1H HR-MAS NMR reveals the degradation mechanisms of ancient documents

Water is highly important in regulating the physico-chemical properties of every biological system it interacts with. In this frame, paper is mainly constituted by an almost equimolar ratio of cellulose and water and the degradation mechanism of ancient documents is linked with the action of hydration water. Indeed, the interaction between water and cellulose within the fibres structure is the cause of breaking of the hydrogen bonds and of the consequent swelling of the cellulose fibres. In this paper, Nuclear Magnetic Resonance (NMR) spectroscopy results obtained by means of the High-Resolution Magic Angle Spinning (HR-MAS) technique have been shown for modern paper samples made of pure cellulose not aged and artificially aged as well as on ancient paper samples. These results show that water gradually affects the cellulose degradation in aged samples providing fundamental information for industrial applications and for the preservation and restoration of cultural heritage materials based on cellulose such as ancient paper or textiles.