US3784420A

US3784420A - Thermally stable high density-impulse energetic composition of matter

Info

Publication number: US3784420A
Application number: US00785024A
Authority: US
Inventors: M Frankel; G Lo
Original assignee: Rockwell International Corp
Current assignee: Boeing North American Inc
Priority date: 1968-12-09
Filing date: 1968-12-09
Publication date: 1974-01-08
Anticipated expiration: 1991-01-08

Abstract

This invention is concerned with a novel, energetic, thermally stable, dense binder system suitable for formulating energetic compositions of matter wherein said binder system comprises the energetic prepolymer of a compound of the formula

IN WHICH R is alkylene of 1 to 4 carbon atoms and the energetic plasticizer bis-(dinitrofluoroethyl)-formal. The energetic composition also contains at least one fuel and at least one oxidizer homogeneously dispersed in and held together by said binder system.

Description

United States Patent Frankel et al. 1 Jan. 8, 1974 THERMALLY STABLE HIGH 3,393,104 7/1968 Mayes et a1 .1 149 19 DENSITY-IMPULSE ENERGETIC COMPOSITION OF MATTER Primary Examiner-Carl D. Quarforth Assistant Examiner-Stephen J. Lechert, Jr. [75] Inventors 2 g g i g gigi zg z gg Att0rney-Thomas S. MacDonald and L. Lee

g Humphries [73] Assignee: RockwellInternationalCorporation,

El Segundo, Calif. ABSTRACT [22] Flled: 1968 This invention is concerned with a novel, energetic, [21] Appl. No.: 785,024 thermally stable, dense binder system suitable for formulating energetic compositions of matter wherein said binder system comprises the energetic prepoly- [52] U.S. Cl 149/22, 149/19, 149/38,

l49/2O 49/42, *9/43, 49/44, 49/47, mer ofa compound of the formula 149/62, 149/76, 149/78, 149/85, 149/88 [51] lnt. Cl C06b 15/00 [58] Field of Search 149/70, 19, 20, 78, H

149 22, 47,38, 42, 43,44, 45, 88, 62 l m wh1ch R 1s alkylene of 1 to 4 carbon atoms and the [56] References Cited energetic plasticizer bis-(dinitrofluoroethyl)-formal. The energetic composition also contains at least one UNITED STATES PATENTS fuel and at least one oxidizer homogeneously dis- 3,111,439 11/1963 Brunauer 149/38 X parsed in and held together by said binder systerm 3,332,811 7/1967 Guthrie et al 149/38 X 3,351,506 11/1967 Grigor et al. 149/38 X 18 Claims, 2 Drawing Figures SPECIFIC IMPULSE, SEC.

PAIENIEDJA11 81974 3,784,420 SHEEI 10F 2 AMMONIUM PERCHLORATEwALUMINUM-GDNFE/FEFO (40/60) IOOO I4.7 PSIA 20%ALl I 258 I I ,..18%

I a a I 4 I 1 l6% I I I l I r I 256 x I ,l4/o

I I I I r z I I a I l U u 254 I 500 I 1 7 20%111 u 252 490 5' x. l I6% 3 1: E 250 -SPECIFIC IMPULSE 480 E DENSITY IMPULSE Q I I l I 20 22 24 26 28 30 WEIGHT PERCENT BINDER INVENTOR. MILTON B. FRANKEL BY GEORGE A. 1.0

f l #JMLE ATTORNEY THERMALLY STABLE HIGH DENSITY-IMPULSE ENERGETIC COMPOSITION OF MATTER CROSS-REFERENCE TO RELATED APPLICATION This application is related to commonly assigned application Ser. No. 729,822, filed May 16, 1968, for Certain Energetic Monomeric Epoxy Ethers and polymers Prepared Therefrom in the name of M. B. Frankel et al.

