Abstract
The effect of sulphur dioxide on chemical and physical properties of white writing paper (WWP) made from kraft softwood pulp and yellow writing paper (YWP) made from bagasse dissolving pulp for different time intervals (1-5 h) in the presence of ultraviolet light at constant temperature, pressure and relative humidity were investigated. The crystallinity changes in these pulps during exposure to sulphur dioxide were studied by X-ray diffraction. FTIR spectra showed changes in some function groups during exposure time as a result of reaction of sulphur dioxide with chemical constituent of the paper. Scanning electron microscopy (SEM) showed changes in fracture surfaces of the paper exposed to sulphur dioxide. The changes in the mechanical properties during exposure were also investigated. (C) 1999 Elsevier Science Ltd. All rights reserved.