Synthesis of polyaspartic acid–aminobenzenesulfonic acid grafted copolymer and its scale inhibition performance and dispersion capacity

摘要

Polysuccinimide (abridged as PSI) was synthesized by urea and maleic anhydride.nAminobenzenesulfonic acid (ABSA) was introduced at different mole ratio to PSI to generatenpolyaspartic acid (abridged as PASP)/ABSA graft copolymer. The scale inhibition behavior of resultantnPASP/ABSA copolymer was evaluated by using static scale inhibition method. The transmittance ofnthe supernatant of the copolymer solution was measured to evaluate its dispersion ability for ferricnoxide. The corrosion inhibition performance of the copolymer for iron plates immersed in the refinedntesting water (including 0.555 g of CaCl2·2H2O, 0.493 g of MgSO4·7H2O, 50 mg PASP/ABSA graftncopolymer and 0.168 g of NaCl) was tested. It was found that PASP/ABSA copolymer was able tonefficiently inhibit CaCO3 and Ca3(PO4)2 scales and had good corrosion inhibition ability as well, and itnalso had good dispersion ability for Fe2O3. Besides, the inhibition efficiency of PASP/ABSA againstnCaCO3 and Ca3(PO4)2 scales and its dispersion capacity for Fe2O3 was highly dependent on dosage.nThe reason may lie in that PASP/ABSA copolymer simultaneously possesses carboxylic ion andnsulfonic group which can chelate Ca2þ to form stabilized and dissoluble chelates, resulting innincrease of solubility of calcium salts in water. Also it may lie in that the introduction of acidicnhydrophilic sulfonic group with a strong electrolytic capacity into PASP molecule simultaneouslynenhances the dispersion of the inhibitor molecules and hinders the formation of Ca (PO ) scale.