SOLID COMPOSITE PROPELLANT WITH AUTOCONDENSATION PRODUCT OF TRIAMINOGUANIDINIUM AZIDE AS BINDER
United States Patent 3844855
Propellants in which particulated solid oxidizer and metallic fuel are combined with a binder low in carbon and rich in nitrogen are disclosed. The binders are autocondensation products of triaminoguanidinium azide. An additional organic high nitrogen gas producing compound may be included.
US Patent References:
Solid rocket propellants containing polylactams
Hedrick et al. - July 1961 - 2992908
Solid composite rubber base propellants containing reinforcing agent of resinous aldehyde condensate
Corley et al. - August 1961 - 2995432
High nitrogen polymers prepared by reacting aldehydes with aminoguanidines, tetrazoles, or triazoles
Oja et al. - March 1968 - 3375230
Solid rocket propellants containing polylactams
Hedrick et al. - July 1961 - 2992908
Solid composite rubber base propellants containing reinforcing agent of resinous aldehyde condensate
Corley et al. - August 1961 - 2995432
High nitrogen polymers prepared by reacting aldehydes with aminoguanidines, tetrazoles, or triazoles
Oja et al. - March 1968 - 3375230
Inventors:
Plomer, John J. (Midland, MI)
Filter, Harold E. (Midland, MI)
Lane, George A. (Midland, MI)
Filter, Harold E. (Midland, MI)
Lane, George A. (Midland, MI)
Application Number:
04/589183
Publication Date:
10/29/1974
Filing Date:
10/19/1966
View Patent Images:
Export Citation:
Assignee:
The Dow Chemical Company (Midland, MI)
Primary Class:
Other Classes:
149/36, 149/42, 149/38, 149/43, 149/20
International Classes:
C06B43/00; C06B45/10; C06B45/00; C06D5/06
Field of Search:
149/18,109,19,20,36,42,75,83,92,38,19.1,43
Primary Examiner:
Padgett, Benjamin R.
Attorney, Agent or Firm:
Bjork, Kenneth C.
Claims:
1. A solid propellant composition comprising on a weight basis
2. The solid propellant composition as defined in claim 1 wherein on a weight basis the binder ranges from about 15 to about 40 per cent, the particulated solid fuel is from about 8 to about 30 per cent, said fuel being a member selected from the group consisting of aluminum, beryllium, aluminum hydride, beryllium hydride and mixtures thereof, and, the particulate solid oxidizer ranges from about 30 to about 77 per cent, said oxidizer being a member selected from the group consisting of ammonium perchlorate, nitronium perchlorate, hydrazine nitroformate and mixtures
3. The composition as defined in claim 1 and including, based on the total composition weight, up to about 25 per cent of an organic high nitrogen
4. The composition as defined in claim 2 and including from about 5 to about 20 weight per cent triaminoguanidinium azide.
2. The solid propellant composition as defined in claim 1 wherein on a weight basis the binder ranges from about 15 to about 40 per cent, the particulated solid fuel is from about 8 to about 30 per cent, said fuel being a member selected from the group consisting of aluminum, beryllium, aluminum hydride, beryllium hydride and mixtures thereof, and, the particulate solid oxidizer ranges from about 30 to about 77 per cent, said oxidizer being a member selected from the group consisting of ammonium perchlorate, nitronium perchlorate, hydrazine nitroformate and mixtures
3. The composition as defined in claim 1 and including, based on the total composition weight, up to about 25 per cent of an organic high nitrogen
4. The composition as defined in claim 2 and including from about 5 to about 20 weight per cent triaminoguanidinium azide.
Description:
This invention relates to propellants and more particularly is concerned with a novel solid propellant composition exhibiting a high specific impulse.
Conventional solid propellants based on carbon-rich binders, e.g., polyurethane, polybutadiene-acrylic acid, nitro-plasticized nitrocellulose and the like, suffer from the disadvantage that extra oxidizer must be included to oxidize the carbon. Additionally, such propellants are limited in performance by the equilibria between carbon, hydrogen, and oxygen containing compounds in the combustion products.
It is a principal object of the present invention, therefore, to provide a novel solid propellant having a binder low in carbon and rich in nitrogen which avoids these problems associated with conventional binders as well as provides a composition exhibiting a high energy content.
This and other objects and advantages readily will become apparent from the detailed description presented hereinafter.
