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

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 CaCO3 and Ca3(PO4)2 scales was evaluated using static scale inhibition method, and its dispersion capacity for ferric oxide and ability to retard deposition of CaCO3 were also examined. It was found that PASPM was able to efficiently inhibit deposition of CaCO3 and had good dispersion ability for Fe2O3. The maximum inhibition efficiency, as high as 98.97%, was reached at an inhibitor concentration of 10 mg/L. The best dispersion efficiency for Fe2O3 was reached when 34 mg/L of PASPM was introduced into the tested solution, corresponding to 39.1% of light transmittance of the solution.

► Polyaspartic acid–melamine (abridged as PASPM) graft copolymer containing triazine ring was systhesized in an aqueous system in this article. ► The polyaspartic acid–melamine (abridged as PASPM) graft copolymer effectively improved the performance of aspartic acid on inhibition efficiency against CaCO3 scale and dispersion of ferric oxide. ► The whole pathway of the synthesis was green. ► Polyaspartic acid–melamine (abridged as PASPM) graft copolymer have excellent biodegradation performance.