The oxidative fragmentation of Polyethyleneglycol by ozone is investigated by means of batch and semibatch ozonation experiments in the pH range 4.0-9.0. Chemical mechanisms and reaction kinetics of the ozonation processes are determined by also exploiting chemical information from experiments on Diethyleneglycol and Ethyleneglycol ozonation. A kinetic model is proposed capable of describing the fragmentation process due to the direct polymer oxidation by ozone. Copyright (C) 1996 Elsevier Science Ltd