The present invention comprises a solid propellant composition containing as a binder from about 5 to about 60 weight per cent of the autocondensation product of triaminoquanidinium azide [hereinafter referred to as Polytaz], the autocondensation products of triaminoquanidinium azide modified with from about 2 to about 20 weight per cent, based on the weight of triaminoguanidinium azide, of malononitrile [this condensation product hereinafter being referred to as Malonitaz] or cyanamide[this product being referred to herein as Cyanitaz] and mixtures thereof, from about 3 to about 65 weight per cent of a particulated solid fuel and, balance, a particulated solid oxidizer. Additionally, organic high nitrogen gas-producers such as triaminoguanidinium azide (TAZ), triaminoguanidinium hydrazinium diazide (THA), diaminoguanidinium azide, aminoguanidinium azide, hydrazinium azide hydrazinate, hydrazinium azide, ammonium azide and the like up to about 25 weight per cent of the composition weight optionally can be included in the composition. Triaminoguanidinium azide has been found to be particularly suitable.
Ordinarily the composition comprises from about 15 to about 40 weight per cent of the high nitrogen material binder, from about 8 to about 30 weight per cent of a particulated solid fuel and from about 30 to about 77 weight per cent of particulated solid oxidizer, with or without from about 5 to about 20 weight per cent of a gas producing additive.
The Polytaz binders usually have a N/C gram atom ratio of from about 2.5/1 to about 3.3/1. The malononitrile modified products (Malonitaz) ordinarily have a N/C gram atom ratio of about 3. The cyanamide modified materials (Cyanitaz) have a N/C gram atom ratio of about 5.
Conveniently these autocondensation products are prepared by pyrolyzing triaminoguanidinium azide or mixtures of from about 80 to about 98 parts by weight triaminoguanidinium azide and from about 2 to about 20 parts by weight malononitrile or cyanamide.
Fuels found to be suitable for use in the present composition include, for example, light metals such as magnesium, aluminum, beryllium, light metal hydrides such as aluminum hydride, magnesium hydride, lithium aluminum hydride and the like. Aluminum, beryllium, the hydrides of these metals and mixtures thereof are preferred fuels.
The oxidizer employed in the composition usually is selected from the group consisting of ammonium perchlorate (herein designated as AP), ammonium nitrate, (designated as AN), hydrazine nitroformate (designated as HNF), nitronium perchlorate (designated as NP), cyclotrimethylene-trinitramine, cyclotetramethylenetetranitramine and mixtures thereof. Ammonium perchlorate, nitronium perchlorate, hydrazine nitroformate and mixtures thereof have been found to be particularly effective oxidizers for use in the formulation of the high energy compositions. For optimum in mix compatibility and storageability when nitronium perchlorate is used ordinarily a hard, fairly non-porous polymeric surface coating is applied to the nitronium perchlorate in an amount of from about 5 to about 12 weight per cent based on the nitronium perchlorate weight.
The various solid components as used in the present formulations are employed in a finely divided, particulate form as conventionally employed in solid propellant grains.
The present propellants usually are fabricated by mixing and blending the fuel, oxidizer and binder to provide a substantially homogeneous blend. The formulation is cast, extruded or otherwise formed and cured to produce a solid, elastomeric propellant grain of predetermined configuration.
Satisfactory propellant grains are produced by mixing and blending at a temperature of from about 30° to about 60° C. where the thermoplastic high nitrogen binder is in the liquid state, casting and curing at room temperature. Alternatively, the components can be mixed, blended and shaped or formed under pressure at room temperature thereby to provide a substantially void free, compacted propellant grain.
The following Examples will serve further to illustrate the present invention but are not meant to limit it thereto.
EXAMPLE 1
A number of propellant grains were formed by blending finely divided solid fuel, oxidizer and Polytaz. Each of the blends was cast into a propellant grain, cured and fired in a closed bomb. The heat energy liberated and actual specific impulse were determined for each grain. The efficiency of each grain was determined by comparing the observed specific impulse with that theoretically calculated for the composition. Table I, which follows, summarizes the data and results of this study.
