A polyether solid propellant containing phenyl POSS and a preparation method thereof

Abstract

The present invention relates to a polyether solid propellant containing phenyl-caged oligosilsesquioxane (POSS) and a preparation method thereof, belonging to the technical field of propellant preparation. The composite propellant uses hydroxyl-terminated ethylene oxide-tetrahydrofuran copolymer ether or polyethylene glycol as the binder. In a typical propellant formulation, the mass fraction of the binder system is 28.5%, aluminum powder accounts for 18%, the oxidizer accounts for 52.5%, and the phenyl POSS material accounts for 1%. It is prepared by a kneading-casting process. The organic-inorganic hybrid skeleton of the phenyl POSS material can burn to form a carbonaceous material, enabling the prepared propellant to have both good mechanical properties and combustion properties.

Description

[0001] This application claims the priority of a Chinese patent application titled "A Polyether Solid Propellant Containing Phenyl POSS and Its Preparation Method" with the application number CN202210237060.X filed with the Chinese Patent Office on March 10, 2022. The entire content of which is incorporated herein by reference. Technical Field

[0002] The present invention relates to a polyether solid propellant containing phenyl POSS and its preparation method, belonging to the technical field of propellant preparation. Background Art

[0003] Polyether solid propellants are common high-energy composite solid propellant systems today. The binder system can improve the combustion environment of oxidants and metal fuels during propellant combustion, release more energy at the same time, improve the combustion performance of the propellant, and have good mechanical properties and processability, but there are defects of incomplete and unstable combustion. Introducing combustion catalysts into the polyether propellant formulation can effectively regulate the combustion performance of the propellant. Common combustion catalysts such as Fe 2 O 3 etc. are mainly used to increase or decrease the burning rate and do not have other functions. The content of aluminum powder fuel in high-energy polyether propellants is high, up to 18% - 20% at most, and the problem of aluminum combustion agglomeration will reduce the combustion efficiency of solid propellants.

[0004] Cage-like oligosilsesquioxane (POSS) is an organosilicon compound with a unique molecular structure. The inorganic silicon-oxygen framework core provides good hardness and thermal stability for it, and the peripheral organic groups can enhance the compatibility with the polymer matrix. Its structure is similar to that of porous zeolites, with voids unique to POSS molecules and voids generated by ineffective packing between cage-like molecules, and has catalytic characteristics. Phenyl-containing POSS compounds can produce silicon oxide and nano-layered carbonaceous materials by self-combustion and have a porous structure, which is expected to have a beneficial impact on the combustion and mechanical properties of solid propellants. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a polyether solid propellant containing phenyl POSS compound and its preparation method.

[0006] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a polyether solid propellant containing phenyl POSS. Calculated based on the total mass of the polyether solid propellant containing phenyl POSS being 100 parts, the components and their mass parts are as follows:

[0008] 25 to 28.5 parts of binder system, the binder system includes binder, plasticizer, curing agent and curing catalyst; the binder is hydroxyl-terminated ethylene oxide-tetrahydrofuran copolymer ether (PET) or polyethylene glycol (PEG);

[0009] 5 to 20 parts of aluminum powder;

[0010] 1 part of phenyl POSS;

[0011] The balance is high-energy oxidizer.

[0012] Preferably, the phenyl POSS is octaphenylsilsesquioxane (OPS), octanitrophenylsilsesquioxane (ONPS), octa(dinitrophenyl)silsesquioxane (ODNPS) or octaaminophenylsilsesquioxane (OAPS).

[0013] Preferably, the plasticizer is a mixture of 2,2-dinitropropyl formal and 2,2-dinitropropyl acetal (A3).

[0014] Preferably, the curing agent is polyfunctional isocyanate (N100) or diphenylmethane diisocyanate (MDI).

[0015] Preferably, the isocyanate content of the polyfunctional isocyanate is 5.25 mmol / g and the average functionality is 3.9.

[0016] Preferably, the number average molecular weight of the diphenylmethane diisocyanate is 250.

[0017] Preferably, the particle size of the aluminum powder is 1 to 15 μm.

[0018] Preferably, the high-energy oxidizer includes one or more of ammonium perchlorate, RDX and HMX.

[0019] Preferably, the ammonium perchlorate includes ammonium perchlorate with a particle size of 100 to 150 μm and ammonium perchlorate with a particle size of 5 to 10 μm, and the mass ratio of the ammonium perchlorate with a particle size of 100 to 150 μm to the ammonium perchlorate with a particle size of 5 to 10 μm is 4:1.

