Kinetic predictions for CL-20 and its PBXs using models obtained by master plots and combined kinetic methods

摘要

In this paper, the decomposition reaction models and thermal hazard properties of different 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) crystals and their PBXs bonded by Semtex 10, C4, Viton A and Fluorel polymer matrices have been investigated based on master plots and combined kinetic methods. The established kinetic triplets are used to simulate isothermal behaviour at temperature of 82 °C. It has been found that the use of "isoconversional and combined kinetic analysis" method yield reliable kinetic triplets, which could be employed to predict the thermal behaviour of energetic materials. The effect of the Fluoropolymers on the decomposition mechanism of CL-20 is and significant and similar. They can change its decomposition mechanism from "AC1, first order au-toaccelerated model" to "A3, three dimensional nucleation and growth model". It has also been shown that the polymer matrices containing mineral oil materials and plasticizers (Semtex and C4) have little effect on decomposition mechanism of CL-20, resulting in comparable activation energies and model. According to isothermal simulations, he threshold cook-off time until loss of functionality at 82 °C for all involved materials are much more than 500 days, and under the effect of polymer matrices, the storage time of CL-20 has been greatly extended.