BACKGROUND OF THE INVENTION This invention pertains to a new and improved com-, position of matter. More particularly, the invention relates to a novel, homogeneous, energetic, explosive and propellant composition of matter comprising at least one fuel, at least one oxidizer, an energetic, thermally stable, dense polymeric binder, a curing agent for said binder and an energetic plasticizer. Specifically, the invention is directed to a novel binder system comprising an energetic binder and an energetic plasticizer for use in preparing castable explosive and propellant systems. Explosive and propellant compositions of matter are important for providing energy sources for use in guided missiles, auxiliary power units in aircraft, ordnance, demolition and the like. The prior art in preparing explosive and propellant compositions routinely mixed a fuel, an oxidizer, a non-energetic binder and a non-energetic plasticizer to form a composition possessing acceptable utility but characterized by a decreased energy level. The decreased energy level for said prior art compositions was generally due to the binder and plasticizer employed for formulating said compositions. Generally, the binders used for manufacturing the prior art compositions were thermosetting, elastomeric, polymeric non-energetic materials of the natural or synthetic rubber type, such as polybutadiene or a copolymer of butadiene and a vinyl pyridine and the like. The plasticizers usually employed by the prior art were non-energetic derivatives of the fatty acid type, such as lauric acid, stearic acid and the like. The use of binders and plasticizers of the type described supra presents many serious disadvantages for the successful utilization of this kind of material. For example, the available energy per unit mass of the explosive and propellant system is decreased in relation to the total weight of the composition by the presence of nonenergetic binders and plasticizers in the system. Another disadvantage of some of the prior art binders and plasticizers is that they tend to exhibit thermal instability and a low shock resistance. Still another disadvantage of many of the prior art binders and plasticizers is that they cannot be easily used in castable explosive and propellant systems or the binder may have a prolonged cure time. In view of these and other disadvantages it becomes desirable that an explosive and propellant system be made available utilizing an energetic binder and energetic plasticizer to overcome the above stated disadvantages. It is also desirable that an energetic binder system be made available that can easily be employed for manufacturing castable explosive and propellant systems.

It is, therefore, an object of this invention to provide to the art novel, explosive and propellant compositions of matter wherein the binder and the plasticizer employed to formulate said compositions are characterized as possessing innate energy.

It is a further object of this invention to provide an energetic composition of matter wherein said composition possesses high energy, high thermal stability, and high density.

It is a further object of this invention to provide an explosive and propellant composition wherein said composition contains a thermally stable energetic prepolymer suitable for use in forming castable explosive and propellant systems.

Yet another object of this invention is to provide an energetic binder system for explosives and propellants wherein said binder system comprises an energetic binder, a curing agent for said binder and an energetic plasticizer.

Yet still a further object of this invention is to make available to the art an improved explosive and propellant composition of matter wherein said composition comprises a fuel, an oxidizer, an energetic binder, a curing agent, an energetic plasticizer and wherein said improved composition has a high energy level per unit mass of composition.

Other objects and advantages of the invention will become apparent from the following detailed description and the accompanying claims.

SUMMARY OF THE INVENTION Briefly, the present invention is concerned with an energetic binder system comprising an energetic prepolymer of the general formula wherein R is alkylene of l to 4 carbon atoms and n is S to 25, an energetic plasticizer T T FCCH OCH OCHJIIF and a curing agent. The binder system is used to form a castable propellant or explosive composition of an oxidizer and a fuel and cured in situ.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The novel energetic compositions of this invention can be prepared by intimately blending a fuel, an oxidizer, a prepolymer, a curing agent and a plasticizer. The fuels suitable for formulating the energetic composition are generally powdered metals, for example, boron, aluminum, magnesium, beryllium and the like. Alloys can also be used, for example alloys such as aluminum and boron, aluminum and magnesium, aluminum and copper and the like. Generally, the fuel component of the energetic composition is present in the range of from 5 to 25 weight percent.

Exemplary of the oxidizing agent suitable for the purpose of the present invention are the organic or inorganic compounds which contain oxygen, which oxygen they readily give up to the propellant system. Typical oxidizers are ammonium, alkali metal and alkaline earth metal salts of nitric, perchloric and chloric acid such as ammonium nitrate, ammonium perchlorate, hydroxylammonium perchlorate, potassium perchlorate, lithium perchlorate, calcium nitrate, barium perchlorate and mixtures thereof. In the use of the oxidizers, the oxidants are powdered to a particle size of about to 350 microns average particle size. The amount of ox idant employed is generally in the range of 40 to 80 weight percent with the presently preferred range of 50 to 65 weight percent as based on the weight of the final explosive or propellant composition.

