Synthesis and characterization of trimeric phosphazene based ionic liquids with tetrafluoroborate anions and their thermal investigations

Abstract

The quaternized compounds (PzIL1–9) reacted with sodium tetrafluoroborate (NaBF4) to generate phosphazene based ionic liquids (PzILs), PzIL1a–9a. The newly synthesized ionic compounds (PzIL1a–9a) were verified using elemental CHN analyses and functional and spectroscopic (FTIR and 1H, 13C, 31P-NMR) analyses techniques. The thermal properties of PzIL1a–9a were investigated using thermogravimetric analysis (TGA). According to the initial decomposition temperature values calculated based on the TGA thermograms, PzIL7a (213 °C) was recognized to be more thermally stable than the other PzILs studied. PzIL1a–9a exhibited good solubility in the water and demonstrate a typical dielectric relaxation behavior, conductivity levels for both low and high-frequency regions. AC conductivity mechanisms and dielectric relaxation behavior of each sample are investigated by fabricating parallel plate capacitors.