阅读说明：本技术 ADN/AlH3复合微球、制备方法和包含该微球的固体推进剂 (ADN/AlH3Composite microspheres, preparation method and solid propellant containing microspheres ) 是由 李磊 陈红 胡翔 黄丹椿 汪慧思 杜芳 陶博文 邱贤平 顾健 庞爱民 于 2020-11-27 设计创作，主要内容包括：本发明涉及一种二硝酰胺铵/三氢化铝(ADN/AlH_3)复合微球、其制备方法及包含该复合微球的固体推进剂,该复合微球结构从内到外依次为ADN层,第一反应型保护层,AlH_3层和第二反应型保护层,结构-性能可调,制备工艺简单、安全、稳定,适合放大生产的需要,该微球吸湿率低、机械感度低,应用前景广阔。本发明复合微球适用于不同的粘合剂-固化体系,可以用在HTPB、GAP粘合剂-异氰酸酯固化剂体系中亦可以用在GAP粘合剂-炔基固化剂体系中,具有优异的安全性能和成药性能,能显著提高固体推进剂低特征信号性能,可用于高能推进剂配方研究,也适用于丁羟推进剂性能提升研究。(The invention relates to ammonium dinitramide/aluminum trihydride (ADN/AlH) 3 ) The composite microsphere structure sequentially comprises an ADN layer, a first reactive protective layer and AlH from inside to outside 3 The layer and the second reactive protective layer have adjustable structure-performance, simple, safe and stable preparation process, low moisture absorption rate, low mechanical sensitivity and wide application prospect, and are suitable for the requirement of amplified production. The composite microsphere is suitable for different adhesive-curing systems, can be used in HTPB and GAP adhesive-isocyanate curing agent systems and can also be used in GAP adhesive-alkynyl curing agent systems, has excellent safety performance and patent drug performance, can obviously improve the low characteristic signal performance of the solid propellant, can be used for the formula research of high-energy propellants and is also suitable for the performance improvement research of the hydroxyl propellant.)

1. ADN/AlH₃The composite microsphere is characterized in that the composite microsphere structure sequentially comprises an ADN layer, a first reactive protective layer and AlH from inside to outside₃A layer and a second reactive type protective layer.

2. An ADN/AlH according to claim 1₃The composite microsphere is characterized in that the first reactive protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE and a curing agent; the second reaction type protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE and a curing agent; the first reactive type protective layer and the second reactive type protective layer have the same or different components.

3. An ADN/AlH according to claim 2₃The composite microsphere is characterized in that the curing agent is isophorone diisocyanate (IPDI) or toluene diisocyanate (T)One or more than one combination of DI or polyfunctional aliphatic isocyanate N-100.

4. An ADN/AlH according to any of claims 1 to 4₃The composite microsphere is characterized in that the first reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere, and the second reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere.

5. An ADN/AlH according to claim 1₃The preparation method of the composite microspheres is characterized by comprising the following steps:

(1) dissolving ADN in a solvent, adding a first reactive protective layer precursor, and uniformly stirring for later use, wherein the first reactive protective layer comprises a prepolymer, a curing agent and a catalyst;

(2)AlH₃mixing with antisolvent, and maintaining AlH under stirring and ultrasonic action₃In a suspended state;

(3) dripping the solution obtained in the step (1) into the solution obtained in the step (2), and reacting for 3-6h at the temperature of 30-70 ℃;

(4) dissolving a second reactive protective layer precursor in a solvent, dropwise adding the solution obtained in the step (3), continuously reacting for 3-12 h, cooling to room temperature, filtering and drying to obtain ADN/AlH₃The second reactive protective layer precursor comprises a prepolymer, a curing agent and a catalyst.

6. An ADN/AlH according to claim 5₃The preparation method of the composite microsphere is characterized in that ADN and AlH are added₃The mass ratio of (A) to (B) is 1: 5-5: 1; preferably, ADN and AlH are added₃The mass ratio of (A) to (B) is 1: 4-4: 1.

7. An ADN/AlH according to claim 5₃The preparation method of the composite microspheres is characterized in that the solvent in the step (1) and the step (4) is one or more of acetonitrile or acetone, and the anti-solvent in the step (2) isCyclohexane, dichloromethane, trichloromethane or toluene.

8. An ADN/AlH according to claim 5₃The preparation method of the composite microspheres is characterized in that the solution obtained in the step (1) is an ADN saturated solution.

9. An ADN/AlH according to claim 5₃The preparation method of the composite microspheres is characterized in that in the step (1), the prepolymer is one or more of terminal hydroxyl glycidyl ether GAP, terminal hydroxyl polybutadiene HTPB or terminal hydroxyl perfluoropolyether PFPE, the curing agent is one or more of isophorone diisocyanate IPDI, toluene diisocyanate TDI or polyfunctional aliphatic isocyanate N-100, and the catalyst is di-N-butyltin dilaurate;

in the step (4), the prepolymer is one or more of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE, the curing agent is one or more of isophorone diisocyanate IPDI, toluene diisocyanate TDI or polyfunctional aliphatic isocyanate N-100, and the catalyst is di-N-butyltin dilaurate.