The prepolymer compounds of the present invention are prepared from monomers of the general formula in which R is alkylene of l i?) 4 carbon atoms. These monomers can be prepared by the by the following procedure: first, the addition of an unsaturated, lower ali phatic alcohol to an unsaturated, lower aliphatic dinitro substituted olefin to produce the corresponding unsaturated ether, as represented by the reaction equation,

wherein R is an alkylene of l to 4 carbon atorr1s next,

fluorinating said ether to form the unsaturated dinitrofluoroether,

and, finally, direct oxidation of the olefin to the epoxide with peracids, as depicted by the chemical reaction:

R"CO3H FCCH2ORCH=CH2 The l,l-dinitroethylene is a reactive intermediate generated in situ from 2-brorno-2,2-dinitroethyl acetate, 1,2-dichloro-l, l-dinitroethane or l,l,l-trinitroethane. For the synthesis described herein, the 1,1- dinitroethylene was generated from l,2-chloro-l,1- dinitroethane according to the procedure as set forth in The Journal of Organic Chemistry, Vol. 31, p, 369, 1966.

The next step in the synthesis is the fluorination of allyl 2,2-dinitroethyl ether with perchloryl fluoride to form the corresponding allyl 2,2-dinitro-2-fluoroethyl ether which fluorination can be represented by the reaction H(NO CCH OCH CH=CH FClO alkali F(NO CCH OCH CH=CH The final step of the synthesis consists in the epoxidation of the allyl 2,2-dinitro-2-fluoroethyl ether with peroxytrifluoroacetic acid to form the desired glycidyl 2,2-dinitro-2-fluoroethoxide. The epoxidation reaction can be represented by the equation Additional compositions of matter can easily be prepared by the above described synthesis by employing a suitable alcohol such as 3-butene-l-ol or 2-methyl-3- butene-l-ol.

Generally, the above described dinitroethylation, fluorination and epoxidation reactions are carried out under normal atmospheric conditions. The initial temperature of the dinitroethylation reaction was usually about 15 to 25 C followed by agitation or stirring at room temperature for 10 to 15 hours. The beginning temperature of the fluorination process was its refluxing temperature followed by a reaction temperature of about 20 to 25 C for about 3 to 4 hours. The epoxidation reaction was carreed out at its refluxing temperature for about 1 to 3 hours. The above reactions were usually performed in the presence of an inert solvent, such as methylene chloride, carbon tetrachloride, chlorobenzene, chloroform or any other inert solvent that does not adversely affect the reactions.

The polymeric compounds as used herein are of the general formula wherein R was as defined supra, and wherein n is the degree of polymerization for said polymer and it is from 3 to 25.

ving material. The polymer is isolated from the reaction medium by first water extracting the solvent to remove the catalysts and then drying the extracted solvent and extracting the polymer with alcohol. Finally, the alco ho] is evaporated to give the polymer.

Exemplary of the Lewis acid catalysts suitable for polymerizing the monomers are catalysts such as aluminum chloride, zinc chloride, ferric chloride, boron trifluoride, boron trifluoride hydrate, stannic chloride arrd like metal halides.

Representative of initiator compounds containing an OH group suitable for the polymerization reaction are compounds such as water, glycerine, glycols like ethylene glycol, polypropylene glycol, polyethylene glycol, mixed polyethylene polypropylene glycols, glycerol nnd the like.

Solvents suitable for the polymerization reaction generally include methylene chloride, carbon tetrachloride, ethylene chloride, methylene dichloride, methyl bromide, propyl chloride and like hydrocarbon solvents.

Generally, about weight percent to about 20 weight percent of the prepolymer is employed to effect the desired composition. The usual working range for the prepolymer is in the neighborhood of about 6 to about 10 weight percent.

The curing agents employed herein to cure the liquid prepolymer are the conventional, commercially available curing agents. Generally, curing agents such as polyphenylpolyisocyanate, hexamethylene diisocyanate, bis-isocyanatophenyl methane, toluene diisocyanate, 3nitraza-l,5-pentane diisocyanate, polymethylene polyphenylisocyanate, and the like will give a satisfactory cure. Usually, about up to 5 weight percent of the curing agent based on the weight of the composition is employed with a range of l to 3 weight percent effectively curing the desired explosive and propellant composition.

