Stone artifacts conservation: synthesis and study of new partially flourinated compounds

The survival of our mankind’s stone heritage is confronted with severe, diverse degradation events that derive from physical, chemical and biological origins. Nowadays, to mitigate or/and halt the decay phenomena, synthetic polymers are widely used owing to their good hydrophobicity, chemical compatibility, stability and in some cases, the ability to act also as consolidation agents. Yet, they also show several drawbacks in long-term use. Acrylic polymers have poor photo-oxidative stability due to structural reasons, while silicon based resins are reactive with some specific stones and may become insoluble after in-situ polymerization. Weighing the pros and cons of these commercial protective agents, new products that incorporate high hydrophobicity, compatibility, stability and reversibility are urgently demanded. During the research for my Master’s thesis, a partially fluorinated oligoadipamide which contains pendant perfluoropolyether (PFPE) segments (FAD) has been synthesized and partially studied. FAD was proved to be a good water repellent for low porous stones, but it is not very effective for the protection of stones of high porosity. In general, the aim of my PhD research is the synthesis, characterization, performance, stability and durability testing of new compounds as protective agents for both low and high porous stone materials. Specifically, the first aim is the synthesis, characterization and performance testing of novel oligoamides containing PFPE blocks that are homologous to FAD. The similarities and differences of these compounds, in terms of physiochemical properties, performance as water repellents etc. was investigated and understood. Secondly, innovative, bioinspired ultra repellent coatings were also developed for building materials including stone artifacts. Meanwhile, by varying the synthetic routes, reagents, conditions etc. superamphiphobic coatings with self-cleaning and anti-biofouling properties were achieved. Last but not least, the stability and durability of newly synthesized products were evaluated as well.