10. An ADN/AlH according to claim 5₃The preparation method of the composite microspheres is characterized in that in the step (2), AlH₃Mixing with anti-solvent, ultrasonic pulverizing in cell pulverizer for 5-30min, and maintaining AlH under the dual effects of stirring and ultrasonic₃Is in a suspended state.

11. An ADN/AlH according to claim 5₃The preparation method of the composite microspheres is characterized in that the mass ratio of the anti-solvent added in the step (2) to the solvent in the step (1) is 4: 1-50: 1.

12. An ADN/AlH according to claim 5₃A preparation method of a composite microsphere, which comprises the following steps of,the method is characterized in that in the step (2), the stirring speed is 600-1000 rpm, and the ultrasonic power is 600-2000 w.

13. Comprises ADN/AlH₃The solid propellant of the composite microspheres is characterized by comprising the following components in percentage by mass:

ADN/AlH according to any of claims 1 to 4₃Compounding the microspheres: 20 to 40 percent;

adhesive: GAP or HTPB: 7 to 20 percent;

plasticizer: 5% -20%;

curing agent: 0.5 to 5.0 percent;

oxidizing agent: 10% -60%;

fuel: 0% -20%;

functional auxiliary agents: 0 to 3 percent.

14. An ADN/AlH containing composition according to claim 13₃The solid propellant of the composite microspheres is characterized in that the plasticizer is one or more of a combination of nitroglycerin NG and triethylene glycol dinitrate TEGDN, a combination of nitroglycerin NG and 1,2, 4-tributyl triol trinitrate BTTN, and triethylene glycol dinitrate TEGDN or dioctyl sebacate DOS; the oxidant is one or more of ammonium perchlorate AP, ammonium nitrate AN, ADN, hexogen RDX, octogen HMX or hexanitrohexaazaisowurtzitane CL-20.

15. An ADN/AlH containing composition according to claim 13₃The solid propellant of the composite microspheres is characterized in that the fuel is aluminum powder or AlH₃One or a combination of more than one of; the curing agent is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), polyfunctional aliphatic isocyanate N-100 or dipropargyl butanediol succinate (BPS).

16. An ADN/AlH containing composition according to claim 13₃Solid propellant of composite microspheres, characterized in thatWherein the functional auxiliary agent comprises a burning rate catalyst, a curing catalyst and a stabilizer; the burning rate catalyst is one or more of lead oxide, iron oxide or aluminum oxide; the curing catalyst is triphenyl bismuth TPB; the stabilizer is a combination of N-methyl-p-nitroaniline MNA and 2-dinitrodiphenylamine 2-NDPA.

Technical Field

The invention belongs to the technical field of propellants, and particularly relates to ADN/AlH₃Composite microspheres, a preparation method thereof and a solid propellant containing the microspheres.

Background

ADN (ammonium dinitramide) has an available oxygen content close to that of AP (ammonium perchlorate), an oxygen balance of + 25.8%, a formation enthalpy of-149.8 kJ/mol and a crystal density of 1.812g/cm³The environment-friendly high-energy propellant has the characteristics of high energy, large gas forming amount, low toxicity, clean fuel gas, environmental friendliness and the like, and can greatly improve the energy performance of the propellant, reduce characteristic signals and reduce environmental pollution by replacing an AP oxidizing agent. Research shows that the specific impulse of the propellant can be improved by 98 N.s/kg by using 40 percent of ADN in HTPB (hydroxyl-terminated polybutadiene) propellant; ADN is used for low characteristic signal propellant, can improve the specific impulse by 7 percent, and is used for aluminum-containing propellant, can improve the specific impulse by 10 percent.

AlH₃(aluminum trihydride) having a standard molar enthalpy of formation of-11.8 kJ/mol and a density of 1.48g/cm³The hydrogen content is 10.08%, the hydrogen storage density is 148g/L, which is twice of that of liquid hydrogen, and compared with aluminum powder, the hydrogen storage fuel has the advantages of higher combustion heat and capability of generating small molecular gas, and is an ideal fuel for replacing the aluminum powder in the solid composite propellant. The use of AlH in solid propellants is reported₃The specific impulse can be increased to 98 Ns/kg by replacing Al powder; the AlH is adopted in the solid-liquid propellant₃The specific impulse can be improved by 313.6 Ns/kg by replacing Al powder; addition of AlH to liquid propellants₃The specific impulse can be increased by 264.6 Ns/kg.

With AlH₃ADN and energy contentThe standard theoretical specific impulse of the solid propellant consisting of the adhesive can reach 2881.2 N.s/kg, is 20 to 25 percent higher than that of the traditional solid propellant, is environment-friendly and clean, and is a typical high-energy low-characteristic signal propellant and a clean propellant, so that the AlH is used as the AlH₃The high-energy solid propellant applied in combination with ADN becomes the focus of attention of researchers at home and abroad.

