US2970899A - Ammunition propellant - Google Patents

Description

Feb. 7, 1961 D. w. RYKER 2,970,899

AMMUNITION PROPELLANT Filed sept. 28, 1955 s sheets-sheet 1 cARBoHYDRAzlDE- NITRIC ACID-WATER SYSTEM AAVAVAV VAYA VAVAVAVAVAVAVAVA N H 2 N H\ 9:0 loo/ v v HNO3 NHZNH MoNoNlTRATE K DINITRATE '00A H 2 O |007., A SEMICARBAZIDE- NITRIC ACID WATER SYSTEM FIGURE 2 AVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAVAVAVA AvAVAVAVAVAVAVAVAVAVAVAVAVA VAVAVAVAVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAVAVAVAVAVAVA AVAVAVAVAVAVAVAVAVAYAVAVAVAVAVA N H 2 N H\ AVAVAVAVAVAVAVAAVAVAVAVAVAVAVAVAVA 9: o H N O 3 NH2 O04 MoNoN|TRATE-\ DINITRATE O04 l CC CHARGES INVENToR. e N0 F|RE DON W.RYKER FIRING RESULTS ATT R NEY CHAMBER PRESSURE (LBS./SQ.IN.X IO) Feb. 7, 1961 Filed Sept. 28, 1955 3 Sheets-Sheet 2 EFFECT OF CHARGE VOLUME ON CHAMBER PRESSURE IOO CHARGE VOLUME (cc) f vs -2 CHAMBEF PRES SU RE (LBS./SQ.|N.XIO)

CHARGE VOLUME (CC) FIGURE 3 INVENTOR. DoN w.RYKl-:R

ATToNEY D. W. RYKER AMMUNITION PROPELLANT Feb. 7, l1961 Filed Sept. 28, 1955 OOO OOO N OOOm (oas/ld) imo-ISA lA/vToR. DON. W ./RYKER W RNEY 2,970,899 AMMUNITIN PROPELLANT Don W. Ryker, Woodbridge, Conn., assignor to Olin Mathieson Chemical Corporation, New Haven, Conn., a corporation of Virginia Filed Sept. 28, 1955, Ser. No. 537,151

c6 Claims. (Cl. 52-1) This invention relates to a propellant and more particularly to a liquid propellant.

The recent trend in propellants for use in the ammunition iield has been directed toward those of the liquid type. Liquid propellants are favored because they are easy to store, do not require grain formation, are easily loaded and dispensed and can be used in such manner to utilize substantially all of their potential. There are many known liquid propellants. However all of these are not useful for use in ammunition because they are either unstable, sensitive, brisant, too slow or too fast burning or of an undesirable low or high potential.

. An object of this invention is to provide a novel class of liquid propellants. Another object of this invention is to provide a method for making this novel class of liquid propellants. A further object of this invention is to provide compositions utilizing this novel class of liquid propellants useful for ammunition. And a further object of this invention is to provide liquid propellant compositions that are stable, insensitive `and slow burning. Other objects will become apparent to those skilled in the art upon reading the following detailed disclosure and description, with accompanying drawings in which j Figure 1 is a graph illustrating the desirable range of mixtures of carbohydrazide-nitric acid-water particularly useful as propellants.

Figure 2 is a graph showing the desirable range of mixtures of semicarbazide-nitric acid-water particularly useful as propellants.

Figure 3 is a graph showing the effect of charge volume of the carbohydrazide nitrate of Figure 1 on chamber pressure, and

Figure 4 is a graph showing the effect of charge volume of the carbohydrazide nitrate of Figure l on velocity.

Broadly, the objects of this invention are accomplished by the use of carbohydrazide and/ or semicarbazide-nitric acid-water mixtures with or without additives, such as urea, urea mono-nitrate, guanidine nitrate, methanol and benzene.

In one of its aspects the invention may be accomplished by providing a liquid propellant composition consisting essentially of a 100 part composition yof about 34 to 64 parts by weight of a substance selected 4from the lgroup consisting of semicarbazide and carbohydrazidc, .about 25 to 55 parts by weight nitric acid and about 7.5 to 16 parts by weight Water.

A more thorough discussion of the method of making and using the propellants of this invention can be shown by reference to specific examples, illustrating preferred techniques.