Table I ____________________________________________________________ ______________ Combustion Results Propellant Composition ΔH ex Isp (obs.) Isp (theo) Eff. Run No. Polytaz Al Be AlH 3 AP (1) NP (2) (cal./g) (sec.) (sec.) (%) ____________________________________________________________ ______________ (% by weight) 1 35 17 -- -- 48 -- 1435±20 226 273.5 82.7 (incomplete combustion of Al) 2 30 -- -- 24 46 -- 1607±7 266 288.5 92.3 3 25 -- -- 30 -- 45 2129±79 286 299.9 95.2 4 10 -- -- 48 -- 42 2067±44 284 304 93.5 ____________________________________________________________ ______________ (1) Ammonium perchlorate (2) Nitronium perchlorate
EXAMPLE 2
Propellant grains were prepared by blending, casting and curing mixtures of Polytaz, aluminum hydride and ammonium perchlorate. In this preparation the binder and oxidizer were first mixed and the fuel component then blended into the composition. The grains were used as propellant in 50 gram end-burning motors. Smooth burning of the grain to completion was realized.
Composition data and motor firing results are summarized in Table II.
Table II ____________________________________________________________ ______________ Composition Motor Firing Results ____________________________________________________________ ______________ Isp, sec. Pa C* Burning Rate Run No. Polytaz AlH 3 NH 4 ClO 4 (calc.) psi ft/sec. in/sec. ____________________________________________________________ ______________ (weight percent) 1 40 18 42 281 220 4368 0.96 2 40 18 42 281 358 4841 1.45 3 40 18 42 281 391 4708 2.56 4 40 18 42 281 673 4947 1.69 5 35 21 44 286 392 4776 1.44 6 30 24 46 291 302 4890 1.20 ____________________________________________________________ ______________ C* is the characteristic exhaust velocity
EXAMPLE 3
To evaluate the properties of the high nitrogen binders, the tensile properties of standard tensile test specimen prepared by compressing 50/50 weight per cent mixtures of Polytaz or Malonitaz with aluminum hydride were determined using an Instron tester at a cross-head speed of 2 inches/minute. The hardness was determined using a Shore Durometer tester. Additionally, a simulated propellant grain was fabricated by the same technique wherein small glass beads were incorporated into the mix to simulate particulate nitronium perchlorate oxidizer. Table III summarizes the physical properties obtained in these studies.
Table III ____________________________________________________________ ______________ Max. Tensile Elongation Strength at yield max. Durometer Run No. Composition (psi) (%) (Hardness A) ____________________________________________________________ ______________ 1 Polytaz + AlH 3 19 8 16 85 2 Malonitaz + AlH 3 240 3 16 97 3 Malonitaz + AlH 3 308 8 22 96 + simulated oxi- dizer ____________________________________________________________ ______________
EXAMPLE 4
A number of propellant motor grains and strands were prepared based on Polytaz, aluminum hydride and nitronium perchlorate, ammonium perchlorate or nitronium perchlorate-ammonium perchlorate mixtures. In these studies, the nitronium perchlorate used was coated with from about 5 to about 10 per cent of a proprietary polymeric composition.
The motor grains and strands were fabricated by first chilling the Polytaz binder whereupon it became brittle. The chilled binder and finely divided fuel components were blended in a Waring Blender to provide a homogeneous, free-flowing mix having a coating of the aluminum hydride fuel on the sheared polymer particles. Nitronium perchlorate was added and the resulting mixture blended. After blending, the composition was poured into a motor case or strand mold where it was pressurized to from about 100 to about 200 pounds per square inch, warmed to about 30° C. and then subjected to a low pressure. The resulting cured grains or strands were substantially void free.
Bomb combustion data were carried out on a number of compositions to determine the heat of explosion. The data and results from this test are summarized in Table IV.
Table IV ____________________________________________________________ ______________ Composition Nitronium Ammonium ΔH ex Run. No. Polytaz AlH 3 Perchlorate Perchlorate (cal/gram) ____________________________________________________________ ______________ (weight per cent) 1 30 25 45 -- 1529 2 20 30 50 -- 1835 3 20 30 45 5 1943 ____________________________________________________________ ______________
A pressed strand of the composition employed in Run 2 was tested to determine the burning rate. This system gave a burning rate of 1.2 inches/second at 1000 psi with a pressure exponent of 0.45.
Thirty gram end-burning motors were prepared and tested at various pressures from about 50 to about 750 psia. The compositions employed in these runs are summarized in Table V.
Table V ______________________________________ Comp. Ingredients No. Polytaz AlH 3 NH 4 ClO 4 NO 2 ClO 4 (NP) ______________________________________ 1 30 24 46 -- 2 35 21 44 -- 3 40 18 42 -- 4 20 31 -- 49 ______________________________________
All motors burned smoothly with stable, normal burning being obtained at all test pressures.
