Reinforced anticorrosive composite coating with mesh-brick structures and excellent air permeability on concrete

Abstract

The commonly used resin coatings have excellent anti-corrosion properties, but cannot meet demanding performance requirements in marine environment, such as high mechanical stability and water vapor permeability. Water vapor permeability is important for concrete coating, which will discharge the residual water in the process of cement hydration. In this work, regulated poly(methyl methacrylate) (PMMA) porous and reticulated membrane (“mesh”) and two-dimensional modified zirconium phosphate (S–ZrP, “brick”) were used to form a novel “mesh-brick” structure, constructing organic-inorganic coating (S–ZrP/PMMA coating). Then, the microscopic structure of composite coatings was detailed studied, and the performance were characterized by the capillary water absorption, rapid chloride migration, abrasion resistance, and water vapor permeability (WVP) test. The results show that the coating with “mesh-brick” structures can significantly improve the hydrophobicity, impermeability, and chloride ion penetration resistance of the concrete mortar. The effect of S–ZrP concentration on the properties of composite coatings was studied, with the best impermeability performance at a concentration of S–ZrP of about 9 wt%. Benefit from the “mesh-brick” structures, the abrasion resistance of the coating has been improved, the contact angle of S–ZrP/PMMA coating did not decrease significantly, showing better stability, which reached 123.8° ± 3° even after rubbing 1000 cm. And it also greatly improved the mortar's WVP, keeping the cement-based materials air permeable. It is promising to provide long-lasting and stable protection for concrete.