Ionic liquid, an organic molten salt, has efficient flame-retardant performance. Few researchers have attempted to study its flame-retardant mechanism. Moreover, thermal stability and pyrolysis products have a great impact on the flame retardancy. Therefore, this paper focused on the phosphate ionic liquid of 1-butyl-3-methylimidazolium dibutyl phosphate ([Bmim][DBP]) and analyzed its thermal decomposition products and characteristics. The major bond energies of [Bmim][DBP] were calculated using B3LYP/6–311++G(d,p)//M06–2X/6–311++G(d,p) level. The experimental results show that the pyrolysis products were as followed: alkane or alkene with a carbon chain length of 1–4; imidazole and its derivatives; esters. Furthermore, Gas chromatography-mass spectrometer and Fourier transform infrared spectrometer were utilized to measure the gaseous products and solid phase products of [Bmim][DBP], which were obtained during thermogravimetric analysis. The results of theoretical and experimental analysis were highly consistent. Finally, the possible flame-retardant mechanism of [Bmim][DBP] was proposed.

离子液体，一种有机熔盐，具有高效的阻燃性能。很少有研究人员尝试研究其阻燃机理。此外，热稳定性和热解产物对阻燃性有很大影响。因此，本文重点研究了1-丁基-3-甲基咪唑鎓二丁基磷酸酯（[Bmim] [DBP]）的磷酸根离子液体，并分析了其热分解产物和特性。[Bmim] [DBP]的主要键能是使用B3LYP / 6–311 ++ G（d，p）// M06–2X / 6–311 ++ G（d，p）水平计算的。实验结果表明，热解产物如下：碳链长度为1-4的烷烃或烯烃；咪唑及其衍生物；酯。此外，利用气相色谱-质谱仪和傅里叶变换红外光谱仪测量在热重分析中获得的[Bmim] [DBP]的气态产物和固相产物。理论和实验分析的结果高度一致。最后，提出了[Bmim] [DBP]可能的阻燃机理。