NEPE propellant and preparation method thereof

Abstract

The invention provides an NEPE propellant and a preparation method thereof, and belongs to the field of propellants. The NEPE propellant provided by the invention is prepared from the following components in parts by mass: 11.001 to 33.01 parts of an adhesive system; the bonding system comprises an adhesive, a plasticizer, a curing agent and a curing catalyst; the adhesive comprises tetrahydrofuran-ethylene oxide copolyether, and the degree of functionality of the tetrahydrofuran-ethylene oxide copolyether is 2.5 to 3; the curing agent comprises dimer acid diisocyanate; 5-20 parts of aluminum powder; 0 to 52 parts of cyclotrimethylene trinitramine; and 5-75 parts of ammonium perchlorate. By changing a bonding system of the propellant and using the tetrahydrofuran-ethylene oxide copolyether and the curing agent dimer acid diisocyanate (DDI), the burning rate and the burning rate pressure index of the NEPE propellant are successfully reduced, and the problem that the burning rate and the burning rate pressure index of the NEPE propellant are too high is solved.

Description

Technical Field

[0001] This invention relates to the field of propellants, specifically to a NEPE propellant and its preparation method. Background Technology

[0002] Modern weaponry requires engines to provide continuous and stable thrust, which necessitates propellants with low burning rates and low burning rate pressure indices. Commonly used NEPE propellants contain large amounts of nitrate esters and nitramine explosives, resulting in generally high burning rates and burning rate pressure indices. Current NEPE propellant technologies mostly reduce these indices by adjusting the particle size distribution of the oxidizer or high-energy filler, adding rate-degrading agents, or a combination of both. However, these methods may affect the propellant's mechanical and energy properties. Summary of the Invention

[0003] This invention provides a NEPE propellant and its preparation method. The NEPE propellant of this invention achieves a reduction in burning rate and burning rate pressure index while ensuring mechanical and energy performance.

[0004] This invention provides a NEPE propellant, comprising the following components in parts by mass:

[0005] The adhesive system consists of 11.001 to 33.01 parts.

[0006] The adhesive system includes an adhesive, a plasticizer, a curing agent, and a curing catalyst; the adhesive includes tetrahydrofuran-ethylene oxide copolyether, the functionality of which is 2.5 to 3; the curing agent includes dimer diisocyanate.

[0007] 5-20 parts aluminum powder;

[0008] Cyclotrimethylenetrinitramine 0-52 parts;

[0009] Ammonium perchlorate, 5-75 parts.

[0010] Preferably, the adhesive system comprises, by weight, 5-10 parts adhesive, 5-20 parts plasticizer, 1-3 parts curing agent and 0.001-0.01 parts curing catalyst.

[0011] Preferably, the branched tetrahydrofuran-ethylene oxide copolyether has a functionality of 2.6 to 2.8.

[0012] Preferably, the plasticizer includes one or more of butyl-nitroethyl nitramine, nitroglycerin, and 1,2,4-butanetriol trinitrate.

[0013] Preferably, the curing catalyst comprises one or more of dibutyltin dilaurate, triphenylbismuth, iron acetylacetone, magnesium naphthenate, and triethylamine.

[0014] Preferably, the particle size of the aluminum powder is 1–15 μm.

[0015] Preferably, the ammonium perchlorate has a particle size of 5–150 μm.

[0016] Preferably, the particle size of the cyclotrimethylenetrinitramine is 5–100 μm.

[0017] This invention also provides a method for preparing the NEPE propellant described in the above technical solution, comprising the following steps:

[0018] The raw materials for preparing NEPE propellant are mixed and then cured to obtain the NEPE propellant.

[0019] Preferably, the mixture includes:

[0020] The adhesive and plasticizer are first mixed, and then the resulting first mixture is second mixed with aluminum powder, ammonium perchlorate and cyclotrimethylenetrinitramine to obtain a second mixture;

[0021] The second mixture is then mixed with a curing agent and a curing catalyst in a third mixture, and the resulting third mixture is then vacuum cast.

[0022] The curing temperature is 40–50°C, and the curing time is 5–7 days.

[0023] This invention successfully reduced the burning rate and burning rate pressure index of NEPE propellant by changing the propellant's bonding system and using tetrahydrofuran-ethylene oxide copolyether with appropriate functionality and dimer diisocyanate (DDI) as a curing agent, thus solving the problem of excessively high burning rate and burning rate pressure index of NEPE propellant. Detailed Implementation

[0024] This invention provides a NEPE propellant, comprising the following components in parts by mass:

[0025] The adhesive system consists of 11.001 to 33.01 parts.

