采用XPS与接触角法研究氟聚合物表面结构与性能

本文采用接触角和变角XPS方法对FA共聚物的表面能、 表面微相结构做了进一步的研究.

Surface Structure and Properties of Fluorocopolymers Studied by XPS and Contact Angle

The surface composition and properties of the copolymer miniemulsions containing fluorinated acrylate(FA) were investigated by X-ray photoelectron spectroscopy(XPS) and contact angle measurements.The surface energy of these copolymers was calculated by the harmonic equation from the static contact angles.The surfaces of the copolymers are very hydrophobic even with a low content of FA due to the surface enrichment of FA segments.The surface energy of copolymers decreases drastically with the increase of FA content and can reach 11.6 mN/m when the concentration of FA in copolymerization increases to 17.54%.The element composition and surface segregation of the fluorinated component as a function of depth of fluorocopolymer thick films were investigated by angle-dependent XPS.The content of fluorine on the surface of copolymers was higher than the calculated value according to the feeds.Our analyses demonstrate that the side groups containing fluorine tend to enrich on the copolymer-air interface.The surface segregation is enhanced when the samples are annealed,which results in further decrease of surface energy.