An energetic perfluoroborate binder, its preparation method and applications

Abstract

The present invention relates to an energetic perfluoroborate binder, a preparation method thereof and an application thereof, belonging to the technical field of energetic binders. The structural formula of the binder is:; wherein, n is a positive integer less than or equal to 20. The main raw materials of the binder are 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid and polyazidoglycidyl ether; boric acid forms a borate bond with 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, and polyazidoglycidyl ether is compounded through the boron-nitrogen coordination action with 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, realizing the controllable preparation of the energetic perfluoroborate binder. The energetic perfluoroborate binder has high energy and stable storage, and can improve the energy and mechanical properties of the propellant.

Description

Technical Field

[0001] The present invention relates to an energetic perfluoroborate binder, a preparation method thereof, and an application thereof, belonging to the technical field of energetic binders. Background Art

[0002] Solid propellants determine the damage and delivery capabilities of weaponry and have great strategic significance in fields such as aerospace. The commonly used solid propellant is a three-component propellant of hydroxyl-terminated polybutadiene / ammonium perchlorate / aluminum powder (HTPB / AP / Al). Due to the weak interfacial adhesion between the HTPB polyurethane matrix and solid fillers such as AP and Al, "dewetting" is likely to occur during the processing. In most cases, "dewetting" is the main reason for the decline in the mechanical properties of solid propellants. Therefore, it is necessary to additionally add a small amount of binder to increase the adhesion between the fillers, thereby mechanically enhancing the propellant.

[0003] For propellant systems composed of different oxidizers and binders, different types of binders have been developed. For example, traditional small molecule binders such as alkanolamine bonding agents, polyamine bonding agents, nitrogen pyridine bonding agents, borate ester bonding agents, and haiying ketone bonding agents, as well as neutral polymer bonding agents, amide tree bonding agents, and hyperbranched polyether bonding agents. However, these binders are not energetic compounds, and their addition will reduce the energy and burning rate of the propellant. Therefore, there is an urgent need for a binder that can both increase the mechanical properties of the propellant and enhance the energy of the propellant system to replace part of the HTPB. Summary of the Invention

[0004] In order to overcome the defects existing in the prior art, one of the objectives of the present invention is to provide an energetic perfluoroborate binder; the energetic perfluoroborate binder has high energy and stable storage, and can improve the energy and mechanical properties of the propellant.

[0005] Another objective of the present invention is to provide a preparation method of an energetic perfluoroborate binder. The preparation method is simple and easy to operate. The prepared composite contains both fluoride (reducing aluminum powder agglomeration), borate ester groups (enhancing the mechanical properties of the propellant), and an energetic binder (increasing energy and enhancing the mechanical properties of the propellant), achieving structural multifunctionalization in one composite.

[0006] Another objective of the present invention is to provide an application of an energetic perfluoroborate binder. The binder is used to replace part of the solid propellant binder, which can enhance the mechanical properties and combustion heat of the solid propellant.

[0007] To achieve the objectives of the present invention, the following technical solutions are provided.

[0008] An energetic perfluoroborate binder, the structural formula of the binder is:

[0009] ; wherein, n is a positive integer less than or equal to 20.

[0010] Preferably, n is 4 - 10.

[0011] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0012] 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol (PFND) 30% - 50%,

[0013] Boric acid 5% - 10%,

[0014] Glycidyl azide polymer (GAP) 40% - 65%;

[0015] The auxiliary raw material is solvent dimethyl sulfoxide (DMSO) or N,N - dimethylformamide (DMF);

[0016] Boric acid forms a borate bond with 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol, and glycidyl azide polymer is compounded with 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol through boron - nitrogen coordination.

[0017] Preferably, the molecular weight of the glycidyl azide polymer is 480 - 1000.

[0018] A preparation method of the energetic perfluoroborate binder of the present invention, the method steps include:

[0019] (1) Completely dissolve 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol in a solvent to obtain a 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution;

[0020] (2) Completely dissolve boric acid in a solvent, pour the boric acid solution into the 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution, and then stir at 95°C - 105°C for 4h - 6h, and remove the solvent by vacuum rotary evaporation to obtain perfluoroborate;

[0021] (3) Add glycidyl azide polymer and the perfluoroborate to a solvent, stir at 60°C - 80°C for 2h - 3h, and remove the solvent by vacuum rotary evaporation to obtain an energetic perfluoroborate binder.

