US Government As Represented by the Secretary of the Army

Other

USA As Represented by Secretary of the Navy

The United States of America

David C Sayles

Edward L Wilkinson

Polycyclic spiroorthoester which undergo expansion on polymerization to f resins, rather than shrinkage on polymerization, are employed in fabrication of composite, filament-reinforced, interceptor motor cases. The advantages which accrue to such use of the specified resins relate to the imparting of unique characteristics to the interceptor motor case such as increased structural strength, a reduction in the number of microcracks and voids, and improved bonding between resin and reinforcement. These unique characteristics impart benefits where needed since composite motor cases are fabricated from high strength filaments or tapes such as fiberglass, graphite, poly-p-phenyleneterephthalamide (Kevlar), in a polymeric matrix, and the primary mode of failure is due either to poor adhesion between the matrix and the filament or tapes or because of the development of microcracks or voids in the matrix. The spiroorthoester, 1,4,6-trioxaspiro [4.4]nonane, is an example of a resin modifier which converts the basic resin composition into an expandable resin. The basic resin composition is comprised of basically a three component system for use in fabrication of a graphite-composite motor case. One component EA-953A is a mixture of Bisphenol A-epichlorohydrin and epoxidized dimer of oleic acid, the second component is RD-2 which is butanediol diglycidyl ether, and the third component is TONOX 60/40 which is a mixture of 65% diaminodiphenylmethane, 10% triamines, and 25% polyamines. These components are employed in a ratio of about 100, 25, and 20 parts by weight in the HBRF-215 formulation. The spiroorthester is substituted for a portion of the second component in an amount from about 2 to about parts by weight.

Composite motor case polymers that expand on polymerization

The conversion of carbon-carbon of a composite material at the surface to licon carbide-hybridized carbon-carbon in accordance with the method of invention is accomplished by reacting the carbon fibers and matrix with silicon monooxide at elevated temperature from about 1500.degree.-1700.degree. C. The conversion of bulk graphite or carbon-carbon composite materials is achieved in 30-60 minutes at 1700.degree. C. With conversion the density is increased from the density of carbon of 1.45 grams/cc to that of silicon carbide of 3.21 grams/cc. The method of reaction in the vapor phase of silicon monooxide with the carbon-carbon bond releases a C atom in exchange for the Si atom with a release of CO from the composite material. Photomicrographic studies indicates a depth of conversion from about 50 to 100 mils. The reaction rate of silicon monooxide increases with increased temperature; therefore, to avoid too rapid a release of the by-product carbon monooxide which might damage the composite material in its escape, the reaction temperature should not exceed 1700.degree. C.

Method of manufacturing hybrid fiber-reinforced composite nozzle material

A process for fabrication of a filler for a ballast container used with frescent lighting employs a mixture of a high-density polyethylene in powdered form (derived from recycled milk containers) and dry sand. After loading the specified mixture into a ballast container to fill the unfilled volume remaining after the ballast container has electrical components installed, a closure means is placed on the loaded and filled ballast container, subsequently heated for a predetermined time period to achieve melting of the specified high-density polyethylene and dry sand mixture. After cooling the melted, high-density polyethylene, the high-density polyethylene and dry sand mixture fuses into a solid mass. A preferred mixture is comprised of a 50/50 weight percent ratio of the specified high-density polyethylene and dry sand.

Composite thermoplastic filler for ballast cans for use with fluorescent

Para-polyphenylene sulfide, a non-composite, ultrahigh-temperature-resist, thermoplastic resin, is employed for the manufacture of interceptor motor cases. The thermoplastic resin, para-polyphenylene sulfide, has a combination of properties which are of particular interest in the fabrication of interceptor rocket motor cases. Para-polyphenylene sulfide in ribbonized forth is wound directly onto the required mandrel and then fused into a solid mass. The fused, solid mass has the properties which enables it to serve as both insulator and motor case material. The manufacture of a combination insulated motor case is achieved by the following method: The equipment, first, involves the fabrication of a breakout mandrel by one of several methods. The para-polyphenylene sulfide is ribbonized by extrusion and wound down on the breakout mandrel to the required thickness and fused into a solid mass by heating to its melt temperature of about 285.degree. C. The breakout mandrel is removed to release the interceptor rocket motor case which functions as both insulator and interceptor rocket motor case material.