On the one hand, however, ADN is highly hygroscopic, and the ADN crystals are deliquesced in 10h in an environment with a relative humidity of more than 50% and are incompatible with the adhesive systems commonly used in propellants; and AlH₃The self-stability is poor, the danger of decomposition, spontaneous combustion and spontaneous explosion exists, meanwhile, the chemical compatibility of the plasticizer and the oxidant containing energy is poor, the explosion is easy to cause in the pharmaceutical process, and higher safety risk exists in the practical popularization and application process. Thus, the hygroscopicity of ADN and AlH are solved₃Are ADN and AlH and their compatibility with the propellant component₃The bottleneck technology for realizing large-scale application in the field of composite explosives and solid propellants is realized.

In order to reduce the hygroscopicity of ADN, the following two solutions are mainly adopted at home and abroad: firstly, the morphology of ADN is changed by adopting a spheroidization technology; and secondly, the surface treatment is carried out on the ADN, so that the surface energy is reduced, the hydrophobicity is improved, and the contact with water is blocked, thereby achieving the effect of improving the hygroscopicity. For example, ADN is utilized by United states company to spheroidize the particles in a molten state by a capillary granulation technology; the chemical division of NAWC of the American aviation war center adopts a mode of high-temperature mineral oil emulsification-low-temperature crystallization to prepare the sphericized ADN; polysulfide corporation prepares moisture-resistant spherical ADN by spray dispersion with the fumed silica method. The german ICT uses a fluidized bed to improve coating granulation to prepare the spheroidized coated ADN. The similar method is adopted by national institute of western-ampere modern chemistry to prepare the coated-spheroidized ADN. However, the above methods require spheroidization around the melting point (90 ℃) of ADN, and the local overheating or aggregation of the material is liable to cause safety accidents, and it is difficult to industrially produce the spherical particles.

To increase AlH₃Stability and reduction of AlH₃The sensitivity of the base propellant is generally surface passivation method and surface coating at home and abroadAlH by method, doping method and crystal transformation method₃And (4) carrying out modification. Organic coating of AlH, e.g. by James et al₃. Norman et al have studied the precipitation of AlH by adsorption in the gaseous state or by using liquid inorganic substances₃To increase its stability. Mark et al in alpha-AlH₃Surface coating energy adjusting Al³⁺The substance(s) of (a) is (are) a polyhydroxy monomer and a polymer. Donald to AlH₃The crystal is coated with a cyano-containing substance, simple substance aluminum and the like, and the coating substance plays a role in physical isolation. Although these methods can increase AlH to some extent₃But generally causes the problems of reduced hydrogen content, non-compact surface coating and the like, and can not meet the requirement of the propellant on the safety performance in the development process.

Disclosure of Invention

The invention aims to overcome the defects and provide an ADN/AlH₃The (ammonium dinitramide/aluminum trihydride) composite microspheres have simple, safe and stable preparation method and are easy to be produced in an enlarged way; on the one hand, the hygroscopicity and AlH of ADN can be effectively reduced₃The sensitivity of (c); on the other hand, ADN and AlH are avoided₃Poor compatibility caused by direct contact with the common components of the propellant, and simultaneously solves the problems of strong ADN hygroscopicity and AlH in the application process₃High sensitivity.

The invention also aims to provide a preparation method of the composite microsphere.

It is a further object of the present invention to provide a solid propellant comprising the composite energetic microspheres.

In order to achieve the above purpose, the invention provides the following technical scheme:

ADN/AlH₃The composite microsphere structure comprises an ADN layer, a first reactive protective layer and AlH in sequence from inside to outside₃A layer and a second reactive type protective layer.

Further, the first reaction type protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE and a curing agent; the second reaction type protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE and a curing agent; the first reactive type protective layer and the second reactive type protective layer have the same or different compositions.

Further, the curing agent is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI) or polyfunctional aliphatic isocyanate N-100.

Furthermore, the first reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere, and the second reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere.

ADN/AlH₃The preparation method of the composite microsphere comprises the following steps:

(1) dissolving ADN in a solvent, adding a first reactive protective layer precursor, and uniformly stirring for later use, wherein the first reactive protective layer comprises a prepolymer, a curing agent and a catalyst;

(2)AlH₃mixing with antisolvent, and maintaining AlH under stirring and ultrasonic action₃In a suspended state;

(3) dripping the solution obtained in the step (1) into the solution obtained in the step (2), and reacting for 3-6h at the temperature of 30-70 ℃;

(4) dissolving a second reactive protective layer precursor in a solvent, dropwise adding the solution obtained in the step (3), continuously reacting for 3-12 h, cooling to room temperature, filtering and drying to obtain ADN/AlH₃The second reactive protective layer precursor comprises a prepolymer, a curing agent and a catalyst.

Further, ADN and AlH are added₃The mass ratio of (A) to (B) is 1: 5-5: 1; preferably, ADN and AlH are added₃The mass ratio of (A) to (B) is 1: 4-4: 1.