EXAMPLE I.-SYNTHESIS OF CARBOHYDRAZIDE For every mole of diethyl carbonate used, two moles Vplus some excess of hydrazine in the form of an 85% hydrazine hydrate solution is used. The mixture is heated and distilled until the temperature reaches about y120 C. The reaction is then allowed to cool to enable the carbo- Patented Feb. 7, i961 hydrazide to crystallize. The crystals are ltered and dried. A yield of about 65-85% is obtained.

The required quantities of carbohydrazide and concentrated nitric acid (70%) were mixed to form the desired ratio by slowly adding the nitric acid to the carbohydrazide. Heat and some slight vaporization of the water of the nitric acid occurred. The nitrate salts formed were clear, faintly yellow, viscous liquids.

A liquid reaction product made by use of equimolar quantities of the carbohydrazide and nitric acid was dehydrated by an extraction with ethyl alcoholk and then dried over anhydrous magnesium perchlorate in a vacuum dessicator at l0 mm. pressure.

An analysis of the resultant dried solution of the mononitrate was performed using the Karl Fisher method and the xylene distillation method for water determination. The ethyl alcohol content was determined by distillation of the liquid salt product with water, oxidizing with dichromate and back titrating the dichromate with vferric sulfate. The purity of the salt was checked with a nitrate determination. 'Ihe percentages of each ingredient were determined to be (by weight):

Percent Carbohydrazide mononitrate 87.1 Water 10.8 Ethyl alcohol 0.9

The properties of the mono and dinitrate of carbohydrazide in the liquid salt form are tabulated as follows:

EXAMPLE in sYNTHEsIs 0F sI-:MiCARBAzID- E- Semicarbazide may be synthesized by various techniques as disclosed in C. C. Clark, Hydrazine, tirst edition, 1953, pages 59-61, published by the Mathieson Chemical Corporation, Baltimore, Maryland. The method here used involves the relluxing of urea and hydrazine hydrate in amyl alcohol according to the following equation:

Equal molar quantities of urea and hydrazine in the form of an hydrazine hydrate solution are reuxed at 118 C. for several hours. Water is removed under vacuum until the mixture attains a temperature of C. The molten semicarbazide is then dissolved in methanol, filtered hot and the liltrate cooled with stirring to precipitate the semicarbazide. The semicarbazide is filtered, washed with methanol and dried under vacuum. A yield of 70% semicarbazide melting at 92-95" C. is obtained.

EXAMPLE IV.-SEMCARBAZIDENITRIC ACID-WATER SYSTEM The required quantities of semicarbazide and concentrated nitric acid (70%) were mixed to form the desired ratio by slowly adding the nitric acidj tothe semicarbazide. Heat and slight vaporization of the water of the nitric acid occurred. The nitrate salts formed were clear, faintly green, viscous liquids.

An aqueous salt mixture made by use of equmolar quantities of the semicarbazide and nitric acid was concentrated by an extraction with ethyl alcohol. A simi-` -lar analysis as performed ou the carbohydrazide nitrateV mixture of Example II was performed on the semicarbazide nitrate mixture and gave the following result (by weight):

\ Percent Semicarbazide mononitrate 92.0 Water 7.5 Ethyl alcohol 0.7

These systems were subjected to ballistic tests in their aqueous solution form with or without additives.

Table II.-Ballistic tests SEMICARBAZIDENITRIC ACID-WATER sYs'rm/i liNitrocellulose 88.3%, dnitrotoluene 8.8%, K2SO4 0.6%, diphenyl amine 0.6%.

Table IIL- Ballistic tests CARBOHYDRAZIDE AND SEMICARBAZIDE-NITRIC ACID- WATER SYSTEM System (by Weight) Charge Velocity, Pressure, (cc.) ftJsec. lbs./sq.in. Carbohydrazlde Semicar- Nitric Water bazide Acid 1 N itrocellulose 88.3%. dinitrotoluene 8.8%, KzSO4 0.6%, diphenylaruinc 0.6%.