Thermoplastic para-polyphenylene sulfide, high temperature-resistant

The coacervation of ferrocene and ferrocene derivative is carried out in a ater-soluble polyol, coacervation mixture at a reaction temperature from about 40.degree. C. to about 55.degree. C. The coacervation mixture is comprised of about 70 to about 80 parts of a 1:1 ratio of water and a water soluble polyol selected from glycol, a glycerol, and an erythritol, a urea derivative selected from melamine and triazine, and an aldehyde or ketone selected from the water soluble aldehydes or ketones consisting of methanal, ethanal, propanal, propanone, and 2-butanone. Micro-droplets of the ferrocene derivative, 2,2-bis(ethylferrocenyl)propane, are formed by vigorous agitation of the coacervation mixture containing the ferrocene derivative. A polymeric coating on the outer surface of the micro-droplets produces a coacervate which is separated from the coacervation mixture. The coacervate polymeric coating of about 10 percent by weight enables the coated ferrocene derivative to be mixed in a solid propellant composition without rupturing and to achieve improved stability and compatibility as compared to liquid ferrocene and liquid ferrocene derivatives.

Microcoacervation of propellant ingredients

Para-polyphenylene sulfide, a non-composite, ultrahigh-temperature-resist, thermoplastic resin, is employed for the manufacture of interceptor motor cases. The thermoplastic resin, para-polyphenylene sulfide, has a combination of properties which are of particular interest in the fabrication of interceptor rocket motor cases. Para-polyphenylene sulfide in ribbonized form is wound directly onto the required mandrel and then fused into a solid mass. The fused, solid mass has the properties which enables it to serve as both insulator and motor case material. The manufacture of a combination insulated motor case is achieved by the following method: The equipment, first, involves the fabrication of a breakout mandrel by one of several methods. The para-polyphenylene sulfide is ribbonized by extrusion and wound down on the breakout mandrel to the required thickness and fused into a solid mass by heating to its melt temperature of about 285.degree. C. The breakout mandrel is removed to release the interceptor rocket motor case which functions as both insulator and interceptor rocket motor case material.

Method of preparing non-composite, thermoplastic,

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. Tensile adhesion strength, shear composite adhesion strength, and peel strength are higher for cloth mat faced or fabric faced insulator on propellant-to-insulator bonding as compared with insulator-propellant bonding without cloth mat facing.

Cloth-lined interceptor motor insulation for strong

Edible coatings for protecting perishable foods against spoilage and for significantly extending the life of such foods as fruits and vegetables. A protein derived film is prepared from soybeans, wheat, corn, and mixtures thereof by a process of soaking the grain in water to soften the layer, subjecting the grain-water mixture to the shearing action in a blender to form a milky suspension which is filtered to remove the solids. The residual liquid is heated to denature the higher molecular constituents which are coagulated, allowed to float to the surface, and removed from the denatured proteinaceous solution. The denatured proteinaceous solution is cooled and subsequently employed to coat fruits and vegetable with coatings which function as excellent barriers for preventing the fruits and vegetables from reacting with atmospheric oxygen or carbon dioxide while providing barriers which are permeable to water which precludes their drying out due to dehydration during storage.

Method of making edible coatings for protecting perishable foods against

Tris(N-nitrosophenylhydroxylaminium)aluminum is employed in amounts from about 0.1% by weight to about 0.2% by weight to inhibit the polymerization reaction during propellant mixing. With a weight percent of 0.2 percent, the inhibitor inhibited polymerizaiton to control end-of-mix viscosities to 12 Kp and 13 Kp compared to control propellant viscosities of 26 Kp and 39 Kp after 8 hours and 10 hours respectively. The test propellant and control propellant contained the name ingredients with the exception of the 0.2% additive of the inhibitor in the test propellant. The propellant composition for control and test comprised ammonium perchlorate of 400 micrometer, 200 micrometers, and 20 micrometers in weight percent amounts of 29.5,30.0, and 5.0 respectively, aluminum powder 14.0 weight percent, cyclotetramethylenetetranitramine oxidizer of 4 micrometers particle size in amount of 10.0 weight percent, and hydroxyl-terminated polybutadiene prepolymer binder in a weight percent amount of 11.4 with an isophorone diisocyanate curative and crosslinking agent with an isocyanate to hydroxyl ratio of 0.89 weight percent.

