LAUSR

Abstract Proton conductivity, structural and morphological characteristics of new polymer containing composite membranes based on CsH 2 PO 4 and ultra-dispersed polytetrafluoroethylene (UPTFE) have been investigated. Optimization of the preparation method of membranes was carried out. The CsH 2 PO 4 (P2 1 /m) phase was shown to persist in the UPTFE polymer matrix in a whole range of compositions. The proton conductivity of (1 − x)CsH 2 PO 4  − xUPTFE (x = 0.035–0.3 x-weight fraction) electrolytes with various composition was studied as a function of temperature and partial pressure of water vapor. The conductivity values were close to the pure CsH 2 PO 4 at x  2 PO 4 in polymer matrix were calculated and microstructure of electrolytes was studied.