Abstract
Degradation of historical written documents, drawings and manuscripts containing iron-gall inks is a significant problem for years. Many researches proved that iron (II) ions and acids in the iron-gall inks cause damage of these documents. The purpose of this study was to assess the possibility of using degree of polymerization based on viscometric data in study of kinetic of degradation and determination of kinetic constant of degradation of model systems iron-gall inks - paper substrate. The obtained results were compared to the results obtained using degrees of polymerization based on gel permeation chromatography data. It was found, that the kinetic constants of degradation of model systems obtained from viscometric and from gel permeation chromatography data correlate.