[0026] The adhesive system includes an adhesive, a plasticizer, a curing agent, and a curing catalyst; the adhesive includes tetrahydrofuran-ethylene oxide copolyether, the functionality of which is 2.5 to 3; the curing agent includes dimer diisocyanate.

[0027] 5-20 parts aluminum powder;

[0028] Cyclotrimethylenetrinitramine 0-52 parts;

[0029] Ammonium perchlorate, 5-75 parts.

[0030] The raw materials for preparing the NEPE propellant provided by the present invention, by weight, include 11.001 to 33.01 parts of a binder system. In specific embodiments of the present invention, the weight of the binder system can be 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, or 33 parts; the binder system includes a binder, a plasticizer, a curing agent, and a curing catalyst.

[0031] The adhesive system comprises 5 to 10 parts by weight of adhesive. In specific embodiments of the present invention, the adhesive component in the adhesive system may be 6, 7, 8, or 9 parts by weight. The adhesive includes tetrahydrofuran. Tetrahydrofuran-ethylene oxide copolyether, wherein the functional group of the tetrahydrofuran-ethylene oxide copolyether is... The functionality is 2.5 to 3. In specific embodiments of the present invention, the functionality of the tetrahydrofuran-ethylene oxide copolyether can be 2.6, 2.7, 2.8 or 2.9.

[0032] Based on the mass fraction of the adhesive system, the components of the adhesive system include 5 to 20 parts of plasticizer. In specific embodiments of the present invention, the mass fraction of the plasticizer in the adhesive system can be 6, 8, 10, 12, 15, 16, or 18 parts. The plasticizer includes one or more of butyl-nitroethyl nitramine, nitroglycerin, and 1,2,4-butanetriol trinitrate.

[0033] Based on the mass fraction of the adhesive system, the components of the adhesive system include 1 to 3 parts of curing agent. In specific embodiments of the present invention, the mass fraction of curing agent in the adhesive system can be 1.5 parts, 2 parts, or 2.5 parts, and the curing agent includes dimer diisocyanate.

[0034] Based on the mass fraction of the adhesive system, the components of the adhesive system include 0.001 to 0.01 parts of curing catalyst. In specific embodiments of the present invention, the mass fraction of the curing catalyst in the adhesive system can be 0.002 parts, 0.003 parts, 0.004 parts, 0.005 parts, 0.006 parts, 0.007 parts, 0.008 parts, or 0.009 parts. The curing catalyst preferably includes one or more of dibutyltin dilaurate, triphenylbismuth, iron acetylacetone, magnesium naphthenate, and triethylamine.

[0035] Based on the mass fraction of the adhesive system, the raw materials for preparing the NEPE propellant provided by the present invention include 5 to 20 parts of aluminum powder. In specific embodiments of the present invention, the mass fraction of the aluminum powder can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 parts. The particle size of the aluminum powder is preferably 1 to 15 μm. In specific embodiments of the present invention, the particle size of the aluminum powder can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, or 14 μm.

[0036] Aluminum powder is used as a metallic fuel.

[0037] Based on the mass fraction of the adhesive system, the raw materials for preparing the NEPE propellant provided by this invention include 0 to 52 parts of cyclotrimethylenetrinitramine. In specific embodiments of this invention, the mass fraction of cyclotrimethylenetrinitramine can be 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 parts. The particle size of the cyclotrimethylenetrinitramine is preferably 5 to 100 μm. In specific embodiments of this invention, the particle size of the aluminum powder can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm.

[0038] Based on the mass fraction of the adhesive system, the raw materials for preparing the NEPE propellant provided by this invention include 5-75 parts of ammonium perchlorate. In specific embodiments of this invention, the mass fraction of the ammonium perchlorate can be... Thinking of 5 portions, 10 portions, 15 portions, 20, 25, 30, 35, 40, 45, or 50 servings; The particle size of the cyclotrimethylenetrinitramine is preferably 5-150 μm. In specific embodiments of the present invention, the particle size of the ammonium perchlorate can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm or 140 μm.

[0039] Ammonium perchlorate acts as an oxidizing agent.

[0040] This invention also provides a method for preparing the NEPE propellant described in the above technical solution, comprising the following steps:

[0041] The raw materials for preparing NEPE propellant are mixed and then cured to obtain the NEPE propellant.

[0042] In this invention, the mixing preferably includes: first mixing the adhesive and plasticizer, then second mixing the resulting first mixture with aluminum powder, ammonium perchlorate, and cyclotrimethylenetrinitramine to obtain a second mixture; third mixing the second mixture with a curing agent and a curing catalyst, and then vacuum casting the resulting third mixture.

[0043] In this invention, the temperature of the first mixing is preferably 40-50°C; the temperature of the curing is preferably 40-50°C, and the time is preferably 5-7 days.

