Effect of iron on the long-term stability of cellulose: comparison between spectroscopic and molecular kinetics

Oxidizing properties of transition metal ions towards cellulose are well know and widely studied in respect to an induced discoloration as well as the formation of oxidized groups on the substrate. Iron gall inks represent the most well-know and highly degrading iron complexes in paper conservation. In order to investigate its influence on the oxidative breakdown of cellulose, a kinetic study on artificially aged model samples was carried out to ascertain the relationship between changes in optical properties and oxidized groups formation. Kinetic data show that iron enhances the degradation of cellulose but differently affects optical and molecular properties of sized and non-sized cellulose. Moreover, a good agreement in the kinetic parameters proves the reliability of the correlation between the formation of chromophores and oxidized groups over aging