Application of thermal analysis methods for damage assessment of leather in an old military coat belonging to the History Museum of BraAYov-Romania

The aim of this work has been the assessment of the thermo-oxidative, hydrothermal and crystalline zone stabilities of several leather samples taken by the conservators from a military coat dated sixteenth-seventeenth centuries, belonging to the History Museum of BraAYov-Romania. For this purpose, the thermo-gravimetry/derivative thermo-gravimetry (TG/DTG), differential scanning calorimetry (DSC) and micro hot table (MHT) methods have been employed. The thermo-oxidative damage of leather has been characterized by the rate of the first thermo-oxidation process highlighted in TG/DTG curves recorded in static air atmosphere. The hydrothermal denaturation of leather has been characterized by MHT method and DSC analysis in excess water conditions. The damage of crystalline zone of collagen in leather has been determined by DSC analysis in nitrogen flow. The qualitative damage for each leather sample and each kind of deterioration has been evaluated using the criteria resulted by thermal analysis of a large number of collagen-based materials (pure collagens, new and old parchments and leathers). The obtained results could facilitate the choice of the restoration and conservation procedures applicable for the investigated military coat.