The composition of matter made within the scope and spirit of this invention can be formulated with or without a catalyst, depending on if it is desired to effect a faster rate of cure of the prepolymer. Of course, if no catalyst is employed, the pre polymer will satisfactorily cure at ambient conditions. Non-limiting examples of catalysts are aluminum chloride, tris-trimethylsilyl borate, ferric acetonyl acetonate and the like. The curing catalysts are added in amounts of from 0.01 weight percent to about 0.5 weight percent based on the weight of the prepolymer, preferably about 0.01 to 0.05 weight percent. Often, it is convenient and effective to add trace amounts of the catalysts.

The plasticizer employed herein, bis-(2-fluoro-2,2' dinitroethyl)-formal can easily be prepared according to the procedure in The Journal of Organic Chemistry, Vol. 33, No. 8, 1968, pp. 3073 to 3080 and Tetrahedron, Suppl. Vol. 1, No. 19, 1963, p. 219. Generally, about 5 weight percent to about 25 weight percent of the plasticizer is employed to form the desired, novel energetic composition of matter. In most cases,

the preferred amount of plasticizer is about 10 to 20 weight percent.

The components of the composition of this invention are thoroughly mixed together in a suitable conventional mixer, such as a Banbury mixer or Barker Perkins mixer and the like. The components, that is, prepolymer, plasticizer, fuel and oxidizer are generally mixed to form the master batch and the curing agent added later with a final mixing of the composition. The composition is then cast into a propellant casing or an ordnance cartridge and allowed to cure in situ.

The above discussion is merely illustrative of the mode and manner of carrying out the present invention, and it is to be understood that the discussion is not intended to be limited to the instant disclosure, as other techniques may be successfully employed.

The following examples are representative of embodiments of the present invention and these examples are not to be construed as limiting as other obvious embodiments will be readily apparent to those versed in the art.

EXAMPLE 1 Preparation of allyl 2,2-dinitroethyl ether: 50 grams (0.264 mole) of 1,2 dichloro-l,l-dinitroethane were added dropwise over a minute period to a well stirred mixture of 200 ml of methylene chloride, 85.5 grams (1.48 moles) of allyl alcohol and 219 grams (1.32 moles) of potassium iodide. The slightly exothermic reaction was controlled at -25 C with an ice bath. The resulting red solution was stirred at room temperature for 12 hours. About 200 ml of water was added to dissolve the inorganic salts and the layers were separated. The water layer was extracted with methylene chloride and the combined organic portion was then washed several times with a 10 percent sodium thiosulfate to remove iodine. After a final water wash, the methylene chloride solution was dried over magnesium sulfate. Removal of excess methylene chloride yielded a red oil and a white solid. These materials were separated by crystallization of the solid from carbon tetrachloride. The white solid was found to be 1,2 diiodopropanol and the red oil was crude allyl 2,2- dinitroethyl ether. The crude allyl 2,2-dinitroethyl ether was purified by first forming the potassium salt through reaction with potassium hydroxide, recrystallization from methanol, and then acidifying to pH of 1 with hydrochloric acid. The resulting pure allyl 2,2- dinitroethyl ether, was obtained in 55 percent overall yield as a colorless oil, n 1.4527, (1 1.3. The calculated elemental analysis for C H N O was C, 34.09; H, 4.55; N, 15.19. The found analysis was C, 34.20; H, 4.29; N, 16.1 1. lnfrared spectrum for the compound, in Nujol, exhibited maximum peaks at 6.35, 7.5, and 9.0 microns.

EXAMPLE 11 Preparation of allyl 2,2-dinitro-2-fluoroethy] ether: The pure allyl 2,2-dinitroethyl ether, prepared according to the procedure set forth in Example I, was added (4.1 1 grams; 0.0234 mole) slowly to a well stirred solution of sodium hydroxide (0.935 grams; 0.0234 mole) water (15 mls) and methanol mls). The slightly exothermic reaction yielded an immediate orange color; the final pH was approximately 8. Perchloryl fluoride was then metered into the system to which was added a dry ice reflux condenser to prevent excess perchloryl fluoride from sweeping out of the reaction flask. When the perchloryl fluoride began to reflux vigorously, it was shut off and under slight nitrogen flow reflux was maintained for about 4 hours. The reaction temperature was maintained between 2025 C with a water bath. The reaction mixture had changed from deep orange to pale orange in color. Water (50 mls) was added and a yello oil dropped out of solution. The mixture was then extracted with 3-60 ml portions of methylene chloride. The methylene chloride extracts were washed with 3-30 ml portions of 3 percent sodium hydroxide and finally with water. After dryings with magnesium sulfate, excess methylene chloride was removed under vacuum and the residual liquid was distilled through a small Vigreux column. The distillation yielded 2.4 grams (53 percent yield) of allyl, 2,2-dinitro-2-fluoroethyl ether, b.p. 42 C/l.l mm, 11 1.4240, (F 1.28. The calculated elemental analysis for C H N O was C, 30.93; H, 3.64; N, 14.43. The found analysis was C, 30.86; H, 3.45; N, 14.43. The infrared spectrum for the compound, in Nujol, exhibited maximum peaks at 6.2, 7.6 and 9.0 microns.

