Sulfonated polytriazoles from a new fluorinated diazide monomer and investigation of their proton exchange properties

Hexafluoroisopropylidene based sulfonated new copolytriazoles: investigation of proton exchange membrane properties

“…The PTFOSXX copolymers were synthesized by the same procedure as described in the earlier reports as shown in the Scheme 2 (35)(36)(37) cooling to room temperature, the polymer solution was pre cipitated out in 250 ml isopropanol. The resulting fibrous polymers were washed with 20% aqueous ammonia solu tion and deionized water, and dried at 100°C for overnight under vacuum.…”

“…The experimental IEC w values of the acidified membranes were also determined by both titri metric and 1 HNMR analysis. The volumetric ion exchange capacities (IEC v ) of the membranes in dry and wet states were obtained by multiplying the density of the membrane with the IEC w , and by considering the water uptake of the membranes, respectively (35,36). The water uptake and dimensional change of the samples were measured accord ing to a previously reported method (35,36).…”

“…The volumetric ion exchange capacities (IEC v ) of the membranes in dry and wet states were obtained by multiplying the density of the membrane with the IEC w , and by considering the water uptake of the membranes, respectively (35,36). The water uptake and dimensional change of the samples were measured accord ing to a previously reported method (35,36). The proton conductivity of all membranes (10 mm × 20 mm) in the plane direction was determined by a fourprobe conduc tivity cell attached to the electrochemical impedance spec troscopy in the frequency range 100 Hz to 1 MHz, using a GAMRY reference 3000 TM instrument.…”

“…Chang and coworkers prepared sulfonated polytriazoles for PEM application, which showed high proton conductivity (107 mS cm − 1 ) (33). Our group has also prepared several fluorinated sulfonated polytriazoles and their PEM properties have been investigated (35)(36)(37). In the present work, we have increased the IEC w values of the polymers by designing the new polytriazole copolymers with smaller repeat unit structures.…”

“…Therefore, many efforts have been made in order to replace these materials. Several hydro carbon basedsulfonated aromatic PEM materials, such as sulfonated poly(arylene ether sulfone)s (9)(10)(11)(12)(13)(14)(15), sulfonated poly(arylene ether ketone)s (16)(17)(18)(19), sulfonated polyimides (20)(21)(22)(23)(24)(25), sulfonated poly(benzimidazole)s (26)(27)(28), sul fonated polybenzothiazoles (29)(30)(31) and sulfonated poly triazoles (32)(33)(34)(35)(36)(37), have been developed in the recent years. It is well known, that the hydrocarbonbased sulfonated aromatic copolymers display lower proton conductivity in comparison to the perfluoro sulfonated polymers, due to poor phase separation between the hydrophilic and hydrophobic domains and the weak acidic nature of SO 3 H group (38).…”