Proton transfer reactions under anhydrous conditions have attracted remarkable interest due to chemical energy conversions in polymer electrolyte membrane fuel cells. In this work, 1H-1,2,4-triazole (Tri) was used as a proton solvent in different polymer host matrices such as Poly(vinylphosphonic acid) (PVPA), and poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS). PVPATri x and PAMPSTri x electrolytes were investigated where x is the molar ratio of Tri to corresponding polymer repeat unit. The interaction between polymer and Tri was studied via FTIR spectroscopy. Thermogravimetry analysis and differential scanning calorimetry were employed to examine the thermal stability and homogeneity of the materials, respectively. PVPATri 1.5 showed a maximum water-free proton conductivity of 2.3 Â 10 À3 S/cm at 120 8C and that of PAMP-STri 2 was 9.3 Â 10 À4 S/cm at 140 8C. The results were interpreted in terms of different acidic functional groups and composition.

BACKGROUND: High proton conduction through anhydrous polymer electrolyte membranes is crucial for the application to chemical energy conversion devices such as fuel cells. In this context, novel proton conductors were produced by doping poly(styrene sulfonic acid) (PSSA) with 1H-1,2,4-triazole (Tri) and 1.12-diimidazol-2yl-2,5,8,11-tetraoxadodecane (imi3), and their physicochemical properties were investigated. RESULTS: Different polymer electrolyte membranes were produced by doping of PSSA with Tri and imi3. PSSATri x and PSSAimi3 x electrolytes were obtained where x is the doping ratio describing moles of Tri or imi3 per mole of -SO 3 H unit. The membranes demonstrated adequate thermal stability at least up to 200 • C and the dopants acted as plasticizers shifting the T g values to lower temperatures. PSSATri 1 has a maximum proton conductivity of 0.016 S cm −1 at 150 • C and the proton conductivity of PSSAimi3 0.5 is approximately 10 −4 S cm −1 at room temperature.CONCLUSIONS: Transparent, homogeneous and freestanding films of PSSATri x and PSSAimi3 x were produced. It was demonstrated that both Tri and imi3 are efficient proton solvents in PSSA host matrix, and they yielded promising defect-type conductivities compared to benzimidazole. Tri-doped membranes clearly showed better conductivity performance at higher temperatures (T > 100 • C). Both PSSATri x and PSSAimi3 x polymer electrolytes can be suggested for fuel cell applications.

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