In situ polymerization of 3-glycidoxypropyl trimethoxysilane (GLYTS) as a new tool for stone conservation

The effectiveness, as stone restoration materials, of a series of polymers obtained by "in situ polymerization" of the epoxy derivative 3-glycidoxypropyltrimethoxysilane (GLYTS) with the primary amine 3-aminopropyltriethoxysilane (ATS), at various molar ratios and concentrations, has been explored through selected preliminary tests. The experiments carried on a low-porosity quartzite show that, independently from concentration and molar ratio, all of the mixtures fail to significantly affect the porosimetric and hydric properties of this stone while inducing not negligible chromatic alterations. As it concerns high porosity stones, such as Comiso calcarenite, the 2:1 15% mixture only has been selected for further experiments since preliminary tests show that it acts as an excellent barrier against water penetration either by capillarity as by total immersion while showing only negligible chromatic alterations.