EXAMPLE 11] Preparation of glycidyl 2,2-dinitro-2-fluoroethoxide: A solution of peroxytrifluoroacetic acid was prepared from 0.78 ml (0.028 mole) of 90 percent hydrogen peroxide, 4.73 ml (0.0335 mole) of trifluoroacetic anhydride and ml of methylene chloride. This reagent was added over a 25 minute period to a well stirred boiling mixture of 3.18 g (0.0164 mole) of allyl 2,2-dinitro-2-fluoroethyl ether, 25 ml methylene chloride, and 12.4 g (0.088 mole) of disodium hydrogen phosphate (predried in vacuum oven overnight at 50 C). After the mild exothermic reaction had subsided, the solution was heated under reflux for 2 additional hours. The resulting mixture was stirred with 60 ml of water until all the inorganic salts had dissolved. The organic layer was separated and the aqueous layer was extracted with 3-25 ml portions of methylene chloride. The combined methylene chloride portion was washed with 50 m1 of 10 percent sodium bicarbonate and dried over magnesium sulfate. The solvent was removed at reduced pressure and the residual liquid was fractionated through a small Vigreux column to yield 1.99 g (58 percent yield) of glycidyl 2,2-dinitro-2- fluoroethoxide, b.p. 66 C/0.l5 mm, n 1.4350, ri' 1.45. The calculated elemental analysis for C H N O F was C, 28.6; 3.36; N, The found analysis was C, 28.78; H, 3.29; N, 13.46. The infrared spectrum for the compound, in Nujol, exhibited maximum peaks at 6.25, 7.65, 9.4 and 11.10 microns.

EXAMPLE IV Polymerization of glycidyl 2,2-dinitro-2- fluoroethoxide: To a reaction flask, consisting of a twonecked -milliliter round-bottom flask wherein one neck was fitted with a 4'mi1limeter vacuum stopcock and the other neck stoppered for use in the introduction and removal of reagents and samples, was added 1.50 grams (7.13 mmoles) of glycidyl 2,2-dinitro-2- fluoroethoxide and 20 milliliters of methylene chloride. The contents of the flask were next frozen in a liquid nitrogen bath, and the flask was opened to the vacuum line. After pumping the flask down to 20 microns, 60.1 cc of boron trifiuoride at a pressure of 100 millimeters was condensed into the reaction flask. The reaction flask was then removed from the vacuum line and gently warmed to room temperature, and, as soon as the monomer solution thawed, stirring was done with a magnetic stirring bar. The reaction was allowed to proceed for 12 hours, or, until the 1 1.1 micron epoxide band in the infrared spectrum had disappeared. The samples were removed for infrared examination by first opening the reaction flasks stopcock under a nitrogen flow, and after the contents of the flask were blanketed with nitrogen, the side-arm stopper was removed and a sample was withdrawn with a hypodermic syringe. After completion of the reaction, approximately 10 milliliters of water was added to the reaction flask and stirring continued for several minutes. The contents of the flask were then transferred to a l25-milliliter separatory funnel. After two additional water washes of the methylene chloride solution, the sample was dried over anhydrous sodium sulfate, and the sodium sulfate was washed with methylene chloride several times. The washes were combined with the decanted solution. Finally, the methylene chloride was evaporated under vacuum. The polymer residue produced was dissolved in methanol and filtered through a conventional Millipore filter to remove small quantities of insoluble solids. Following vacuum removal of the methanol, the liquid polymer was dried in a vacuum oven at 40 C for several days. The yield of polymer was quantitative.