EXAMPLE 5
A number of formulations of the present invention provide high energy propellants fabricated into propellant grains. The combustion temperature and theoretical impulse of a number of such propellants were calculated. The propellant formulation data and performance results from this study are presented in Table VI which follows.
Table VI ____________________________________________________________ ______________ Propellant Composition Results Run Comb. Temp. Specific Imp. No. Polytaz Malonitaz Al Be AlH 3 BeH 2 AP NP HNF TAZ °K Isp. ____________________________________________________________ ______________ (sec.) 1 10 36 54 4250 291.8 2 10 45 45 3905 297.3 3 15 30 55 4238 296.1 4 15 39 46 3981 301.1 5 20 30 50 4099 300.5 6 20 36 44 3901 301.5 7 25 24 51 4062 296.2 8 25 30 45 3943 302.3 9 25 36 39 3599 292.6 10 30 24 46 3936 300.5 11 30 27 43 3852 301.7 12 30 30 40 3722 300.2 13 35 27 38 3619 298.4 14 35 24 41 3756 300.4 15 35 21 44 3840 299.2 16 40 24 36 3505 296.4 17 40 18 42 3731 296.9 18 15 30 55 3297 297.1 19 15 22 63 3531 298.4 20 20 27 53 3230 295.8 21 20 18 62 3438 293.9 22 15 35 50 3330 293.8 23 15 28 57 3487 291.3 24 20 30 50 3440 292.6 25 20 25 55 3398 290.4 26 30 27 43 3025 285.8 27 30 21 49 3172 286.0 28 40 18 42 2893 278.9 29 20 30 50 3858 262.7 30 20 15 65 3679 265.9 31 30 28 42 3448 265.8 32 30 19 51 3601 274.0 33 30 13 57 3490 272.5 34 35 17 48 3443 275.7 35 40 12 48 3218 270.6 36 40 9 51 3146 266.6 37 40 18 42 3276 274.8 38 45 17 38 3060 269.0 39 30 29 41 4174 268.9 40 30 23 47 4256 273.6 41 30 17 53 4163 272.7 42 30 23 47 3316 274.5 43 30 17 53 285.6 44 30 11 59 3465 281.5 45 15 21 64 3974 280.5 46 15 15 70 4003 281.0 47 20 20 60 3802 281.9 48 20 14 66 3907 284.1 49 25 12 63 3769 286.0 50 25 18 57 3710 285.4 51 30 19 51 3506 280.8 52 30 13 57 3712 290.7 53 30 7 63 3495 281.8 54 35 12 53 3587 292.6 55 40 13 47 3318 289.2 56 40 7 53 3304 283.3 57 45 9 46 3277 289.3 58 30 22 48 3932 279.4 59 30 16 54 4461 289.9 60 30 13 57 4370 286.8 61 30 10 60 4188 282.0 62 40 16 44 3862 290.1 63 40 13 47 4120 296.3 64 40 10 50 4081 293.6 65 50 10 40 3750 299.1 66 50 13 37 3502 290.1 67 50 7 43 3744 296.0 68 60 7 33 3309 291.9 69 60 4 36 3197 283.5 70 60 10 30 3082 288.1 71 30 16 54 3447 288.2 72 30 10 60 3599 299.6 73 30 7 63 3489 293.8 74 30 4 66 3354 285.1 75 20 16 64 3706 295.1 76 20 10 70 3777 296.7 77 40 7 53 3280 291.8 78 40 13 47 3248 287.4 79 18 11.4 50.6 20 3553 294.1 80 23 10.5 46.5 20 3417 294.1 81 30 11.1 48.9 10 3477 293.8 82 35 11 47.5 65 3417 293.0 83 20 17 63 3441 312.6 84 20 23 57 3214 319.5 85 20 29 51 2823 327.2 86 20 32 48 3004 318.4 87 30 19 51 3136 313.1 88 30 25 45 2820 319.5 89 30 28 42 2845 310.7 90 20 22 58 3972 322.3 91 20 31 49 3239 328.4 92 20 34 46 3369 324.5 93 30 25 45 3390 323.8 94 30 31 39 2759 336.7 95 30 34 36 3139 316.6 96 20 15 65 3414 318.8 97 20 21 59 3209 319.1 98 30 14 56 3171 313.5 99 30 20 50 3012 310.6 100 25 14.3 40.7 20 3940 286.9 101 30 13 37 20 3765 286.5 102 35 14.3 40.7 10 3924 286.3 103 40 13 37 10 3740 285.8 104 45 12.4 32.6 10 3506 283.2 105 35 11 44 10 3896 297.0 106 40 10 40 10 3727 298.2 107 45 9 36 10 3538 297.1 108 30 3 12 55 3081 299.5 109 30 5 20 45 2887 309.7 110 30 6 24 40 2823 307.3 111 40 2 8 50 2850 285.9 112 40 5 20 35 2749 299.8 113 10 36 54 4232 298.1 114 10 45 45 3869 296.4 115 15 33 52 4151 298.8 116 15 42 43 3753 294.6 117 20 30 50 4048 298.2 118 20 36 44 3819 297.6 119 20 39 41 3619 291.5 120 25 27 48 3953 297.9 121 25 30 45 3851 298.3 122 25 33 42 3698 295.4 123 30 24 46 3844 296.3 124 30 27 43 3735 296.4 125 30 30 40 3561 292.3 126 10 30 50 10 4118 300.2 127 10 33 52 5 4195 299.6 128 10 42 43 5 3837 298.0 129 10 39 41 10 3765 298.2 130 10 33 52 5 4174 299.6 131 10 39 46 5 3959 300.0 132 10 42 43 5 3799 296.8 133 10 30 50 10 4091 299.8 134 10 36 44 10 3892 300.8 135 10 27 48 15 4020 300.3 136 10 33 42 15 3821 301.2 137 10 24 46 20 3944 300.3 138 10 30 40 20 3745 300.9 139 10 33 37 20 3558 295.5 ____________________________________________________________ ______________
