A liner is the product of reaction of (a) a hydrophilic prepolymer bearing isocyanate groups; and (b) a water-borne polymer dispersion, the polymer bearing groups that are reactive to isocyanate groups; wherein the dispersion has a sufficiently high solids content, and the polymer has a sufficiently high modulus and glass transition or crystalline melting temperature, that the product of reaction exhibits a 24-hour Tensile Strength of at least about 2.5 MPa.