New Advances in Perfluoroalkoxyl Co- and Terpolymers with Tetrafluoroethylene

Tetrafluoroethylene (TFE) is a well-known and widely used monomer in the fluoropolymer industry. Unfortunately, both the lack of availability and safety concerns with this monomer have restricted its use in academia. Through the use of expired patent technologies from 3M and DuPont, TFE has been safety prepared and used on a kilogram scale with the aid of a new barricade facility at Clemson University. Thus beginning in 2012, a program was undertaken with the goal of preparing and characterizing new perfluoroalkoxy (PFA) resins with potentially increased mechanical strength and wearability. Benchmark PFA copolymers were first prepared by both solution and emulsion polymerization techniques so that a comparison of new co- and terpolymers with commercial grade materials would be feasible. The first aim was the synthesis of aliphatic and olefinic trifluorovinyl-terminal olefins and their terpolymerization with tetrafluoroethylene and perfluoroalkyl trifluorovinyl ethers, the polymers from which could then be subjected to electron beam irradiation for crosslinking as a mean of increasing molecular weight and thus mechanical resistance. In addition, the novel synthesis of a pentafluorosulfanyl-(SF5)-substituted perfluoroalkyl trifluorovinyl ether monomer and its subsequent copolymerization with tetrafluoroethylene to afford the first pentafluorosulfanyl-containing PFA was accomplished. The surface properties of this unique PFA are still under investigation. The synthesis of multifunctional sulfonamide vinyl ether monomers and their subsequent copolymerization with tetrafluoroethylene were also carried out for the development of low equivalent weight (EW) binders for fuel cell applications