[0044] The following detailed description of the NEPE propellant and its preparation method provided by the present invention, with reference to specific embodiments, should not be construed as limiting the scope of protection of the present invention.

[0045] Example 1

[0046] Formula composition: 8.22g adhesive, 16.43g plasticizer, 1.35g curing agent, 0.001g curing catalyst, 17g aluminum powder, 32g cyclotrimethylenetrinitramine, and 25g ammonium perchlorate.

[0047] The adhesive used is ethylene oxide-tetrahydrofuran copolymer ether with a functionality of 2.8 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.);

[0048] The plasticizer is butyl-nitroethyl nitramine (Bu-NENA);

[0049] The curing agent is dimer diisocyanate (DDI);

[0050] The curing catalyst is dibutyltin dilaurate (T12);

[0051] The aluminum powder (Al) has a particle size of 5 μm;

[0052] Ammonium perchlorate (AP) has a particle size of 100–150 μm;

[0053] The particle size of cyclotrimethylenetrinitramine (RDX) is 50–100 μm;

[0054] The adhesive and plasticizer were mixed at 50°C, and then aluminum powder, ammonium perchlorate and cyclotrimethylenetrinitramine were added and mixed thoroughly. After that, the curing agent and curing catalyst were added and mixed thoroughly again. The resulting mixture was then vacuum cast and cured at 50°C for 7 days. After curing, NEPE propellant containing 32% cyclotrimethylenetrinitramine was obtained.

[0055] The only difference between the ordinary NEPE propellant and that in Example 1 is that the binder is tetrahydrofuran-ethylene oxide copolymer with a functionality of 1.9 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.), and the curing agent is hexamethylene diisocyanate biuret.

[0056] The NEPE propellant in Example 1 has an elongation at break of approximately 104.6% and a tensile strength of approximately 0.243 MPa; the ordinary NEPE propellant has an elongation at break of 70.2% and a tensile strength of 0.208 MPa.

[0057] Table 1. Burning rate and burning rate pressure index of NEPE propellant and ordinary NEPE propellant in Example 1.

[0058]

[0059] As shown in Table 1, compared with ordinary NEPE propellant, the burning rate of this propellant at 15–22 MPa decreased by about 5–15%, and the burning rate pressure index at 15–22 MPa decreased from about 0.86 to about 0.61.

[0060] Example 2

[0061] Formula composition: 8.22g adhesive, 16.43g plasticizer, 1.35g curing agent, 0.001g curing catalyst, 17g aluminum powder, 42g cyclotrimethylenetrinitramine, and 15g ammonium perchlorate.

[0062] The adhesive used is ethylene oxide-tetrahydrofuran copolymer ether with a functionality of 2.8 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.);

[0063] The plasticizer is butyl-nitroethyl nitramine (Bu-NENA);

[0064] The curing agent is dimer diisocyanate (DDI);

[0065] The curing catalyst is dibutyltin dilaurate (T12);

[0066] The aluminum powder has a particle size of 5μm;

[0067] Ammonium perchlorate has a particle size of 100–150 μm;

[0068] Cyclotrimethylenetrinitramine has a particle size of 50–100 μm.

[0069] The adhesive and plasticizer were mixed at 50°C, and then aluminum powder, ammonium perchlorate and cyclotrimethylenetrinitramine were added and mixed thoroughly. After that, the curing agent and curing catalyst were added and mixed thoroughly again. The resulting mixture was then vacuum cast and cured at 50°C for 7 days. After curing, NEPE propellant containing 42% cyclotrimethylenetrinitramine was obtained.

[0070] The only difference between the ordinary NEPE propellant and that in Example 2 is that the binder is tetrahydrofuran-ethylene oxide copolymer with a functionality of 1.9 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.), and the curing agent is hexamethylene diisocyanate biuret.

[0071] The common NEPE propellant has an elongation at break of 114.5% and a tensile strength of 0.161 MPa (this system is currently the commonly used propellant system); the NEPE propellant in Example 2 has an elongation at break of approximately 166.7% and a tensile strength of approximately 0.200 MPa.

[0072] Table 2 shows the burning rate and burning rate pressure index of NEPE propellant and ordinary NEPE propellant in Example 2.

[0073]

[0074] As shown in Table 2, compared with ordinary NEPE propellant, the burning rate of this propellant at 15–22 MPa decreased by about 5–15%, and the burning rate pressure index at 15–22 MPa decreased from about 0.96 to about 0.79.

[0075] Example 3

[0076] Formula composition: 8.22 g adhesive, 16.43 g plasticizer, 1.35 g curing agent, 0.001 g curing catalyst, 17 g aluminum powder, 52 g cyclotrimethylenetrinitramine, and 5 g ammonium perchlorate.

