Towards to some published misconceptions about TNT and ɛ-CL20
Svatopluk Zeman, Veerabhadragouda B. Patil
Abstract
The literature widely reported information about apparent high impact sensitivities of both the pure 2,4,6-trinitrotoluene (TNT; i.e. of 14 - 16 J) and ɛ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ɛ-CL20; i.e. of 2 - 4.4 J), which mostly correspond to the BAM method of determination. This brief overview discusses the reasons of these error data. The physical organic chemistry approach to this problem has confirmed the Beijing Inst. of Technology value of 13.2 J for ɛ-CL20 and the LANL value of 39.2 J for TNT. The morphological instability of ɛ-CL20, when in contact with polar binders or plasticizers, might not have much influence on its application in propellants. The stabilization of ɛ- to β-CL20 upon its entry into a cocrystal with a coformer having the character of a polynitro compound (especially with nitramines) could be of practical importance. The high impact sensitivity of TNT and ɛ-CL20 is important for handling and processing safety when related to the specific practical samples. However, they cannot be used for molecular-structural analyses and predictions or as a comparative standard, which is currently widespread in the literature.