Chitosan-acrylic acid-polysuccinimide terpolymer as environmentally friendly scale and corrosion inhibitor in artificial seawater

A biodegradable and non-phosphorus chitosan derivative (CTS-AA-PSI) was synthesized with chitosan, acrylic acid and polysuccinimide, which can be used as a new environmentally friendly scale and corrosion inhibitor. The structure of CTS-AA-PSI was confirmed by FTIR, 1H NMR and 13C NMR. The CTS-AA-PSI showed outstanding scale inhibition performance with a scale inhibition rate of 87.96% at the concentration of 25 mg/L. The electrochemical impedance results indicated that CTS-AA-PSI showed a significant corrosion inhibition effect in a 3.5% NaCl solution with a corrosion inhibition rate of 71.17% when the dosage was 500 mg/L. In addition, the biodegradability experiment showed that its degradation rate was 72.32% on the 28th day. It was demonstrated that the CTS-AA-PSI is a readily biodegradable material. The possible scale inhibition mechanism was explored by SEM, XRD, XPS and EEM. The results indicated that the excellent scale inhibition performance of CTS-AA-PSI was related to its chelating and lattice-distortion ability, which inhibited the formation and precipitation of CaCO3 crystal. These findings suggest that CTS-AA-PSI is a quite promising candidate for an environmentally friendly scale and corrosion inhibitor.