Phosphoric acid doped poly(2,5‐benzimidazole)‐based proton exchange membrane for high temperature fuel cell application

Abstract

Undoped and doped poly(2,5‐benzimidazole) (ABPBI) membrane was prepared by solvent casting method using methane sulfonic acid as a solvent and phosphoric acid (H3PO4) as a doping agent. The concentration of H3PO4 was varied from 0 to 60 vol% to enhance the proton conductivity of the ABPBI membrane at higher temperature. Wide angle X‐ray diffraction analysis showed a decrease in crystallinity in ABPBI membrane with increase in H3PO4 doping concentration. The molecular signature and the presence of H3PO4 was observed in 1000–1500 cm−1 in the Fourier transform infrared spectra, which was also supported by a corresponding weight loss at 180°C–200°C in the thermogravimetric analysis. Undoped ABPBI membrane registered the Young's modulus (E) and hardness (H) values of 2.46 and 0.92 GPa, respectively, and the corresponding E and H values for 1.65 doping level of 60 vol% H3PO4 doped ABPBI membrane were 0.14 and 0.067 GPa, respectively. The 60 vol% H3PO4 doped ABPBI membrane with doping level of 1.65 showed highest proton conductivity value of 2.2 × 10−2 S/cm. The impedance spectroscopic analysis and the equivalent circuit model were discussed to understand the nature of proton conduction in H3PO4 doped ABPBI membrane. POLYM. ENG. SCI., 56:1366–1374, 2016. © 2016 Society of Plastics Engineers

Approaching Highly Leaching-Resistant Fire-Retardant Wood by In Situ Polymerization with Melamine Formaldehyde Resin

“… 8 Simultaneously, the phosphate segment in GUP undergoes dehydration with formation of a pyrophosphate bond. 54 The pyrophosphate will further condense as polyphosphate, with the polyphosphate acting as protective glassy layers preventing further degradation of the wood. The thermal degradation of BA occurs instantaneously at 180 °C.…”

“…The nitrogen-rich guanyl-urea segment in GUP releases low-combustible or incombustible gases, such as NH 3 and CO 2 . Simultaneously, the phosphate segment in GUP undergoes dehydration with formation of a pyrophosphate bond . The pyrophosphate will further condense as polyphosphate, with the polyphosphate acting as protective glassy layers preventing further degradation of the wood.…”

Investigation on carbon nanotube oxide for anhydrous proton exchange membranes application

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High Cyclability Energy Storage Device with Optimized Hydroxyethyl Cellulose-Dextran-Based Polymer Electrolytes: Structural, Electrical and Electrochemical Investigations

“…A study by Shukur et al [ 19 , 20 ] has revealed that the ionic conductivity value increased when chitosan is incorporated into a starch–ammonium bromide electrolyte from (5.57 ± 1.88) × 10 −5 to (9.72 ± 0.95) × 10 −5 S cm −1 . Phosphoric acid [ 21 ] and sulfuric acid [ 22 ] are proton donors but suffer from chemical degradation and deteriorate mechanical integrity, making them less suitable for practical applications [ 23 ]. Thus, ammonium salts are regularly reported as proton donors.…”