Product design of ADN-PRILLS for applications in solid propellants

Ammonium dinitramide (ADN) is the upcoming oxidizer for defence and space applications. This trend requires the design of ADN key products like ADN-prills. The properties of ADN-prills are determined by obvious features like particle size, particle shape and particle surface. But also less apparent properties like crystal structure, thermal stability and small amounts of additives or residuals have significant effects on application relevant properties. Over the years the product design for spherical ADN-particles, so-called ADN-prills, was adjusted to the requirements of application in solid propellants. ADN-prills are producible in the particle size range between 40 and 200 mm. If necessary the ADN-prills can be refined by fluidized bed technology, e.g. by creating coating layers with improved bonding behaviour to binder systems. This leads to comparatively better mechanical propertied of propellants made with such coated ADN-prills than with uncoated ADN-prills. The crystal structure was investigated by X-ray diffraction. The thermal stability was determined by vacuum stability test and mass loss.