Abstract: An apparatus for suppressing a fire comprises a gas generator in communication with a vaporizable liquid by means of a first conduit. When activated, the gas generator generates an elevated temperature burst of a first gas containing carbon dioxide, nitrogen, and/or water vapor. This first gas vaporizes substantially all of the vaporizable liquid, generating a second gas having flame suppressing capabilities. The second gas is directed at the fire to suppress and extinguish it.

Abstract: Slurry and spray dried azide-based gas generant intermediates are made having a hydrazoic acid content of less than about 3.times.10 EXP(-3) M/L, a pH of greater than 8.0 up to about 12.5, and impurity metal ions Ca, Mg, Pb, Fe, Mn and Cu, each below about 25 ppm. These intermediates are made by slurrying powdered ingredients of the azide and oxidizer/reactant in water, wet grinding the slurry and spray drying to form a particulate material which is molded into pellets or tablets which are useful as the gas generant in vehicle crash bags or inflators. The basicity of the water is adjusted to a pH of greater than 8.0 up to about 12.5, preferably about 10, by the addition of a base, such as NaOH, followed by the addition of such solid ingredients as S, MoS.sub.2 and NaN.sub.3, and preferably the NaN.sub.3 is added last, whereby hydrazoic acid production is minimized. The contaminant Ca and Mg ions are minimized by softening the water supplied.

Abstract: A gas generant composition contains as a fuel a mixture of a major portion of a triazole or tetrazole and a minor portion of a water soluble fuel; and an oxidizer component, at least 20 wt % of said oxidizer component being a transition metal oxide, such as CuO. Generant compositions in accordance with the invention autoignite in a range around 170.degree. C., providing autoignition of the generant without the need for separate autoignition devices. Also, the generant compositions are useful as autoignition pyrotechnic in autoignition devices.

Abstract: There is provided a lead-free primer mix having high sensitivity. The primer mix contains an initiating explosive, a sensitizer, a propellant, calcium silicide and an oxidizer. The ignition exhaust products are essentially free of toxic oxides such as lead oxide, barium oxide and antimony oxide.

Abstract: A process, apparatus, and composition are disclosed for forming a molded foamed polyurethane explosive block with pentaerythritol tetranitrate in a manner in which the generation of excessive exothermic heat is inhibited during the reaction to form the foamed polyurethane. In one aspect of the invention, the exothermic heat generation is controlled by the use of non-reactive filler materials. In a preferred embodiment, a monoammonium phosphate filler is used to further impart fire retardant properties to the resultant molded foam explosive block.

Abstract: The present invention relates to metal filaments for use as fuel additives for rocket propellants, explosives, and other pyrotechnic devices. Preferred filaments are those such as zirconium, niobium and titanium (and alloys thereof) which have very high heat of combustion.

Abstract: Composition and process for inflating an automobile or aircraft occupant safety restraint bag which reduces the toxicity of the gases produced by gas generants. A relatively low energy nitrogen containing fuel is combined with a burn rate accelerator, such as an alkali metal salt, to form an azide-free gas generant composition which lowers the combustion temperature of the gas generants while also maintaining a rapid burn rate, thereby reducing toxicity of the resultant gases.

Abstract: Methods and materials for modifying rocket motors to render them safer are disclosed. The invention is primarily related to placing within the bore of a rocket motor a sufficient quantity of a material mitigant such that if the rocket motor receives an unintended impact, the material mitigates the effects of the impact, and prevents ignition or explosion of the propellant. The material mitigant may take a number of forms; however, polymer foams and fibers of various types have been found to work well. It is presently preferred that the material mitigants have a density of not less than approximately 0.04 grams/cc. Examples of such materials include polyurethane foam, polystyrene, and Kevlar.RTM. fibers. It is also preferred that the material mitigant not be reactive with the propellant in the rocket motor.

Abstract: An igniter for solid fuel rockets in which hot gases from an initiator are hanneled to drive a piston against a reservoir of combustion modifying fluid, like ethylene glycol, so as to spray the fluid onto the propellant grain just before ignition. After the piston moves, the hot gases escape the igniter as to ignite the propellant directly or through an intermediate main ignition charge.

