Synthesis and characterization of an ionic liquid- carboxylic acid copolymer scale inhibitor and its scale inhibition performance

摘要

A phosphorus-free scale inhibitor (ionic liquid-carboxylic acid copolymer) was successfully synthesized by the reaction of 1-sulfobutyl-3-vinylimidazolium hydrogen sulfate (SVIS) and acrylic acid (AA). The structure of the product was characterized by Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (H-1 NMR) and carbon-13 nuclear magnetic resonance (C-13 NMR). Then the scale inhibition efficiency of 1-sulfobutyl-3-vinylimidazolium hydrogen sulfate-acrylic acid (SVIS-AA) copolymer against CaCO3 and CaSO4 was determined. The results indicated that SVIS-AA copolymer showed better scale inhibition efficiency than poly (acrylic acid) (PAA). After that, the effects of temperature and Ca2+ concentration on the scale inhibition efficiency against CaCO 3 were studied. Results showed that when the temperature reached 90 degrees C, the scale inhibition efficiency could still remain 91% at a concentration of 18 mg L-1. When the concentration of Ca2+ reached 1,200 mg L-1, the scale inhibition efficiency could remain 70% at a concentration of 20 mg L-1. At last, the effect of SVIS-AA copolymer on the morphologies of CaCO3 and CaSO4 scale was studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD).