Pervaporation membranes containing hyperbranched polymer were prepared from the blends of ethyl cellulose (EC) and hyperbranched polyester (HBPE). The FT-IR analysis indicated that the interactions between EC and HBPE decreased as increasing the generation of HBPE. The membrane containing HBPE (EC-HBPE) showed both higher sorption ratio and selectivity than pure EC membrane. The effects of HBPE content as well as temperature of feed solutions on the membrane performance were investigated in detail. The EC-HBPE membrane exhibited much higher permeate flux than the EC membrane, while the separation factor maintained at same level. (C) 2008 Elsevier B.V. All rights reserved.