EXAMPLE V Other polymers of this invention were prepared according to the procedure of Example IV and they are set forth in Table I immediately below:

Table POLYMERIZATION OF GLYCIDYL 2,2-DlNlTRO-2FLUOROETHOX1DE Monomer] Catalyst H,O/BF= Temperature Functionality M, (Molar)(2) (Molar) (3) (4) Strong OH in infrared.

(1) Solvent was carbon tetrachloride, all other runs carried out in methylene chloride solvent.

(2) Catalyst was Lewis acid BF,.

(3) Functionality indicates the average number of OH groupu per polymer chain. (4) M, indicates the average molecular weight of the polymer.

The parameters that were used to characterize the prepolymers are functionality and molecular weight. Functionality is indicative of the number of hydroxyl groups per polymer molecule and was determined by the diborane method. This method involves the reaction of diborane with prototonic material and subsequent measurement of the evolved hydrogen: B H6 +6 ROH 2B(OR) +6H The apparatus con-, sists of a reaction vessel fitted with a serum cap and a manometer. The vessel contains excess diboranetetrahydrofuran solution into which the weighed, care fully dried sample is injected with a syringe. The resulting hydrogen evolution is then measured. The method was modified somewhat in that the diboranetetrahy' drofuran solution was metered onto a carefully weighed unknown sample contained in a vessel evacuated on a vacuum system. The hydrogen evolved is then removed with a Toepler pump and carefully measured. The analysis is quite rapid requiring approximately 30 minutes per sample. The method is especially suitable for epoxy compounds, and sterically hindered hydroxyl compounds. Nitro, nitrato, and other energetic groups do not interfere with the analysis. The other parameter, that is, molecular weight, was measured with the Mechrolob Vapor Phase Osmometer.

EXAMPLE VI A novel, energetic composition employing the energetic binder system of this invention was prepared as follows: 15 weight percent of bis-(2-fluoro-2,2-dinitroethyl)-formal, 8.3 weight percent of p-glycidyl 2,2dinitro-2-fluoroethoxide and 16 weight percent of aluminum powder were placed in a conventional mixer and thoroughly mixed under normal atmospheric pressure and at room temperature for about minutes. Then, 59 weight percent of ammonium perchlorate was added in 2 increments and the entire batch was mixed for about 5 minutes.

Finally, 1.7 weight percent of polymethylene polyphenyl isocyanate was added and the entire batch was mixed under a vacuum of about 2 mm for about minutes. The homogeneous composition was then cast into a propellant casing and permitted to cure in situ for several days at ambient temperature.

EXAMPLE VII The procedure of Example VI was followed in this example with the additional feature that a trace of the curing catalysts ferric acetonyl acetonate was added before the addition of polymethylene polyphenyl isocyanate. All the mixing conditions and reagents were as above stated, except that the casted composition cured in about 24 hours as a result of the presence of the catalysts.

EXAMPLE VIII The procedure of Example VII as reported herein, and, all the reagents and conditions were as set forth supra. However, in this example the curing was performed at 50 C and the composition cured overnight at this temperature. Generally, with the aid of heat and a curing catalyst, a composition can usually be cured at elevated temperatures, 50 C or the like, in about 4 to 24 hours.

EXAMPLE IX A novel, energetic composition employing the energetic binder system of this invention was prepared as follows: 16 weight percent of bis-(2-fluoro-2,2-dinitroethyl)-formal, 8.5 weight percent of p-glycidyl 2,2dinitro-2-fluoroethoxide and 15 weight percent of aluminum hydride (AIH powder were placed in a conventional mixer and thoroughly mixed under normal atmospheric pressure and at room temperature for about 5 minutes. Then, 58 weight percent of ammonium perchlorate was added in two increments and the entire batch was mixed for about 5 minutes. Finally, 1.5 weight percent of polymethylene polyphenyl isocyanate was added and the entire batch was mixed under a slight vacuum of about 2 mm for about 15 minutes. The homogeneous composition was then cast into a propellant casing and permitted to cure in situ at ambient temperature.

