Cellulose protection during ozone treatments of oxygen delignified Eucalyptus kraft pulp

Various totally chlorine-free sequences with a Z stage (XOZP, XOAZP, XOZRP, and XOAZRP) were implemented with a view to examining the individual and combined effects of using an additive (A), consisting of oxalic acid and a post-treatment (R) based on sodium borohydride on the properties of the resulting pulp and effluents. The performance of the reagents was analyzed through the study of: chain scission number in the cellulose chain; selectivity and efficiency of the process; crystallinity and carbohydrates composition of the pulps. Finally, the pulp, paper and effluents properties of the sequence including both treatments (XOAZRP) were compared with an ECF sequence of the XODPD type. The results were highly favorable.