THERMAL-DECOMPOSITION RDX AND MIXTURE

Thermal decomposition of pure cyclotrimethylene trinitramine (RDX) sho ws an endothermic peak at 205 degrees C attributed to melting, followe d by exothermic decomposition leading to a strong peak at 240 degrees C, and a very strong thermogravimetric peak at 260 degrees C with a ma ss loss of 95%. However, the mixture of RDX, nitrocellulose and carbon (FX 300) shows a melting peak at 202 degrees C with reduced intensity , and a decomposition peak at 255 degrees C. A strong exothermic shoul der at 218 degrees C, from the decomposition of nitrocellulose and oth er materials in the mixture is also seen. Addition of NH4ClO4 to RDX c auses decomposition, after melting, to take place abruptly, resulting in a very sharp and strong peak at 210 degrees C. However, in the case of FX300 no melting is observed; instead two strong exothermic peaks at 195 and 210 degrees C occur, corresponding to the oxidation of nitr ocellulose and RDX in the mixture. This indicates that the addition of NH4ClO4 increases the decomposition of RDX, this effect being more pr onounced in FX300. The most appropriate concentration of NH4ClO4 is 10 wt%. Although NH4NO3 decomposes prior to the melting decomposition of RDX, it does not show a marked effect on the decomposition of RDX and FX300. Additions of KClO4, NaClO4 and KNO3 have no effect.