Published 6 issues per year
ISSN Print: 2150-766X
ISSN Online: 2150-7678
Indexed in
SOLID SOLUTION FORMATION BETWEEN RDX AND COMMON SOLID PROPELLANT BINDERS
ABSTRACT
Because of many favorable characteristics, RDX has been extensively utilized as an ingredient in both gun and solid rocket propellants. Much work has been done on the decomposition and subsequent reactions involving RDX and other propellant ingredients, but very little attention has been given to the effects of solid-state interactions in the condensed phase. The combination of ingredients in solid propellants (e.g., oxidizer, binders, plasticizers, etc.) may not be adequately modeled as just a physical mixture since interactions between these components can change intermolecular forces in the propellant mixture, leading to changes in physical properties and combustion behavior. In this work, the solubilities of common propellant ingredients including acetyl triethyl citrate (ATEC), cellulose acetate butyrate (CAB), nitrocellulose (NC), and an energetic plasticizer (EP) and their effects on RDX unit cell dimensions were investigated. X-ray powder diffraction analysis showed that all binders tested formed a solid solution with RDX indicated by expansion of the RDX unit cell volume. CAB was found to have a solubility limit greater than 16 wt%, while EP had the least. NC and ATEC both showed solubility up to about the 9 wt% level. Changes in material and combustion properties due to the solid solution formation should therefore be closely examined in the modeling of combustion processes of RDX-based composite propellants.