Preparation of modified epoxy–SiO2 hybrid materials and their application in the stone protection

Abstract

• Preparation of epoxy–SiO 2 –PDMS-OH polymer. • Structural properties of epoxy–SiO 2 –PDMS-OH polymer were characterized. • Protective ability of epoxy–SiO 2 –PDMS-OH agents for limestone was evaluated. Epoxy–SiO 2 polymers modified by poly(dimethylsiloxane) hydroxyl terminated (PDMS-OH) were presented in this paper in order to evaluate their potential use as protective agents for stone surface. No volatile organic components were employed in this synthesis route which was environmentally friendly. FTIR, TG-DSC, SEM and AFM techniques were used to investigate the effect of adding PDMS-OH to (3-glycidyloxypropyl)-methyldiethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (ATS), which leaded to epoxy–SiO 2 –PDMS-OH materials. The addition of PDMS-OH into GPTMS and ATS accelerated the curing process and increased the viscosity of sol. It was found that PDMS-OH was chemically incorporated into the polymer matrix via Si O Si bonds by FTIR analysis. Furthermore, an appreciable reduction of microcracks was obtained for epoxy–SiO 2 –PDMS-OH polymers when adding 30% w/w of PDMS-OH. The effectiveness of the epoxy–SiO 2 –PDMS-OH polymers synthesized as stone protective agents was evaluated.