Surface functionalization of poly(tetrafluoroethylene) films via consecutive graft copolymerization with glycidyl methacrylate and aniline

Chemical modification of argon-plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by W-induced surface graft copolymerization with glycidyl methacrylate (GMA), followed by epoxide-ring-opening reaction with aniline (An), and finally oxidative graft polymerization with aniline had been carried out to render the PTFE surface conductive. The surface composition and microstructure of the graft-copolymerized PTFE films were studied by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The graft concentration of the GMA polymer and An polymer increased with increasing concentration of the respective monomer used for graft polymerization. Ethanol, when used as a solvent, catalyzed the coupling reaction of epoxide with An and should be of more than 40 vol % in concentration to achieve the optimum effect. The physicochemical characteristics of the polyaniline (PANI) chains grafted onto PTFE film surface were grossly similar to those of the PANI homopolymer. The surface resistance of the aniline graft-polymerized PTFE film was reduced to the order of about 10(4) Omega/square, in comparison to the value of 10(16) Omega/square for the pristine PTFE film.