PARTIALLY SULFONATED POLY(ARYLENE ETHER SULFONE) - A VERSATILE PROTONCONDUCTING MEMBRANE MATERIAL FOR MODERN ENERGY-CONVERSION TECHNOLOGIES

Sulfonated poly(arylene ether sulfones) with various sulfonation level s have been prepared and evaluated as solid polymer electrolytes in el ectrolysers and fuel cells. Solution and slurry sulfonation of poly(ar ylene ether sulfones) such as Udel(R) P-1700 (PSU) and Victrex(R) PES 5200P (PES) yield polyelectrolytes which have been characterized using FTIR and H-1-NMR spectroscopy, titration, thermal analysis, and elect rochemical characterization such as resistivity, selectivity of ion pe rmeation, current/voltage plot and life time test in an electrolysis c ell. In contrast to the sulfonated PSU, the PES sulfonated in a slurry process was water insoluble, even at high sulfonation levels of 90 mo l%, and gave significantly improved electrochemical properties similar to those of fluorine-containing polyelectrolytes used in commercial m embrane systems. A versatile in-situ crosslinking technique has been d eveloped to crosslink the sulfonated poly(arylene ether sulfone) elect rolytes during membrane processing in order to substantially reduce wa ter swelling without impairing other membrane properties such as proto n conductivity.