Preparation of silica/epoxy hybrid polymers as sealing layers on ceramic coatings and their stability study upon thermal treatment

Abstract

Amine end silica sol (NH2‐silica) was prepared to react with epoxy to make hybrid polymers. With the addition of NH2‐silica, the viscosity exhibited a declining trend until their amount reached around 20%. The hybrids possessed higher decomposing temperatures and higher residues relative to neat epoxy in air; their decomposing behaviors depended on the silica additions, attributing to the joint effects of incorporation of Si‐O segments and unstable state of silica sol upon heating. When these hybrids were brushed on ceramic coatings, they infiltrated into a depth of around 60 μm. As sealing layers, they probably experienced partially decomposing, slumping, and then filling the internal defects of the ceramic coatings, some hybrid residue even moved to the boundary areas adjacent to the steel substrates after repeated heating. These hybrids may be applied as sealants on ceramic coatings to prolong the lifespan of steel construction structure at high temperature. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47481.