Abstract: An interpenetrating network combination of ultraviolet and thermally curable rocket motor liner formulation comprising an optional solid filler, at least one ultraviolet curable polymer, an optional ultraviolet reactive diluent, at least one thermally curable polymer and at least one curing agent.

Abstract: Propellant formulations are provided which include non-toxic burn rate modifiers. In order to produce a usable propellant formulation, it is necessary to control the burn rate of the propellant. Failure to adequately control the propellant burn rate often results in unacceptable performance of the propellant. For example, during the operation of a rocket motor, or similar device which contains a propellant, the propellant may produce operating pressures which are too high or too low for the intended purpose of the device.It has often been the practice to add lead to rocket motor propellants in order to modify the burn rate and to maintain the burn rate within acceptable parameters. Lead, however, is known to be toxic and a pollutant. Accordingly, it is desirable to replace the lead in the formulation. It has been found herein that bismuth trioxide is capable of modifying the burn rate of propellants without resorting to lead as a burn rate additive.

Abstract: The present invention relates to a priming charge with annular percussion, free from any toxic metal, which corresponds to the following weight composition:40 to 70% of a dinitrobenzofuroxan salt as impact-sensitive primary explosive,3 to 15% of tetrazene as sensitizing explosive,10 to 30% of cupric oxide as oxidizing agent,5 to 25% of a pulverulent reducing agent,0.5 to 20% of an inert abrasive powder and0 to 5% of a binder.It also relates to a process for its manufacture, wherein the following successive stages are carried out:the cupric oxide and the pulverulent reducing agent and the inert abrasive powder are mixed dry;the dinitrobenzofuroxan salt and the tetrazene are then added to this mixture thus formed, andthe mixture thus obtained is homogenized.If appropriate, a solution of binder, for example in the form of an aqueous solution of gum arabic, is added to the inert mixture.

Abstract: A vehicle occupant safety restraint gas generator is provided in which the ignition system for the propellant comprises a pyrotechnic layer (22), e.g. a reactive film, preferably comprising a substrate of oxidizing polymeric film such as polytetrafluoro-ethylene (PTFE) having at least a portion of its surface covered with a layer of oxidizable material, for example magnesium, which may be vapour-deposited on the surface. The propellant is preferably a propellant train (12, 14, 16, 18) which comprises a plurality of adjacent propellant grains such as toroidal discs which surround the pyrotechnic layer or are completeley encased thereby. The gas generator is simpler and more economical to manufacture, and has improved safety during use.

Abstract: An inflator, preferably for an automotive gas bag restraint system, containing a plurality of gas generant bodies which have a relatively inert burn inhibitor coating material thereon. The inhibitor material is preferably a plastic resin. The inhibitor material may also be alumina, titania, silica or a silicate compound,e.g. bentonite. The inhibitors are preferably applied to the generant bodies as a spray. The gas generant may be an azide or a non-azide, preferably an azide and most preferably sodium azide. The inhibited bodies may be any shape, preferably washer-shaped discs in side by side array.

Abstract: A gun propellant having reduced sensitivity to impact and improved burning ate, comprising crystallized NNHT particles admixed with a binder and at least one plasticizer. In a preferred embodiment, the binder is a nitrocellulose binder and the plasticizer is a liquid nitramine plasticizer. A preferred liquid nitramine plasticizer is selected from the group of ethyl nitrato ethyl nitramine and methyl nitrato ethyl nitramine. The propellant of this invention may be used or alone or may also include a quantity of RDX propellant. The propellant is suitable to be formulated for an artillery application or for a tank system.

Abstract: The present invention relates to metal filaments for use as fuel additives for rocket propellants, explosives, and other pyrotechnic devices. Preferred filaments are those such as zirconium, niobium and titanium (and alloys thereof) which have very high heat of combustion.