In a manner similar to that described for the preceding Examples, solid propellant compositions can be formulated using particulate fuels and oxidizers, gas producing additives, and binder components set forth herein. These can be used in various combinations within the disclosed ranges.
Various modifications can be made in the present invention without departing from the spirit or scope thereof for it is understood that we limit ourselves only as defined in the appended claims.
Conventional solid propellants based on carbon-rich binders, e.g., polyurethane, polybutadiene-acrylic acid, nitro-plasticized nitrocellulose and the like, suffer from the disadvantage that extra oxidizer must be included to oxidize the carbon. Additionally, such propellants are limited in performance by the equilibria between carbon, hydrogen, and oxygen containing compounds in the combustion products.
It is a principal object of the present invention, therefore, to provide a novel solid propellant having a binder low in carbon and rich in nitrogen which avoids these problems associated with conventional binders as well as provides a composition exhibiting a high energy content.
This and other objects and advantages readily will become apparent from the detailed description presented hereinafter.
The present invention comprises a solid propellant composition containing as a binder from about 5 to about 60 weight per cent of the autocondensation product of triaminoquanidinium azide [hereinafter referred to as Polytaz], the autocondensation products of triaminoquanidinium azide modified with from about 2 to about 20 weight per cent, based on the weight of triaminoguanidinium azide, of malononitrile [this condensation product hereinafter being referred to as Malonitaz] or cyanamide[this product being referred to herein as Cyanitaz] and mixtures thereof, from about 3 to about 65 weight per cent of a particulated solid fuel and, balance, a particulated solid oxidizer. Additionally, organic high nitrogen gas-producers such as triaminoguanidinium azide (TAZ), triaminoguanidinium hydrazinium diazide (THA), diaminoguanidinium azide, aminoguanidinium azide, hydrazinium azide hydrazinate, hydrazinium azide, ammonium azide and the like up to about 25 weight per cent of the composition weight optionally can be included in the composition. Triaminoguanidinium azide has been found to be particularly suitable.
Ordinarily the composition comprises from about 15 to about 40 weight per cent of the high nitrogen material binder, from about 8 to about 30 weight per cent of a particulated solid fuel and from about 30 to about 77 weight per cent of particulated solid oxidizer, with or without from about 5 to about 20 weight per cent of a gas producing additive.
The Polytaz binders usually have a N/C gram atom ratio of from about 2.5/1 to about 3.3/1. The malononitrile modified products (Malonitaz) ordinarily have a N/C gram atom ratio of about 3. The cyanamide modified materials (Cyanitaz) have a N/C gram atom ratio of about 5.
Conveniently these autocondensation products are prepared by pyrolyzing triaminoguanidinium azide or mixtures of from about 80 to about 98 parts by weight triaminoguanidinium azide and from about 2 to about 20 parts by weight malononitrile or cyanamide.