EXAMPLE X A novel, energetic binder system was prepared by first mixing for 15 minutes 60 weight percent of bis-(2- fluoro-2,2-dinitroethyl)-formal and 33.4 weight percent of p-glycidyl 2,2-dinitro-2-fluoroethoxide. Then, 6.6 weight percent of polymethylene polyphenyl isocyanate was added and the three components mixed for' 15 minutes. The final binder system was allowed to cure at room temperature in a couple of days.

The novel compositions of this invention are seen to exhibit ideal properties for formulating energetic pro-' pellant systems. For example, a composition consisting essentially of 59 weight percent ammonium perchlorate, 16 weight percent powdered aluminum, 15 weight percent bis(2-fluoro-2,2-dinitroethyl)-formal, 8.5 weight percent p-glycidyl 2,2-dinitro-2-fluoroethoxide and 1.5 weight percent polymethylene polyphenyl isocyanate exhibited very good castability, cured overnight at 50 C, had an impact sensitivity of 21 inch pounds, an auto-ignition of 250 C at 5 seconds to igni-' tion, a differential thermal analysis at the onset of the exotherm of 220 C and a peak of the exotherm of 340 C. A cured binder system consisting essentially of 60 weight percent bis-(2-fluoro-2,2dinitroethyl)-formal, 33.4 weight percent p-glycidyl 2,2-dinitro-2- fluoroethoxide and 6.6 weight percent polymethylene polyphenyl isocyanate exhibited an impact sensitvity of greater than 200 inch-pound.

Accompanying FIG. 1 shows the advantages obtained from this invention, as exhibited by the density impulse measurements (which are important for a volume limited missile system such as a tactical air-to-air missile) for a composition consisting of ammonium perchlorate, aluminum, p-glycidyl 2,2-dinitro-2- fluoroethoxide, bis-(2-fluoro-2,2-dinitroethyl)-formal system. The density impulse for this latter system ranges from 480 to 490 g-sec/cc (gram-seconds per cubic centimeter) at aluminum levels of 14 to 20 weight percent. At 16 weight percent of aluminum, the value from FIG. 1 indicates a density impulse of 486 gsec/cc. This latter figure represents an advantageous 5 ing of 40 weight percent p-glycidyl 2,2-dinitro-2- fluoroethoxide, and 60 weight percent bis-(2-fluoro- 2,2-dinitroethyl)-formal. The calculations are given for the equilibrium expansion from 1,000 to 14.7 psia, wherein the latter abbreviation indicates pounds per square inch absolute.

Accompanying P16. 2 further shows that an increase in density impulse can be realized by using the novel binder system to formulate a composition similar to the composition of FIG. 1 except that the ammonium perchlorate of FIG. 1 was replaced by hydroxyl ammonium perchlorate in FIG. 2. Thus, in FIG. 2, the density impulse is in the range of from about 503 to 515 gsec/cc at the aluminum levels of 14 to 20 weight percent. The density impulse measurements for the vari ous aluminum levels are readily apparent from the data as set forth in FIG. 2.

The energetic binder system of this invention can be used to formulate compositions of matter, which compositions find utility in military fields such as ordnance, incendiary, missiles, rockets and the like and also find utility in the commercial fields such as rock quarry blasting, oil well shooting and the like.

As many possible embodiments can be made of this invention without departing from the scope thereof, it is to be understood that all matter herein set forth is to be interpreted as illustrative only and not as unduly limiting the disclosed claimed invention.

We claim:

1. A composition of matter comprising, by weight, about to about 25 percent of a metal fuel, about 40 to about 80 percent of an oxidizer, about 5 to about percent of a polymer of a compound of the formula in which R is alkylene of l to 4 carbon atoms, about 5 to about percent of bis-(2-fluoro-2,2-dinitroethyl)- formal and about 1 to about 5 percent of a curing agent.

2. The composition of claim 1 in which the polymer has the formula in which R is alkylene of l to 4 carbon atoms and n is an integer of from about 3 to 25.

3. The composition of claim 1 in which the metal fuel is boron, aluminum, magnesium, beryllium or mixtures thereof.

4. The composition of claim 1 in which the oxidizer is an ammonium, alkali metal or alkaline earth metal salt of nitric acid, chloric acid or perchloric acid.

5. The composition of claim 1 in which the curing agent is polyphenylpolyisocyanate, hexamethylene diisocyanate, bis-isocyanatophenyl methane, toluene diisocyanate, 3-nitraza-l, S-pentane diisocyanate or polymethylene polyphenylisocyanate.

