Preparation and characterization of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquids

The alkyl imidazolium-based ionic liquids,Br was synthesized from N-methylimidazole and C4H9Br.Reacting with C2H5ONa and HBF4 at room temperature,Br was converted into BF4.The results showed that the reaction temperature 80 ℃,reaction time 24 h,the yield of intermediate was 83.7%,then the yield of BF4 ionic liquid is about 98.6%.The DSC indicated ionic liquids synthesized have lower melting points.