Process for forming a dinitramide salt or acid by reaction of a salt or free acid of an N(alkoxycarbonyl)N-nitroamide with a nitronium-containing compound followed by reaction of the intermediate product respectively with a base or alcohol

• US 5,415,852 A
• Filed: 10/30/1992
• Issued: 05/16/1995
• Est. Priority Date: 01/29/1992
• Status: Expired due to Fees

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Schmitt, Robert J., Bottaro, Jeffrey C., Penwell, Paul E., Bomberger, David C.
• Primary Examiner(s): Miller, Edward A.
• Application Number:
  US07/968,928
• Time in Patent Office: 928 Days
• Field of Search: 423/385, 423/387, 564/107, 564/109
• US Class Current: 423/385
• CPC Class Codes: C01B 21/082 Compounds containing nitrogen and non-metals and optionally metalsC01B21/06, C01B21/08 take precedence
• CPC Class Codes: C06B 25/00 Compositions containing a nitrated organic compound
• CPC Class Codes: C06B 25/34 the compound being a nitrated acyclic, alicyclic or heterocyclic amine
• CPC Class Codes: C06B 31/00 Compositions containing an inorganic nitrogen-oxygen salt
• CPC Class Codes: C06B 41/00 Compositions containing a nitrated metallo-organic compound
• CPC Class Codes: C07C 271/08 having oxygen atoms of carbamate groups bound to acyclic carbon atoms

Abstract

A method is disclosed for forming an ionically bonded dinitramide salt or acid useful as a stable oxidizer for solid fuel rocket propellant or explosive formulations is disclosed. The dinitramide salt is formed by the reaction of an N(alkoxycarbonyl)N-nitroamide and a nitronium-containing compound, at a temperature of from about +60° C. to about -120° C., followed by contacting the reaction mass with a base to form the dinitramide salt, or an alcohol to form the corresponding dinitramidic acid. The N(alkoxycarbonyl)N-nitroamide may be formed by first mixing the corresponding alkylcarbamate with an anhydride of one or more 1-20 carbon organic acids, then adding nitric acid to the reaction mixture. If the salt of the N(alkoxycarbonyl)N-nitroamide is to be formed, a base is then added until the pH reaches about 7-10. The nitronium-containing reactant may be a covalently bonded compound containing a NO₂ -- group; a nitryl halide; or a nitronium salt having the formula (NO₂⁺)_q X^-q, where X is the anion of the nitronium salt and q=1-2.

Claims

1. A process for the formation of a dinitramide salt having the formula M⁺ⁿ (N(NO₂)₂ ^-)_n, where M is selected from the group consisting of a metal ion, hydrogen, and a nitrogen-containing cation having from 1 to 8 nitrogen atoms and n is the cationic charge of M, which comprises:

(a) reacting an N(alkoxycarbonyl)N-nitroamide reactant with a nitronium-containing compound; and

(b) treating the reaction mixture with a base to form the dinitramide salt.

2. The process of claim 1 wherein said N(alkoxycarbonyl)N-nitroamide reactant has the formula:

M⁺ⁿ ((O₂ NNCO₂ R)^-)_n, where M is selected from the group consisting of a metal ion, hydrogen, and a nitrogen-containing cation having from 1 to 8 nitrogen atoms, n is the cationic charge of M, and R is selected from the group consisting of a 1-20 carbon branched or straight chain alkyl and a 1-20 carbon branched or straight chain fluoroalkyl.

3. The process of claim 1 wherein said metal ion is selected from the group of metals consisting of alkali metals, Li, Na, K, Rb, and Cs;

alkaline earth metals, Be, Ca, Ba, Sr, and Mg;

Group Ib metals, Ga, In, and the Lanthanide elements (57-71);

Group IV metals, Ti, Zr, Hf, Ge, and Sn;

Group V metals, V, Nb, and Ta;

Group VI metals, Cr, Mo, and W;

Group VIIa metals, Mn, Tc, and Re; and

Group VIII metals, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt.

