Esterification of furfuryl alcohol to butyl levulinate over ion-exchange resins

The esterification of furfuryl alcohol with 1-butanol was successfully tested at low initial butanol/furfuryl alcohol molar ratio values (4 and 8) in the temperature range 80-110 degrees C over different ion-exchange resins. The polymerization reaction of furfuryl alcohol also occurs, being more affected by the initial 1-butanol to furfuryl alcohol molar ratio than temperature under the conditions tested. The accessibility to acid centers conditioned the activity of ion-exchange resins. While for gel-type resins this can be related to the specific volume of the swollen polymer, for macroreticular resins there is a compromise between permanent porosity (for stiff resins) and the existence of a very flexible gel-phase zone for low crosslinked macroreticular resins. The maximum yield to butyl levulinate obtained was 63% at 110 degrees C and a molar butanol/furfuryl alcohol ratio of 8 on the macroreticular resin Amberlyst 39.