Two Acid sites PEG thermoregulated ionic liquid was prepared and used as the catalyst for the esterification of aromatic acid and alcohol.The yield of esterification catalyzed by ionic liquid was 99% in 1 h at 80 ℃ with 0.1%(molar fraction)acidic PEG ionic liquid.The catalyst system could be applied to a wide range of esterification of aromatic acids and alcohols.The ionic liquid has the advantages of both homogeneous and heterogeneous phase at different temperature with a high product yield and the ease of product as well as catalyst separation.The ionic liquid studied plays the role of catalyst and is recycled up to seven times without any significant loss of activity.Morover,by simple phase separation the ionic liquid phase could be re-utilized up to seven times without leaching.
