Study of acid-resistant behavior of hydroxylated hexagonal boron nitride/isobutyltriethoxysilane composite coatings on sulfoaluminate concrete surfaces.

The corrosion resistance mechanism of h-BN/IBTS hybrid latex in acidic environment is elucidated as follows: The addition of h-BN improves shrinkage cracking during silane drying and enhances the densification of the composite coating. h-BN/IBTS hybrid latex reduces the leaching of hydration products from the concrete by blocking the entry of harmful ions and minimizes the formation of gypsum. [Display omitted] • A hybrid latex of hydroxylated h-BN and silane was synthesized via sol–gel method. • Incorporating h-BN reduces silane drying shrinkage and enhances coating densification. • After coating, h-BN adheres to the surface of hydration products, displaying excellent dispersion. • Hybrid latex reduces the dissolution of hydration products and blocking corrosive ion infiltration. Concrete, as the most common building material, is susceptible to erosion in acidic environments, leading to issues such as surface cracking and aggregate exposure. This study employs iso -butyltrimethoxysilane (IBTS) as the coating matrix and incorporates h-BN as a filler material to prepare h-BN/IBTS hybrid latex for addressing the problem of acid corrosion in concrete. By characterizing the binding state between h-BN and IBTS, tracking changes in mortar specimen composition during the corrosion process, this study analyzes the acid corrosion protection mechanism provided by h-BN/IBTS hybrid latex on the surface of mortar specimens. The experimental results demonstrate that hydroxylation-modified h-BN can effectively disperse within IBTS, thus alleviating the agglomeration phenomenon caused by silane volatilization. This enhancement improves the film quality of silane and increases coating tightness. The h-BN/IBTS hybrid latex significantly reduces the corrosion rate of cement mortar specimens in a sulfuric acid environment. This reduction is attributed to the introduction of h-BN, which substantially prolongs the erosion pathway for H+ and S O 4 2 - in sulfuric acid, reduces the formation of gypsum within the concrete's internal structure, and effectively preserves the microscale pore structure within the concrete. [ABSTRACT FROM AUTHOR]