Alliant Techsystems Inc.

Thiokol Corporation

USA As Represented by Secretary of the Navy

Morton International, Inc.

Orbital Atk, Inc.

Cordant Technologies Inc.

Robert M Hajik

Louis F Cannizzo

Thomas K Highsmith

Gary K Lund

Robert B Wardle

Kirstin F Warner

Jerald C Hinshaw

Harold E Johnston

R Scott Hamilton

Andrew J Sanderson

Reed J Blau

Gerald E Manser

Bonding agents for use in formulating solid propellants are described. The bonding agents have a Schiff base, or Schiff base and hydroxyl or amine functionality. These materials are synthesized by reacting a primary amine with an aldehyde to form a Schiff base. By definition, a Schiff base comprises the reaction product of a primary amine and an aldehyde. In one embodiment of the invention, such a product is produced by the reaction of a polyoxyalkyleneamine (JEFFAMINE&#xae;) with p-nitrobenzaldehyde and glycidol. The result is a polyether having both hydroxyl and Schiff base functionality. The bonding agents provide superior performance, while avoiding problems, such as ammonia production during processing, encountered when using existing bonding agents. Propellants formulated using these bonding agents have mechanical properties within acceptable ranges.

Solid propellant bonding agents and methods for their use

Nitramines are one of the more expensive and often the more plentiful ingredients found in energetic materials, such as solid rocket motor propellants, explosives, and pyrotechnics. By treating aluminized energetic material with an aqueous nitric acid solution containing not more than 55% by weight aqueous nitric acid at a weight ratio of aqueous nitric acid to energetic material of about 4:1 to about 6:1, most constituents of conventional aluminized energetic materials are digested into solution, with the exception of nitramines, which remain substantially insoluble in the aqueous nitric acid and can be recovered without requiring recrystallization of the nitramines. A mineral acid other than nitric acid, preferably hydrochloric acid, may be added to increase the rate of aluminum digestion. Treatment of the energetic material can be performed without volatile organic solvents, thus obviating ecological, cost, and safety concerns raised by the use of volatile organic solvents.

Method for recovery of nitramines from aluminized energetic materials

A process for preparing 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo&lsqb;5.5.0.0  &rsqb;-dodecane involves reacting at least one hexa-substituted piperazine derivative with at least one nitrate source and optionally at least one strong acid and heating the mixture to a temperature sufficient to induce an exothermic initial stage of the between the hexa-substituted piperazine derivative and the nitrate source. The mixture is maintained at a temperature in a range of at least ambient to not more than about 80&deg; C. during the exothermic initial stage and at least a portion of a subsequent non-exothermic intermediate stage of the reaction by cooling the mixture during at least a portion of the exothermic initial stage of the reaction so that the reaction proceeds in a controlled manner. The mixture is then cooled to a temperature sufficiently low to prevent commencement of an exothermic NO autocatalytic stage.

Synthesis for 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo&lsqb;5.5.0.05,903,11&rsqb;-dodecane

Nitramines are one of the more expensive and often the more plentiful ingredients found in energetic materials, such as solid rocket motor propellants, explosives, and pyrotechnics. By treating aluminized energetic material with an aqueous nitric acid solution containing not more than 55% by weight aqueous nitric acid at a weight ratio of aqueous nitric acid to energetic material of about 4:1 to about 6:1, most constituents of conventional aluminized energetic materials are digested into solution, with the exception of nitramines, which remain substantially insoluble in the aqueous nitric acid and can be recovered without requiring recrystallization of the nitramines. A mineral acid other than nitric acid, preferably hydrochloric acid, is added to increase the rate of aluminum digestion. Treatment of the energetic material can be performed without volatile organic solvents, thus obviating ecological, cost, and safety concerns raised by the use of volatile organic solvents.

Method of recovery for nitramines from aluminized energetic materials

Glycerol is nitrated with at least one nitrating source in a solvent to form a nitrated glycerol solution containing dinitroglycerin. The nitrated glycerol solution is treated with at least one cyclizing agent to convert the dinitroglycerin into glycidyl nitrate, which is polymerized into poly(glycidyl nitrate) (PGN). Distillation or other vaporization techniques are not required to remove nitroglycerin from the glycidyl nitrate prior to polymerization of the glycidyl nitrate. Rather, the nitroglycerin can be carried along with the dinitroglycerin during polymerization. As a consequence, the glycidyl nitrate is not exposed to elevated temperatures sufficient to cause accidental explosion or deflagration of the nitrate ester. Still more preferably, the glycidyl nitrate is not heated above room temperature at any time prior to polymerization. Moreover, given the high energy performance of nitroglycerin, the nitroglycerin can optionally be retained with the PGN, i.e., not washed out, for subsequent processing and end use.

