PBX COMPOSITION

Abstract

The invention relates to a cast explosive composition. There is provided a precure castable explosive composition comprising an explosive material, a polymerisable binder, said cross linking reagent comprising at least two reactive groups each of which is protected by a labile blocking group.

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Claims

1-15. (canceled)

16. A batch process for filling a munition with a cross linked polymer bonded explosive composition, the batch process comprising: forming an admixture of precure castable explosive composition, comprising an explosive material, a polymerisable binder, and a cross-linking reagent comprising a first reactive group protected by a first labile blocking group and a second reactive group protected by a second labile blocking group; filling the munition with the admixture; and causing the removal of the first and second labile blocking groups in situ to furnish said cross linking reagent to the reactive groups.

17. The batch process according to claim 16, further comprising causing the cure of said polymerisable binder to form a polymer bonded cast explosive composition.

18. The batch process according to claim 16, wherein forming the admixture includes selecting the cross-linking reagent comprising a polyisocyanate.

19. The batch process according to claim 18, wherein forming the admixture includes selecting the cross-linking reagent comprising a diisocyanate.

20. The batch process according to claim 18, wherein the first and second labile blocking groups are independently selected from (i) NHR.sup.2R.sup.3, wherein R.sup.2 and R.sup.3 are an alkyl, an alkenyl, a branched-chain alkyl, C(O)R.sup.12, an aryl, a phenyl, or together form a heterocycle, wherein R.sup.12 is an alkyl, an alkenyl, a branched chain alkyl, a branched chain aryl, a phenyl, or R.sup.2 and R.sup.3 together form a lactam; (ii) OR.sup.15, wherein R.sup.15 is an aryl, a phenyl, or a benzyl having at least two nitro groups on the ring; or (iii) O—N═CR.sup.9R.sup.10, wherein R.sup.9 and R.sup.10 are independently selected from an alkyl, an alkenyl, a branched chain alkyl, an aryl, or a phenyl, and wherein at least one of R.sup.9 or R.sup.10 is a branched chain alkyl, a branched chain aryl, or a phenyl.

21. The batch process according to claim 20, wherein the first labile blocking group is the same as the second labile blocking group.

22. The batch process according to claim 16, wherein causing the removal of the first and second labile blocking groups includes heating the admixture.

23. The batch process according to claim 22, wherein heating the admixture is performed to a temperature not greater than 200° C.

24. The batch process according to claim 23, wherein the temperature is in the range of from 50° C. to 150° C.

25. The batch process according to claim 23, wherein the temperature is in the range of from 80° C. to 120° C.

26. The batch process according to claim 16, wherein forming the admixture includes selecting the polymerisable binder comprising a cellulosic material.

27. The batch process according to claim 16, wherein forming the admixture includes selecting the explosive material from RDX, HMX, FOX-7, TATND, HNS, TATB, NTO, HNIW, GUDN, picrite, aromatic nitramine, ethylene dinitramine, nitroglycerine, butane triol trinitrate, pentaerythritol tetranitrate, DNAN trinitrotoluene, inorganic oxidiser, ADN, ammonium perchlorate, energetic alkali metal salt, energetic alkaline earth metal salt, and combinations thereof.

28. The batch process according to claim 16, wherein at least one of the first and second labile blocking groups comprises a sterically hindered branched chain hydrocarbyl group.

29. The batch process according to claim 16, wherein causing the removal of the first and second labile blocking groups results in a polymer bonded explosive composition and one or more protonated blocking groups.

30. A batch process for filling a munition with a cross linked polymer bonded explosive composition, the batch process comprising: forming an admixture of precure castable explosive composition, comprising an explosive material, a polymerisable binder, and a cross-linking reagent comprising a first reactive group protected by a first labile blocking group and a second reactive group protected by a second labile blocking group; partially reacting the polymerisable binder with the cross-linking reagent to result in the admixture including partially polymerized binder-cross-linking reagent, wherein at least one of the first and second reactive groups of the cross linking reagent is protected by the respective first or second labile blocking group; filling the munition with the admixture; and causing the removal of the unreacted first and second labile blocking groups in situ to furnish said cross linking reagent to the first and second reactive groups.