4. The process of claim 1 wherein said metal ion is selected from the group of metals consisting of Li, Na, K, Ba, and Mg.

5. The process of claim 1 wherein said M⁺ ion is a 1-2 nitrogen-containing cation, it may have the formula wherein x=1 to 2, k=0 to 3+x, m=3+x-k, and each R is the same or different 1-6 carbon straight chain or branched alkyl.

6. The process of claim 1 wherein said M⁺ ion is a cubane-1,4-bis ammonium ion selected from the group consisting of a cubane-1,2,4,7-tetra ammonium ion;

a cubane-1,3,5,7-tetra ammonium ion;

a cubane-1,2,3,4,-tetra ammonium ion;

a cubane-1,2,3,4,7-penta ammonium ion; and

a cubane-1,2,4,6,8-penta ammonium ion.

7. The process of claim 1 wherein said M⁺ ion is selected from the group consisting of guanidium (C(NH₂)₃ ⁺);

triaminoguanidinium (C(N₂ H₃)₃ ⁺);

nitronium (O═

N═

O⁺); and

nitrosonium (N.tbd.O⁺).

8. The process of claim 1 wherein said N(alkoxycarbonyl)N-nitroamide reactant is a salt having the formula:

(M⁺ⁿ ((O₂ NNCO₂)^-)_n)_r ^R, where M is selected from the group consisting of a metal ion, n is the cationic charge of M, r is 1-1000, and a nitrogen-containing cation having from 1 to 8 nitrogen atoms, and R'"'"' is a polymer of up to 100,000 Daltons.

9. The process of claim 1 wherein said nitronium-containing compound is selected from the group consisting of a covalently bonded compound containing a NO₂ -- group, a nitryl halide, and a nitronium salt having the formula (NO₂⁺)_n X^-n, where X is the anion of the nitronium salt and n=1-2.

10. The process of claim 1 wherein said reaction to form said dinitramide salt is carried out at a temperature ranging from about +60°

C. to about -120°

C.

11. The process of claim 10 wherein said reaction temperature to form said dinitramide salt ranges from about 0°

C. to about -90°

C.

12. A process for the formation of an ammonium dinitramide salt having the formula NH₄ ⁺ N(NO₂)₂ ^-, which comprises reacting an N(alkoxycarbonyl)N-nitroamide with a nitronium-containing compound followed by addition of ammonia.

13. The process of claim 12 wherein said alkyl in said N(alkoxycarbonyl)N-nitroamide is selected from the group consisting of a 1-20 carbon branched or straight chain alkyl and a 1-20 carbon branched or straight chain fluoroalkyl.

14. The process of claim 13 wherein said N(alkoxycarbonyl)N-nitroamide is formed by the steps of:

(a) mixing an alkylcarbamate with an anhydride of one or more 1-20 carbon organic acids; and

(b) then reacting the resulting mixture with nitric acid.

15. The process of claim 14 wherein a salt of said N(alkoxycarbonyl)N-nitroamide is formed by the additional step of reacting said N(alkoxycarbonyl)N-nitroamide with a base.

16. The process of claim 12 wherein said alkyl in said N(alkoxycarbonyl)N-nitroamide salt is a polymer of up to 100,000 Daltons.

17. The process of claim 12 wherein said nitronium-containing compound is selected from the group consisting of a covalently bonded compound containing a NO₂ - group, a nitryl halide, and a nitronium salt having the formula (NO₂ ⁺)_q X^-q, where X is the anion of the nitronium salt and q=1-2.

18. A process for the formation of an ammonium dinitramide salt having the formula NH₄ ⁺ N(NO₂)₂ ^-, which comprises reacting an N(alkoxycarbonyl)N-nitroamide reactant selected from the group consisting of N(methoxycarbonyl)N-nitroamide and N(ethoxycarbonyl)N-nitroamide with a nitronium-containing reactant to form an intermediate product;

followed by reacting the intermediate product with ammonia.

