PLASMA POLYMERIZATION OF SULFONATED FLUOROCHLOROCARBON IONOMER FILMS

Sulfonated fluorochlorocarbon ionomer films were prepared by radio fre quency plasma polymerization of trifluorochloroethylene (TFCE) and tri fluoromethane sulfonic acid (TFMSA). The TFMSA was introduced into the plasma chamber by bubbling a carrier gas through a vessel containing the neat acid. We show that the sulfonate content of the film prepared can be controlled by varying the temperature of the TFMSA-containing vessel. We also show that films with high sulfonate contents can be pr epared by using TFCE as the carrier gas for the TFMSA and then allowin g this gas mixture to sustain the plasma. This may be contrasted to pr evious experiments of this type, where Ar was used to sustain the plas ma and as the carrier gas. To our knowledge, this approach (i.e., of u sing the reactant gases to support the plasma) has never been used in the synthesis of plasma-polymerized films. Finally, we have measured t he ionic conductivities of the plasma-polymerized films. The films pre pared from the TFCE plasma are an order of magnitude more conductive t han the films prepared from the Ar plasma.