Therapy against metal corrosion based on polystyrene thin films: implication in cultural heritage conservation

For the protection of metal artefacts most of the used methods are based on organic substances that undergo various degradation processes, making necessary their removal with specific solvents, often dangerous both for the artefacts itself and the conservators. A possible solution to eliminate the problem of the solvents for the removal of the protection once degraded might be to put onto the objects surface a thin film witha low adhesion and strong internal cohesion, a “peel off'” protective, which, once deteriorated, can be easily removed without leaving any residues. The present contribution reports the application on metallic objects of films obtained from polystyrene solutions , that have the characteristics of low adhesion to the surface. In particular, tests were carried out on iron nails immerged in a corrosive solution and on some samples of “bronzed” brass artificially degraded. Morphological and chemical analysis carried out using SEM/EDX showed promising results in terms of protection against corrosion, also in view of a possible innovative therapy for the so called “bronze cancer”.