19. The process of claim 18 wherein said nitronium-containing reactant is selected from the group consisting of nitronium nitrate (NO₂ NO₃), nitryl fluoride (FNO₂), and nitronium tetrafluoroborate (NO₂ ⁺ BF₄ ^-).

20. The process of claim 18 wherein said reaction to form said ammonium dinitramide salt is carried out at a temperature ranging from about +60°

C. to about -120°

C.

21. The process of claim 18 wherein said N(alkoxy-carbonyl)N-nitroamide reactant is formed by the steps of:

(a) mixing an alkylcarbamate selected from the group consisting of methylcarbamate and ethylcarbamate with acetic anhydride; and

(b) then adding nitric acid to the resulting mixture.

22. The process of claim 21 wherein an ammonium N(alkoxycarbonyl)N-nitroamide reactant is then formed by the addition of NH₃ to the reaction mixture.

23. The process of claim 21 wherein an ammonium N(alkoxycarbonyl)N-nitroamide reactant is then formed by the addition of ammonium acetate to the reaction mixture.

24. The process of claim 21 wherein said reaction to form said N(alkoxycarbonyl)N-nitroamide reactant is carried out at a temperature ranging from about -30°

C. to about 30°

C.

25. A process for the formation of an ammonium dinitramide salt having the formula NH₄ ⁺ N(NO₂)₂ ^-, which comprises:

(a) forming an ammonium N(alkoxycarbonyl)N-nitroamide salt selected from the group consisting of ammonium N(methoxycarbonyl)N-nitroamide and ammonium N(ethoxycarbonyl)N-nitroamide at a temperature ranging from about -30°

C. to about 30°

C. by the steps of;

(i) first mixing an alkylcarbamate selected from the group consisting of methylcarbamate and ethylcarbamate with acetic anhydride;

(ii) then adding nitric acid to the resulting mixture; and

(iii) then adding NH₃ to the reaction mixture; and

(b) then reacting said ammonium N(alkoxycarbonyl)N-nitroamide with a nitronium-containing compound selected from the group consisting of nitronium nitrate (NO₂ NO₃), nitryl fluoride (FNO₂), and nitronium tetrafluoroborate (NO₂ ⁺ BF₄ ^-) at a temperature ranging from about +60°

C. to about -120°

C.; and

(c) then contacting the reaction mass with NH₃ to form said ammonium dinitramide salt.

26. A process for the formation of ammonium dinitramide salt having the formula NH₄ ⁺ N(NO₂)₂ ^-, which comprises:

(a) reacting together, at a temperature ranging from about +60°

C. to about -120°

C., an ammonium N(alkoxycarbonyl)N-nitroamide selected from the group consisting of ammonium N(methoxycarbonyl)N-nitroamide and ammonium N(ethoxycarbonyl)N-nitroamide with a nitronium-containing reactant selected from the group consisting of nitronium nitrate (NO₂ NO₃), nitryl fluoride (FNO₂), and nitronium tetrafluoroborate (NO₂ +BF₄ hu -); and

(b) then contacting the reaction mass with NH₃ to form said ammonium dinitramide salt.

27. The process of claim 26 wherein said ammonium N(alkoxycarbonyl)N-nitroamide reactant consists essentially of ammonium N(methoxycarbonyl)N-nitroamide.

28. The process of claim 26 wherein said ammonium N(alkoxycarbonyl)N-nitroamide reactant consists essentially of ammonium N(ethoxycarbonyl)N-nitroamide.

29. The process of claim 26 wherein said nitronium-containing reactant consists essentially of nitronium nitrate (NO₂ NO₃).

30. The process of claim 26 wherein said nitronium-containing reactant consists essentially of nitronium tetrafluoroborate (NO₂ ⁺ BF₄^-)

31. A process for the formation of dinitramidic acid having the formula H⁺ N(NO₂)₂ ^- which comprises:

(a) reacting an N(alkoxycarbonyl)N-nitroamide reactant with a nitronium-containing compound; and

(b) treating the reaction mixture with an alcohol to form dinitramidic acid.