Ionic associations in the poly (ethylene glycol)-NaSCN system are studied by means of the salt concentration dependence of the ionic conductivity. The discussion is;additionally supported by the DSC and rheological experiments showing the change of the electrolyte flexibility as a function of the salt concentration. Based on the Fuoss-Kraus formalism, the ion pairs and ion triplets formation constants are calculated and used for calculation of the fraction of free ions, ion pairs and higher aggregates present in the system studied at room temperature. (C) 2000 Elsevier Science Ltd. All rights reserved.