Hydroxy-terminated polybutadiene-based porous and nonporous polyurethaneurea membranes were prepared and used to study the phenol separation efficiency from dilute aqueous solution. The porosity was developed by incorporation of lithium chloride in polymer matrix with subsequent leaching of the same in hot water. The porous membrane showed higher phenol flux over that of nonporous membrane. Permeate containing about 97 wt % phenol was obtained from feed containing 7 wt % phenol, when pervaporation was carried out with porous polyurethaneurea membrane at 75 degrees C. The activation energies for diffusion, permeation, and pervaporation were calculated from Arrhenius plots. From the activation energy values, it was observed that the pervaporation process became easier with increased phenol concentration in the feed and porosity of the membrane used. The membrane boundary resistance was observed to decrease with increase in temperature. (c) 2006 Wiley Periodicals, Inc.