6. The composition of claim 1 in which the composition contains a curing catalyst in an amount from about 0.01 to about 0.05 weight percent based on the .weight of the polymer in the composition.

7. The composition of claim 6 in which the curing catalyst is aluminum chloride, tris-trimethylsilyl borate or ferric acetonyl acetonate.

8. A composition of matter comprising, by weight, about 5 to about 25 percent of a metal fuel, about 40 to about percent of an oxidizer, about 5 to about 20 percent of a polymer of glycidyl 2,2-dinitro-2- fluoroethoxide, about 10 to about 20 percent of bis-(2- fluoro-Z,2-dinitroethyl)-formal and about 1 to about 3 percent of a curing agent.

9. The composition of claim 8 in which the polymer has the formula in which n is an integer of from about 3 to 25.

10. The composition of claim 8 in which the metal fuel is boron, aluminum, magnesium, beryllium or mixtures thereof.

11. The composition of claim 8 in which the oxidizer is an ammonium, alkali metal or alkaline earth metal salt of nitric acid, chloric acid or perchloric acid.

12. The composition of claim 8 in which the composition contains, by weight, about 50 to about 65 percent of the oxidizer.

13. The composition of claim 8 in which the composition contains, by weight, about 6 to about 10 percent of the polymer.

14. The composition of claim 8 in which the curing agent is polymethylene polyphenylisocyanate.

15. The composition of claim 8 in which the oxidizer is hydroxyl ammonium perchlorate and the metal fuel is aluminum.

16. The composition of claim 8 in which the oxidizer is ammonium perchlorate and the fuel is aluminum.

17. The composition of claim 8 in which the composition contains ferric acetonyl acetonate curing catalyst.

18. The composition of claim 8 in which the metal fuel is aluminum and the composition contains, by weight, about 14 to about 20 percent of said aluminum.

Claims

2. The composition of claim 1 in which the polymer has the formula
3. The composition of claim 1 in which the metal fuel is boron, aluminum, magnesium, beryllium or mixtures thereof.
4. The composition of claim 1 in which the oxidizer is an ammonium, alkali metal or alkaline earth metal salt of nitric acid, chloric acid or perchloric acid.
5. The composition of claim 1 in which the curing agent is polyphenylpolyisocyanate, hexamethylene diisocyanate, bis-isocyanatophenyl methane, toluene diisocyanate, 3-nitraza-1, 5-pentane diisocyanate or polymethylene polyphenylisocyanate.
6. The composition of claim 1 in which the composition contains a curing catalyst in an amount from about 0.01 to about 0.05 weight percent based on the weight of the polymer in the composition.
7. The composition of claim 6 in which the curing catalyst is aluminum chloride, tris-trimethylsilyl borate or ferric acetonyl acetonate.
8. A composition of matter comprising, by weight, about 5 to about 25 percent of a metal fuel, about 40 to about 80 percent of an oxidizer, about 5 to about 20 percent of a polymer of glycidyl 2,2-dinitro-2-fluoroethoxide, about 10 to about 20 percent of bis-(2-fluoro-2,2-dinitroethyl)-formal and about 1 to about 3 percent of a curing agent.
9. The composition of claim 8 in which the polymer has the formula
10. The composition of claim 8 in which the metal fuel is boron, aluminum, magnesium, beryllium or mixtures thereof.
11. The composition of claim 8 in which the oxidizer is an ammonium, alkali metal or alkaline earth metal salt of nitric acid, chloric acid or perchloric acid.
12. The composition of claim 8 in which the composition contains, by weight, about 50 to about 65 percent of the oxidizer.
13. The composition of claim 8 in which the composition contains, by weight, about 6 to about 10 percent of the polymer.
14. The composition of claim 8 in which the curing agent is polymethylene polyphenylisocyanate.
15. The composition of claim 8 in which the oxidizer is hydroxyl ammonium perchlorate and the metal fuel is aluminum.
16. The composition of claim 8 in which the oxidizer is ammonium perchlorate and the fuel is aluminum.
17. The composition of claim 8 in which the composition contains ferric acetonyl acetonate curing catalyst.
18. The composition of claim 8 in which the metal fuel is aluminum and the composition contains, by weight, about 14 to about 20 percent of said aluminum.