Influence of acrylic coatings on the interfacial, physical, and mechanical properties of stone-based monuments

Conservation of historical buildings is an important issue. The environmental conditions seriously affect the monumental stones. Although different coating materials were tested, the polymeric materials have been showing the most promising results for protection of archeological stones. Therefore, in the current study, the acrylic polymer was used for conservation of monuments made of sandstone and limestone. The adsorption of the acrylic polymer onto both stones was analyzed and the durability of the coatings under different environmental conditions was tested and simulated by artificial aging. Moreover, the mechanism of polymer-stone interactions was elucidated by interfacial characterization techniques. The results showed that the adsorption of polymer onto either stones is physical as shown by Fourier transform infra-red (FTIR) and electrokinetic measurements. In addition, the presence of polymer coating shows a significant improvement in physical and mechanical properties of the treated stones, e.g., increase in bulk density from 1.9 to 2.3 g/cm(3) and decrease in porosity from 15.8% to 2.7% as well as the noticeable increase in compressive strength. All these measures indicated the suitability of acrylic polymer for conservation of either stones. (C) 2011 Elsevier B.V. All rights reserved.