1_丁基_3_甲基咪唑二氰胺盐离子液体的热稳定性和热分解动力学_英文_.pdfVIP

CATALYSIS, KINETICS AND REACTORS Chinese Journal of Chemical Engineering, 18(5) 736—741 (2010) Thermal Stability and Thermal Decomposition Kinetics of 1-Butyl-3-methylimidazolium Dicyanamide* LIANG Rui (梁蕊)**, YANG Meirong (杨美荣) and XUAN Xiaopeng (轩小鹏) School of Chemistry and Environmental Sciences, Henan Normal University, Xinxiang 453007, China Abstract Thermal stability and thermal decomposition kinetics of 1-butyl-3-methylimidazolium dicyanamide +? ([bmin ][N(CN)2 ] ) were investigated using both isothermal and non-isothermal thermogravimetric analyses (TGA) under high pure nitrogen as carrier gas. The long-term thermogravimetric studies revealed that the highest tempera- +? ture used should be 110 °C, at which [bmin ][N(CN)2 ] lost less than 10% by mass in 10 hours. The non-isothermal activation energy values determined using Friedman and ASTM methods were (150±13) and (147±2) kJ·mol–1, re- spectively. Multivariate non-linear- regression methods showed that expanded Fn and CnB models were the best fit models with highest correlation coefficient of 0.9994, and the apparent activation energies were consistent with iso-conversional methods. Keywords ionic liquids, long-term thermal stability, kinetics of thermal decomposition, iso-conversional method 1 INTRODUCTION from scanning TGA experiments [9, 12-14]. Hence, the stable temperature limit of ionic liquids is not pre- Ionic liquids (ILs) are salts typically comprised cisely defined by the onset decomposition temperature. from the combination of large organic cations with Scarcity of reliable long-term thermal stability of di- various substituents (alkyls, oligoethers, etc.) and in- alkylimidazolium dicyanamide ionic liquids leads to t