[0077] The adhesive used is ethylene oxide-tetrahydrofuran copolymer ether with a functionality of 2.8 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.);

[0078] The plasticizer is butyl-nitroethyl nitramine (Bu-NENA);

[0079] The curing agent is dimer diisocyanate (DDI);

[0080] The curing catalyst is dibutyltin dilaurate (T12);

[0081] The aluminum powder has a particle size of 5μm;

[0082] Ammonium perchlorate has a particle size of 100–150 μm;

[0083] Cyclotrimethylenetrinitramine has a particle size of 50–100 μm.

[0084] The adhesive and plasticizer were mixed at 50°C, and then aluminum powder, ammonium perchlorate and cyclotrimethylenetrinitramine were added and mixed thoroughly. After that, the curing agent and curing catalyst were added and mixed thoroughly again. The resulting mixture was then vacuum cast and cured at 50°C for 7 days. After curing, NEPE propellant containing 52% cyclotrimethylenetrinitramine was obtained.

[0085] The only difference between the ordinary NEPE propellant and Example 3 is that the binder is tetrahydrofuran-ethylene oxide copolymer with a functionality of 1.9 (purchased from Luoyang Liming Chemical Research and Design Institute Co., Ltd.), and the curing agent is hexamethylene diisocyanate biuret.

[0086] The ordinary NEPE propellant has an elongation at break of 167.7% and a tensile strength of 0.125 MPa, while the NEPE propellant in Example 3 has an elongation at break of 218.1% and a tensile strength of 0.169 MPa.

[0087] Table 3 shows the burning rate and burning rate pressure index of NEPE propellant and ordinary NEPE propellant in Example 3.

[0088]

[0089] As shown in Table 3, compared with ordinary NEPE propellant, the burning rate of this propellant at 15–22 MPa decreased by about 5–15%, and the burning rate pressure index at 15–22 MPa decreased from about 1.07 to about 0.92.

[0090] Comparative Example 1

[0091] The only difference from Example 2 is that the adhesive is tetrahydrofuran ethylene oxide copolyether with a functionality of 2.8, and the curing agent is hexamethylene diisocyanate.

[0092] The propellant of Comparative Example 1 had an elongation at break of 170.1%, a tensile strength of 0.117 MPa, a burning rate of approximately 9.8 mm / s at 15 MPa, and a burning rate pressure index of approximately 0.99 at 15–22 MPa.

[0093] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A NEPE propellant, characterized in that, Based on parts by mass, it includes the following components: The adhesive system consists of 11.001 to 33.01 parts. The adhesive system includes an adhesive, a plasticizer, a curing agent, and a curing catalyst; the adhesive includes tetrahydrofuran-ethylene oxide copolyether, the functionality of which is 2.5 to 3; the curing agent includes dimer diisocyanate. 5-20 parts aluminum powder; Cyclotrimethylenetrinitramine 0-52 parts; Ammonium perchlorate, 5-75 parts.

2. The NEPE propellant according to claim 1, characterized in that, The adhesive system comprises, by weight, 5-10 parts adhesive, 5-20 parts plasticizer, 1-3 parts curing agent and 0.001-0.01 parts curing catalyst.

3. The NEPE propellant according to claim 1, characterized in that, The branched tetrahydrofuran-ethylene oxide copolyether has a functionality of 2.6 to 2.

8.

4. The NEPE propellant according to claim 1 or 2, characterized in that, The plasticizer includes one or more of butyl-nitroethyl nitramine, nitroglycerin, and 1,2,4-butanetriol trinitrate.

5. The NEPE propellant according to claim 1 or 2, characterized in that, The curing catalyst includes one or more of dibutyltin dilaurate, triphenylbismuth, iron acetylacetone, magnesium naphthenate, and triethylamine.

6. The NEPE propellant according to claim 1, characterized in that, The aluminum powder has a particle size of 1–15 μm.

7. The NEPE propellant according to claim 1, characterized in that, The ammonium perchlorate has a particle size of 5–150 μm.

8. The NEPE propellant according to claim 1, characterized in that, The particle size of the cyclotrimethylenetrinitramine is 5–100 μm.

9. A method for preparing the NEPE propellant according to any one of claims 1 to 8, characterized in that, Includes the following steps: The raw materials for preparing NEPE propellant are mixed and then cured to obtain the NEPE propellant.

10. The preparation method according to claim 9, characterized in that, The mixture includes: The adhesive and plasticizer are first mixed, and then the resulting first mixture is second mixed with aluminum powder, ammonium perchlorate and cyclotrimethylenetrinitramine to obtain a second mixture; The second mixture is then mixed with a curing agent and a curing catalyst in a third mixture, and the resulting third mixture is then vacuum cast. The curing temperature is 40–50°C, and the curing time is 5–7 days.

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