Azole substituted polyphosphazenes as nonhumidified proton conducting membranes

Abstract

Novel nonhumidified proton conducting membranes have been prepared from the reactions of triazole (Tri) and aminotriazole (Atri) compounds with poly[(4-methylphenoxy)chlorophosphazene] (PMPCP). The composition of the novel polymers (TriP and AtriP) was verified by elemental analysis (EA) and the structure was characterized by FT-IR, 1 H and 31 P NMR. Size exclusion chromatography was used to confirm the polymer formation. Thermogravimetric analysis (TGA) showed that the samples are thermally stable up to approximately 150 C. Differential scanning calorimetry (DSC) results illustrated the homogeneity of the materials. To obtain sufficient proton conductivity at high temperatures in the anhydrous state, the polymers were doped with trifluoromethanesulfonic acid (TA) at various molar ratios, x ¼ 0.5, 1, 2 and 3 with respect to the azole unit. The proton conductivity of the polymer electrolytes was measured using high resolution dielectric-impedance analyzer. The proton conductivity of these materials increased with dopant concentration and temperature. Maximum proton conductivity of TriP2TA and AtriP2TA were obtained as 3 Â 10 À3 S cm À1 at 50 C and 0.0412 S cm À1 at 130 C respectively, in the anhydrous state.

Research Progress in Energy Based on Polyphosphazene Materials in the Past Ten Years

“…Bozkurt and colleagues synthesized a series of triazole-containing polyphosphazene PEMs [ 101 ]. They first substituted 4–methylphenoxy with one chlorine atom on the side chain to obtain poly(4–methylphenoxy)–chlorophosphazene (PMPCP).…”

Inorganic and organometallic polymers

“…59 A novel proton-conducting polyphosphazene 15 for use in PEM fuel cells was recently discovered with conductivities as high as 0.04 S cm À1 noted at 130 1C under anhydrous conditions. 60 Polyphosphazenes with para-substituted phenoxy groups [(4-RC 6 H 4 O) 2 PQN] n (R = Me, i Pr and t Bu) were prepared and their permeability to O 2 , N 2 , CO 2 and CH 4 were tested; when smaller alkyl groups were present, high gas permeabilities were observed, however selectivity (and gas separation abilities) improved with the most hindered tert-butylated polyphosphazene [(4-tBu-C 6 H 4 O) 2 PQN] n . 61…”

A novel polyphosphazene with nitroxide radical side groups as cathode‐active material in Li‐ion batteries

“…Furthermore, nucleophilic replacement reactions of alkoxides, aryloxides, amines, or various organic/organometallic substituents with chlorine atoms of polyphosphazenes can be used for obtaining new polyphosphazene derivatives . Thus, with the minor changes in the substituents, diverse properties can be achieved for specific applications such as low‐temperature elastomers, proton‐conductive materials for fuel cells, solid or gel polymer lithium‐ion conductors, and polymer electrolyte membranes for rechargeable LIBs …”