Further, the solvent in the step (1) and the step (4) is one or more of acetonitrile or acetone, and the antisolvent in the step (2) is one or more of cyclohexane, dichloromethane, trichloromethane or toluene.

Further, the solution obtained in the step (1) is an ADN saturated solution.

Further, in the step (1), the prepolymer is one or more of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE, the curing agent is one or more of isophorone diisocyanate IPDI, toluene diisocyanate TDI or polyfunctional aliphatic isocyanate N-100, and the catalyst is di-N-butyltin dilaurate;

in the step (4), the prepolymer is one or more of hydroxyl-terminated glycidyl ether GAP, hydroxyl-terminated polybutadiene HTPB or hydroxyl-terminated perfluoropolyether PFPE, the curing agent is one or more of isophorone diisocyanate IPDI, toluene diisocyanate TDI or polyfunctional aliphatic isocyanate N-100, and the catalyst is di-N-butyltin dilaurate;

further, in the step (2), AlH₃Mixing with anti-solvent, ultrasonic pulverizing in cell pulverizer for 5-30min, and maintaining AlH under the dual effects of stirring and ultrasonic₃Is in a suspended state.

Further, the mass ratio of the anti-solvent added in the step (2) to the solvent in the step (1) is 4: 1-50: 1.

Further, in the step (2), the stirring speed is 600-1000 rpm, and the ultrasonic power is 600-2000 w.

Comprises ADN/AlH₃The solid propellant of the composite microsphere comprises the following components in percentage by mass:

ADN/AlH₃compounding the microspheres: 20 to 40 percent;

adhesive: GAP or HTPB: 7 to 20 percent;

plasticizer: 5% -20%;

curing agent: 0.5 to 5.0 percent;

oxidizing agent: 10% -60%;

fuel: 0% -20%;

functional auxiliary agents: 0 to 3 percent.

Further, the plasticizer is one or more of a combination of nitroglycerin NG and triethylene glycol dinitrate TEGDN, a combination of nitroglycerin NG and 1,2, 4-tributyl triol trinitrate BTTN, triethylene glycol dinitrate TEGDN or dioctyl sebacate DOS; the oxidant is one or more of ammonium perchlorate AP, ammonium nitrate AN, ADN, hexogen RDX, octogen HMX or hexanitrohexaazaisowurtzitane CL-20.

Further, the fuel is aluminum powder or AlH₃One or a combination of more than one of; the curing agent is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), polyfunctional aliphatic isocyanate N-100 or dipropargyl alcohol succinate (BPS).

Further, the functional auxiliary agent comprises a burning rate catalyst, a curing catalyst and a stabilizer; the burning rate catalyst is one or more of lead oxide, iron oxide or aluminum oxide; the curing catalyst is triphenyl bismuth TPB; the stabilizer is a combination of N-methyl-p-nitroaniline MNA and 2-dinitrodiphenylamine 2-NDPA.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention firstly combines ADN and AlH₃Compounding to prepare the novel ADN/AlH₃Composite energetic microsphere, ADN and AlH in the composite microsphere₃The proportion of the propellant is adjustable, so that the energy of the propellant can be adjusted; meanwhile, the halogen-free flame retardant has excellent compatibility with propellant components, can obviously improve the performance of patent drugs and the safety performance when used in the propellant, does not contain halogen, and can obviously improve the performance of low characteristic signals of the propellant.

(2) Respectively reducing the hygroscopicity of ammonium dinitramide and AlH in the conventional method₃The method adopts in-situ self-assembly, and utilizes a first reaction type protective layer to realize in-situ coating of ADN and adsorption of AlH₃Then AlH is precipitated by liquid phase precipitation using a second reactive type protective layer₃Immobilization to form ADN/AlH₃And (3) compounding the microspheres. The first reaction type protective layer is chemically connected with the ADN, and has physical adsorption, compact structure, moisture barrier function, reduced ADN hygroscopicity, and coated AlH₃Surface, reducing AlH₃Mechanical sensitivity of (3).

(3) ADN/AlH of the invention₃The composite energetic microsphere has the advantages of low hygroscopicity, low mechanical sensitivity, strong universality and the like, an outer protective layer is a common component of a propellant, is suitable for different adhesive-curing systems, can be used in an HTPB-isocyanate curing system and a GAP-isocyanate curing system, can also be used in a GAP-alkynyl curing agent system, can be used for formula research of a high-energy propellant, and is also suitable for performance improvement of a hydroxyl-terminated propellant.

(4) The invention has mild, simple and safe process conditions and controllable microsphere structure, and is suitable for industrial production.

(5) A large number of experiments show that the composite energy-containing microspheres can be used for high-energy solid propellants, the chemical performance of the high-energy solid propellants can be obviously improved, the composite energy-containing microspheres have good application prospects in the high-energy solid propellants, and a new reliable technical approach is provided for a new generation of high-energy, green and low-characteristic signal solid propellants.

