Epoxy-silica hybrids as stone restoration materials

Hybrid organic-inorganic systems based on two epoxy-resins, the aromatic DGEBA and the aliphatic Eurostac 2101, and the amine ATS were developed for stone conservation. Their efficacy, explored through some preliminary tests such as water absorption, mercury porosimetry and appearance, was evaluated on two selected lithic typologies, Mistretta quartzite (MIS) and Comiso calcarenite (COM). The experiments carried out on MIS showed that none of the employed mixtures is able to significantly affect its porosimetric properties, while only DGEBA/ATS solutions reduce its water absorption, but cause not negligible alterations in appearance. The treatment of COM with DGEBA/ATS solutions does not alter significantly the porosimetric features while preventing the water migration inside the stone. On the contrary EP/ATS mixtures perform better in porosimetric terms, while water absorption tests are not promising.