A mechanism for two-step thermal decomposition of 2, 6-diamino-3, 5-dinitropyrazine-1-oxide (LLM-105). Issue 24 (12th June 2020)

• Record Type: Journal Article
• Authors: Yu, Qian; Zhao, Chuande; Liao, Longyu; Li, Hongzhen; Sui, Heliang; Yin, Ying; Li, Jinshan
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 24(2020)
• Page Start: 13729
• Page End: 13736
• Publication Date: 2020-06-12
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp02159h
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The thermal decomposition mechanism of the consecutive reactions of LLM-105 was investigated based on the gaseous products and solid reactants. Abstract : 2, 6-Diamino-3, 5-dinitropyrazine-1-oxide (LLM-105) is a representative of the new generation of low-sensitivity energetic materials and has been applied extensively in formulations as an insensitive high-energetic ingredient. Although the initial thermal decomposition mechanism of LLM-105 has been studied based on quantum chemical calculations, the internal mechanism of the two-step thermal decomposition still lacks experimental research. Thus, this study involves a detailed experimental study to reveal the mechanism of the two-step thermal decomposition of LLM-105. The results showed that LLM-105 decay was a consecutive reaction. The first-step reaction dominated the early stage of the LLM-105 decomposition, and its products participated in the reaction of the second step. The cleavage of NO2 and NH2 groups of LLM-105 mainly occurred in the first step, while gaseous products NO and C2 N2 were released during the second reaction step. The first-step reaction had a higher oxygen consumption rate and a lower carbon consumption rate, producing more heat due to more extensive oxidation of the carbon backbone. The difference in the oxidative ability and reaction rate between the two steps resulted in a two-step exothermic and mass loss behavior. This study provides further insights into the entire reaction process of LLM-105 and would be helpful for its better application and for the design of new explosives.