[0020] The present invention also provides a preparation method of the polyether solid propellant containing phenyl POSS according to the above technical solution, including the following steps:

[0021] (1) Mix the plasticizer and the binder at a temperature of 50 to 60 °C, then add the aluminum powder, the oxidizer, and the phenyl POSS, and mix well to obtain mixture A;

[0022] (2) Add the curing agent to the mixture A and mix well to obtain mixture B;

[0023] (3) Vacuum cast the mixture B, and perform curing after the casting is completed. The curing temperature is 50 - 60 °C, and the curing time is 5 - 7 days. After the curing is completed, the polyether solid propellant containing phenyl POSS is obtained.

[0024] In the present invention, the curing catalyst is preferably added last.

[0025] The present invention provides a polyether solid propellant containing phenyl POSS. Calculated based on the total mass of the polyether solid propellant containing phenyl POSS being 100 parts, the components and their mass parts are as follows: 25 - 28.5 parts of the binder system, and the binder system includes a binder, a plasticizer, a curing agent, and a curing catalyst; the binder is a hydroxyl-terminated ethylene oxide - tetrahydrofuran copolymer ether or polyethylene glycol; 5 - 20 parts of aluminum powder; 1 part of phenyl POSS; and the balance is a high-energy oxidizer.

[0026] Beneficial effects:

[0027] (1) The beneficial effects of the present invention are that for the polyether solid propellant, by adding functional additives, the mechanical properties are improved synchronously, the burning rate is adjusted, the aluminum agglomeration during combustion is reduced, and different types of phenyl POSS materials are added to the propellant formulation, and a polyether solid propellant formulation containing phenyl POSS is designed.

[0028] (2) The beneficial effects of the present invention also lie in that the tensile properties of the propellant are enhanced through the organic - inorganic hybrid framework of the phenyl POSS material, and through the combustion of the phenyl POSS material, nano-porous carbonaceous materials are in-situ generated, promoting the combustion of aluminum in the propellant, reducing the aluminum agglomeration during the combustion of the propellant, reducing the particle size of the alumina condensed-phase product, improving the combustion efficiency of aluminum, and significantly improving the comprehensive performance of the polyether solid propellant. Specific embodiments

[0029] Example 1

[0030] Formulation composition: 10 g of binder, 17.4 g of plasticizer, 1 g of curing agent, 0.1 g of curing catalyst, 18 g of aluminum powder, 52.5 g of oxidizer, and 1 g of octaphenylsilsesquioxane (OPS).

[0031] The binder uses a hydroxyl-terminated ethylene oxide - tetrahydrofuran copolymer ether (PET) with a number-average molecular weight of 4000 and a hydroxyl content of 0.435 mmol / g;

[0032] The plasticizer is a mixture of 2,2-dinitropropyl formal and 2,2-dinitropropyl acetal (A3);

[0033] The curing agent is a polyfunctional isocyanate (N100) with an isocyanate content of 5.25 mmol / g and an average functionality of 3.9;

[0034] The particle size of the aluminum powder is 5 μm.

[0035] The oxidizer is ammonium perchlorate with particle sizes of 100 - 150 μm and 5 - 10 μm, and the mass ratio is 4:1;

[0036] The plasticizer and the binder are mixed at a temperature of 60°C, then the aluminum powder, the oxidizer and OPS are added, and after thorough mixing, the curing agent is added and mixed well again. The obtained mixture is subjected to vacuum casting, and after the casting is completed, curing is carried out. The curing temperature is 60°C and the curing time is 7 days. After the curing is completed, a polyether solid propellant containing OPS is obtained.

[0037] The obtained PET propellant has a tensile strength of 0.81 ± 0.07 MPa, an elongation at break ε b of 72.30 ± 1.36%, a burning rate of 12.9 mm / s in a 7 MPa nitrogen environment, a combustion heat of 8.2672 MJ / kg in a 3 MPa nitrogen environment, and the particle size D 90 of the combustion product condensed phase particles is 6.182 μm.

[0038] Example 2

[0039] Formulation composition: 10 g of binder, 17.4 g of plasticizer, 1 g of curing agent, 0.1 g of curing catalyst, 18 g of aluminum powder, 52.5 g of oxidizer, and 1 g of octanitrophenylsilsesquioxane (ONPS).

[0040] The binder uses hydroxyl - terminated ethylene oxide - tetrahydrofuran copolymer ether (PET) with a number - average molecular weight of 4000 and a hydroxyl content of 0.435 mmol / g;

[0041] The plasticizer is a mixture of 2,2 - dinitropropyl alcohol formaldehyde and 2,2 - dinitropropyl alcohol acetaldehyde (A3);

[0042] The curing agent is a polyfunctional isocyanate (N100) with an isocyanate content of 5.25 mmol / g and an average functionality of 3.9;

[0043] The particle size of the aluminum powder is 5 μm.