Abstract: A system and composition is disclosed for binding rocket motor propellants directly to the insulation layer within the rocket motor. Conventionally, it is necessary to place a liner layer between the insulation and the propellant. The present invention is particularly adaptable for use with hydroxy-terminated polybutadiene-type (HTPB) propellants. The method of the invention involves coating the insulation layer with a reactive material, such as a solution of isophorone diisocyanate (IPDI). The reactive material is then allowed to penetrate the insulation layer. Once sufficient penetration is achieved, the HTPB-based propellant is applied over the insulation layer to form a rocket motor propellant grain. The IPDI reacts with both the insulation layer and the propellant and forms a strong bond between the two. In the case of the propellant, additional urethane linkages are generally formed, which results in an area near the bond which may be harder than the propellant grain as a whole.

Abstract: A unitary propellant charge module for use in separate ammunition comprises a combustible container having a generally hollow cylindrical shape, a generally cylindrical charge body of interconnected compacted spheroidal propellant grains disposed within the container, each of the grains having an uncompacted propellant grain diameter of at least 100 mils, and at least one generally tubular center core igniter body of interconnected compacted spheroidal propellant grains having an unrolled grain size between about 20 to less than 100 mils in diameter. The igniter body is disposed within a central bore extending along the longitudinal axis of the charge body.

Abstract: The present invention relates to propellent powders in multi-perforated sticks (1) divided by radial slits (7) cutting the peripheral channels (6) of the stick (1) but allowing a continuous cover (8) to remain around its central channel (5). The invention also relates to equipment for obtaining such sticks, comprising:--a drive shaft (17) carrying circular cutting members (18),--a positioning shaft (19) carrying rollers (20) and a thrust shaft (21) carrying rollers (22). The sticks (1) advantageously constitute bundles for artillery ammunition which divide up into elementary particles at the moment of firing.

Abstract: A method of providing a very strong mechanical interlock between the insuor and propellant of an interceptor rocket motor by employing a first lay-up material comprised of a cloth mat of woven cotton cloth (muslin) over a release liner with bleeder which covers a mandrel shell with a boss and a second lay-up material of an uncured vulcanizable rubber insulator, e.g., ethylene-propylene-diene-monomer (EPDM) with additives and curatives. The lay-up materials are subjected to a vacuum bag and autoclave curing environment to complete a vulcanization cycle to vulcanize and consolidate the insulator to the cloth mat. The vulcanized insulator/cloth mat is installed in a rocket motor case. The muslin cloth mat has many protruding microfibers which will be in the interface section when an uncured propellant composition is cast onto and cured to the vulcanized insulator/cloth mat. A very strong mechanical interlock is achieved which exceeds breaking strength of propellant and insulator.

Abstract: A gas generator for a long range missile is driven by a solid propellant in assembly which includes a cylindrical inhibitor, a forward closure assembly that is attached to one end of the inhibitor and a propellant grain that is cast into the cylindrical cavity formed by the interior surface of the cylindrical inhibitor. Between the grain and inhibitor and between the grain and forward closure assembly is an adhesive bonding system for attaching the grain to the inhibitor and forward closure assembly. The exposed or aft end of the grain is the initial burning surface and includes a plurality of annular concentric grooves and a configuration that provides optimum burn progression that results in a complete high pressure burn. The external surface of the inhibitor is machined so that the solid propellant grain assembly may be readily inserted and removed from the gas generator.

Abstract: The stability of porous solid high explosives, for purposes of transport or storage, is enhanced by reducing the sensitivity to shock initiation of a reaction that leads to detonation. The pores of the explosive down to a certain size are filled under pressure with a stable, low melt temperature material in liquid form, and the combined material is cooled so the pore filling material solidifies. The stability can be increased to progressively higher levels by filling smaller pores. The pore filling material can be removed, at least partially, by reheating above its melt temperature and drained off so that the explosive is once more suitable for detonation.

Abstract: A rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air bags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.

Abstract: A solid propellant to inhibitor bonding system for use in replaceable prolant grain assemblies is used with an inhibitor sleeve that has one end attached to an end closure having interior insulation, made of the same rubber insulation material as the inhibitor, and forming a cylindrical cavity for receiving a poured propellant mix. The bonding system is employed prior to pouring the propellant mix. This bonding system involves cleaning the interior surface of the cavity with freon solvent and brush applying a barrier coat, comprising an epoxy resin with amine curing agents, to the interior surface of the cleaned inhibitor. The barrier coat is then cured and a liner is then brush coated onto the cured interior surface of the barrier coat. The liner is then cured and the propellant is then cast into the cavity formed by the lined inhibitor sleeve and insulated closure.

