NOVEL FLUOROALKYLATION OF POLYESTER SURFACES - GRAFTING WITH PERFLUOROALKANOYL PEROXIDES

Perfluoroalkanoyl peroxides such as (C3F7COO)2 have been found to reac t with polyester film only on the surface. The modified polyester surf aces were characterized by contact angle measurements using a two-liqu id phase system and by ESCA spectroscopy. These provided surface free energy values and surface atom content values as a function of reactio n time. Perfluoroalkyl groups substituted on the aromatic rings of the polyester surface influenced both the dispersive component gamma(Sd) of surface free energy and the polar one gamma(Sp). The surface free e nergies decreased with the reaction time and reached a plateau at abou t 1 hour. There was a large decrease in gamma(Sd). Based on the ESCA c haracterization, the area ratio of the F1s peak to the O1s peak was li nearly correlated not only to gamma(Sd) but also to gamma(Sp).