Corrosion inhibitors are frequently added to corrosive environments for metal corrosion protection due to their economic and convenient advantages. However, most traditional inhibitors suffer from high biotoxicity and poor stability, limiting their long-term use in industrial applications. Herein, this study has developed a guanidino-functionalized hyperbranched polysiloxane corrosion inhibitor exhibiting outstanding stability, high efficiency, and low-toxicity potential. The guanidino functional groups grafted onto the ends of hyperbranched siloxanes rapidly adsorb onto metal surfaces like anchors. Simultaneously, the hyperbranched siloxane macromolecules “cover” these anchoring points, cross-linking to form a dense, robust hydrophobic barrier film. The “chemical targeting-physical barrier” synergy demonstrates outstanding corrosion protection performance and high corrosion inhibition efficiency for Q235 carbon steel in 1 M HCl, exhibiting 96.5% at a concentration of 150 mg/L. Its adsorption behavior conforms to the Langmuir adsorption isotherm model. Calculations indicate an adsorption enthalpy change ΔGads of −36.89 kJ/mol, demonstrating a synergistic effect between physisorption and chemisorption, which collectively contribute to the high inhibition efficiency. The developed stable and long-lasting low-toxicity corrosion inhibitor has significant industrial application potential in the acid washing descaling process.
Jia et al. (2026) studied this question.