The synthesis and characterization of poly (itaconic acid) (PIA) with a novel initiator/activator system is presented. The initiator in this system was potassium persulfate, whereas the activator was N,N-dimethylethanolamine (DMEA). PIA was synthesized indistilled water and in 0.1M HCl at 40 degrees C with reaction times of 72 and 96 h. PIA was investigated with differential scanning calorimetry, gel permeation chromatography, and pulse gradient spin echo-NMR and compared to the same polymer synthesized in dioxane with 2,2'-azobisiso-butyronitrile as the initiator. It was shown that, despite the fact that some residual DMEA remained in the system, the properties of the PIA polymerized in the aqueous phase were very similar to the dioxane-synthesized polymer, which will enable a faster, cheaper, and environmentally more acceptable polymerization of itaconic acid. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 3275-3282, 2008