Abstract: A flame inhibitor coating for application to those surfaces of a solid prllant grain in a rocket motor where burning is not desired such as the aft end of a perforated propellant grain which includes a barrier layer of a mixture of amine silane, a trialkoxypropylsilylamino prepolymer, and diglycidylether of polypropylene glycol, an epoxy applied to the grain surface and allowed to cure to a polysiloxane layer, and a flame inhibitor layer applied over the barrier layer consisting of a mixture of hydroxyl terminated polybutadiene and dimeryl diisocyanate with flake aluminum which is applied over the barrier layer and allowed to cure. The barrier layer prevents migration of nitrate esters from the solid propellant grain to the flame inhibitor layer thus preventing peeling and reduction of flame inhibiting properties. The polysiloxane barrier layer is also useful in itself as a flame inhibitor and can also be employed between the insulator/liner of the rocket motor and the solid propellant grain.

Abstract: Improved bonding of hydroxyl-terminated polybutadiene based propellant grains to rocket motor liners and liners which are ultraviolet light radiation curable are provided by employing an acrylated polymer and an [[[(isocyanatoorgano)amino]carbonyl]oxy] alkyl propenoate in the liner composition.

Abstract: A rapid burning propellant charge for applications including igniters, launch eject motor, and gas generators for automobile air bags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.

Abstract: An explosive sheet which is formed by a layer of explosive material, a layer of foil, and an inert space forming material. These three layers are repeated to number, n, times to form a composite plane-wave forming explosive sheet.

Abstract: A method of making an elastomer lined vessel or portion of such vessel is disclosed. The method comprises causing a thin, tacky ribbon comprising an elastomer (preferably curable) to continuously so encircle a center rotational axis of a mandrel as to adjacently position and tack together integral segments of the ribbon substantially circumferentially relative to this center rotational axis thereby forming a layer of the elastomer about the mandrel which may be the shell of the vessel in case of internal application of the insulator or may be a workpiece around which the shell is built over the so-laid ribbon.

Abstract: A radial pulse rocket motor having a nozzle at the aft end includes longitudinally spaced hollow boost and sustain propellant grains in the combustion chamber thereof with an elongated tubular thermal barrier covering substantially the whole of the interior surface of the sustain grain to enable the production of separate boost and sustain pulses. At the forward end of the motor, mounted within a reentrant motor bulkhead position, is a multiple pulse arm-fire device which, when commanded, produces an igniting signal that is transmitted to a boost igniter for igniting the boost grain and a subsequent igniting signal that is transmitted to a sustain igniter for igniting the sustain grain. The sustain igniter is positioned in surrounding relation to the motor forward bulkhead reentrant portion, the multiple pulse arm-fire device, and the forward end of the tubular barrier, and comprises a consumable, molded, polyurethane case having two interlocking tubes with a thin 0.10 inch (2.5 mm.

Abstract: Solid propellant test strands are inhibited, i.e., prevented from burning in an uncontrolled fashion, by coating the strands with a liquid composition containing a partially cured phenolformaldehyde in a volatile solvent, then volatizing the solvent.

Abstract: Method for producing novel deterred granular nitrocellulose propellant powder compositions having a stable burn rate gradient. The invention comprises coating nitrocellulose propellant granules with a minor amount by weight of a polycaprolactone polymer which is soluble in nitrocellulose under conditions which cause the polymer to be gradually dissolved into the granules to produce maximum burn deterrence at the surface of the granules which gradually decreases inwardly therefrom to produce a desired burn rate gradient in the granules.

Abstract: A method for preparing free-flowing, particulate fuel components for use in solid propellant systems, which comprises dispersing fine-sized solid fuels in a latex of a polymer or polymer mixture, and spray drying the resultant dispersion.

Abstract: A signal flare with luminous oscillations resulting from a combustible cosition of octafluorohexanediol, magnesium or aluminum, chlorinated benzene, an inorganic oxidizer, and polyisocyanate.