Drawings

FIG. 1 shows an ADN/AlH of the present invention₃A schematic structure diagram of the composite microsphere;

FIG. 2 shows the use of ADN/AlH in example 1 of the present invention₃ADN-AlH in HTPB propellant replaced by composite microspheres₃Real object diagrams of the medicine blocks before and after the mixture;

FIG. 3 shows the use of ADN/AlH in example 2 of the present invention₃Composite microspheres substitute for ADN-AlH in GAP propellant₃Real object diagrams of the medicine blocks before and after the mixture;

FIG. 4 shows the use of ADN/AlH in example 3 of the present invention₃Composite microspheres substitute for ADN-AlH in GAP propellant₃The material object diagrams of the front and the back medicine blocks of the mixture.

Detailed Description

The features and advantages of the present invention will become more apparent and appreciated from the following detailed description of the invention.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The invention relates to ammonium dinitramide/aluminum trihydride (ADN/AlH)₃) The composite microsphere structure comprises an ADN layer, a first reactive protective layer and AlH in sequence from inside to outside₃Layer, second reactive type protective layer, as shown in fig. 1.

The first reaction type protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether (GAP), hydroxyl-terminated polybutadiene (HTPB) or hydroxyl-terminated perfluoropolyether (PFPE) and a curing agent; the second reaction type protective layer is one or more of polymers obtained by the reaction of hydroxyl-terminated glycidyl ether (GAP), hydroxyl-terminated polybutadiene (HTPB) or hydroxyl-terminated perfluoropolyether (PFPE) and a curing agent.

The curing agent is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI) or polyfunctional aliphatic isocyanate (N-100).

In the composite microsphere, ADN and AlH₃The mass ratio of (A) to (B) is 1: 5-5: 1, preferably 1: 4-4: 1.

In the composite microsphere, the first reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere, and the second reactive protective layer accounts for 0.5-10% of the total mass of the composite microsphere.

Ammonium dinitramide/aluminum trihydride (ADN/AlH) according to the invention₃) The preparation method of the composite microsphere is characterized by being precipitated by combining an in-situ self-assembly method and comprising the following steps of:

(1) dissolving ADN in a solvent, adding a first reaction type protective layer precursor, and uniformly stirring for later use, wherein the first reaction type protective layer comprises a prepolymer, a curing agent and a catalyst, the stirring time is 20-30 min, the rotating speed is 400-800rpm, the prepolymer is one of hydroxyl-terminated glycidyl ether (GAP), hydroxyl-terminated polybutadiene (HTPB) or hydroxyl-terminated perfluoropolyether (PFPE), the curing agent is one or a combination of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI) or polyfunctional aliphatic isocyanate (N-100), and the catalyst is di-N-butyltin dilaurate.

(2) Reacting AlH₃Placing into a beaker, adding antisolvent, ultrasonic pulverizing in a cell pulverizer for 5min to make it more uniform, transferring into a three-neck flask, and maintaining AlH under the dual effects of stirring and ultrasonic₃In a suspended state;

(3) dripping the solution obtained in the step (1) into the solution obtained in the step (2), wherein the dripping speed is 0.2-1 mL/min, and reacting for 3-6h at the temperature of 30-70 ℃;

(4) dissolving a second reactive protective layer precursor in a solvent, stirring the solution in the solvent to pre-react for 0.5 to 1 hour, dropwise adding the solution into the solution obtained in the step (3), continuously reacting for 3 to 12 hours, cooling to room temperature, filtering and drying to obtain ADN/AlH₃The second reactive protective layer precursor comprises a prepolymer, a curing agent and a catalyst. The prepolymer is one of hydroxyl-terminated glycidyl ether (GAP), hydroxyl-terminated polybutadiene (HTPB) or hydroxyl-terminated perfluoropolyether (PFPE), the curing agent is one or a combination of more than one of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI) or polyfunctional aliphatic isocyanate (N-100), the catalyst is di-N-butyltin dilaurate, and the raw materials can be the same as or different from the precursor of the first reaction protective layer in the step (1); the solvent is acetone or acetonitrile; the dropping speed is 0.2mL/min to 1 mL/min.

Further, adding the ADN and AlH₃The mass ratio of (A) to (B) is 1: 5-5: 1, preferably 1: 4-4: 1.

Further, the solvent in the step (1) is one or more of acetonitrile or acetone, and the anti-solvent in the step (2) is one or more of cyclohexane, dichloromethane, trichloromethane or toluene.

Further, the solution obtained in the step (1) is an ADN saturated solution. The mass ratio of the anti-solvent added in the step (2) to the solvent in the step (1) is 4: 1-50: 1.

Further, in the step (2), the stirring speed is 600-1000 rpm, and the ultrasonic power is 600-2000 w.

The invention comprises ammonium dinitramide/aluminum trihydride (ADN/AlH)₃) The solid propellant of the composite microspheres comprises the following components in percentage by massDividing into:

ADN/AlH₃compounding the microspheres: 20 to 40 percent

Adhesive: GAP or HTPB: 7 to 20 percent of

Plasticizer: 5 to 20 percent of

Curing agent: 0.5 to 5.0 percent

Oxidizing agent: 10 to 60 percent.