Fuels found to be suitable for use in the present composition include, for example, light metals such as magnesium, aluminum, beryllium, light metal hydrides such as aluminum hydride, magnesium hydride, lithium aluminum hydride and the like. Aluminum, beryllium, the hydrides of these metals and mixtures thereof are preferred fuels.
The oxidizer employed in the composition usually is selected from the group consisting of ammonium perchlorate (herein designated as AP), ammonium nitrate, (designated as AN), hydrazine nitroformate (designated as HNF), nitronium perchlorate (designated as NP), cyclotrimethylene-trinitramine, cyclotetramethylenetetranitramine and mixtures thereof. Ammonium perchlorate, nitronium perchlorate, hydrazine nitroformate and mixtures thereof have been found to be particularly effective oxidizers for use in the formulation of the high energy compositions. For optimum in mix compatibility and storageability when nitronium perchlorate is used ordinarily a hard, fairly non-porous polymeric surface coating is applied to the nitronium perchlorate in an amount of from about 5 to about 12 weight per cent based on the nitronium perchlorate weight.
The various solid components as used in the present formulations are employed in a finely divided, particulate form as conventionally employed in solid propellant grains.
The present propellants usually are fabricated by mixing and blending the fuel, oxidizer and binder to provide a substantially homogeneous blend. The formulation is cast, extruded or otherwise formed and cured to produce a solid, elastomeric propellant grain of predetermined configuration.
Satisfactory propellant grains are produced by mixing and blending at a temperature of from about 30° to about 60° C. where the thermoplastic high nitrogen binder is in the liquid state, casting and curing at room temperature. Alternatively, the components can be mixed, blended and shaped or formed under pressure at room temperature thereby to provide a substantially void free, compacted propellant grain.
The following Examples will serve further to illustrate the present invention but are not meant to limit it thereto.
EXAMPLE 1
A number of propellant grains were formed by blending finely divided solid fuel, oxidizer and Polytaz. Each of the blends was cast into a propellant grain, cured and fired in a closed bomb. The heat energy liberated and actual specific impulse were determined for each grain. The efficiency of each grain was determined by comparing the observed specific impulse with that theoretically calculated for the composition. Table I, which follows, summarizes the data and results of this study.
Table I ____________________________________________________________ ______________ Combustion Results Propellant Composition ΔH ex Isp (obs.) Isp (theo) Eff. Run No. Polytaz Al Be AlH 3 AP (1) NP (2) (cal./g) (sec.) (sec.) (%) ____________________________________________________________ ______________ (% by weight) 1 35 17 -- -- 48 -- 1435±20 226 273.5 82.7 (incomplete combustion of Al) 2 30 -- -- 24 46 -- 1607±7 266 288.5 92.3 3 25 -- -- 30 -- 45 2129±79 286 299.9 95.2 4 10 -- -- 48 -- 42 2067±44 284 304 93.5 ____________________________________________________________ ______________ (1) Ammonium perchlorate (2) Nitronium perchlorate
EXAMPLE 2
Propellant grains were prepared by blending, casting and curing mixtures of Polytaz, aluminum hydride and ammonium perchlorate. In this preparation the binder and oxidizer were first mixed and the fuel component then blended into the composition. The grains were used as propellant in 50 gram end-burning motors. Smooth burning of the grain to completion was realized.
Composition data and motor firing results are summarized in Table II.
Table II ____________________________________________________________ ______________ Composition Motor Firing Results ____________________________________________________________ ______________ Isp, sec. Pa C* Burning Rate Run No. Polytaz AlH 3 NH 4 ClO 4 (calc.) psi ft/sec. in/sec. ____________________________________________________________ ______________ (weight percent) 1 40 18 42 281 220 4368 0.96 2 40 18 42 281 358 4841 1.45 3 40 18 42 281 391 4708 2.56 4 40 18 42 281 673 4947 1.69 5 35 21 44 286 392 4776 1.44 6 30 24 46 291 302 4890 1.20 ____________________________________________________________ ______________ C* is the characteristic exhaust velocity
EXAMPLE 3
To evaluate the properties of the high nitrogen binders, the tensile properties of standard tensile test specimen prepared by compressing 50/50 weight per cent mixtures of Polytaz or Malonitaz with aluminum hydride were determined using an Instron tester at a cross-head speed of 2 inches/minute. The hardness was determined using a Shore Durometer tester. Additionally, a simulated propellant grain was fabricated by the same technique wherein small glass beads were incorporated into the mix to simulate particulate nitronium perchlorate oxidizer. Table III summarizes the physical properties obtained in these studies.
