Cellulose degradation in newsprint paper ageing

The degradation of cellulose is an important factor influencing its physical, mechanical, optical and chemical properties and the longevity of paper in the electrical industry and in stored paper and books. A study of the accelerated ageing of newsprint paper has been performed at 98 °C during 0, 1, 2, 3, 5, 7, 10, 15, 20, 30 and 60 days. Degradation has been studied by viscometry, gel permeation chromatography (GPC) and saccharides determination. In the first stages of the accelerated ageing the cellulose depolymerisation takes place homogeneously (mainly due to the hydrolysis), later other reactions (oxidation, crosslinking) take place. The saccharides content in the paper decreases and the hemicelluloses are degraded faster.