Fuel: 0 to 20 percent

Functional auxiliary agents: 0 to 3 percent.

The plasticizer is a combination of Nitroglycerin (NG) and triethylene glycol dinitrate (TEGDN), or a combination of Nitroglycerin (NG) and 1,2, 4-tributyl triol trinitrate (BTTN), or triethylene glycol dinitrate (TEGDN), or dioctyl sebacate (DOS).

The oxidant is one or more of Ammonium Perchlorate (AP), Ammonium Nitrate (AN), ADN, hexogen (RDX), octogen (HMX) or hexanitrohexaazaisowurtzitane (CL-20).

The fuel is aluminum powder or AlH₃One or a combination of more than one of them.

The curing agent is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), polyfunctional aliphatic isocyanate (N-100) or dipropargyl alcohol succinate (BPS).

The functional assistant comprises a burning rate catalyst, a curing catalyst and a stabilizer.

The burning rate catalyst is one or more of lead oxide, iron oxide or aluminum oxide.

The curing catalyst was triphenyl bismuth (TPB).

The stabilizer is a combination of N-methyl-p-nitroaniline (MNA) and 2-dinitrodiphenylamine (2-NDPA).

Comprising ADN/AlH₃The solid propellant of the composite energetic microspheres is prepared by adopting a vertical mixing and vacuum casting method, and comprises the following steps:

and mixing by using a vertical mixer, and realizing the production of the propellant grain by using a vacuum spraying and pouring system. Before using HTPB binder or PEG binder or GAP binder and plasticizerPremixing to form uniform liquid (hereinafter referred to as glue); before mixing, fuel Al and ADN/AlH of the invention₃Premixing the composite energetic microspheres and 60% of glue, adding the premixed material into a mixing pot, mixing, adding the energetic oxidant, mixing, adding the curing agent and 10% of glue, and mixing by adding 30% of glue.

After propellant slurry is uniformly mixed, the slurry is poured into a mould with a corresponding size by using a vacuum spraying pouring system, and is cured for 96-192 hours in an oven at 50 +/-2 ℃.

Analysis conditions were as follows: saturated moisture absorption rate: weighing at a relative humidity of 75% and a temperature of 30 ℃ for every 24 hours by adopting a balancer weighing method, and calculating the mass gain rate after the mass difference of two continuous times is less than 0.0002 g; impact sensitivity: the characteristic falling height and critical impact energy of 50% explosion of the specimen were given by the characteristic falling height method (critical impact energy method) (I50). Implements aerospace industry Standard QJ 3039-1998; friction sensitivity: the results are expressed as burst percentage, as 25 tests are carried out under certain gauge pressure (e.g. 2.5MPa, 4.0MPa) and swing angle (e.g. 66 °, 90 °).

Ammonium (mono) dinitramide/aluminium trihydride (ADN/AlH)₃) Preparation and performance characterization of composite energetic microspheres

Example 1

Completely dissolving 5g of ADN and 0.2g of HTPB glue, TDI curing agent and organic tin catalyst in 20mL of acetonitrile; 5gAlH₃Placing into a beaker, adding 100ml of antisolvent dichloromethane, and keeping AlH under the dual action of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 1000 rpm; the ADN solution was added dropwise at a rate of 0.2ml/min to a solution containing 5g of AlH₃The temperature of the dichloromethane dispersion liquid is kept at 40 ℃, the ultrasonic power is 700W, the stirring speed is 1000rpm, and the reaction is carried out for 3 hours; then 20mL of acetonitrile solution containing 0.5g of HTPB glue, TDI curing agent and organic tin catalyst is dripped into the solution, the mixture is cooled to room temperature after continuous reaction for 12h, and filtration and vacuum drying are carried out to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃The moisture absorption test of the composite energetic microspheres and 5g of mixture of ADN and AlH3 with the mass ratio of 1:1 under the conditions of the relative humidity of 75% and the temperature of 30 ℃ shows that: ADN/AlH₃The saturation moisture absorption rate of the composite energetic microspheres is 3.2 percent, and the mixture of ADN and AlH3 is 25.4 percent.

Example 2

Completely dissolving 8g of ADN and 0.12g of GAP glue, TDI curing agent and organic tin catalyst in 20mL of acetone; 4gAlH₃Placing into a beaker, adding 100ml of antisolvent cyclohexane, and keeping AlH under the dual action of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 800 rpm; the ADN solution was added dropwise at a rate of 0.5ml/min to a solution containing 4g of AlH₃In the cyclohexane dispersion liquid, the temperature is kept at 50 ℃, the ultrasonic power is 700W, the stirring speed is 800rpm, and the reaction is carried out for 3 hours; then 20mL of acetone solution containing 0.6g of PFPE glue, TDI curing agent and organic tin catalyst is dripped into the solution to continue to react for 8 hours, and then the solution is cooled to room temperature, filtered and dried in vacuum to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃Composite energetic microspheres and 5g of ADN and AlH with the mass ratio of 2:1₃The mixture is subjected to a hygroscopicity test under the conditions of 75% relative humidity and 30 ℃ temperature, and the results show that: the saturated moisture absorption rate of ADN/AlH3 composite energetic microsphere is 6.2 percent, and ADN and AlH₃The mixture was 37.5%.

