Surface free energy analysis of polymers and its relation to surface composition



The dispersion force component of surface free energy, γmath image, and the nondispersive interaction free energy between solid and water, Imath image, were determined by the two-liquid contact-angle method, i.e., by the measurement of contact angles of water drops on plain solids in hydrocarbon, for commercialy available organic polymers such as nylons, halogenated vinyl polymers, polyesters, etc. A method to estimate the Imath image values from the knowledge of the polymer composition is also proposed, on the basis of the assumption of the spherical monomer unit and the sum of interactions between functional groups and water molecules at the surface.