AbstractThe ability of corona treatment to render polyethylene film self‐adherent has been previously reported and the mechanism explained. A similar effect has now been found with corona‐treated poly(ethylene terephthalate) film which adheres strongly to itself when joined under conditions of heat and pressure that give no adhesion with untreated film. Poly(ethylene terephthalate) films irradiated with short‐wave UV light also become self‐adherent. The behavior of the adhesive joints in both cases is the same as that reported for corona‐treated polythylene film in that the joint strength is zero in the presence of hydrogen‐bonding liquids, but recovers completely if the joint is allowed to dry undisturbed. Chemical and physical tests have shown that the adhesive bond is a hydrogen bond between the hydrogens of phenol groups created by corona or UV irradiation in one surface with carboxyl carbonyl groups in the other surface. Thin‐layer chromatography of surface extracts from corona‐ and UV‐treated films has shown the products of treatment to be practically identical for both types of treatment, supporting the conclusion that the mechanism of corona treatment resembles that of greatly accelerate
展开▼