31. The batch process according to claim 30, wherein the first and second labile blocking groups are independently selected from (i) NHR.sup.2R.sup.3, wherein R.sup.2 and R.sup.3 are an alkyl, an alkenyl, a branched-chain alkyl, C(O)R.sup.12, an aryl, a phenyl, or together form a heterocycle, wherein R.sup.12 is an alkyl, an alkenyl, a branched chain alkyl, a branched chain aryl, a phenyl, or R.sup.2 and R.sup.3 together form a lactam; (ii) OR.sup.15, wherein R.sup.15 is an aryl, a phenyl, or a benzyl having at least two nitro groups on the ring; or (iii) O—N═CR.sup.9R.sup.10, wherein R.sup.9 and R.sup.10 are independently selected from an alkyl, an alkenyl, a branched chain alkyl, an aryl, or a phenyl, and wherein at least one of R.sup.9 or R.sup.10 is a branched chain alkyl, a branched chain aryl, or a phenyl.

32. A batch process for filling a munition with a cross linked polymer bonded explosive composition, the batch process comprising: forming an admixture of precure castable explosive composition, comprising an explosive material, a polymerisable binder, and a polyisocyanate having at least a first reactive group protected by a first labile blocking group B and a second reactive group protected by a second labile blocking group B; filling the munition with the admixture; and causing the removal of the first and second labile blocking groups B in situ to furnish said polyisocyanate to the first and second reactive groups.

33. The batch process according to claim 32, wherein the first and second labile blocking groups B are independently selected from (i) NHR.sup.2R.sup.3, wherein R.sup.2 and R.sup.3 are an alkyl, an alkenyl, a branched-chain alkyl, C(O)R.sup.12, an aryl, a phenyl, or together form a heterocycle, wherein R.sup.12 is an alkyl, an alkenyl, a branched chain alkyl, a branched chain aryl, a phenyl, or R.sup.2 and R.sup.3 together form a lactam; (ii) OR.sup.15, wherein R.sup.15 is an aryl, a phenyl, or a benzyl having at least two nitro groups on the ring; or (iii) O—N═CR.sup.9R.sup.10, wherein R.sup.9 and R.sup.10 are independently selected from an alkyl, an alkenyl, a branched chain alkyl, an aryl, or a phenyl, and wherein at least one of R.sup.9 or R.sup.10 is a branched chain alkyl, a branched chain aryl, or a phenyl.

34. The batch process according to claim 33, wherein forming the admixture includes selecting the explosive material from RDX, HMX, FOX-7, TATND, HNS, TATB, NTO, HNIW, GUDN, picrite, an aromatic nitramine, ethylene dinitramine, nitroglycerine, butane triol trinitrate, pentaerythritol tetranitrate, DNAN trinitrotoluene, an inorganic oxidiser, ADN, ammonium perchlorate, an energetic alkali metal salt, an energetic alkaline earth metal salt, and combinations thereof.

35. The batch process according to claim 33, wherein causing the removal of the unreacted first and second labile blocking groups includes heating the admixture in situ to a temperature in the range of from 50° C. to 150° C.

Description

[0103] Turning to FIG. 1 there is a general scheme 1, for filling a munition 6. The premix formulation 2, is a mixture of the explosive, HTBP polymerisable binder and other processing aids, and optionally a catalyst. The premix formulation 2 is agitated such as by a stirrer 3. A blocked cross linking reagent 4, (either as a solid or dissolved in a minimal aliquot of solvent), is added to the premix to form the precure formulation 5. The blocked cross linking reagent 4 may be a diisocyanate such as IPDI. The resultant precure admixture 5 is thoroughly mixed and is transferred to a munition 6 or mould (not shown) for later insertion into a munition. The munition 6 when filled with the precure 5 may then be exposed to an external stimuli, such as heat, which removes the thermally labile blocking group on the blocked cross linking reagent 4, furnishing the cross linking reagent. The cross linking reagent and HTPB polymerisable binder may then polymerise and form a polymer bonded explosive 7.

[0104] It should be appreciated that the compositions of the invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above.