in accordance with the present invention novel polyurethane psas containing water soluble polymer additives have enhanced water uptake . the water soluble polymer additives suitable for use herein have a solubility parameter in poorly hydrogen - binding solvents in the range of from 8 - 10 . the water soluble polymers must also be free from moieties which will react with isocyanates . such psas retain their transparency and peel strength characteristics and can still be employed as relatively thin films while exhibiting only minimal swelling when in contact with moist environments .