Thermal Decomposition of New and Aged LX-04 and PBX 9501

One-Dimensional-Time-To-Explosion (ODTX) experiments were conducted to study the thermal decomposition of aged LX-04, aged PBX 9501, HMX class 1 and class 2, Estane and Estane/BDNPA-F (PBX 950 1 plasticized-binder) materials. The tests involved heating 12.7 mm diameter spherical samples in pre-heated aluminum anvils until explosion. The times to explosion at different heating temperatures were compared to historical data on new LX-04 and PBX 9501 compounds to study any changes to their thermal stability. New and aged LX-04 showed comparable decomposition kinetics. The data for aged PBX 9501 showed slightly longer explosion times at equivalent temperatures. Analysis of the error in time measurement is limited and complicated by several experimental factors but the small time change appears to be experimentally significant. The thermal decomposition of these PBXs were modeled using a coupled thermal and heat transport code (chemical TOPAZ) using separate kinetics for HMX and binder decomposition. Separate decomposition models were developed for HMX and the reactive PBX 9501 binder component (1:1 Estane:BDNPA/F) based on the measured explosion times. Thermal aging models can describe longer explosion times by the loss of plasticizer-binder constituent which was more thermally reactive