Preparation of Rigid Polyurethane Foams as Inner Wetted Thermal Insulation

This paper provides an overview about the recently performed development of rigid polyurethane (PUR) foams on a cryogenic insulation for liquefied hydrogen (LH2) tanks application and gives information on the characterization test campaigns performed so far. Since this specific insulation is foreseen to be applied on inner surfaces of the propellant tanks it is called Inner Wetted Thermal Insulation (IWTI). The IWTI obtained by spraying method has been especially designed (with apparent core density 85 +/- 2 kg/m(3)) for an optimum chemistry and cell structure morphology in order to achieve superior mechanical and thermal performance under these exceptional conditions. Studies of the foams' tension and compression properties at 295 and 77 K were carried out. The obtained safety coefficient of cryogenic insulation material reached 3.7.