THERMAL STABILITY OF IONIC LIQUIDS

摘要

Long-term thermal stability of ionic liquids is essential for reliable performance of ionic liquids in any engineering applications. TGA studies were carried out on a series of ionic liquids with different cations and anions such as l-butyl-3-methylimidazolium chloride ([C_4mim]Cl), l-hexyl-3-methylimidazolium chloride ([C_6mim]Cl), l-hexyl-3-methylimidazolium tetrafluoborate ([C_6mim]BF_4), l-hexyl-3-methylimidazolium hexafluorophosphate ([C_6mim]PF_6), l-octyl-3-methylimidazolium hexafluorophosphate ([C_8mim]PF_6), and l-butyl-3-methylimidazolium bis(trifluromethanesulflonyl)imide ([C_4mim][Tf_2N]). The short-term thermal stability of ionic liquids was evaluated by measuring the onset temperature of decomposition of ionic liquids, and the long-term thermal stability of ionic liquids was also evaluated by weight loss of ionic liquids over a long period of time at various temperatures. The experimental results showed that the long-term thermal stability of ionic liquids decreased with increasing temperature and was significantly lower than the onset temperature of decomposition of ionic liquids.