TiO2-Mesoporous Ceria Carrier Modified with Sodium Benzoate: An Innovative Polyurethane Matrix for Enhanced Corrosion Protection of steel

Abstract

An advanced corrosion protection system, distinguished by multilevel corrosion inhibition, was developed by integrating modified hybrid carriers strategically reinforced within a polyurethane (PU) matrix. For this purpose, mesoporous ceria (mCeO2) was synthesized via a hydrothermal hydrolysis process and incorporated with titanium butoxide to synthesize a hybrid core-shell titania mesoporous ceria (TiO2/mCeO2) carrier system. The TiO2/mCeO2 carrier system was modified with sodium benzoate (SB used as a corrosion inhibitor) to develop a modified TiO2/mCeO2-SB system. The synthesized modified particles were then reinforced into the polyurethane-based matrix to study the corrosion inhibition performance. Benefitting the corrosion-inhibiting properties of modified polyurethane-based coatings, the reinforcement of these modified TiO2/mCeO2 particles resulted in a notably improved anti-corrosion performance in the coating after immersion in 3.5 wt. % NaCl solution for four weeks, the impedance was estimated to be 96.65 GΩ.cm2, which is nearly four orders of magnitude than that of blank PU coatings. This is attributed to the synergistic anti-corrosion performance of TiO2 and SB. The protective layer formed due to the interaction of titania and hydroxyl ions resulted in the formation of Ti(OH)4 and SB absorbed on the steel surface, making iron unavailable for further electrochemical reaction. This work reports on the strategy to build a corrosion inhibition coating system, which introduces a new perspective for extending the lifespan of metals.