Polymer surface reconstruction by diffusion of organic functional groups from and to the surface

Three nonpolar organic polymers containing small amounts of polar functionality were studied with regard to their surface characteristics. Two of the materials, potassium chlorate/sulfuric acid-oxidized polyethylene and poly(ethylene-co-acrylic acid) display variable surface polarities which can be reversibly accessed by heating films of the polymers in air or aqueous sodium hydroxide. Sodium-reduced Teflon–FEP did not exhibit this characteristic. A combination of contact angle, ESCA, and ATR IR data are used to display that the surface changes are caused by migration of functional groups within the outer few tens of angstroms of the surface.