Abstract: The present disclosure relates to prosthesis systems having trays and liners having an asymmetrical locking mechanism to bias the strength of the liner to resist loading forces and associated methods. The tray has a lateral groove disposed in an inner surface of a lateral circumferential portion of the tray and a medial groove disposed in an inner surface of a medial circumferential portion of the tray. The liner has an upper segment and a lower segment. The liner has a locking portion for lockingly engaging the tray that includes the lower segment. The locking portion has a lateral toe positioned generally diametrically opposite a plurality of resiliently deformable medial fingers defined therein. The liner and the tray are engageable in a lateral-to-medial direction so that the plurality of medial fingers can resiliently deform to engage the medial groove subsequent to engagement of the lateral toe within the lateral groove.

Abstract: This invention relates to the preparation of N-(phosphonomethyl)glycine (“glyphosate”) from N-(phosphonomethyl)iminodiacetic acid (“PMIDA”), and more particularly to methods for control of the conversion of PMIDA, for the identification of reaction end points relating to PMIDA conversion and the preparation of glyphosate products having controlled PMIDA content.

Abstract: A composition consisting essentially of a polyphosphazene binder having the following repeating units: ##STR1## wherein n is from about 20 to about 50,000, A is selected from --O-- and --NH--, and R.sup.1 and R.sup.2 are independently selected from alkyl having from one to about 20 carbon atoms, aryl having from 6 to about 14 carbon atoms, alkaryl having from 7 to about 30 carbon atoms, any of the preceding moieties substituted with halogen, hydroxyl, alkoxy, aryloxy, or nitro groups, or any of the preceding moieties linked by ether or amine linkages. Combined with an organic fiber filler, this material provides an erosion resistant insulation composition for temporarily protecting the interior of a rocket motor combustion chamber from thermal damage while the rocket is firing.

Abstract: Improved resistance of fiber filled insulation to erosion from combustion gas flow ina solid propellant rocket motor is produced by orienting the fiber direction of the grain of the fibers in the insulation to a direction in which the direction of the fiber grain is substantially perpendicular to the direction of the flow of combustion gas in the rocket motor. Unvulcanized fiber filled insulation sheet stock is folded and compacted in accordion-like style such that the fiber grain direction is reoriented eassentially 90 degrees in the roll direction of the sheet stock.

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: 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: An improvement to the process of applying a rocket motor liner to an inside surface of a rocket motor casing by coating the casing with a rocket motor liner composition and then curing the liner composition. Typical rocket motor liner compositions include the product of 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. This invention may use an alkaline carbon black filler and/or a curing catalyst which does not include magnesium oxide.

Abstract: An improvement to the process of applying a rocket motor liner to an inside surface of a rocket motor casing by coating the casing with a rocket motor liner composition and then curing the liner composition. Typical rocket motor liner compositions include the product of 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. This invention may use an alkaline carbon black filler and/or a curing catalyst which does not include magnesium oxide.

Abstract: An elastomeric composition suitable for use as a rocket motor case insulation is disclosed. The composition comprises a vulcanizable elastomeric material and reinforcing polybenzimidazole polymer fibers in combination with a powder filler. A preferred embodiment utilizes polyisoprene as the elastomer and silica as the powder filler. These compositions have better erosion resistance than asbestos-reinforced compositions, and do not pose the environmental or safety risks associated with asbestos-reinforced insulation.

Abstract: An elastomeric composition suitable for use as a rocket motor case insulation is disclosed. The composition consists of a vulcanizable elastomeric composition and reinforcing aramid polymer fibers in combination with a powder filler. A preferred embodiment utilizes polyisoprene as the elastomer, KELVAR.RTM. fibers as the aramid polymer fibers, and silica as the powder filler.

Abstract: Bonding of hydroxy terminated polybutadiene based propellant grains to rocket motor liners and of the liner to the motor case is greatly improved by incorporating an aziridine in a urethane cured hydroxy terminated polybutadiene based liner.

Abstract: A mechanical method of case bonding a solid propellant to a rocket motor e wherein a coating of a liner material is first applied to the internal surface of a rocket motor case. While the liner material is uncured a mechanical structural material selected from wire grid, wire hooks, rubber spikes, steel wool, metal grid, polyamide material, or polypropylene material is embedded in the liner material but allowed to protrude above the liner material. The liner material is allowed to cure, and an uncured propellant composition is cast against the cured liner and allowed to flow around the protruding mechanical structural material. On curing, the propellant composition attaches itself to both the liner and the mechanical structural material. The combination of the liner material, the mechanical reinforcing material, and the propellant composition provides a mechanical reinforcement in the propellant which is held in place with improved tensile adhesion against the rocket motor case wall.