[0044] The oxidizer is ammonium perchlorate with particle sizes of 100 - 150 μm and 5 - 10 μm, and the mass ratio is 4:1;

[0045] The plasticizer and the binder are mixed at a temperature of 60°C, then the aluminum powder, the oxidizer and ONPS are added, and after thorough mixing, the curing agent is added and mixed well again. The obtained mixture is subjected to vacuum casting, and after the casting is completed, curing is carried out. The curing temperature is 60°C and the curing time is 7 days. After the curing is completed, a polyether solid propellant containing ONPS is obtained.

[0046] The obtained PET propellant has a tensile strength of 0.85 ± 0.07 MPa and an elongation at break ε b of 77.28 ± 1.68%, a burning rate of 14.8 mm / s in a 7 MPa nitrogen environment, a combustion heat of 8.6003 MJ / kg in a 3 MPa nitrogen environment, and the particle size D of the combustion product condensed phase particles 90 is 4.699 μm.

[0047] Example 3

[0048] Formulation composition: 10 g of binder, 17.4 g of plasticizer, 1 g of curing agent, 0.1 g of curing catalyst, 18 g of aluminum powder, 52.5 g of oxidizer, and 1 g of octakis(dinitrophenyl)silsesquioxane (ODNPS).

[0049] The binder is a hydroxyl-terminated ethylene oxide-tetrahydrofuran copolymer ether (PET) with a number average molecular weight of 4000 and a hydroxyl content of 0.435 mmol / g;

[0050] The plasticizer is a mixture of 2,2-dinitropropyl formal and 2,2-dinitropropyl acetal (A3);

[0051] The curing agent is a polyfunctional isocyanate (N100) with an isocyanate content of 5.25 mmol / g and an average functionality of 3.9;

[0052] The particle size of the aluminum powder is 5 μm.

[0053] The oxidizer is ammonium perchlorate with particle sizes of 100 - 150 μm and 5 - 10 μm, and a mass ratio of 4:1;

[0054] The plasticizer and the binder are mixed at a temperature of 60°C, then aluminum powder, oxidizer, and ODNPS are added, and after thorough mixing, the curing agent is added and mixed well again. The obtained mixture is subjected to vacuum casting, and after the casting is completed, it is cured at a curing temperature of 60°C for 7 days to obtain a polyether solid propellant containing ODNPS.

[0055] The obtained PET propellant has a tensile strength of 0.88 ± 0.05 MPa and an elongation at break ε b of 80.96 ± 1.24%, a burning rate of 16.9 mm / s in a 7 MPa nitrogen environment, a combustion heat of 8.7788 MJ / kg in a 3 MPa nitrogen environment, and the particle size D of the combustion product condensed phase particles 90 is 3.009 μm.

[0056] Example 4

[0057] Formulation composition: 10 g of binder, 17.4 g of plasticizer, 1 g of curing agent, 0.1 g of curing catalyst, 18 g of aluminum powder, 52.5 g of oxidizer, and 1 g of octa - aminophenylsilsesquioxane (OAPS).

[0058] The binder is a hydroxyl - terminated ethylene oxide - tetrahydrofuran copolymer ether (PET) with a number - average molecular weight of 4000 and a hydroxyl content of 0.435 mmol / g;

[0059] The plasticizer is a mixture of 2,2 - dinitropropyl alcohol formaldehyde and 2,2 - dinitropropyl alcohol acetaldehyde (A3);

[0060] The curing agent is a polyfunctional isocyanate (N100) with an isocyanate content of 5.25 mmol / g and an average functionality of 3.9;

[0061] The particle size of the aluminum powder is 5 μm.

[0062] The oxidizer is ammonium perchlorate with particle sizes of 100 - 150 μm and 5 - 10 μm, and the mass ratio is 4:1;

[0063] The plasticizer and the binder are mixed at a temperature of 60 °C, then aluminum powder, oxidizer, and OAPS are added, and after thorough mixing, the curing agent is added and mixed thoroughly. The resulting mixture is subjected to vacuum casting. After the casting is completed, it is cured at a curing temperature of 60 °C for 7 days. After curing, a polyether solid propellant containing OAPS is obtained.

[0064] The obtained PET propellant has a tensile strength of 1.09 ± 0.04 MPa, an elongation at break ε b of 92.32 ± 1.55%, a burning rate of 13.6 mm / s in a 7 - MPa nitrogen environment, a combustion heat of 8.4197 MJ / kg in a 3 - MPa nitrogen environment, and the particle size D 90 of the condensed - phase particles of the combustion products is 4.040 μm.

