Hydroxyl-terminated polybutadiene (HTPB), 4,4 '-dicyclohexyl methane diiscyanate (H12MDI), and 1,4-butane diol are used to synthesize polyurethane (PU) solutions by two-stage process. Interpenetrating networks (IPNs) of HTPB-based PU and poly(methyl methacrylate) (PMMA) with HTPB/MMA (wt/wt % ratio) = 2.0, 1.5, 1.0, 1.5, 0.8, and 0.6, whicli are designated as IPN1 to IPN5, respectively, are synthesized by sequential polymerization technique. Thermal properties, tensile strength, and contact angle of membranes increase with the increase of MMA content, while the elongation of membranes show the reverse trend. Characterization of membranes are investigated by C=C/C=O absorption ratio and infrared absorption frequency shiftment. These PU and IPN membranes are used for the separation of ethanol/water and isopropanol/water solution by pervaporation test. IPN3 membrane possesses the largest pervaporation permeability and the separation factor. The pervaporation results of ethanol/ water feed has the same trend as that of isopropyl alcohol (IPA)/water solution. (C) 2007 Wiley Periodicals, Inc. J Appl Polym Sci 106: 4277-4286, 2007