High‐Performance Poly(biphenyl acetylpyridine) and Poly(ether ketone cardo) Blend Membranes for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

Abstract

Developing high‐temperature polymer electrolyte membranes with sufficient performance and competitive cost is a major scientific checkpoint for promoting the popularization of fuel cells. Herein, poly(biphenyl acetylpyridine) (PBAP) is synthesized by a facile one‐pot Friedel‐Crafts polymerization between 4‐acetylpyridine and biphenyl. The PBAP has excellent solubility in polar solvents, while its membrane shows a significantly high phosphoric acid (PA) absorption capacity due to the presence of amounts of pyridine groups. However, the pure PBAP membrane is dissolved in 85 wt.% PA solution. In order to solve excessive expansion and poor mechanical stability, a series of PBAP blend membranes are fabricated by mixing PBAP with commercial engineering thermoplastic of poly(ether ketone cardo) (PEKC). Blending PEKC significantly improves the dimensional and mechanical stabilities. In particular, blend membranes exhibit remarkable chemical stability as documented by Fenton test, while membranes after Fenton test display slightly higher acid uptakes and conductivities. As a result, the PBAP‐50wt.%PEKC/170%PA membrane shows a conductivity of 0.051 S cm−1 at 160 °C and mechanical strength of 8.3 MPa at 25 °C. The peak power density at 160 °C of the H2‐O2 single cell with above membrane is 632 mW cm−2, indicating the potential of PBAP‐x%PEKC/PA membranes for fuel cells.

Side Chain Crosslinked Anion Exchange Membrane for Acid Concentration by Electrodialysis

“…The poly(alkyl-biphenylpyridine) (PAB) was synthesized via polyhydroxy alkylation. , Initially, biphenyl (7.71 g) was dissolved in dichloromethane (12.5 mL). Then, 4-acetylpyridine (7.87 g) was added and thoroughly stirred.…”

The effect of grafted alkyl side chains on the properties of poly(terphenyl piperidinium) based high temperature proton exchange membranes

“…The PA absorption of various films was determined by immersing the dry films in 85 wt% PA solution at 60 °C for 72 h for the sake of measuring the amount of doped acid and swelling, as described previously. 25,26 After gently wiping PA off the surface of the membranes, the membranes were placed in a vacuum oven at 100 °C to remove free water, and then immediately weighed. The PA absorption capability of the membrane was expressed as the acid doping level (ADL), which is defined as the number of adsorbed PA molecules per polymer repeat unit as depicted in eqn (1).…”

“…For example, aromatic polymer materials containing pyridine 16 and quinolone 17 have been synthesized, and pyrrolidone 18,19 and imine 20,21 containing polyolefins have been selected as HT-PEMs as well. Recently, inspired by the synthesis of wholly aromatic polymers by Zolotukhin et al 22 and Tröger base (TB) containing polymers by McKeown et al, 23 we successfully synthesized ether free polymers containing pendant pyridine 24,25 and a TB (i.e., 1,5-methano-1,5diazocine) 26 unit through one-step superacid catalyzed polymerization. Both the above membranes displayed considerable organic solubility, excellent chemical stability and remarkable PA doping capability, resulting in high fuel cell performance.…”

Scalable and interfacial gap‐free mixed matrix membranes for efficient anion separation

“…The ionic polymer HPABP was prepared by the superacid-catalyzed polymerization of 4-acetylpyridine and biphenyl, as reported in the previous literatures (Figure S2). 32,33 For the synthesis of CC3 crystals, 2 g TFB in 40 mL DCM and 2 g CHDA in 40 mL DCM reacted for 4 days at room temperature. TFA was used as a catalyst in the reaction.…”