Phosphorous Acid‐Functionalized Polyamidoamine Dendrimer: Efficient Scale and Corrosion Inhibition

Abstract Phosphorous‐based polymeric scale and corrosion are widely used for industrial water treatment. In this paper, phosphorous acid modified polyamidoamine dendrimer (PDD) was prepared for scale inhibition and corrosion inhibition and compared with the existing inhibitors, 2‐phosphonobutane‐1,2,4‐tricarboxylic acid (PBTCA) and polyacrylic. The scale inhibition efficiency of CaCO 3 was evaluated using the static scale inhibition and conductivity method. Compared to polyacrylic acid, the dendritic structure can effectively improve the calcium carbonate scale inhibition performance of the scale inhibitor. When the concentration of PDD is 40 mg/L, the scale inhibition rate is 96%, which is higher than the scale inhibition rate of 91% for PBTCA. The conductivity experimental results reveal that PDD endows the solution with higher supersaturation degree than that of PBTCA at the same concentration. Furthermore, the nucleation induction period of PDD is 1300 s, which is more than twice that of PBTCA at a concentration below 20 mg/L. The XPS, XRD, and SEM results exhibited that PDD can adsorb on the surface of calcium carbonate crystals, changing the crystals from stable calcite to metastable aragonite and vaterite. In addition, electrochemical measurements show a corrosion inhibition rate of 82.67% at a PDD concentration of 100 mg/L. This article provides data support for the application of phosphorous acid functionalization PAMAM in scale and corrosion inhibition.