Ultraviolet light assisted fluorination of polymer surfaces

The process for fluorinating a polymer to form a fluorinated polymer surface which comprises generating an ultraviolet light having a wave length of less than 400 nm and less than the absorption limit of the polymer in a first zone, contacting the surface of said polymer with a fluorinated gaseous species selected from the group consisting of fluorine, tetrafluoromethane, hydrogen fluoride, hexafluoroethane, sulfur hexafluoride, difluoromethane, trifluoromethane and mixtures thereof and a diluent gas in a second reactor zone, exposing said polymer to said ultraviolet light from said first zone under conditions to effect fluorination of the surface of said polymer at a temperature below the melting point of said polymer.