77%).

[0027] Structure identification:

[0028] 1 H NMR (600MHz, CDCl3): δ (ppm) 4.80-4.93 (m, 1H), 4.40-4.45 (m, 1H), 3.87-3.95 (m, 1H), 3.38-3.48 (m, 2H), 1.14 (s, 9H);

[0029] 13 C NMR (150MHz, DMSO-d6): δ (ppm) 84.01, 83.25, 71.60, 70.80, 31.76;

[0030] IR (KBr, νcm- 1 ): 3130, 3040, 2995 (-CH2), 1740, 1729 (-NO2), 1398, 1321, 1130, 1093, 1021, 927, 867, 842 (-CH2-), 716.

[0031] Elemental analysis (%): C7H 14N2O7 (238.20), calculated values: C, 35.30; H, 5.92; N, 11.76; found values: C, 34.29; H, 6.85; N, 10.13.

[0032] Thermal stability analysis: T d :180.4℃,T g :<-70℃.

[0033] Example 2. Synthesis of the compound 3-methoxy-1,2-dioxonitropropane (MDNP) of formula (II)

[0034]

[0035] Under ice bath, compound 3-methoxy-1,2-diol (1.06 g, 10 mmol) was dispersed in a dichloromethane solution containing concentrated sulfuric acid (2 ml). Subsequently, fuming nitric acid (0.5 mL) was slowly added dropwise to the system. After the addition was completed, the temperature was slowly raised to room temperature. After reacting for 2 h, the mixed solution was poured into 15 mL of ice water and stirred for 30 min to separate the organic phase. The aqueous phase was extracted with dichloromethane, and the extracted organic phases were combined and washed several times with saturated potassium bicarbonate solution and pure water, respectively. Residual water was removed by anhydrous magnesium sulfate, and dichloromethane was removed by distillation under reduced pressure to obtain 1.19 g of a light yellow liquid (yield 61%).

[0036] 1 H NMR (600MHz, DMSO-d6): δ (ppm) 4.60-4.67 (m, 1H), 4.47-4.49 (m, 1H), 3.84-3.91 (m, 1H), 3.36-3.43 (m, 2H), 3.08 (s, 3H);

[0037] 13 C NMR (150MHz, DMSO-d6): δ (ppm) 83.83, 72.01, 71.15, 59.77;

[0038] IR (KBr, νcm- 1 ): 3150, 3050, 2996 (-CH2), 1745, 1730 (-NO2), 1493, 1398, 1332, 1167, 1097, 1030, 921, 866, 840 (-CH2-), 721.

[0039] Elemental analysis (%): C4H8N2O7 (196.12), calculated value: C, 24.50; H, 4.11; N, 14.28; found value: C, 23.12; H, 5.24; N, 13.78.

[0040] Thermal stability analysis: Td :172.4℃;T g :<-70℃.

[0041] Example 3. Synthesis of the compound 3-allyloxy-1,2-dioxonitropropane (ADNP) of formula (II)

[0042]

[0043] Under ice bath, compound 3-allyloxy-1,2-diol (0.66 g, 5 mmol) was dispersed in a dichloromethane solution containing concentrated sulfuric acid (1 ml). Subsequently, fuming nitric acid (0.25 mL) was slowly added dropwise to the system. After the addition was completed, the temperature was slowly raised to room temperature. After reacting for 2 h, the mixed solution was poured into 15 mL of ice water and stirred for 30 min to separate the organic phase. The aqueous phase was extracted with dichloromethane, and the extracted organic phases were combined and washed several times with saturated potassium bicarbonate solution and pure water, respectively. Residual water was removed by anhydrous magnesium sulfate, and dichloromethane was removed by distillation under reduced pressure to obtain 0.65 g of a light yellow liquid (yield 60%).

[0044] 1 H NMR (600MHz, DMSO-d6): δ (ppm) 5.85-5.90 (m, 1H), 5.24-5.28 (m, 1H), 5.14-5.16 (m , 1H), 4.58-4.60(m, 1H), 4.42-4.45(m, 1H), 3.91-3.97(m, 3H), 3.36-3.43(m, 2H);

[0045] 13 C NMR (150MHz, DMSO-d6): δ (ppm) 135.48, 117.04, 84.60, 75.61, 71.84, 71.32;

[0046] IR (KBr, νcm- 1 ): 3140, 3012 (-CH2), 1743, 1725 (-NO2), 1397, 1332, 1322, 1147, 1099, 1027, 966, 920, 866, 840 (-CH2-), 723.

[0047] Elemental analysis (%): C6H 10 Calculated for N2O7 (222.15): C, 32.44; H, 4.54; N, 12.61; Found: C, 30.25; H, 6.02; N, 10.78.

[0048] Thermal stability analysis: T d :189.1℃;T g :-55.5℃.

[0049] Although the present invention is described herein with reference to illustrative embodiments of the present invention, the above embodiments are merely preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A nitrate ester energetic plasticizer, having the following structural formula: Where R is CH3, Any one of .

2. The method for synthesizing a nitrate ester energetic plasticizer according to claim 1, wherein: Formula I 3-alkoxy-1,2-diol propane is used as the starting material, and an energetic plasticizer is obtained through a one-step nitration reaction; The synthesis method is carried out according to the following reaction formula:

3. The method for synthesizing a nitrate ester energetic plasticizer according to claim 2, wherein: The specific steps include: Step S1, dispersing the compound 3-alkoxy-1,2-diol propane in an organic solvent containing 0.5-4 ml of concentrated sulfuric acid in an ice bath to obtain an organic solution system; Step S2, adding a nitrating agent dropwise to the organic solution system, raising the temperature to the reaction temperature after the addition is complete, and reacting for 0.5-3 hours; Step S3, pouring the mixed solution into ice water to quench, stirring for 10-40 minutes to separate the organic phase, extracting the aqueous phase with dichloromethane, and combining the extracted organic phases; Step S4, washing the organic phase several times with a saturated potassium bicarbonate solution and pure water, removing residual water with anhydrous magnesium sulfate, and removing dichloromethane by vacuum distillation to obtain a liquid product II.

4. The method for synthesizing a nitrate ester energetic plasticizer according to claim 3, wherein: The organic solvent in step S1 is one of dichloromethane and acetonitrile.

5. The method for synthesizing a nitrate ester energetic plasticizer according to claim 4, wherein: The nitrating agent in step S2 is one of nitric and sulfuric acid, fuming nitric acid, and nitrogen pentoxide.

6. The method for synthesizing a nitrate ester energetic plasticizer according to claim 5, wherein: The volume ratio of the nitrating agent to concentrated sulfuric acid is 1:(1-4).

7. The method for synthesizing a nitrate ester energetic plasticizer according to claim 6, wherein: The molar ratio of 3-alkoxy-1,2-diol propane to the nitrating agent is 1:(3-10).

8. The method for synthesizing a nitrate ester energetic plasticizer according to claim 7, wherein: The reaction temperature in step S2 is room temperature or other temperatures between 25-40°C.

9. The use of a nitrate energetic plasticizer according to claim 1, characterized in that: As a plasticizer in formulated explosives or propellants.

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