Determination of environmental persistence and thermogravimetric analysis of paper artificially aged by photoirradiation.

Fabriano paper was aged by irradiation with ultraviolet light (k=310) in a veterometer for 300 hours. At fixed time intervals, samples of the paper under test were analysed by titanium dioxide photosensor to determine electrochemically the "environmental persistence" index, by a suitable conductimeter method, to determine the specific conductivity variation and by thermogravimetry to determine the moisture content, the onset temperature of the cellulose degradation process and the value of the activation energy of the same process. The behaviour of these different types of indicators displayed approximately monotonous trends as a function of time.