Synthesis, Performance And Mechanism Of ESA/AMPS Copolymer

A novel environmentally friendly multifunctional scale inhibition dispersing agent ESA/AMPS copolymer was achieved by copolymerization of epoxysuccinic acid（ESA） and 2-acrylamido-2-methyl propane sulfonic acid（AMPS） with ammonium persulfate as initiator. Using maleic anhydride（MA） as the raw material, based on the synthesis conditions such as molar ratio of MA to NaOH, H2O2 dosage, reaction temperature and time, it was studied that the selection, the ratio and the dosage of catalyst to obtain higher yield of ESA. The optimum synthesizing conditions of ESA/AMPS, such as mass ratio of MA to AMPS, reaction temperature and time, initiator dosage, was discussed by the single factor experiment.The scale inhibition performance of ESA/AMPS copolymer were measured by the static anti-scaling experiments. The dispersion performance of ESA/AMPS copolymer on ferric oxide and its biodegradability were studied. The results showed that the ESA/AMPS copolymer has good performance of scale inhibition, dispersion performance and biodegradability. When the concentration of ESA/AMPS copolymer was 28 mg·L-1, the static scale inhibition rate on CaCO₃ was 74.9%. When the concentration of ESA/AMPS copolymer was 35 mg·L-1, the static scale inhibition rate on Ca3（PO4）2 reached 100%. The ESA/AMPS copolymer has good dispersion capacity for ferric oxide. When the concentration of ESA/AMPS copolymer was 35 mg·L-1, the transmittance was only 57.0%. In addition, 61% of the copolymer could be biodegraded within 28 days, which indicates that the copolymer is an environmentally friendly product.The structure of ESA/AMPS copolymer was characterized by fourier transform infrared spectrometry（FT-IR）, nuclear magnetic resonance（NMR） and elementary analyzer. The influences of ESA/AMPS copolymer on the crystal form and morphology of CaCO₃ scale samples were observed and analyzed by scanning electron microscope（SEM）, X-ray diffraction（XRD） and laser particle analyzer, and then the inhibition mechanism of ESA/AMPS copolymer was discussed. The results showed that the product preparing from the synthesis was the target product of ESA/AMPS copolymer, and the copolymer had effect of lattice distortion and dispersion on calcium carbonate. The effect could twist the morphology of the crystals, which inhibited the formation and growth of calcium carbonate.