Anton S. Wallner

Magnetic resonance imaging study of solid rocket propellants and liners

Magnetic resonance imaging (MRI) has been used to study solid rocket propellants and liner material. The samples studied were simulants, used mainly for safety reasons, of real systems using ammonium sulfate in place of the energetic materials. The polymeric binder was hydroxy-terminated poly(butadiene) (HTPB) reacted with isopherone diisocyanate. MRI was used to observe variations in intensity in the simulant samples due to differing percentages of solids loading. It also showed the homogeneous intensity obtained for an unfilled sample used for comparison with the 82% filled material. The liner material, HTPB and dimeryl diisocyanate, was imaged despite its relative rigidity observed from its short T2 value. Samples of poly(alkylene) oxide simulants were imaged, and various bubbles and regions of filler inhomogeneity were observed. These defects were correlated with photo-micrographs of the sample. MRI can be used to image real systems of solid rocket components.