Synthesis and ionic conductivity of comb-like polysiloxanes with pendant oligo(oxyethylene) side chains and quaternary ammonium groups

A series of novel comb-like polysiloxanes with oligo(oxyethylene) side chains and quaternary ammonium groups, has been synthesized by hydrosilylation of poly(methylhydrosiloxane) with poly(ethylene glycol) allyl methyl ether and N,N-dimethylallylamine, followed by quaternization with methyl iodide. The glass transition temperature of these solvent-free electrolytes was measured and found to be dependent on the content of quaternary ammonium side groups anchored to the polysiloxane backbone. The influence of quaternary ammonium group content and temperature on the ionic conductivity has been investigated. A maximum conductivity of 1.57 X 10(-5) S cm(-1) at 25 degreesC was achieved for a polysiloxane containing 30 % quaternary ammonium side groups. The temperature dependence of the ionic conductivity shows the "Vogel-Tammann-Fulcher" (VTF) behavior. The values of the VTF parameters were calculated.