Example 3

Completely dissolving 5g of ADN and 0.2g of PFPE glue, TDI curing agent and organic tin catalyst in 15mL of acetone; 5gAlH₃Placing into a beaker, adding 75ml of antisolvent cyclohexane, and keeping AlH under the double actions of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 600 rpm; and the ADN solution was added dropwise at a dropping rate of 1ml/min to a solution containing 5g of AlH₃In the cyclohexane dispersion liquid, the temperature is kept at 40 ℃, the ultrasonic power is 700W, the stirring speed is 600rpm, and the reaction is carried out for 3 hours; then 8mL of acetone solution containing 0.3g of PFPE glue, TDI curing agent and organic tin catalyst is dripped into the solution, the solution is cooled to room temperature after continuous reaction for 6 hours, and filtration and vacuum drying are carried out to obtain offwhite ADN/AlH₃Composite energetic microspheres. Taking 5g of ADN/AlH3 composite energetic microspheres and 5g of mixture of ADN and AlH3 with the mass ratio of 1:1, and carrying out the steps of reaction at the relative humidity of 75% and the temperature of 30 DEG CMoisture absorption test, the result shows that: ADN/AlH₃The saturated moisture absorption rate of the composite energetic microsphere is 3.6 percent, and ADN and AlH₃The mixture was 25.4%.

Example 4

Completely dissolving 4g of ADN and 0.24g of PFPE glue, TDI curing agent and organotin catalyst in 15mL of acetone; 8gAlH₃Placing into a beaker, adding 75ml of antisolvent cyclohexane, and keeping AlH under the double actions of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 700 rpm; and the ADN solution was added dropwise at a dropping rate of 0.5ml/min to a solution containing 8g of AlH₃In the cyclohexane dispersion liquid, the temperature is kept at 60 ℃, the ultrasonic power is 700W, the stirring speed is 700rpm, and the reaction is carried out for 3 hours; then, 10mL of acetone solution containing 0.48g of GAP glue, IPDI curing agent and organic tin catalyst is dripped into the solution, the solution is cooled to room temperature after continuous reaction for 6 hours, and filtration and vacuum drying are carried out to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃Composite energetic microspheres and 5g of ADN and AlH with the mass ratio of 1:2₃The mixture is subjected to a hygroscopicity test under the conditions of 75% relative humidity and 30 ℃ temperature, and the results show that: ADN/AlH₃The saturated moisture absorption rate of the composite energetic microsphere is 1.2 percent, and ADN and AlH₃The mixture was 18.3%.

Example 5

Completely dissolving 5g of ADN and 0.5g of PFPE glue, TDI curing agent and organic tin catalyst in 15mL of acetone; 5gAlH₃Placing into a beaker, adding 75ml of anti-solvent toluene, and keeping AlH under the double actions of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 600 rpm; and the ADN solution was added dropwise at a dropping rate of 0.5ml/min to a solution containing 5g of AlH₃In the toluene dispersion liquid, the temperature is kept at 50 ℃, the ultrasonic power is 700W, the stirring speed is 600rpm, and the reaction is carried out for 3 hours; then, 10mL of acetone solution containing 0.5g of GAP glue, N-100 curing agent and organic tin catalyst is dripped into the solution, the solution is cooled to room temperature after continuous reaction for 6 hours, and filtration and vacuum drying are carried out to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃The mass ratio of the composite energetic microspheres to 5g is 11 ADN and AlH₃The mixture is subjected to a hygroscopicity test under the conditions of 75% relative humidity and 30 ℃ temperature, and the results show that: ADN/AlH₃The saturated moisture absorption rate of the composite energetic microsphere is 2.2 percent, and ADN and AlH₃The mixture was 37.5%.

Example 6

Completely dissolving 2g of ADN and 0.2g of PFPE glue, TDI curing agent and organic tin catalyst in 10mL of acetone; 8gAlH₃Placing into a beaker, adding 50ml of antisolvent cyclohexane, and keeping AlH under the double actions of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 700 rpm; and the ADN solution was added dropwise at a dropping rate of 0.2ml/min to a solution containing 8g of AlH₃In the cyclohexane dispersion liquid, the temperature is kept at 40 ℃, the ultrasonic power is 700W, the stirring speed is 700rpm, and the reaction is carried out for 3 hours; then, 10mL of acetone solution containing 0.5g of GAP glue, N-100 curing agent and organic tin catalyst is dripped into the solution, the solution is cooled to room temperature after continuous reaction for 6 hours, and filtration and vacuum drying are carried out to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃Composite energetic microspheres and 5g of ADN and AlH with the mass ratio of 1:4₃The mixture is subjected to a hygroscopicity test under the conditions of 75% relative humidity and 30 ℃ temperature, and the results show that: ADN/AlH₃The saturated moisture absorption rate of the composite energetic microsphere is 0.4 percent, and ADN and AlH₃The mixture was 13.8%.

