L-222 Life Assessment of NC Based Energetic Materials

Nitrocellulose (NC), with its variable energetic content, solubility with energetic and non-energetic plasticisers, and formation of structural materials, makes it a very versatile material. This flexibility has allowed nitrocellulose to be used in multiple products within the energetics community, from propellants to igniter compositions, combustible cartridge cases (CCC) to flares.

International guidance currently provided by AOP-7 and AOP-48, for qualification of energetic materials and stabiliser content of nitrocellulose-based propellants, needs to be discussed and addressed for non-propellant based energetic materials. This is the case for several low content nitrocellulose-based materials, such as Low Vulnerability Ammunition (LOVA) and some Infrared Decoy Flares, which have stabiliser content below the AOP-48 requirement. There is also concern about potential ageing mechanisms that need to be highlighted.

Another area that requires development of guidance for life assessment is migration of energetic plasticisers for non-standard propellant materials. For example, combustible cartridge cases can be filled with single, double or triple base propellant grains. Migration of plasticisers from the DB grains into the CCC could lead to a reduction in the life of the cartridge.   

This paper will review the use of propellant-based AOPs, STANAGs and other techniques for determining life assessment of these nitrocellulose-based energetic materials. It will also highlight potential safety issues and propose recommendations for capturing the required safety information.