Abstract
Proton conducting polymer electrolytes bearing phosphonic acid units are very promising due to their high conductivity, thermal and chemical stability. In the present work, proton conducting nanocomposite electrolytes containing poly(vinylphosphonic acid) (PVPA) and SiO
2
were prepared by two different methods. The interaction existed between PVPA and SiO
2
was confirmed by FT-IR spectroscopy. The surface roughness of the nanocomposites was studied using AFM. Thermogravimetric analysis revealed that the samples were thermally stable up to 200 °C. The glass transition temperature (Tg) of the materials were determined using DSC. In the anhydrous state, the proton conductivity of PVPA(10)SiO
2
(in situ) was found to be 0,009 (Scm
−1
) at 120 °C. The proton conductivity of PVPA(10)SiO
2
increased to 0.08 (Scm
−1
) at 50 % relative humidity. The SiO
2
nanoparticles in the composite membranes improved the thermal properties and increased the proton conductivity.