[0022] Preferably, in step (1), stir at 50°C to 70°C for 3 min to 6 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in the solvent; the mass ratio of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol to the volume of the solvent is 1 g:10 mL to 20 mL.

[0023] Preferably, in step (2), stir at 50°C to 70°C for 3 to 6 min to completely dissolve boric acid in the solvent; the mass ratio of boric acid to the volume of the solvent is 1 g:10 mL to 20 mL.

[0024] Preferably, in step (2), after stirring, perform vacuum rotary evaporation at 80°C to 95°C for 3 to 5 h.

[0025] Preferably, in step (3), the mass ratio of glycidyl azide polymer to the volume of the solvent is 1 g:10 mL to 20 mL; the molecular weight of glycidyl azide polymer is 480 to 1000.

[0026] Preferably, in step (3), perform vacuum rotary evaporation on the obtained solution at 80°C to 95°C for 3 to 5 h.

[0027] An application of an energetic perfluoroborate binder, the binder is used as part of a solid propellant binder, and the addition amount of the binder is 1% to 2% of the total amount of the solid propellant binder.

[0028] Preferably, the solid propellant is HTPB propellant.

[0029] Beneficial effects

[0030] (1) The present invention provides an energetic perfluoroborate binder. The thermal decomposition products of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in the energetic perfluoroborate binder can react with aluminum and aluminum oxide before the aluminum powder reaches its melting point, causing a pre-ignition effect on the aluminum powder, thereby reducing the ignition temperature of the aluminum powder, accelerating the energy release rate of the aluminum powder, and reducing the agglomeration between aluminum powder particles; the chemical bridging effect of boric acid enables glycidyl azide polymer and 1H,1H,2H,3H,3H-perfluorononane-1,2-diol to firmly coat the surface of the aluminum powder, reducing the dehumidification of the propellant and enhancing the mechanical properties of the propellant. The addition of glycidyl azide polymer increases the energy of the propellant.

[0031] (2) The present invention provides an energetic perfluoroborate binder. The main raw materials of the binder are 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid and polyazidoglycidyl ether; boric acid forms a borate bond with 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, and polyazidoglycidyl ether is compounded through the boron-nitrogen coordination with 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, realizing the controllable preparation of the energetic perfluoroborate binder.

[0032] (3) The present invention provides an energetic perfluoroborate binder. The auxiliary raw material of the energetic binder is dimethyl sulfoxide or N,N-dimethylformamide; the reaction of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid will produce water by-product. In order to remove water, only dimethyl sulfoxide or N,N-dimethylformamide with a higher boiling point can be selected; and 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid and polyazidoglycidyl ether are all soluble in dimethyl sulfoxide and DMF to a certain extent. Therefore, dimethyl sulfoxide or DMF is selected as the solvent.

[0033] (4) The present invention provides a preparation method of an energetic perfluoroborate binder. Due to the high boiling point of dimethyl sulfoxide or N,N-dimethylformamide, the by-product water is removed by heating and stirring at a high temperature. If the reaction temperature is low, the water generated by the reaction is difficult to remove, and the reaction yield is low, affecting the progress of subsequent reactions; the treatment by high-temperature vacuum rotary evaporation can well remove the solvent and obtain a product with high purity.

[0034] (5) The present invention provides an application of an energetic perfluoroborate binder. The application is as an energetic binder for solid propellants or explosives; the azide group of the GAP group can increase the energy of explosives or solid propellants, and has good compatibility and dispersibility in propellants or explosives. The tight connection of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid and polyazidoglycidyl ether with aluminum powder can increase the mechanical properties of solid propellants, which is not possessed by ordinary binders. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the synthesis route of the energetic perfluoroborate binder described in the present invention.

[0036] Figure 2 It is the infrared spectra of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), polyazidoglycidyl ether and the final product of Example 1.

[0037] Figure 3The mechanical properties of HTPB / AP / Al (14 / 68 / 18) propellant and the propellant (2 / 12 / 68 / 18) prepared by replacing 2% of HTPB with an energetic perfluoroborate binder. Detailed implementation manners

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but it is not intended to limit the patent of the present invention.

