Nitrocellulose (NC) is a widely used constituent of minimum smoke propellants. The main role of nitrocellulose in crosslinked double base (XLDB) propellants is increasing of crosslinking density of the elastomeric binder due to its polyolic chemical structure. Thus, since the typical NC content in XLDB formulations is less than 0.5%, the NC contribution to the energetic performance, as well as to the burning behavior of the XLDB propellants, may be assumed negligible in comparison with that of the other energetic components (nitrate ester plasticizers and nitramine fillers). Surprisingly, it was found that introduction of NC to RDX based XLDB formulations has a strong catalytic effect, in addition to the expected toughening effect. The burning rate of NC containing propellants was increased by up to 30% relatively to NC free samples. In spite of the similar chemical structure of RDX and HMX, the response of HMX based XLDB propellants to introduction of NC is different from that of RDX based propellants: while toughening effect is still considerable, the burning rate and pressure exponent values remain practically unchanged. The different burning behavior of RDX and HMX based XLDB propellants may be explained by different physical properties of molten layer which is created at the propellant surface during the burning process.
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