Mineral scales are formed in cooling water systems and they cause heat transfer problems. This study has been carried out to reduce the carbonate and sulphate scales of calcium. To inhibit the scale formation in cooling water systems, polyacrylic acid was synthesized, characterized and the ability of the polymer to mitigate the calcium carbonate and calcium sulphate scale formation was tested through chemical screening and electrochemical impedance techniques. X-ray diffraction (XRD) and scanning electron microscope (SEM) studies were performed to understand the morphological changes of the scales in the presence of the polymer. The gelation and iron dispersion ability of the polymer were also noted. The synthesized polyacrylic acid was compared with the commercial product AQUASUPER B99, which is basically a polyacrylamide. It was observed that this polyacrylic acid could be used for the cooling water applications. Among the two inhibitors, polyacrylic acid shows slightly better antiscaling properties even at higher temperatures and pH for both CaCO3 and CaSO4 scales compared to the commercial product. (C) 2010 Elsevier B.V. All rights reserved.