Abstract: Non-asbestos elastomeric insulating materials for rocket motors are disclosed. The insulating materials are low in density (between about 0.035 and 0.050 lb./cubic inch) and comprise crosslinked elastomeric polymers (100 parts by weight of a crosslinkable elastomeric polymer that is substantially saturated and about 5-50 parts by weight of a crosslinkable, substantially unsaturated, elastomeric polymer) in which are dispersed between about 10 and 100 (preferably 15-75) parts by weight of a char forming organic fiber selected from polyaramide pulps, between 1 and 15 parts by weight of a peroxide crosslinker, and between about 0 and 150 parts by weight organic and/or inorganic particulate. The insulating materials issue little smoke, have notable erosion resistance and can be tailored to have thermal, mechanical and other properties of desired character. Ingredients such as supplemental elastomers, oils and lubricants enhance the processability and green properties such as tack of the insulating materials.

Abstract: A woven, silicon carbide fiber inner wall forms a combustor liner and a nozzle throat liner, and a woven silicon carbide fiber outer wall is spaced from the inner wall to form a fuel passageway. The silicon carbide fibers are woven to conduct heat from the combustor and nozzle throat to the fuel passageway and thereby provide heat for the endothermic pyrolysis of the fuel in a propulsion system having a rocket casing containing a combustor, propellant injectors, nozzle throat and nozzle. The fuel passageway is adjacent to and surrounds the combustor and nozzle throat, and fuel is endothermically pyrolyzed in the fuel passageway.

Abstract: A method of and apparatus for casting uncured solid propellant in solid propellant rocket motors includes a casting bayonet having annular slits formed in the exit end thereof that improve the fluidity and self-leveling behavior of the uncured propellant. Both of these effects eliminate or reduce the trapping of air in the cast propellant, thus providing a better product.

Abstract: The present invention relates to a novel type of flare charge insulation for retally burning flare charges. The flare charge insulation according to the present invention is produced by compaction of a particulate material or granulate of a mean particle size which does not exceed 1 mm. The major component parts of the granulate are an organic metal salt, and minor amounts of a combustible binder. Moreover, particulate melamine may be included in an amount of up to 20 weight per cent.The present invention also includes a novel method of producing flare charges in which both the flare charge and flare charge insulation are terminally compacted together to form a continuous unit.Consequently, the present invention also relates to the finished flare charge manufactured according thereto.

Abstract: A curable liner for a solid propellent rocket motor includes a radiopaque material uniformly blended therein to provide a sufficient density difference between the propellant and insulator to enhance non-destructive X-ray evaluation of the liner propellant interface. Up to 10% powdered tungsten is added to a liner component mixture prior to incorporation in a rocket motor. Utilizing this radiopaque material in the liner mixture allows detection of previously undetectable voids, disbands or flaws at the liner propellant interface, thereby reducing the potential for failure of the rocket motor during operation.

Abstract: Process for forming a liner and cast propellant charge in a rocket engine casing without separately precuring the liner, comprising the steps of providing a blocked curable liner composition which is the reaction product of a prepolymer, an isocyanate curing agent, and a blocking agent; applying the liner composition to an internal surface of a rocket casing; preheating the casing and liner assembly to simultaneously prepare the assembly for receiving a propellant, unblock the liner, and precure the liner to a tacky state; casting the propellant change into interfacial contact with the liner; and cocuring the liner and propellant compositions. The blocked, curable liner composition has a very long pot life which is terminated by heating the composition sufficiently to uncouple the blocking agent from the isocyanate curing agent and initiate a rapid cure. The liner composition does not require precuring, as it is unblocked by preheating the liner and rocket casing sufficiently to receive to cast propellant.

Abstract: A rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air gags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.

Abstract: In order to achieve a stable burn characteristic, improved mechanical proties and reduced smoke development during burn, a composite solid propellant includes nitrides, borides, and carbonitrides of the metals zirconium, titanium, tungsten, hafnium, tantalum, or niobium as a burn moderator.

