Preparation of hydroxylated hexagonal boron nitride/isobutyltriethoxysilane hybrid latices for improved waterproofing performance of cement coating

•The optimum reaction conditions were obtained by comparing the modification effects of hydrothermal method on h-BN.•h-BN was dispersed in silane coating by means of covalent bonding.•The binding mechanism between h-BN and silane was investigated.•The enhancement effect of h-BN on waterproofing performance of silane coating under different dosage was studied. In this study, to improve the waterproofing of cement, hexagonal boron nitride (h-BN) underwent hydroxylation modification, and h-BN/isobutyltriethoxysilane (IBTS) hybrid latex was prepared by sol–gel method. The hydroxylation and structure of h-BN were investigated under different preparation and modification conditions. The optimal hydroxylation was obtained in the h-BN prepared at 140℃ for a heating time of 18 h with 8 mol/L NaOH. The bonding and interaction mechanisms of hydroxylated h-BN and silane were analyzed. Modified h-BN exhibited good dispersion in silane, thereby filling defects. Applying h-BN/IBTS on cement, the water absorption coefficient and average surface energy decreased.