[0065] Comparative example

[0066] Formulation composition: 10 g of binder, 17.4 g of plasticizer, 1 g of curing agent, 0.1 g of curing catalyst, 18 g of aluminum powder, 53.5 g of oxidizer.

[0067] The binder is a hydroxyl - terminated ethylene oxide - tetrahydrofuran copolymer ether (PET) with a number - average molecular weight of 4000 and a hydroxyl content of 0.435 mmol / g;

[0068] The plasticizer is a mixture of 2,2 - dinitropropyl alcohol formaldehyde and 2,2 - dinitropropyl alcohol acetaldehyde (A3);

[0069] The curing agent is a polyfunctional isocyanate (N100), with an isocyanate content of 5.25 mmol / g and an average functionality of 3.9;

[0070] The aluminum powder has a particle size of 5 μm.

[0071] The oxidizer is ammonium perchlorate, with particle sizes of 100 - 150 μm and 5 - 10 μm, and a mass ratio of 4:1;

[0072] The plasticizer and binder are mixed at a temperature of 60°C, then aluminum powder and oxidizer are added, and after thorough mixing, the curing agent is added and further mixed thoroughly. The resulting mixture is subjected to vacuum casting. After the casting is completed, it is cured at a temperature of 60°C for 7 days. After curing, a polyether solid propellant is obtained.

[0073] The obtained PET propellant has a tensile strength of 0.73 ± 0.08 MPa, an elongation at break ε b of 63.65 ± 1.74%, a burning rate of 12.5 mm / s in a 7 MPa nitrogen environment, a combustion heat of 8.8713 MJ / kg in a 3 MPa nitrogen environment, and the particle size D 90 of the combustion product condensed phase particles is 12.450 μm.

[0074] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A polyether solid propellant containing phenyl POSS, characterized in that, calculated based on the total mass of the polyether solid propellant containing phenyl POSS being 100 parts, the components and their mass parts are as follows: The binder system is 25 - 28.5 parts, and the binder system includes a binder, a plasticizer, a curing agent, and a curing catalyst; the binder is a hydroxyl-terminated ethylene oxide-tetrahydrofuran copolymer ether; Aluminum powder is 5 - 20 parts; Phenyl POSS is 1 part; The balance is a high-energy oxidizer.

2. The polyether solid propellant containing phenyl POSS according to claim 1, characterized in that, The phenyl POSS is octaphenylsilsesquioxane, octanitrophenylsilsesquioxane, octa(dinitrophenyl)silsesquioxane, or octaaminophenylsilsesquioxane.

3. The polyether solid propellant containing phenyl POSS according to claim 1, characterized in that, The plasticizer is a mixture of 2,2-dinitropropyl formal and 2,2-dinitropropyl acetal.

4. The polyether solid propellant containing phenyl POSS according to claim 1, characterized in that, The curing agent is a polyfunctional isocyanate or diphenylmethane diisocyanate.

5. The polyether solid propellant containing phenyl POSS according to claim 4, characterized in that, The isocyanate content of the polyfunctional isocyanate is 5.25 mmol / g, and the average functionality is 3.

9.

6. The polyether solid propellant containing phenyl POSS according to claim 1, characterized in that, The particle size of the aluminum powder is 1 - 15 μm.

7. The polyether solid propellant containing phenyl POSS according to claim 1, characterized in that, The high-energy oxidizer includes one or more of ammonium perchlorate, RDX, and HMX.

8. The polyether solid propellant containing phenyl POSS according to claim 7, characterized in that, The ammonium perchlorate includes ammonium perchlorate with a particle size of 100 - 150 μm and ammonium perchlorate with a particle size of 5 - 10 μm, and the mass ratio of the ammonium perchlorate with a particle size of 100 - 150 μm to the ammonium perchlorate with a particle size of 5 - 10 μm is 4:

1.

9. The preparation method of the polyether solid propellant containing phenyl POSS according to any one of claims 1 - 8, characterized in that, includes the following steps: (1) Mix the plasticizer and the binder at a temperature of 50 - 60 °C, then add aluminum powder, high-energy oxidizer, and phenyl POSS, and mix well to obtain mixture A; (2) Add the curing agent to mixture A and mix well to obtain mixture B; (3) Carry out vacuum casting on mixture B, and after the vacuum casting is completed, carry out curing. The curing temperature is 50 - 60 °C, the curing time is 5 - 7 days, and after the curing is completed, the polyether solid propellant containing phenyl POSS is obtained.