Keywords solid propellant, ammonium dinitramide, ADN, HTPB, performance, compatibility, formulation
Abstract The aim of this work is to perform an initial evaluation of ammonium dinitramide, ADN, as substitute for ammonium perchlorate, AP, in solid rocket propellants for large space launch boosters. This midterm report covers work performed during May - November 2009 and include performance evaluation, compatibility and curing assessment. The results show that the theoretical specific impulse increases from 262 s to 270 s by replacing AP with the same volume ADN in a typical HTPB/Albased formulation. ADN is found to be chemically compatible with HTPB. However, ADN seems to accelerate the oxidative degradation of HTPB and thus a suitable antioxidant is required. Small batches of ADN/HTPB/Albased propellants have been formulated and cured successfully using isocyanates. The project success criteria specified in the contract have been met. This encourages continued evaluation. The report also includes information on how to handle ADN with respect to transportation, toxicity and hazard properties. This work was performed on NASA contract NNC09CA11C.