Composite Cryogenic Fuel Tank Polymer Matrix Formulation

UAH-P-11016-Composite Cryogenic Fuel Tank Polymer Matrix Formulation

Docket: UAH-P-11016


NASA and other major aerospace companies have difficulties in developing a composite tank to substitute for the aluminum-lithium (AL-LI) tanks. The current solution of using an external tank on the spacecraft as a substitute for AL-LI tanks has a major problem. Potential weight savings of 30% were predicted but the tanks were failing prematurely under thermal cycling. The thermal cycling causes moisture diffusion which in turn introduces micro-cracks that weaken the tanks causing them to leak.

Researchers at UAH have developed a unique Ionic Liquid Epoxy (ILE) as an aerospace adhesive which provides a solution to this problem. Ionic liquids (ILs) are a novel class of green organic materials that have low vapor pressure and low flammability. The ILE retains all the valuable properties of ILs such as high toughness at cryogenic temperatures and outstanding strength. The unique ILE monomer that was synthesized at UAH which when applied to the tanks solves the problem of micro-cracks without compromising strength and integrity.

ILE developed here is an excellent matrix for a carbon fiber reinforced composite tank for cryogenic fuels like liquid hydrogen and liquid oxygen. Besides the tank, the fuel lines and turbo pump housing can also be made from UAH's ILE.


  • Fuel tanks
  • Cryogenic wind tunnel
  • Turbo pumps
  • Fuel lines


  • High toughness at low temperatures
  • Vacuum compatible
  • Low vapor pressure
  • Low shrinkage on cure
  • Low moisture permeability


  • State of Development: Proof of Concept
  • Licensing Status: Available for licensing
  • Patent Status: Proprietary