Example 7

Completely dissolving 8g of ADN and 0.2g of PFPE glue, TDI curing agent and organic tin catalyst in 25mL of acetone; 2gAlH₃Placing into a beaker, adding 125ml of antisolvent cyclohexane, and keeping AlH under the double actions of stirring and ultrasound₃In a suspension state, the ultrasonic power is 700W, and the stirring speed is 800 rpm; and the ADN solution was added dropwise at a dropping rate of 0.5ml/min to a solution containing 2g of AlH₃In the cyclohexane dispersion liquid, the temperature is kept at 40 ℃, the ultrasonic power is 700W, the stirring speed is 800rpm, and the reaction is carried out for 3 hours; then 20mL of acetone solution containing 0.8g of PFPE + TDI curing agent and organotin catalyst is dripped into the solution, after the solution is continuously reacted for 6 hours, the solution is cooled to room temperature, filtered and dried in vacuum to obtain offwhite ADN/AlH₃Composite energetic microspheres. 5g ADN/AlH was taken₃Composite energetic microspheres and 5g of ADN and AlH with the mass ratio of 1:1₃The mixture is subjected to a hygroscopicity test under the conditions of 75% relative humidity and 30 ℃ temperature, and the results show that: ADN/AlH₃The saturated moisture absorption rate of the composite energetic microsphere is 8.4 percent, and ADN and AlH₃The mixture is 44%

(II) application of composite microspheres in high-energy propellant formula

Example 8

Examine ADN AlH₃ADN/AlH with mass ratio of 2:1₃The HTPB adhesive-TDI curing system propellant of the composite microsphere has the application performance, and the formula composition is shown in table 1. The mechanical sensitivity performance of the propellant is shown in the table 2, and the patent drug property is shown in the table 2.

TABLE 1 HTPB adhesive-TDI curing System propellant composition

Formulation composition	Content/% wt
		HTPB	16
DOS	8
		AP	25.5
HMX	10
		Al	8
TDI	1
		Functional auxiliary agent	1.5
ADN/AlH3Composite microspheres	30

TABLE 2 ADN/AlH₃Composite microsphere replacing ADN-AlH₃Influence of the mixture on the sensitivity of the propellant

Formulation composition	Impact sensitivity/J	Degree of friction sensitivity/%)
			ADN+AlH3Mixture of	10	80
ADN/AlH3Composite microspheres	15	20

Example 9

Examine ADN AlH₃ADN/AlH with mass ratio of 1:1₃The application performance of the GAP adhesive-TDI curing system propellant of the composite microsphere is shown in the formula composition in table 3. Mechanical sensitivity of propellantThe patent refers to Table 4 and the patent refers to FIG. 3.

TABLE 3 GAP Binder-TDI curing System propellant composition

Formulation composition	Content/% wt
		GAP	8
NG+BTTN	15
		HMX	34.5
N-100	1
		Functional auxiliary agent	1.5
ADN/AlH3Composite microspheres	40

TABLE 4 ADN/AlH₃Composite microsphere replacing ADN-AlH₃Influence of the mixture on the sensitivity of the propellant

Formulation composition	Impact sensitivity/J	Degree of friction sensitivity/%)
			ADN+AlH3Mixture of	6.2	100
ADN/AlH3Composite microspheres	25.5	36

Example 10

Examine ADN AlH₃ADN/AlH with mass ratio of 3:1₃The application performance of the GAP adhesive-BPS curing system propellant of the composite microsphere is shown in the formula composition in the table 5. The mechanical sensitivity performance of the propellant is shown in Table 6, and the patent drug property is shown in figure 4.

TABLE 5 GAP Binder-BPS curing System propellant composition

Formulation composition	Content/% wt
		GAP	8
NG+BTTN	15
		HMX	31.5
BPS	4
		Functional auxiliary agent	1.5
ADN/AlH3Composite microspheres	40

TABLE 6 ADN/AlH₃Composite microsphere replacing ADN-AlH₃Influence of the mixture on the sensitivity of the propellant

Formulation composition	Impact sensitivity/J	Degree of friction sensitivity/%)
			ADN+AlH3Mixture of	7.2	100
ADN/AlH3Composite microspheres	26.5	36

As can be seen from tables 1-6, ADN/AlH was used in both HTPB and GAP propellants₃Composite microspheres to replace ADN and AlH in propellants₃Impact feeling of mixture, propellant slurryThe degree and the friction sensitivity are both obviously reduced; as can be seen from FIGS. 2 to 4, the reactive pores of the blocks after the propellant is cured and molded are obviously reduced or eliminated, the curing and medicine forming properties of HTPB adhesive-TDI curing system and GAP adhesive-N-100 curing system (BPS) propellant are obviously improved, and the ADN/AlH is proved₃The composite microsphere has better application performance.

The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.