Waterborne polyurethane/poly(vinyl alcohol) membranes: Preparation, characterization, and potential application for pervaporation

Abstract Waterborne polyurethane (PU) was prepared by the prepolymer mixing method with (3‐aminopropyl)triethoxysilane in different dosages as the modifier. Then, it was mixed with poly(vinyl alcohol) (PVA) to get waterborne PU/PVA blending membranes. The membranes showed phase separation with the aggregations of the waterborne PU particles in a continuous phase of PVA. The possible cause for the formation of such a membrane morphology is explained. The physicochemical properties of the membranes were characterized. As the PVA content increased, the membrane's swelling in water and the thermal stability decreased somehow, whereas the resistance to ethanol and the tensile strength were significantly improved. Membranes with higher alcohol resistance were chosen for the pervaporation separation of 80 wt % ethanol in water. The separation factor at 40°C reached 38.4, and the permeation flux was 128.0 g m −2 h −1 . © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012