Effect of nitrogen oxides on aging processes of cellulosic materials

Exhibits deposited in museums or depositories, are exposed to surrounding environment, effecting material lifetime. Many factors are concerned, effecting the material degradation. Among the factors which cannot be influenced, there is material composition. Due to continuously rising of nitrogen oxide content in atmosphere, it is inevitable to deal with questions, what are the impacts of this atmosphere on the cellulose materials, new and historical, deposited in archives and book depositories. Mechanism of depolymerization during nitroxide-mediated oxidation of native cellulose is presented that has been studied under various conditions. Lignocellulosic materials containing poly-anhydroglucuronic acid is of very versatile lifetime. During storage of those materials, decaying of PAGA takes place, which is manifested by colour change and by loss of tensile properties.