[0039] Example 1

[0040] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0041] 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol (PFND) 30%,

[0042] Boric acid 5%,

[0043] Glycidyl azide polymer (GAP) 65%;

[0044] The auxiliary raw material is dimethyl sulfoxide (DMSO) as a solvent.

[0045] As Figure 1 shown, the method steps are as follows:

[0046] (1) Stir at 50 °C for 6 min to completely dissolve 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol in DMSO to obtain a 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution;

[0047] The mass ratio (g) of 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol to the volume (mL) of DMSO is 1:10;

[0048] (2) Stir at 50 °C for 6 min to completely dissolve boric acid in DMSO, pour the boric acid solution into the 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution prepared in (1), then stir at 95 °C for 6 h, and perform vacuum rotary evaporation on the obtained solution at 95 °C for 3 h to obtain perfluoroborate ester;

[0049] The mass ratio (g) of boric acid to the volume (mL) of DMSO is 1:20;

[0050] (3) Add glycidyl azide polymer and perfluoroborate ester to DMSO, stir at 80 °C for 2 h, and perform vacuum rotary evaporation on the obtained solution at 95 °C for 3 h again to obtain an energetic perfluoroborate binder;

[0051] The mass ratio of glycidyl azide polymer (GAP) to the volume of DMSO is 1:20; the molecular weight of GAP is 480.

[0052] Perform infrared spectroscopy tests on 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), GAP, and the final product prepared in Example 1. The results are as Figure 2 shown. The absorption peak at 1360 cm -1 is for the B-O-C bond, and the absorption peaks in the range of 1190 - 1140 cm -1 are characteristic peaks of C-F, indicating the successful synthesis of perfluoroborate. The stretching vibration of -OH in GAP appears at 3419 cm -1 , and the N3 characteristic peak exists at 2097 cm -1 . Both the hydroxyl and N3 characteristic peaks appear in the infrared spectrum of the final product in Example 1. Additionally, the C-F characteristic peak in the range of 1190 - 1140 cm -1 appears, indicating the successful synthesis of the final product prepared in Example 1.

[0053] Determined by the results of infrared spectroscopy tests and proton nuclear magnetic resonance spectroscopy tests, the structural formula of the adhesive is:

[0054] , where n is 5.

[0055] Perform mechanical property tests on the HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared with the final product in Example 1 (final product in Example 1 / HTPB / AP / Al = 2 / 12 / 68 / 18). The results are as Figure 3 shown. The tensile strength and elongation at break of HTPB / AP / Al are 0.85 MPa and 42% respectively, while those of the propellant prepared with the final product in Example 1 are 0.98 MPa and 47% respectively, indicating that the energetic perfluoroborate adhesive can be used as an energetic adhesive in solid propellants to improve the mechanical properties of the propellants.

[0056] Perform combustion heat tests on the HTPB / AP / Al propellant and the propellant prepared with the final product in Example 1. The combustion heat of HTPB / AP / Al is 16.1 kJ / g, while that of the propellant prepared with the final product in Example 1 is 17.2 kJ / g, indicating that the energetic perfluoroborate adhesive can be used as an energetic adhesive in solid propellants to improve the energy of the propellants.

[0057] Example 2

[0058] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0059] 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (PFND) 50%,

[0060] Boric acid 10%,

[0061] Glycidyl azide polymer (GAP) 40%;

[0062] The auxiliary raw material is dimethyl sulfoxide (DMSO) as a solvent.

[0063] The method steps are as follows:

[0064] (1) Stir at 70 °C for 3 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in DMSO to obtain a 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution;

[0065] The proportional relationship between the mass (g) of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and the volume (mL) of DMSO is 1:20;

[0066] (2) Stir at 70 °C for 3 min to completely dissolve boric acid in DMSO, pour the boric acid solution into the 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution prepared in (1), and then stir at 105 °C for 4 h. The obtained solution is subjected to vacuum rotary evaporation at 80 °C for 5 h to obtain perfluoroborate;

[0067] The proportional relationship between the mass (g) of boric acid and the volume (mL) of DMSO is 1:10;

[0068] (3) Add glycidyl azide polymer and perfluoroborate to DMSO, stir at 60 °C for 3 h, and subject the obtained solution to vacuum rotary evaporation at 80 °C for 5 h again to obtain an energetic perfluoroborate binder;

[0069] The proportional relationship between the mass (g) of glycidyl azide polymer and the volume (mL) of DMSO is 1:10; the molecular weight of glycidyl azide polymer is 760.

