Sensitivity and Phase Transition of Heated ϵ‐CL‐20 in Drop‐Weight Impact Test. Issue 11 (26th September 2018)

• Record Type: Journal Article
• Authors: Zheng, Xue; Yu, Shaojun; Wen, Wen; Wen, Yushi; Wang, Pei; Lan, Lingang; Dai, Xiaogan; Han, Yong; Li, Jingming; Li, Yubin
• Is Part Of: Propellants, explosives, pyrotechnics. Volume 43:Issue 11(2018)
• Page Start: 1164
• Page End: 1170
• Publication Date: 2018-09-26
• Subjects: hexanitrohexaazaisowurtzitane(CL-20) -- polymorphic transformation -- impact sensitivity -- PDA coating -- heating; Propellants -- Periodicals; Explosives -- Periodicals; 662.2
• DOI: 10.1002/prep.201800173
• Languages: English
• ISSNs: 0721-3115

Abstract

Abstract: In order to understand the effect of polymorphic transformation on the impact sensitivity of heated hexanitrohexaazaisowurtzitane (CL‐20) and its composite, the polymorphic transition of CL‐20 crystal under heat stimulation was investigated using powder X‐ray diffraction (PXRD) and microscopic methods. The effects of particle size and PDA coating on polymorphic transition of CL‐20 were explored. The experiments showed that the polymorphic transition at 160 °C was related to the particle size and surroundings of CL‐20 crystals. As the temperature increases, changes in the molecule conformation of larger crystals were more facilitated than in smaller ones, the ϵ → γ solid‐solid phase transitions went along thoroughly in larger crystals. Poly (dopamine) (PDA) coating played a key role in the significant inhibition of phase transition owing to the restriction effect via its compact and rigid shell. The lower pressure caused by drop‐weight impact can facilitate the ϵ → γ phase transition of heated CL‐20. This investigation contributes to comprehend the polymorphic transformation mechanism of CL‐20 and provides guidance for effective control on the CL‐20 polymorphs in CL‐20‐based composites. Abstract :