Polyphosphazenes Functionalized with Sulfone or Sulfoxide Groups:  Synthesis, Characterization, and Possible Polymer Electrolyte Applications

Abstract

A method for the introduction of sulfone or sulfoxide functional groups into the side groups of polyphosphazenes has been developed. This procedure involves the prior introduction of thioether-containing side groups into phosphazenes followed by oxidation of the sulfur atoms by H2O2 or m-chloroperbenzoic acid (MCPBA). This method was first explored at the level of model small molecule cyclic species as a prelude to the polymer oxidation reactions. The attractive forces generated by sulfone or sulfoxide functional groups produce alkyloxy-substituted polyphosphazenes with relatively high glass transition temperatures (up to +19 °C). The potential of these materials as polymer electrolytes, both in the solid state and in systems with added propylene carbonate, was explored by means of impedance analysis conductivity studies. The competition between the polymer and the solvent for lithium ions was also investigated.

Polymers and Sulfur: what are Organic Polysulfides Good For? Preparative Strategies and Biological Applications

“…A certain degree of contradictory evidence can be found in literature on this regard: earlier reports claimed the oxidation of polysulfides to lead directly to sulfones, with sulfoxides present only as intermediates 163. On the other hand, using generally less‐drastic conditions (and, above all, reasonably low temperature154), sulfoxides have been unequivocally demonstrated to be the main oxidation product for main‐chain polymers, such as poly(ethylene sulfide),154 poly(hexamethylene sulfide)164 and polyphosphazenes,165 and for side‐chain polymers 166. Therefore, it can be assumed that, under “milder” conditions, polysulfoxides will be main product of the polysulfide oxidation.…”

The effects of cations and anions on the ionic conductivity of poly[bis(2-(2-methoxyethoxy)ethoxy)phosphazene] doped with lithium and magnesium salts of trifluoromethanesulfonate and bis(trifluoromethanesulfonyl)imidate

“…When T 0 was set at T g −30 K, the data points consistently fitted better. Setting T 0 to be 30-50 K below the T g is a common practice during curve fitting of the VTF equation and has been reported previously for polyphosphazene solid polymer electrolytes [26]. If the T 0 value was set as T g in the VTF equation, it might be assumed that the segmental motion of the polymer is the rate limiting step in ionic conduction.…”

Synthesis and ionic conductivity of mixed substituted polysiloxanes with oligoethyleneoxy and cyclic carbonate substituents

“…However, PEOLiX complexes exhibit very low ambient conductivity, typically 10 −7 S/cm. Recently, several classes of polymer electrolytes based on comb polyphosphazene [17][18][19][20][21][22][23][24][25], polysiloxane [26][27][28][29][30][31][32][33][34][35] and borane containing polyethers [36] were found to exhibit higher ambient ionic conductivity. These results demonstrated that apWe dedicate this paper to Professor Dick Jones, polysilane pioneer and valued friend.…”