Plasma Modification Of PTFE Surface And Graft Copolymerization With Polymerizable Monomers

Dielectric barrier discharge (DBD) was used to prepare the surface of polytetrafluoroethylene (PTFE) film, and then graft copolymerization was carried out on the surface. Two aspects were studied: the effect of discharge parameters on the surface structure and the properties of the PTFE film and the effect of polymerization parameters on the surface structure and properties of the plasma-treated PTFE film.The surface of plasma-treated PTFE film was investigated through the characterization methods of X-ray photoelectron spectroscopy (XPS), attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), DCA (dynamic contact angle), and scanning electron microscopy (SEM). etc. The results showed ideal surface properties of the PTFE film after the plasma treatment.The transfer of energy from plasma particles or from photons during the plasma treatment causes bond scission and the formation of radicals.The radicals undergo secondary reactions to form peroxy radicals and other functional chemical groups.The peroxy radicals can initiate graft copolymerization in certain conditions. The density of peroxy radicals governs the efficiency of the graft copolymerization process. It was calculated with DPPH method; to determin the optimal discharge parameters.Argon plasma-pretreated PTFE films were subjected to further surface modification by graft copolymerization with glycidyl methacrylate (GMA) and styrene. Graft copolymerization with GMA was 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 XPS and SEM, respectively.