Synthesis and structural characterization of MA /AA/AMPS copolymer and its inhibition mechanism to CaCO_3 scale

MA /AA /AMPS copolymer was synthesized using maleic anhydride( MA),acrylic acid( AA) and 2-acrylamino-2-methyl-propane sulphonic acid( AMPS) as materials by radical solution copolymerization. The structure and the thermal stability of MA /AA /AMPS copolymer are investigated by FTIR,NMR( H1 NMR and C13NMR) and TG-DTA,respectively. The inhibition perform-ance of MA /AA /AMPS copolymer to CaCO3 scale is studied through static scale inhibition tests,and the morphologies and the crystal habits of CaCO3 precipitates are investigated using scanning electronic microscopy( SEM) and X-ray powder diffraction( XRD) analysis. The results show that MA /AA /AMPS copolymer is a very good CaCO3 scale inhibitor,and it is also suitable to water treatment system at high temperature. The addition of MA /AA /AMPS copolymer changes the morphology and structure of CaCO3 crystal,which makes metastable vaterite and aragonite in the system stable. The produced CaCO3 precipitate is mixture of calcite,vaterite and aragonite.