In previous work, we found that the nitroplasticizer in the HMX-based explosive PBX 9501 played a crucial role in cookoff, especially when predicting response in larger systems1). We have recently completed experiments with a similar explosive, LX-14, that has a relatively nonreactive binder. We expected the ignition times for LX-14 to be longer than PBX 9501 since PBX 9501 has a more reactive binder. However, our experiments show the opposite trend. This paradox can be explained by retention of reactive gases within the interior of LX-14 by the higher strength binder resulting in faster ignition times. In contrast, the binder in PBX 9501 melts at low temperatures and does not retain decomposition gases as well as the LX-14 binder. Retention of reactive gases in LX-14 may also explain the more violent response in oblique impact tests2) when compared to PBX 9501.
PBX 9501, LX-14, cookoff, sealed, vented, binder-effects