Double-Hydrophilic Block Copolymer as an Environmentally Friendly Inhibitor for Calcium Sulfate Dehydrate (Gypsum) Scale in Cooling Water Systems

In this study, a novel environmentally friendly copolymer acrylic acid-itaconic acid-allylpolyethoxy maleic carboxylate was synthesized and used for inhibiting the calcium sulfate dehydrate (gypsum) scale. The properties of the synthesized copolymer were characterized by Fourier-transform infrared, nuclear magnetic resonance spectroscopy and thermal gravity analysis. Also, the structure and morphology changes of scale crystals were studied by scanning electronic microscopy, transmission electron microscopy and X-ray powder diffraction analysis. The copolymer inhibition ability was evaluated by means of static scale inhibition experiments. Results show that the copolymer was effective in inhibiting the scales by changing the size and morphology of the crystals. The maximum inhibition efficiency was 99.8% at a concentration of 2 mg . L-1, far more efficient than most commercial inhibitors.