Largely desensitized and stabilized CL-20 crystals obtained through reinforcement with cross-linked graphene oxide

Abstract

ε-CL-20 is currently the most powerful commercially available explosive, but its high mechanical sensitivity and low phase stability limit its broad applications. In order to reduce the sensitivity of ε-CL-20, cross-linked graphene oxide (GO), using triaminoguanidine–glyoxal polymer (TAGP) as the bridging agent, was prepared in the ε-CL-20 solution, which could constrain the nano-sized ε-CL-20 crystals following a conventional solvent–nonsolvent in situ crystallization method. It was shown that the polymorphic transition temperature of the assembled CL-20/GO–TAGP crystals increased by about 36.0 °C at a maximum level compared with pristine ε-CL-20, and the polymorphic transformation temperature varied depending on the content of the cross-linked GO. Moreover, the heats of formation for the resulting modified products such as CL-20-2 (950.0 kJ kg⁻¹) and CL-20-4 (848.3 kJ kg⁻¹) were 26.9% and 13.3% higher than that of pure ε-CL-20 (748.9 kJ kg⁻¹), respectively. The measured density of assembled CL-20 crystals was almost unchanged as 2.01 g cm⁻³ under a certain condition. The impact and friction sensitivities of the modified samples, such as CL-20-1, CL-20-3, and CL-20-6, were obviously reduced. More importantly, two of the assembled products even showed a certain improvement in specific impulse and detonation performance.