[0070] Perform infrared spectroscopy tests on 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), glycidyl azide polymer, and the final product prepared in Example 2, and 1360 cm can be obtained -1is the B-O-C bond, 1190~1140 cm -1 is the C-F characteristic peak, indicating the successful synthesis of the perfluoroborate ester. The stretching vibration of -OH in poly(glycidyl azide) is at 3419 cm -1 , and the N3 characteristic peak exists at 2097 cm -1 . Both the hydroxyl and N3 characteristic peaks appear in the infrared spectrum of the end product in Example 2. Additionally, the C-F characteristic peak at 1190~1140 cm -1 appears, indicating the successful synthesis of the end product prepared in Example 2.

[0071] Determined by the results of infrared spectrum testing and nuclear magnetic resonance hydrogen spectrum testing, the structural formula of the end product prepared in Example 2 is:

[0072] , where n is 7.

[0073] Mechanical property tests were carried out on HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared from the end product of Example 2 (end product of Example 2 / HTPB / AP / Al = 1 / 13 / 68 / 18). The tensile strength and elongation at break of HTPB / AP / Al are 0.85 MPa and 42% respectively, while the tensile strength and elongation at break of the propellant prepared from the end product of Example 2 are 0.97 MPa and 48% respectively, indicating that the energetic perfluoroborate ester binder can be used as an energetic binder in solid propellants to improve the mechanical properties of the propellants.

[0074] Combustion heat tests were carried out on HTPB / AP / Al propellant and the propellant prepared from the end product of Example 2. The combustion heat of HTPB / AP / Al is 16.1 kJ / g, while the combustion heat of the propellant prepared from the end product of Example 2 is 17.0 kJ / g, indicating that the energetic perfluoroborate ester binder can be used as an energetic binder in solid propellants to improve the energy of the propellants.

[0075] Example 3

[0076] An energetic perfluoroborate ester binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0077] 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (PFND) 40%,

[0078] Boric acid 8%,

[0079] Poly(glycidyl azide) (GAP) 52%;

[0080] The auxiliary raw material is N,N-dimethylformamide (DMF) as a solvent.

[0081] The method steps are as follows:

[0082] (1) Stir at 70 °C for 3 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in DMF to obtain a 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution;

[0083] The mass ratio (g) of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol to the volume (mL) of DMF is 1:10;

[0084] (2) Stir at 60 °C for 5 min to completely dissolve boric acid in DMF, pour the boric acid solution into the 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution prepared in (1), then stir at 100 °C for 4 h, and perform vacuum rotary evaporation on the obtained solution at 85 °C for 5 h to obtain perfluoroborate ester;

[0085] The mass ratio (g) of boric acid to the volume (mL) of DMF is 1:10;

[0086] (3) Add glycidyl azide polymer and perfluoroborate ester to DMF, stir at 60 °C for 3 h, and perform vacuum rotary evaporation on the obtained solution at 85 °C for 5 h again to obtain an energetic perfluoroborate ester binder;

[0087] The mass ratio (g) of glycidyl azide polymer to the volume (mL) of DMF is 1:20; the molecular weight of glycidyl azide polymer is 840.

[0088] Perform infrared spectroscopy tests on 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate ester (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), glycidyl azide polymer, and the final product prepared in Example 3, and it can be obtained that 1360 cm -1 is the B-O-C bond, and 1190 - 1140 cm -1 is the C-F characteristic peak, indicating the successful synthesis of perfluoroborate ester. The stretching vibration of -OH in glycidyl azide polymer is at 3419 cm -1 , and the N3 characteristic peak exists at 2097 cm -1 . Both the hydroxyl and N3 characteristic peaks appear in the infrared spectrum of the final product in Example 3. In addition, the C-F characteristic peak of 1190 - 1140 cm -1 also appears, indicating the successful synthesis of the final product prepared in Example 3.

[0089] It is determined by the test results of infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy that the structural formula of the binder is as follows:

[0090] , where n is 8.

[0091] Mechanical property tests were carried out on HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared from the final product of Example 3 (final product of Example 3 / HTPB / AP / Al = 1.5 / 12.5 / 68 / 18). The tensile strength and elongation at break of HTPB / AP / Al were 0.85 MPa and 42% respectively, while the tensile strength and elongation at break of the propellant prepared from the final product of Example 3 were 0.95 MPa and 49% respectively, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the mechanical properties of the propellants.

