Polyurethane anionomers based on phenolphthalins have been characterized by differential scanning calorimetry, swelling, and mechanical studies. DSC study shows that introduction of ionic groups into the polymer chain lowers the T-g of the polyurethane. Swelling studies reveal that water uptake is high for ionomers. From the tensile data we observe that Zn+2 neutralized ionomers showed enhanced properties.