POLYPHOSPHAZENES FUNCTIONALIZED WITH SULFONE OR SULFOXIDE GROUPS - SYNTHESIS, CHARACTERIZATION, AND POSSIBLE POLYMER ELECTROLYTE APPLICATIONS

A method for the introduction of sulfone or sulfoxide functional group s into the side groups of polyphosphazenes has been developed. This pr ocedure involves the prior introduction of thioether-containing side g roups into phosphazenes followed by oxidation of the sulfur atoms by H 2O2 or m-chloroperbenzoic acid(MCPBA). This method was first explored at the level of model small molecule cyclic species as a prelude to th e polymer oxidation reactions. The attractive forces generated by sulf one or sulfoxide functional groups produce alkyloxy-substituted polyph osphazenes with relatively high glass transition temperatures (up to 19 degrees C). The potential of these materials as polymer electrolyte s, both in the solid state and in systems with added propylene carbona te, was explored by means of impedance analysis conductivity studies. The competition between the polymer and the solvent for lithium ions w as also investigated.