Mechanical Behavior of Energetic Polymeric Materials

Mechanical and thermomechanical properties of NC base propellants

“…3 The onset of a "phase transition",4 at approximately -70'C for NG and at a somewhat 2 M. Mezger, unpublished results.…”

“…However, by going to a lower temperature and a slightly higher strain rate, brittle fragmentation was also observed for JA2. 2 Plans have been made to study the fracture surfaces by scanning electron microscopy and x-ray photoelectron spectroscopy to determine the role of added solids in the failure of the triple-base propellants. Differences in plasticizers and processing may also account for some of the differences in mechanical failure characteristics of M30A2 and JA2.…”

“…e.g., failure o,.onditions as a function of composition, temperature, processing, etc. ; (2) to determine the details of how mechanical failure can lead to undesirable and/or hazardous interior ballistics; (3) to use the understanding gained to modify composition, processing, etc., to eliminate/minimize undesirable properties within the constraints of required perfor:nance; and (4) to develop standard testing procedures to evaluate a given propellant relative to (2) above. The approach then is to study the mechanical properties as a function of the appropriate parameters such as composition and temperature: to determine the conditions for how mechanical failure can lead to undesirable and hazardous interior ballistics' to use the results and the understanding gained to make the aopropriate modifications; and then to perform the necessary tests to demonstrate that a change has been accomplished.…”