Table III ____________________________________________________________ ______________ Max. Tensile Elongation Strength at yield max. Durometer Run No. Composition (psi) (%) (Hardness A) ____________________________________________________________ ______________ 1 Polytaz + AlH 3 19 8 16 85 2 Malonitaz + AlH 3 240 3 16 97 3 Malonitaz + AlH 3 308 8 22 96 + simulated oxi- dizer ____________________________________________________________ ______________
EXAMPLE 4
A number of propellant motor grains and strands were prepared based on Polytaz, aluminum hydride and nitronium perchlorate, ammonium perchlorate or nitronium perchlorate-ammonium perchlorate mixtures. In these studies, the nitronium perchlorate used was coated with from about 5 to about 10 per cent of a proprietary polymeric composition.
The motor grains and strands were fabricated by first chilling the Polytaz binder whereupon it became brittle. The chilled binder and finely divided fuel components were blended in a Waring Blender to provide a homogeneous, free-flowing mix having a coating of the aluminum hydride fuel on the sheared polymer particles. Nitronium perchlorate was added and the resulting mixture blended. After blending, the composition was poured into a motor case or strand mold where it was pressurized to from about 100 to about 200 pounds per square inch, warmed to about 30° C. and then subjected to a low pressure. The resulting cured grains or strands were substantially void free.
Bomb combustion data were carried out on a number of compositions to determine the heat of explosion. The data and results from this test are summarized in Table IV.
Table IV ____________________________________________________________ ______________ Composition Nitronium Ammonium ΔH ex Run. No. Polytaz AlH 3 Perchlorate Perchlorate (cal/gram) ____________________________________________________________ ______________ (weight per cent) 1 30 25 45 -- 1529 2 20 30 50 -- 1835 3 20 30 45 5 1943 ____________________________________________________________ ______________
A pressed strand of the composition employed in Run 2 was tested to determine the burning rate. This system gave a burning rate of 1.2 inches/second at 1000 psi with a pressure exponent of 0.45.
Thirty gram end-burning motors were prepared and tested at various pressures from about 50 to about 750 psia. The compositions employed in these runs are summarized in Table V.
Table V ______________________________________ Comp. Ingredients No. Polytaz AlH 3 NH 4 ClO 4 NO 2 ClO 4 (NP) ______________________________________ 1 30 24 46 -- 2 35 21 44 -- 3 40 18 42 -- 4 20 31 -- 49 ______________________________________
All motors burned smoothly with stable, normal burning being obtained at all test pressures.
EXAMPLE 5
A number of formulations of the present invention provide high energy propellants fabricated into propellant grains. The combustion temperature and theoretical impulse of a number of such propellants were calculated. The propellant formulation data and performance results from this study are presented in Table VI which follows.
