Novel Proton-Conducting Polyelectrolyte Composed of an Aromatic Polyether Containing Main-Chain Pyridine Units for Fuel Cell Applications

Abstract

A new high-molecular-weight, soluble, wholly aromatic polyether bearing polar pyridine and phosphinoxide groups along the main chain is presented. This easily processable polyether presents excellent film-forming properties, high glass-transition temperature (up to 260 °C), and thermal stability up to 500 °C, all together combined with an ability to form ionically conductive materials after doping with phosphoric acid. The polar groups throughout the polymeric chains enable high acid uptake and subsequent high ionic conductivity for the doped membranes in the range of 10 -2 S/cm. Characterization of all polymeric materials prepared was performed using NMR, size exclusion chromatography, thermal and mechanical analysis, and conductivity measurements. The oxidative stability of the materials was studied using hydrogen peroxide, and the treated membranes were further characterized using dynamic mechanical analysis and FT-Raman spectroscopy. The conductivity of the doped membranes was determined as a function of the doping level. The temperature dependence of the conductivity was also studied.

New High Temperature Polymer Electrolyte Membranes. Influence of the Chemical Structure on their Properties

“…2,5-Bis(4-hydroxy-phenyl) pyridine, bis(4-fluorophenyl) phenylphosphinoxide and bis(4-hydroxyphenyl) phenylphosphine oxide were prepared according to literature procedures [13,16,17]. Tetrahydrofuran (THF) was distilled from sodium in the presence of benzophenone prior to use.…”

“…Another approach is the use of aromatic polyethers containing polar groups in the main chain which are also able to absorb strong acids and at the same time keep their mechanical and oxidative stability [13][14][15]. The synthesis of soluble high molecular weight polymers is a key issue [6,13]; however this type of rigid polymers presents inherent insolubility problems due to their structural characteristics.…”

“…The synthesis of soluble high molecular weight polymers is a key issue [6,13]; however this type of rigid polymers presents inherent insolubility problems due to their structural characteristics.…”

Composite polymer electrolytes of sulfonated poly-ether-ether-ketone (SPEEK) with organically functionalized TiO2

“…Low cost and ready availability are important economical requirements. Furthermore, the membrane should work at an operative temperature around 120 • C for long time [1][2][3]. Although there is much interest in the development of an "ideal" membrane, there is nowadays no material that can completely satisfy the required performances [4].…”

Nitrophenoxy groups containing polybenzimidazoles as polymer electrolytes for fuel cells: Synthesis and characterization

“…32 Crosslinking 33 is reported to enhance the oxidative stability of PBI. Experimentally, oxidative stability of PBI membrane is evaluated by Fenton test.…”