Photo-induced degradation of cellulose

Irradiation by light is considered to be one of the primary sources of damage exerted upon cellulosic substrates at ambient conditions. Yet, contrary to studies on thermal ageing of cellulose, only limited attention is devoted to light induced degradation of paper.This research demonstrates that extensive oxidative degradation of cellulose, accompanied by formation of hydroxyl radicals, occurs during exposure to light with λ G 340 nm. As demonstrated by size exclusion chromatography, degradation is not random. No high-molecular weight fraction appears in the irradiated sample, meaning that cross-linking is not a dominant process. This justifies the use of viscometry for light-irradiated cellulosic materials. Studies show that the rate of degradation, carbonyl formation and brightness decrease may be reduced by addition of magnesium carbonate. C 2005 Elsevier Ltd. All rights reserved.