Ballistic tests Test rings using a carbohydrazide or semicarbazidenitric acid-Water system made by the techinque of Ex? amples II and IV were made using a commercially available brass cartridge case (-Super X -05 caliber) with a centerre primer (Type 257W) (both manufactured by the Western Cartridge or Winchester Repeating Arms Plants of the Olin Mathieson Chemical Corporation of New Haven, Connecticut).l Before loading, the flash hole leading from the primer into the main cavity of the cartridge was covered with a polyethylene disc prior to seating the primer. v Y Y Tabulations of the ballistic tests performed for each system are given in Tables I, II and III.

Table 1.-Ballstc tests CARBOHYDRAZIDE-NITRIC ACID-WATER SYSTEM System (by weight) Charge Velocity, Pressure, (cc.) it./sec. lbs/sq. in. Carbohydrazide 1N itric Water Acid 1MB l (control) 50 gr. 2, 600 40, 000 51.5 36. 8 10.8 2 1,714. 40, 2G() 35.9 13.0 2 1,792 55, 200 35. 5 14.0 2 1, 591 41, 500 33. 6 9. 5 2 1, 734 46, 700 31.8 8. 4 2 1, C65 45, 0C() 29. 6 7. 9 2 1. 630 44, 600 39. 5 10.5 2 1, 811 56, 200 43.8 11. 6 2 1,855 59,800 47. 6 12.6 2 1,906 0 600 50. 3 13. 4 2 1, 929 58, 300 49. 0 15. 6 2 1, 941 65, 300 48. 1 17. 2 2 l, 735 43, 000

lNltrocellulcse 88.3 dinitrotolueue 8.8 KSO 0,6 I -he 1 amineu.%, .'75, 2 4 dip ny The systems carbohydrazide-nitric acid-Water and semicarbazde-nitric acid-water were further studied to determine the range of concentrations which gave no misres under the conditions used. The liquids to be red were prepared by adjusting ethyl alcohol-washed CMN or SMN with the desired amount of water. The amount of alcohol retained by the washed nitrate was less than 1%. Pressures and velocities were not measured during these rings. Results for 1 cc. charges are plotted onYFigures v1 and 2. The area bounded by the black lines on each ligure indicates the operable compositions.

In another series of tests under the same conditions the charge volume was varied from 0.5 cc. to 4 cc. of CMN and the pressure and velocity measured. Results are shown on Figures 3 and 4.

In attempting to dehydrate the carbohydrazide mononitrate by lheating C.), it was found that water was driven off. At the cessation of this water evolution, heating was discontinued. The distillate was opaque milky white and very viscous. Upon standing, it scparated into two phases into a clear, colorless, viscous liquid and the white solid. It was found that the solid constituted about 18% of the total weight of the distillate. Repeated attempts at analyzing and classifying this substance were unsuccessful. It was assumed that the solid material was either a decomposition product or a product of molecular rearrangement or both.

The white solid behaved as a propellant. This was demonstrated by firing caliber .30 rounds with a charge containing the solid. Table IV shows the results.

Table IV.-Test of CMN dehydration product The CMN dehydration product was found to be in- 3. A liquid propellant composition consisting essensensitive to the impact of a 2 kilogram weight dropped tially of a semicarbazide-nitric-acid-Water mixture as in- 80 centimeters. It could not be detonated with a #6 dicated by II of Figure 2 of the drawing. electric blasting cap. 4. The method of developing a projectile propelling 'The ballistic results shown above were varied to a 5 pressure within an enclosed chamber which comprises inmore desirable range by adding certain additives to the sorting within said chamber a quantity of a composition carbohydrazide and/or semicarbazide-nitric acid-water made up of 100 parts, said composition consisting essystems. The addition was carried out by adding the sentially of about 34 to 64 parts by weight of carbohyadditive to the propellant system, mixing it and then drazide about to 55 parts by weight of nitric acid and loading cartridge cases with the proper amount of the 10 7.5 to 16 parts by weight of water, and locally igniting mixture. A tabulation of the firing tests is seen in Table said mixture.