[0092] Combustion heat tests were carried out on HTPB / AP / Al propellant and the propellant prepared from the final product of Example 3. The combustion heat of HTPB / AP / Al was 16.1 kJ / g, while the combustion heat of the propellant prepared from the final product of Example 3 was 17.1 kJ / g, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the energy of the propellants.

[0093] Example 4

[0094] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0095] 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (PFND) 30%,

[0096] Boric acid 10%,

[0097] Glycidyl azide polymer (GAP) 60%;

[0098] The auxiliary raw material is N,N-dimethylformamide (DMF) as a solvent.

[0099] The method steps are as follows:

[0100] (1) Stir at 70 °C for 6 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in DMF to obtain a 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution;

[0101] The proportional relationship between the mass (g) of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and the volume (mL) of DMF is 1:15;

[0102] (2) Stir for 6 min at 70 °C to completely dissolve boric acid in DMF. Pour the boric acid solution into the 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution prepared in (1), and then stir at 105 °C for 6 h. The resulting solution is subjected to vacuum rotary evaporation at 95 °C for 3 h to obtain perfluoroborate ester;

[0103] The mass ratio of boric acid (g) to the volume of DMF (mL) is 1:10;

[0104] (3) Add glycidyl azide polymer and perfluoroborate ester to DMF, stir at 60 °C for 2 h, and then subject the resulting solution to vacuum rotary evaporation at 85 °C for 5 h to obtain an energetic perfluoroborate ester binder;

[0105] The mass ratio of glycidyl azide polymer (g) to the volume of DMF (mL) is 1:20; the molecular weight of glycidyl azide polymer is 1030.

[0106] Perform infrared spectroscopy tests on 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate ester (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), glycidyl azide polymer, and the final product prepared in Example 4. The B-O-C bond can be obtained at 1360 cm -1 and the C-F characteristic peak at 1190 - 1140 cm -1 indicating the successful synthesis of perfluoroborate ester. The stretching vibration of -OH in glycidyl azide polymer is at 3419 cm -1 and the N3 characteristic peak exists at 2097 cm -1 In the infrared spectrum of the final product of Example 4, both the hydroxyl and N3 characteristic peaks appear. Additionally, the C-F characteristic peak at 1190 - 1140 cm -1 appears, indicating the successful synthesis of the final product prepared in Example 4.

[0107] It is determined by the results of infrared spectroscopy tests and nuclear magnetic resonance hydrogen spectrum tests that the structural formula of the binder is:

[0108] , where n is 10.

[0109] Mechanical property tests were carried out on HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared from the end product of Example 4 (Example 4 end product / HTPB / AP / Al = 1 / 13 / 68 / 18). The tensile strength and elongation at break of HTPB / AP / Al were 0.85 MPa and 42% respectively, while the tensile strength and elongation at break of the propellant prepared from the end product of Example 4 were 0.99 MPa and 46% respectively, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the mechanical properties of the propellants.

[0110] Combustion heat tests were carried out on HTPB / AP / Al propellant and the propellant prepared from the end product of Example 4. The combustion heat of HTPB / AP / Al was 16.1 kJ / g, while the combustion heat of the propellant prepared from the end product of Example 4 was 17.3 kJ / g, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the energy of the propellants.

[0111] Example 5

[0112] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0113] 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (PFND) 50%,

[0114] Boric acid 5%,

[0115] Glycidyl azide polymer (GAP) 45%;

[0116] The auxiliary raw material is N,N-dimethylformamide (DMF) as a solvent.

[0117] The method steps are as follows:

[0118] (1) Stir at 50 °C for 3 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in DMF to obtain a 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution;

[0119] The proportional relationship between the mass (g) of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and the volume (mL) of DMF is 1:20;

[0120] (2) Stir for 3 min at 70 °C to completely dissolve boric acid in DMF. Pour the boric acid solution into the 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution prepared in (1), and then stir at 105 °C for 6 h. The resulting solution is subjected to vacuum rotary evaporation at 80 °C for 3 h to obtain perfluoroborate ester;

[0121] The mass ratio of boric acid (g) to the volume of DMF (mL) is 1:20;

[0122] (3) Add glycidyl azide polymer and perfluoroborate ester to DMF, stir at 60 °C for 2 h, and then subject the resulting solution to vacuum rotary evaporation at 95 °C for 5 h to obtain an energetic perfluoroborate ester binder;

[0123] The mass ratio of glycidyl azide polymer (g) to the volume of DMF (mL) is 1:20; the molecular weight of glycidyl azide polymer is 760.

