The effect of synthesized hydrolyzed polymaleic anhydride (HPMA) on the crystal of calcium carbonate

Precipitation of calcium carbonate followed by the adhesion of precipitates to equipment surfaces is the main problem of mineral scaling in cooling water systems. Many chemicals and antiscalants have been widely used to mitigate the mineral scaling problems. Hydrolyzed polymaleic anhydride (HPMA) was synthesized and used as antiscalant. The effect of Synthesized HPMA on the crystal of calcium carbonate was investigated through the calcium carbonate precipitation experiments. The synergetic effect of synthesized HPMA with 1-hydroxyethane-1,1-diphosphonic acid (HEDP) and polyacrylic acid (PAA) was also investigated. It was indicated that the order of the ability to prevent the precipitation of Ca2+ from bulk solution was HEDP / HPMA / PAA > HEDP ≈ HPMA > PAA. The morphologies and the crystal structure of the precipitates were investigated using Scanning Electron Microscope (SEM) and X-ray Diffractometer (XRD). It was indicated that HPMA could change the morphologies and crystal structures of CaCO3 precipitates. The irregular framboid spherical shape and vaterite crystal was observed in the presence of HPMA. HEDP and PAA could enhance the effect of synthesized HPMA on the crystal of calcium carbonate. The synthesized HPMA together with HEDP and PAA showed higher antiscale efficiency and synergetic effect on the crystal of calcium carbonate.