Improvement in the separation efficiency of transesterification reaction compounds by the use of supported ionic liquid membranes based on the dicyanamide anion

Abstract

Previously we reported on the selective simultaneous separation of the substrates and products of a transesterification reaction (vinyl butyrate, 1-butanol, butyl butyrate and butyric acid) through supported liquid membranes (SLMs) based on 1-n-alkyl-3-methylimidazolium cations combined with tetrafluoroborate, hexafluorophosphate and bis{(trifluoromethyl)sulfonyl}imide anions. On the base of these previous results, new membranes based on the dicyanamide anion have been developed and tested for the selective simultaneous separation of the target compounds. It was concluded that both the permeability of the compounds and the permselectivity of the membrane were enhanced with the use of dicyanamide based ionic liquids. The operational stability of the SLMs was also studied. They were seen to be remarkably stable when tested over four continuous cycles of 48 h each.