Synthesis of polyaspartic acid–melamine grafted copolymer and evaluation of its scale inhibition performance and dispersion capacity for ferric oxide

Abstract

Polyaspartic acid–melamine grafted copolymer (denoted as PASPM) was synthesized by using polysuccinimide and melamine as the starting materials. Resultant grafted copolymer was characterized by means of Fourier transform infrared spectrometry (FTIR) and NMR. The scale inhibition behavior of PASPM copolymer against CaCO 3 and Ca 3(PO 4) 2 scales was evaluated using static scale inhibition method, and its dispersion capacity for ferric oxide and ability to retard deposition of CaCO 3 were also examined. It was found that PASPM was able to efficiently inhibit deposition of CaCO 3 and had good dispersion ability for Fe 2O 3. The maximum inhibition efficiency, as high as 98.97%, was reached at an inhibitor concentration of 10 mg/L. The best dispersion efficiency for Fe 2O 3 was reached when 34 mg/L of PASPM was introduced into the tested solution, corresponding to 39.1% of light transmittance of the solution.