Method of controlling the increase in potlife of propellants during

An apparatus for testing candidate rocket nozzle materials includes an elated member having a combustion chamber extending therethrough, with an inlet at the forward end of the combustion chamber for admitting and igniting a gaseous mixture of hydrogen and oxygen and a nozzle secured to the combustion chamber at the aft end thereof. The nozzle is made of wafers or petals of materials to be tested, with the wafers being secured together at the edges thereof and having a configuration such that the wafers in transverse cross section form a polygon which has an area which increases with distance from the combustion chamber.

Apparatus for testing candidate rocket nozzle materials

The trimer of 1,6-hexanediisocyanate, which has the chemical name in acconce with (International Union of Pure and Applied Chemistry) (IUPAC) nomenclature of 7-aza-8-oxo-7[1-isocyanato-6-oxohexyl]pentadecanediisocyanate, is employed in a method of chemical bonding of solid propellant grains to the internal insulation of an interceptor motor. Both the propellant composition and the insulation are chemically reactive with the trimmer identified hereinabove. The method comprises providing a solid propellant rocket motor case having the internal insulation installed therein. Following degreasing of the insulation outer surface, the trimer identified hereinabove is spray coated onto the insulation, and the solid propellant composition is placed onto the trimer. A chemical bond is formed between the propellant and the trimer and the insulation to achieve the chemical bonding of an isocyanate curable solid propellant composition to the internal insulation. The insulation employed in the preferred embodiment is formulated with ethylene-propylene-diene monomer prepolymer, peroxide-cured, and plasticized with 9% dioctyl sebacate. The propellant composition is cast onto the spray coated insulation surface where the chemical insulation-to-polyisocyanate-to-propellant bond is achieved which shows superior tensile, shear, and peel strength when compared to conventional insulation-liner-propellant bonding by prior art.

Method of chemical bonding of solid propellant grains to the internal

Gem-difluoroamino compounds are employed as a partial or complete replacement for TVOPA (trisvinoxypropyl adduct), tris-1,2,3-[bis(1,2-difluoroamino)-ethoxy]propane, in accordance with the nomenclature established by the International Union of Pure and Applied Chemistry. A partial or complete replacement of the vicinal-(1,2-)difluoroamino plasticizer of a difluoroamino-based propellant with its structural isomer or a related structural isomer, namely, a geminal-(1,1-)bis-difluoroamino compound has resulted in two beneficial effects, namely, a marked reduction in pressure exponent and an enhancement of the burning rate of the propellant. Representative of the geminal compounds are the compounds identified as SYEP and SYPO and further identified by the following structural formulas and chemical nomenclatures: SYEP

Composite rocket propellant composition with a controllable pressure

Mechanical enhancement of the burning rate of solid propellants is achieved y the incorporation of limited percentages of heat-expandable beads into the solid propellant matrix. When the flame front reaches an individual bead, the bead which contains an expanding or blowing agent (e.g., pentane, 4,4'-oxybis(benzenesulfonyl hydrazide) (Celogen OT), etc., expands to several times its volume and ruptures. Bead expansion or rupture causes a disruption of the propellant's surface, and the flame can penetrate into the propellant. This penetration results in a major increase in burning rate.

Heat-expandable beads as burning rate accelerators

A method of extinguishing burning rocket or missile solid propellant employs a device including an explosive charge which is submerged in an extinguishant agent contained in container positioned near the rocket or missile solid propellant being tested or stored. An electrically initiated detonator or heat initiated detonator initiates the explosive charge which causes the extinguishant agent to be explosively driven or propelled horizontally, almost in a solid mass, to the sites of burning propellant to achieve extinguishment within milliseconds. The composition of a preferred extinguishant agent is ethylene glycol of about 55 weight percent, water of about 25 weight percent, and foaming agent of about 20 weight percent.

Extinguishing rocket/missile solid propellants

A diisocyanate crosslinking agent having a minimum chain length of methylene groups from 25 to 45 which has a coiling-uncoiling ability in a cured solid propellant composition (under stress and relaxing of stress) as a result of the chain length and configuration imparts superior structural strength to the solid propellant composition. A preferred species is 1,37-heptatriacontane diisocyanate, OCN--(CH.sub.2).sub.37 --NCO, which is employed as an effective crosslinking agent in hydroxyl-terminated polybutadiene propellants.

Growing community of inventors

Huntsville, AL, United States of America

David C Sayles