Table VI ____________________________________________________________ ______________ Propellant Composition Results Run Comb. Temp. Specific Imp. No. Polytaz Malonitaz Al Be AlH 3 BeH 2 AP NP HNF TAZ °K Isp. ____________________________________________________________ ______________ (sec.) 1 10 36 54 4250 291.8 2 10 45 45 3905 297.3 3 15 30 55 4238 296.1 4 15 39 46 3981 301.1 5 20 30 50 4099 300.5 6 20 36 44 3901 301.5 7 25 24 51 4062 296.2 8 25 30 45 3943 302.3 9 25 36 39 3599 292.6 10 30 24 46 3936 300.5 11 30 27 43 3852 301.7 12 30 30 40 3722 300.2 13 35 27 38 3619 298.4 14 35 24 41 3756 300.4 15 35 21 44 3840 299.2 16 40 24 36 3505 296.4 17 40 18 42 3731 296.9 18 15 30 55 3297 297.1 19 15 22 63 3531 298.4 20 20 27 53 3230 295.8 21 20 18 62 3438 293.9 22 15 35 50 3330 293.8 23 15 28 57 3487 291.3 24 20 30 50 3440 292.6 25 20 25 55 3398 290.4 26 30 27 43 3025 285.8 27 30 21 49 3172 286.0 28 40 18 42 2893 278.9 29 20 30 50 3858 262.7 30 20 15 65 3679 265.9 31 30 28 42 3448 265.8 32 30 19 51 3601 274.0 33 30 13 57 3490 272.5 34 35 17 48 3443 275.7 35 40 12 48 3218 270.6 36 40 9 51 3146 266.6 37 40 18 42 3276 274.8 38 45 17 38 3060 269.0 39 30 29 41 4174 268.9 40 30 23 47 4256 273.6 41 30 17 53 4163 272.7 42 30 23 47 3316 274.5 43 30 17 53 285.6 44 30 11 59 3465 281.5 45 15 21 64 3974 280.5 46 15 15 70 4003 281.0 47 20 20 60 3802 281.9 48 20 14 66 3907 284.1 49 25 12 63 3769 286.0 50 25 18 57 3710 285.4 51 30 19 51 3506 280.8 52 30 13 57 3712 290.7 53 30 7 63 3495 281.8 54 35 12 53 3587 292.6 55 40 13 47 3318 289.2 56 40 7 53 3304 283.3 57 45 9 46 3277 289.3 58 30 22 48 3932 279.4 59 30 16 54 4461 289.9 60 30 13 57 4370 286.8 61 30 10 60 4188 282.0 62 40 16 44 3862 290.1 63 40 13 47 4120 296.3 64 40 10 50 4081 293.6 65 50 10 40 3750 299.1 66 50 13 37 3502 290.1 67 50 7 43 3744 296.0 68 60 7 33 3309 291.9 69 60 4 36 3197 283.5 70 60 10 30 3082 288.1 71 30 16 54 3447 288.2 72 30 10 60 3599 299.6 73 30 7 63 3489 293.8 74 30 4 66 3354 285.1 75 20 16 64 3706 295.1 76 20 10 70 3777 296.7 77 40 7 53 3280 291.8 78 40 13 47 3248 287.4 79 18 11.4 50.6 20 3553 294.1 80 23 10.5 46.5 20 3417 294.1 81 30 11.1 48.9 10 3477 293.8 82 35 11 47.5 65 3417 293.0 83 20 17 63 3441 312.6 84 20 23 57 3214 319.5 85 20 29 51 2823 327.2 86 20 32 48 3004 318.4 87 30 19 51 3136 313.1 88 30 25 45 2820 319.5 89 30 28 42 2845 310.7 90 20 22 58 3972 322.3 91 20 31 49 3239 328.4 92 20 34 46 3369 324.5 93 30 25 45 3390 323.8 94 30 31 39 2759 336.7 95 30 34 36 3139 316.6 96 20 15 65 3414 318.8 97 20 21 59 3209 319.1 98 30 14 56 3171 313.5 99 30 20 50 3012 310.6 100 25 14.3 40.7 20 3940 286.9 101 30 13 37 20 3765 286.5 102 35 14.3 40.7 10 3924 286.3 103 40 13 37 10 3740 285.8 104 45 12.4 32.6 10 3506 283.2 105 35 11 44 10 3896 297.0 106 40 10 40 10 3727 298.2 107 45 9 36 10 3538 297.1 108 30 3 12 55 3081 299.5 109 30 5 20 45 2887 309.7 110 30 6 24 40 2823 307.3 111 40 2 8 50 2850 285.9 112 40 5 20 35 2749 299.8 113 10 36 54 4232 298.1 114 10 45 45 3869 296.4 115 15 33 52 4151 298.8 116 15 42 43 3753 294.6 117 20 30 50 4048 298.2 118 20 36 44 3819 297.6 119 20 39 41 3619 291.5 120 25 27 48 3953 297.9 121 25 30 45 3851 298.3 122 25 33 42 3698 295.4 123 30 24 46 3844 296.3 124 30 27 43 3735 296.4 125 30 30 40 3561 292.3 126 10 30 50 10 4118 300.2 127 10 33 52 5 4195 299.6 128 10 42 43 5 3837 298.0 129 10 39 41 10 3765 298.2 130 10 33 52 5 4174 299.6 131 10 39 46 5 3959 300.0 132 10 42 43 5 3799 296.8 133 10 30 50 10 4091 299.8 134 10 36 44 10 3892 300.8 135 10 27 48 15 4020 300.3 136 10 33 42 15 3821 301.2 137 10 24 46 20 3944 300.3 138 10 30 40 20 3745 300.9 139 10 33 37 20 3558 295.5 ____________________________________________________________ ______________
In a manner similar to that described for the preceding Examples, solid propellant compositions can be formulated using particulate fuels and oxidizers, gas producing additives, and binder components set forth herein. These can be used in various combinations within the disclosed ranges.
Various modifications can be made in the present invention without departing from the spirit or scope thereof for it is understood that we limit ourselves only as defined in the appended claims.