LIGHTWEIGHT CRYOGENIC FLUID TANKS FOR SPACE-BASED SYSTEMS

CRYOGENIC FUEL TANK MATERIALS HAVING HIGH SPECIFIC STRENGTH AND STIFFNESS, GOOD DIMENSIONAL STABILITY, AND GOOD ENVIRONMENTAL RESISTANCE ARE NEEDED FOR USING LIQUID HYDROGEN AND METHANE FUELS IN PROPULSION, TRANSPORTATION AND SPACE-BASED SYSTEMS. CURRENTLY USED METALS LACK THE DESIRED WEIGHT TO STIFFNESS RATIO WHILE ADVANCED COMPOSITE MATERIALS SUCH AS GRAPHITE/EPOXY SHOW MATRIX FAILURE DURING TEMPERATURE CYCLING. A HIGH-PERFORMANCE ORDERED POLYMER, POLY P-PHEYNLENE BENZOBISTHIAZOLE (PBT), CAN BE USED IN FILM FORM TO MAKE LIGHTWEIGHT CRYOGENIC FLUID TANKS WHICH EXCEED THE PERFORMANCE OF CURRENT MATERIALS. THIS LIGHTWEIGHT POLYMER FILM HAS A SELF-REINFORCING RIGID-ROD STRUCTURE WHICH IS EXPECTED TO YIELD THE DESIRED ADVANCED COMPOSITE STRENGTH WITHOUT THE DRAWBACKS OF FIBER-BASED COMPOSITE MATERIALS. THE EXCELLENT PROPERTIES OF PBT FILMAT LOW TEMPERATURE IS BEING EVALUATED INCLUDING STRENGTH STIFFNESS ANDVERY LOW PERMEABILITY TO HYDROGEN. PBT FILM CAN BE USED AS A STRUCTURAL TAPE IN INNOVATIVE PRESSURE VESSEL DESIGNS TO MAKE A CRYOGENIC FLUID TANK WITH REDUCED WEIGHT, REDUCED LEAKAGE, AND IMPROVED DURABILITY OVER CURRENT ADVANCED MATERIALS SUCH AS GRAPHITE/EXPOXY. PBT FILM ALSO COULD BE USED AS A TANK LINER TO IMPROVE THE PERFORMANCE OF MORE CONVENTIONAL DESIGNS. THIS WILL RESULT IN REDUCED TRANSPORTATION COSTS, IMPROVED RELIABILITY, AND MOREEFFECTIVE LOGISTICS.