Abstract: The invention concerns a protective varnish applied to a caseless or combible-case round of ammunition against thermoinitiation. This varnish includes at least one reactive layer applied to the ammunition, consisting of a synthetic resin and an oxidizer with a decomposition temperature above 350.degree. C., and at least one insulating layer applied to the reactive layer consisting of a synthetic resin and a heat insulating compound. The resins are of the polyurethane, alkyd or oleophenolic type and the oxidizer is selected from the group constituted by potassium perchlorate, lead or barium chromate according to a percentage by mass varying from 1 to 20%. The insulating compound is represented by organic or mineral microballoons. The varnish may include an inner resin layer interposed between the ammunition and the reactive layer, an an outer resin layer applied to the insulating layer. Application to the rounds of ammunition of any caliber.

Abstract: A reinforced split-flap hinge for supporting the unpressurized propellant grain of a rocket motor in a high acceleration environment includes a circular piece of material and an afterwardly spaced first annular piece of material bonded to the convex forward surface of the propellant grain, the material of the circular piece of material and the first annular piece of material being chopped fibers of insulating material in a rubber matrix, with a second annular piece of material bonded to the surface of the circular concave piece of material, the convex forward surface of the propellant grain, and the surface of the first annular piece of material, a third U-shaped annular piece of material having first and second skirts extending aft with a first skirt bonded to the surface of the second annular piece of material, the second and third annular pieces of material being made of fabric reinforced polyisoprene, and a fourth annular piece of insulating material made of powder filled polyisoprene positioned between t

Abstract: A solid propellant grain which comprises an homogeneous mass of propellant material including an oxidant. A variable burn rate is provided by embedding a reticulated structure in a portion only of the propellant mass. The reticulated structure may be coated with a high thermal conductivity material to provide an increased burning rate. The coat of material is selected to preferably provide improved bonding to the propellant mass.

Abstract: Disclosed is a liner-barrier system which is impermeable when cured to the igh concentrations of carboranyl burning rate accelerator which are incorporated into ultrahigh-burning rate propellants which are being developed for advanced interceptors. The liner-barrier composition, when uncured, comprises a polyvinyl butyral resin coblended with thermosetting resins, such as, phenolic, epoxy etc., that employs triphenylbismuthine as a quick cure catalyst, 4,5-epoxycyclohexylmethyl 4',5'-epoxycyclohexyl carboxylate and polyisocyanate as curative and crosslinking agents to further modify the liner-barrier formulation by reacting with the secondary hydroxyl groups. Further modification of the liner-barrier formulation is achieved by incorporation of aluminum powder to impart additional properties of impermeability. The uncured liner-barrier composition contains from 8.90 to about 10.21 weight percent solids in a solvent blend of isopropyl acetate and isopropyl alcohol which comprises from about 89.79 to about 91.

Abstract: The invention relates generally to explosives, and more particularly to dry ammonium nitrate-fuel oil based explosives, containing a high molecular weight polymer characterized by a high stringiness factor.

Abstract: Improved composition, curable to form a rocket engine liner. The uncured liner composition has a long pot life and cures rapidly.The composition comprises a hydroxyl terminated polybutadiene prepolymer; a diisocyanate curing agent for forming urethane linkages with said prepolymer; a trifunctional aziridine bond promoter; a filler; and a curing catalyst comprising maleic anhydride, magnesium oxide, and triphenyl bismuth.

Abstract: The disclosure relates to a method for producing charges for explosive jointing of large-diameter pipes such as pipelines. According to the invention, such charges are formed in that a strip-shaped flat explosive is wound and joined together to form a circular ring of even thickness consisting of a plurality of closely abutting layers.

Abstract: A double base propellant grain inhibitor is comprised of a hydroxyl-termied polybutadiene polymer having from 2 to about 3 hydroxyl groups per average molecule and an approximate molecular weight of 2800 to 3600, an inert filler, a cross-linking agent, a thickening agent, an antioxidant, a curative, and a catalyst. When properly applied to the surface of a propellant grain, the inhibitor bond does not weaken with age and the inhibitor produces planar, no-cone grain burning having a constant chamber pressure during the burning of the propellant grain. A 1,4-butylene oxide-type polyether barrier layer consisting of a poly-1,4-butylene oxide diisocyanate with an approximate molecular weight of 850 to 1000, a diol curative, a triol cross-linker, and antioxidant and a cure catalyst can be added between the propellant grain and inhibitor to reduce propellant plasticizer migration.