V, 5. A method of developing a projectile propelling pres- T able V.Ballslc tests ADDITIVES To GARBOHYDRAZIDE AIIJIDS/gMSEMIOARBAZIDE-NITRIC ACID-WATER S stem b wei ht) y y g Charge Velocity, Pressure,

Additives (ce.) itz/sec. lbs/sq. in. Carbohydrazide Semlcar- Nitric Water bazide Acid IMR l (control) 50 gr. 2, 600 49, 000 51.5 34. 5 10. 5 Urea 2. 6 2 1, 729 54, 000 34. 5 10. 5 Urea mononitrate--- 2. 5 2 1, 821 56, 700 33. 6 10. 3 do 4. 8 2 1, 785 52, 700 32. 8 10.0 7. 2 2 1, 792 47, 400 32. 0 9. 9 9. 3 2 1, 850 58, 100 34. 5 10.5 2. 7 2 1, 805 56, 300 40. 8 7. 2 o 2. 7 2 1, 849 53, 600 35. 7 10. 8 Benzene washed 2 1, 767 51, 600 42. 5 7. 5 do 2 1, 766 49, 400

1 Nitrocellulose 88.3%, dinitrotoluene 8.8%, KzSOi 0.6%, dphenylamlne 0.6%. Y

As seen n the data above the propellant compositions sure within anenclosed chamber which comprises inof this invention are aqueous solutions of carbohydrazide serting within said chamber a composition made up of OI SemicarbaZide mOIlO Or dinitrate 01` dehydration pI'Od- 100 parts, Said composition containing as its essential UCS OI' their IliXui'eS With OI Without additives in trace ,ingredients about to parts by Weight 0f a com.. to substantial quantities of the mixture. The additives pound selected from the group Consisting of Semmai-ba. n'faY be Semfafbazid'e cafbohydl'azide urea urea mono' zide and carbohydrazide, about 25 to 55 parts by weight amate guamdme. nitrate Piethmol and 'benzine' .By of nitric acid and about 7.5 to 16 parts by weight of water trace to substantial quantities is meant anything withand locally igniting said mixture.

in the range of 0.1% to 10% by weight. A trace 40 6. A method of developing a proJectile propelling presquantlty generally results from Washmg of the aqueous sure within an enclosed chamber which comprises insertmixture with an additive. .th. .d h b d f 100 While a detailed description of this invention has been mg W1 1, sal C fr? er a (forlposmon ma e up o parts, said composition consisting essentially of 34 to 64 provided, it is realized that those skilled in the art may make modications in and adaptations of the propellant Parts by Welght 0f Semlcabazlde, 3h01 25 t0 55 PaI'S composition and its method of manufacture described by Weight 0f DTC acid and about 7-5 t0 16 Pal'S by herein without departing from the spirit and scope of this Weight 0f Water and 100311) gHDg Said mXtUIe IO invention. It is, therefore, to be specifically understood cause a burning of the liquid composition therein.

that such obvious modifications are to be considered within the scope of the herein described propellant and method of manufacture.

The invention having thus been described what is to be` secured by Letters Patent is as follows:

1. A liquid propellant composition consisting essen tially of a 100 part composition of about 34 to 64 parts by weight of a substance selectedv from the group con- OTHER REFERENCES sisting of seiriicarbazide and carbohydrazide, about 25 Thiele et al.: Annalen der Chemie VOL 283, pp 22, $1555 bpartelgit vigilt nitric acid and about 7.5 to 16 23. (opy in Scientic. Library) I n 2. A liquid propellant composition consisting essentially & ndnetlh' Tg? ChnultryNcg. Hggzme Jogs Wllilesy of a carbohydrazide-nitric-acid-water mixture as indons? ncl .ew or pp cated by '1 of Figure 1 of the drawing. (COPY m Scl- L12) References Cited in the tile of this patent UNITED STATES PATENTS Whetstone et al. Nov. 30, 1948 Hutchison June 29, 1954

Claims (1)

1. 6. A METHOD OF DEVELOPING A PROJECTILE PROPELLING PRESSURE WITHIN AN ENCLOSED CHAMBER WHICH COMPRISES INSERTING WITHIN SAID CHAMBER A COMPOSITION MADE UP TO 100 PARTS, SAID COMPOSITION CONSISTING ESSENTIALLY OF 34 TO 64 PARTS BY WEIGHT OF SEMICARBAZIDE, ABOUT 25 TO 55 PARTS BY WEIGHT OF NITRIC ACID AND ABOUT 7.5 TO 16 PARTS BY WEIGHT OF WATER AND LOCALLY IGNITING SAID MIXTURE TO CAUSE A BURNING OF THE LIQUID COMPOSITION THEREIN.

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