Thermal yellowing sensitised by pre-photo-oxidation of non-deacidified paper

Abstract: Characterization of oxidation products responsible for yellowing of paper through absorption and through emission is presented using independently UV–visible absorption spectrophotometry and microspectrofluorimetry to survey the thermal oxidation at 100°C and the photo-oxidation at λ ≥340nm and at 60°C of the three types of paper containing low amount of ligneous residues (SA papers) or not (WH and C papers). It was shown that due to secondary oxidation yellowing of product is favoured in the dark. It was shown that pre-photo-oxidation largely increased the yellowing in the dark. The effect of pre-photo-oxidation on yellowing through absorption and on yellowing through emission was shown to be different. [Copyright &y& Elsevier]