Synthesis of polyaspartic acid/5-aminoorotic acid graft copolymer and evaluation of its scale inhibition and corrosion inhibition performance

Polyaspartic acid/5-aminoorotic acid graft copolymer (PASP/5-AOA) was synthesized by the reaction of maleic anhydride, urea and 5-aminoorotic acid (5-AOA). The graft copolymer (PASP/5-AOA) was characterized by FT-IR and UV–VIS analyses. Its performance was evaluated by static scale inhibition method and dynamic corrosion testing. The results showed that PASP/5-AOA possessed super scale inhibition property against CaCO3 and Ca3(PO4)2 as well as good corrosion inhibition property. Inhibition efficiency of PASP/5-AOA was close to 100% against CaCO3 when the dosage was 1 mg/L in the simulation experiment. Corrosion inhibition efficiency was close to 60% and scale inhibition efficiency was close to 100% against Ca3(PO4)2 when the dosage was 12 mg/L in the simulation experiment. When PASP/5-AOA was added to the solution, CaCO3 and Ca3(PO4)2 deposits show flower and cascade patterns with floppy accumulation by scanning electron microscopy (SEM).

► A new biodegradable scale and corrosion inhibitor, PASP/5-AOA, was synthesized.
► Inhibition efficiency is close to 100% against CaCO3 when the dosage is 1 mg/L.
► Inhibition efficiency is close to 100% for Ca3(PO4)2 when the dosage is 12 mg/L.
► Corrosion inhibition efficiency is close to 60% when the dosage is 12 mg/L.
► When PASP/5-AOA was added, CaCO3 and Ca3(PO4)2 crystals become irregular.