One route to melt processing of high glass transition temperature polyelectrolytes, such as disulfonated poly(arylene ether sulfone) (BPS), involves mixing a plasticizer with the polymer. In this study, poly(ethylene glycol) (PEG) was used as a plasticizer for BPS. BPS and PEG are miscible, and the effect of PEG molecular weight (in the range of 200-600 g/mol) and concentration on the T-g of BPS/PEG blends was investigated. As PEG molecular weight decreases and concentration increases, the blend T-g is depressed significantly. Based on isothermal holds in a rheometer at various temperatures and times, the PEG materials considered were thermally stable up to 220 degrees C for 10 min in air or 250 degrees C for at least 10 min under a nitrogen atmosphere, which is long enough to permit melt extrusion of such materials. (C) 2013 Elsevier Ltd. All rights reserved.