Novel one-pot microwave synthesis of maleic anhydride based mineral scale inhibitors and their application

This paper presents our research efforts in discovery of pioneering synthetic routes and designing low molecular-weight maleic-anhydride (MA) homopolymers and MA-n-octylacrylamide (AAO) copolymers (YMR-series) and its application as scale inhibitors for mineral scales. Hence for the first time, solvent free, eco-friendly, rapid microwave-assisted method has been developed to synthetize these antiscalants with higher yield and better efficiency. The inhibition ability on the CaSO4 and CaCO3 scale is 100 % with 3 ppm dosage level at pH 10.45 and temperature 70 °C. Morphological changes of the CaCO3 and CaSO4 scales due to strong inhibition action of YMR-series polymers has been studied by scanning electronic microscopy (SEM) and X-ray powder diffraction (XRD) analysis. It is also observed that the antiscaling effect of the polymers greatly depends on the molecular weight while MA copolymers show better inhibition efficiency compared to MA homopolymers.