[0124] Infrared spectroscopy tests are performed on 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol, boric acid, perfluoroborate ester (the reaction product of 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol and boric acid), glycidyl azide polymer, and the final product prepared in Example 5. A peak at 1360 cm -1 is for the B - O - C bond, and peaks in the range of 1190 - 1140 cm -1 are C - F characteristic peaks, indicating the successful synthesis of perfluoroborate ester. For glycidyl azide polymer, the stretching vibration of - OH is at 3419 cm -1 , and there is an N3 characteristic peak at 2097 cm -1 . In the infrared spectrum of the final product of Example 5, both the hydroxyl and N3 characteristic peaks appear. Additionally, C - F characteristic peaks in the range of 1190 - 1140 cm -1 also appear, indicating the successful synthesis of the final product prepared in Example 5.

[0125] It is determined through infrared spectroscopy test and 1H NMR test results that the structural formula of the binder is:

[0126] , where n is 7.

[0127] Mechanical property tests were carried out on HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared from the end product of Example 5 (end product of Example 5 / HTPB / AP / Al = 1.3 / 12.7 / 68 / 18). The tensile strength and elongation at break of HTPB / AP / Al were 0.85 MPa and 42% respectively, while those of the propellant prepared from the end product of Example 5 were 0.96 MPa and 48% respectively, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the mechanical properties of the propellants.

[0128] Combustion heat tests were carried out on HTPB / AP / Al propellant and the propellant prepared from the end product of Example 5. The combustion heat of HTPB / AP / Al was 16.1 kJ / g, while that of the propellant prepared from the end product of Example 5 was 17.2 kJ / g, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the energy of the propellants.

[0129] Example 6

[0130] An energetic perfluoroborate binder, the raw materials of the binder are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows:

[0131] 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (PFND) 38%,

[0132] Boric acid 8%,

[0133] Glycidyl azide polymer (GAP) 54%;

[0134] The auxiliary raw material is dimethyl sulfoxide (DMSO) as a solvent.

[0135] The method steps are as follows:

[0136] (1) Stir at 70 °C for 5 min to completely dissolve 1H,1H,2H,3H,3H-perfluorononane-1,2-diol in DMSO to obtain a 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution;

[0137] The proportional relationship between the mass (g) of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and the volume (mL) of DMSO is 1:15;

[0138] (2) Stir for 3 min at 60 °C to completely dissolve boric acid in DMSO. Pour the boric acid solution into the 1H,1H,2H,3H,3H-perfluorononane-1,2-diol solution prepared in (1), and then stir at 100 °C for 5 h. The resulting solution is subjected to rotary evaporation under vacuum at 92 °C for 4 h to obtain perfluoroborate ester.

[0139] The mass ratio of boric acid (g) to the volume of DMSO (mL) is 1:15.

[0140] (3) Add glycidyl azide polymer and perfluoroborate ester to DMSO, and stir at 70 °C for 3 h. The resulting solution is again subjected to rotary evaporation under vacuum at 95 °C for 5 h to obtain an energetic perfluoroborate ester binder.

[0141] The mass ratio of glycidyl azide polymer (g) to the volume of DMSO (mL) is 1:10; the molecular weight of glycidyl azide polymer is 630.

[0142] Perform infrared spectroscopy tests on 1H,1H,2H,3H,3H-perfluorononane-1,2-diol, boric acid, perfluoroborate ester (the reaction product of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol and boric acid), glycidyl azide polymer, and the final product prepared in Example 6. It can be obtained that 1360 cm -1 is the B-O-C bond, and 1190 - 1140 cm -1 is the C-F characteristic peak, indicating the successful synthesis of perfluoroborate ester. The stretching vibration of -OH in glycidyl azide polymer is at 3419 cm -1 , and the N3 characteristic peak exists at 2097 cm -1 . Both the hydroxyl and N3 characteristic peaks appear in the infrared spectrum of the final product in Example 6. Additionally, the C-F characteristic peak of 1190 - 1140 cm -1 appears, indicating the successful synthesis of the final product prepared in Example 6.

