Imidazole ionic liquid, as a green solvent, is one of the most widely used ionic liquids. Understanding its thermal safety characteristics and mechanism is the essential basis for its safe application. In this paper, the thermal hazard characteristics of two ionic liquids with typical structural characteristics are systematically studied, which were 1-allyl-3-methylimidazole nitrate and 1-propyl-3-methylimidazole nitrate ionic liquids. The thermal decomposition peculiarities of two ionic liquids were systematically analyzed by thermogravimetric analyzer, differential scanning calorimetry and accelerating rate calorimeter techniques, and the risk of thermal runaway is also evaluated. In addition, the pyrolysis products and microscopic pyrolysis mechanism of ionic liquids were studied via thermogravimetry-Fourier transform infrared spectroscopy, thermogravimetric mass spectrometry and density functional theory calculation, and the essential mechanism of thermal hazard were determined. The influence of substituent structure on the thermal hazard characteristics of imidazole nitrate ionic liquid was preliminarily analyzed from macroscopic experiment and microscopic mechanism two aspects. This study provides a theoretical basis for the safe application, design and development of imidazole nitrate ionic liquids.

中文翻译：

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通过热分析和DFT计算评估1-烯丙基-3-甲基咪唑硝酸盐和1-丙基-3-甲基咪唑硝酸盐的热危害和热解机理：结构特性的影响


咪唑离子液体作为一种绿色溶剂，是应用最广泛的离子液体之一。了解其热安全特性和机理是其安全应用的重要基础。本文对1-烯丙基-3-甲基咪唑硝酸盐和1-丙基-3-甲基咪唑硝酸盐两种具有典型结构特征的离子液体的热危害特性进行了系统研究。利用热重分析仪、差示扫描量热仪和加速量热仪技术系统分析了两种离子液体的热分解特性，并评估了热失控风险。此外，通过热重-傅里叶变换红外光谱、热重质谱和密度泛函理论计算研究了离子液体的热解产物和微观热解机理，确定了热危害的本质机理。从宏观实验和微观机理两个方面初步分析了取代基结构对硝酸咪唑离子液体热危险特性的影响。该研究为硝酸咪唑离子液体的安全应用、设计和开发提供理论依据。