The method of synthesis of functionalized oligoethyleneoxides containing sulfonic, amino, hydroxyl groups and also terminal amino and epoxy groups are developed. The methods of synthesis of oligomeric precursors on the basis of them which contain abovementioned functional groups and are able of sol-gel transformations are developed.
The methods of synthesis of sulfur containing monomeric and α,ω-oligomeric precursors by interaction of 4-aminobenzenesulfonic acid and 3-isocianatopropyltriethoxysilane and by reaction of isocyanate prepolymer on basis of oligooxyethyleneglycol and tolylenediisocyanate with 3-aminopropyltriethoxysilane are developed.
The organic-inorganic proton exchange membranes containing sulfonic groups covalently attached to the host were obtained via joint condensation of two types of alkoxysilane precursors. The opportunity of membranes properties adjustment by variation of the precursors ratio has been shown. The values of ionic conductivity of obtained materials are 10-6-10-3S/cm at 60-100oC in dry nitrogen atmosphere. The proton transfer in these systems is caused by segmental motion of olygooxyethylene chains (Grotthuss mechanism). Membranes wetting causes protonic conduction increasing by 2-3 orders of magnitude.
The membranes with optimal properties were tested in electrochemical cell prototype which was developed at technical electrochemistry department of Ukrainian state chemical-technological university (Dnepropetrovsk). According to the test results the proton conductivities are (1-2)•10-2 S/cm which are two times higher of that shown at test device by membranes of Nafion type which are commonly used for creation of polymer-electrolyte fuel cells.
Keywords: Synthesis, protonconducting solid polymeric membranes, fuel cells, functionalized oligoethers, sol-gel method, organic-inorganic nanostructured composites, thermal stability, proton conductivity.