Synthesis of novel engineering polymers containing basic side groups and their application in acid-base polymer blend membranes

摘要

New modified PSU Udel containing N-basic side groups like pyridine and dimethylamino groups have been developed. The modified PSU was synthesized via (i) lithiation of PSU ortho to the sulfone bridge and (ii) reaction of the lithiated PSU with aromatic ketones like 2,2'-bipyridylketone, 4,4'-dimethylarninobenzophenone, aromatic aldehydes like 2-, 3-, and 4-pyridinealdehyde, and 4-N,N-diethylaminobe~ldehyde, and aromatic carboxylic acid esters like isonicotinic acid ethyl ester and 4-N,N-dimethylaminobenzoic acid ethyl ester. The basic PSU polymers were characterized via NMR, elemental analysis, and thermogravimetry (TGA). Select~d basic polymers were mixed with poly(etheretherketone) (PEEK) sulfonic acid to yield polymeric acid-base blends. The obtained blend mem- branes were characterized in terms of ionic conductivity by impedance spectroscopy, in terms of morphology by transmission electron microscopy (TEM), and in terms of thermal stability by TGA. The jlcid-base blends show good ionic conductivities at ion-exchange capacities of+-1 meq/g, and good thermal stabilities. The :TEM investigations yielded the result that the acid-base-blends are rniscible-no polymer-microphase separation could be observed.