Development of Propellants Containing Ammonium Nitrate.

Abstract

The phase properties of ammoniurn nitrate (AN) were investigated using thermal analysis by means of X-ray diffraction for unambiguous results. A series of X-ray diffraction patterns were measured while the samples were heated and cooled and the phases and their transitions occurring on heating and cooling were identified. Rietveld refinement was used to extract structural data from the diffraction patterns. Attempts were made to improve the phase behaviour of AN by incorporating amine complexes into the lattice. The resulting products as well as pure AN were produced in necessary quantities in a pilot plant, as spherical particles for propellant development. Propellant development was carried out with AN, GAP
and energetic plasticizers as main ingredients. Thermodynamic calculations revealed that specific impulses of about 235 s could be expected, which was confirmed in the experimental work. The prepared propellants showed acceptable stabilities in the Dutch and the vacuum stability test, when stabilizers selected from tbe phenylamine family were used. The propellants yielded burning rates up to 8 mints and pressure exponents n < 0.6 . With the 50 mmgap test usingPMMAmaterial, results were obtained which meet the insensitive ammunition requirements according to MIL Standard.