Polyepoxysuccinic acid with hyper-branched structure as an environmentally friendly scale inhibitor and its scale inhibition mechanism

In order to improve the scale inhibition efficiency of existing polyepoxysuccinic acid (PESA) and to study the impact of their molecular structure on scale inhibition efficiency, a series of PESA with linear and hyper-branched structure have been designed and synthesized through co-polymerization reaction with glycidyl and epoxy succinate. The scale inhibition behavior of PESA with linear and hyper-branched structure against CaCO 3 and CaSO 4 scales was evaluated using static scale inhibition method, and their ability to retard deposition of CaCO 3 was also examined. The experimental results showed that, for CaCO 3 and CaSO 4 , the PESA with hyper-branched structure provides a scale inhibiting efficiency as high as 95.9% and 94.3%, respectively, at an inhibitor concentration of 15 mg/L. In addition, the processes of crystal nucleation, growth and crystal morphology have been analyzed. The experimental results show that the PESA with hyper-branched structure not only prolongs the induction period of CaCO 3 crystal nucleation, but also reduces the number of crystal nuclei and changes the size and morphology of the CaCO 3 crystal. Moreover, the FTIR, SEM and XRD analyses showed that the PESA with hyper-branched structure can induce the irregularity of growing CaCO 3 crystal, destroy the formation of crystals and change the polymorphs of calcium scale crystal. This conclusion indicates that the prepared PESA with hyper-branched structure has great potential for applying in the treatment of industrial water.