Polymerization of poly(glycidyl nitrate) from high purity glycidyl nitrate synthesized from glycerol

A process for synthesizing 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo-[5.5.0.0.sup.5,9 0.sup.3,11 ]-dodecane ('TEX') involves combining at least one hexa-substituted piperazine derivative with a medium containing at least one nitronium anion source and at least one acid sufficiently strong to generate nitronium anions from the nitronium anion source. According to this invention, TEX yield is significantly improved by pre-heating the medium to 55.degree. C. to about 70.degree. C. and maintaining the medium from 55.degree. C. to about 70.degree. C. to permit the hexa-substituted piperazine derivative and nitronium anions to react and form the TEX. At least one NO.sub.x scavenger is added to the medium, preferably before the addition of the hexa-substituted piperazine derivative, to increase TEX yield.

Process for the large-scale synthesis of

Methods of preparing bis-(1(2)H-tetrazol-5-yl)-amine (BTA) having improved physical and chemical characteristics are disclosed. In the process, a dicyanamide salt and an azide salt are reacted at high temperature in the presence of an acid reagent. Best yields are obtained when the reaction is allowed to proceed for approximately 48 hours. The dicyanamide salt is preferably present in a stoichiometric excess. The acid reagent has a pK.sub.a in the range from about 3 to about 9. The reaction mixture is acidified to a pH less than 3. Several variations of the acidification step permit control of particle size and morphology. Small, rounded particles are prepared by rapidly cooling the hot crude reaction product coincidentally with acidification. This is preferably accomplished by adding the hot crude reaction product directly to cold concentrated acid. The precipitated particles are isolated to yield BTA.

Methods for synthesizing and processing bis-(1(2)H-tetrazol-5-yl)-amine

Polyether organic compounds are described which have both imine and hydroxyl functionality. These materials are synthesized by reacting a primary amine with an aldehyde or ketone to form a Schiff base. By definition, a Schiff base comprises the reaction product of a primary amine and an aldehyde. In this case, however, unlike conventional Schiff bases, the reaction product possesses both hydroxyl and Schiff base functionality. In one embodiment of the invention, such a product is produced by the reaction of a polyoxyalkyleneamine (Jeffamine) with p-nitrobenzaldehyde and glycidol. The result is a polyether having both hydroxyl and Schiff base functionality. The compounds produced in this manner are particularly useful as bonding agents in the formulation of solid propellants. The bonding agents provide superior performance, while avoiding the problems encountered when using existing bonding agents. The observed superior performance is believed to arise from the ability of the materials to bond within the propellant matrix by means of the hydroxyl groups, and to align with oxidizers, such as ammonium perchlorate, by means of the Schiff bases.

Polyether compounds having both imine and hydroxyl functionality and

Nitrato alkyl oxetanes are synthesized directly from the corresponding hyxy alkyl oxetanes by nitrating the hydroxy alkyl oxetane under non-acidic anhydrous conditions. A hydroxy alkyl oxetane is reacted with an anhydrous nitrate ester of a carboxylic acid at temperatures below about 10.degree. C. The product of the method, nitrato alkyl oxetane, is produced in relatively high yield without opening of the oxetane ring.

Method of synthesizing nitrato alkyl oxetanes

Automotive airbag gas generant formulation providing an alternative to commercially used formulations containing sodium azide. The composition contains from about 25% to about 75% by weight of 5-nitro-1,2,4-trizal-3-one (usually known as nitrotriazolone). The other principal ingredient of the composition is from about 25% to about 75% by weight of an anhydrous oxidizing salt having a cation selected from metals of Group I-A of the Periodic Table (except sodium), calcium, strontium, or barium, and an anion which is essentially free of carbon, hydrogen, or halogens. From about 0.1% to about 5% of a binder can be added, if necessary. An automotive airbag inflator containing the composition and a method for generating gas comprising the step of igniting the composition stated above are also disclosed.

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Willard, UT, United States of America

Robert M Hajik