Polyalkylphosphazenes as solid proton conducting electrolytes

Proton conductivity of poly(dialkyl)phosphazenes–phosphoric acid composites at low humidity

“…The two copolymers fit the thermal stability and solubility requirements which were necessary for our scope, as they allowed to cast membranes from solutions with phosphoric acid and perform conductivity measurements at relatively high temperature. Phosphoric acid was added to enhance conductivity in dry environment as reported in the above cited previous investigations [11][12][13][14][15][16][17]22,23]. The comparison of the results obtained in this work with those previously reported on poydipropylphosphazene composites [22,23] have allowed us to draw some conclusions on the potential of poly(dialkyl)phosphazenes and other N containing polymers to perform in SPEs.…”

“…Electrical conductivity was measured by impedance spectroscopy using a 1260 Solartron Frequency Response Analyser. The measurements were performed at 11 ± 3% relative humidity (RH) and in dry environment by placing saturated aqueous solutions of LiCl [25] or a P 2 O 5 layer on the bottom of the conductivity cell and [22].…”

“…Also, our literature survey reported above indicated that a high molecular weight phosphazene was not strictly necessary for designing a proton conducting electrolyte to perform in dry conditions. Under these circumstances, our preliminary investigation was started with poly(dipropyl)phosphazenes (PDPrP) [22,23]. The results showed that protonated polydipropylphosphazenium di-H phosphate (PDPrPA) containing 1 mol of phosphoric acid (PA) per polymer repeating unit,…”

“…It was therefore necessary to make composite material with another component assuring good mechanical properties. So far we have reported data on two composite electrolytes made with polyphenylenesulfide (PPS-PDPrPA) with 1:1 N/PA mole ratio [22] and with sulfonated poly[(hydroxy)propyl, phenyl]ether (SPHPE-PDPrP-PA) with 0.16:1:1.7 SO 3 H/N/PA mole ratios [23]. In these composites both polyphenylenesulfide (PPS) and sulfonated poly[(hydroxy)propyl, phenyl]ether (SPHPE) contribute mechanical strength, but the latter has also strong -SO 3 H proton donor groups.…”

Progress in Synthesis of Polyphosphazenes

“…Advanced commercial applications of polyphosphazenes range from membranes to solid polymer electrolytes, from biomedical to optical-electro functional materials, from special elastomers to flame retardants, from liquid crystal materials to polymer conductors, etc. [1,2,4,[24][25][26].…”