Carboxylate-Ended Poly(ethylene glycol) Macromonomers and their Copolymers as Inhibitors for Calcium Phosphate and Calcium Sulfate

Carboxylate-ended poly(ethylene glycol) macromonomers, namely allylpolyethoxy carboxylate (APEC), were prepared by means of a carboxy methylation technique with the obvious advantage of energy conservation. APEC and acrylic acid (AA) were then used as monomers to obtain AA/APEC copolymers. Fourier-transform infrared spectra and nuclear magnetic resonance were employed to characterize AA/APEC structure. Observations showed that AA/APEC was a much better inhibitor both for calcium phosphate and calcium sulfate compared to the commercial inhibitors, and it was also an effective inhibitor, even at elevated temperature, pH, Ca2+ and Fe2+ concentration or in the presence of biocides.