[0143] It is determined through the results of infrared spectroscopy tests and nuclear magnetic resonance hydrogen spectrum tests that the structural formula of the binder is:

[0144] , where n is 6.

[0145] Mechanical property tests were carried out on HTPB / AP / Al (14 / 68 / 18) propellant and the propellant prepared from the end product of Example 6 (end product of Example 6 / HTPB / AP / Al = 1.8 / 12.2 / 68 / 18). The tensile strength and elongation at break of HTPB / AP / Al were 0.85 MPa and 42% respectively, while those of the propellant prepared from the end product of Example 6 were 0.96 MPa and 48% respectively, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the mechanical properties of the propellants.

[0146] Combustion heat tests were carried out on HTPB / AP / Al propellant and the propellant prepared from the end product of Example 6. The combustion heat of HTPB / AP / Al was 16.1 kJ / g, while that of the propellant prepared from the end product of Example 6 was 17.3 kJ / g, indicating that the energetic perfluoroborate binder can be used as an energetic binder in solid propellants to improve the energy of the propellants.

[0147] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention will be regarded as being within the protection scope of the present invention.

Claims

1. An energetic perfluoroborate binder, characterized in that: The structural formula of the adhesive is as follows: ； where n is a positive integer less than or equal to 20.

2. The energetic perfluoroborate binder according to claim 1, wherein: n is 4 - 10.

3. A preparation method of an energetic perfluoroborate binder as described in claim 1 or 2, characterized in that: The method steps include: (1) Completely dissolve 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol in a solvent to obtain a 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution; (2) Completely dissolve boric acid in a solvent, pour the boric acid solution into the 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol solution, then stir at 95°C - 105°C for 4 h - 6 h, and remove the solvent by vacuum rotary evaporation to obtain perfluoroborate ester; (3) Add glycidyl azide polymer and the perfluoroborate ester to a solvent, stir at 60°C - 80°C for 2 h - 3 h, and remove the solvent by vacuum rotary evaporation to obtain an energetic perfluoroborate ester adhesive.

4. The preparation method of an energetic perfluoroborate binder according to claim 3, characterized in that: The raw materials of the adhesive are composed of main raw materials and auxiliary raw materials. Based on the total mass of the main raw materials being 100%, the composition components and their mass fractions are as follows: 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol 30% - 50%, boric acid 5% - 10%, glycidyl azide polymer 40% - 65%; The auxiliary raw material is solvent dimethyl sulfoxide or N,N - dimethylformamide.

5. The preparation method of an energetic perfluoroborate binder according to claim 4, wherein: The molecular weight of the glycidyl azide polymer is 480 - 1000.

6. The preparation method of an energetic perfluoroborate binder according to claim 3, characterized in that: In step (1), stir at 50°C - 70°C for 3 min - 6 min to completely dissolve 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol in the solvent; the mass - to - volume ratio of 1H,1H,2H,3H,3H - perfluorononane - 1,2 - diol to the solvent is 1 g:10 mL - 20 mL.

7. The preparation method of an energetic perfluoroborate binder according to claim 3, characterized in that: In step (2), stir at 50°C - 70°C for 3 - 6 min to completely dissolve boric acid in the solvent; the mass - to - volume ratio of boric acid to the solvent is 1 g:10 mL - 20 mL; After stirring, perform vacuum rotary evaporation at 80°C - 95°C for 3 - 5 h.

8. The preparation method of an energetic perfluoroborate binder according to claim 3, characterized in that: In step (3), the mass - to - volume ratio of glycidyl azide polymer to the solvent is 1 g:10 mL - 20 mL; the molecular weight of glycidyl azide polymer is 480 - 1000; Perform vacuum rotary evaporation on the obtained solution at 80°C - 95°C for 3 - 5 h.

9. Use of an energetic perfluoroborate binder as described in claim 1 or 2, characterized in that: The adhesive is used as part of a solid propellant adhesive, and the addition amount of the adhesive is 1% - 2% of the total amount of the solid propellant adhesive.

10. The application of an energetic perfluoroborate binder according to claim 9, characterized in that: The solid propellant is HTPB propellant.

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