![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
A fully bleached softwood kraft pulp was chosen as a model for pulp carbohydrates. The pulp was submitted to oxygen bleaching stages, to study the action of oxygen upon carbohydrates in the absence of lignin. The pulp was not degraded under mild conditions. In the presence of several metal ions, the carbohydrates were severely degraded by oxygen. Under these conditions, intermediate HO· radicals were detected. The results suggested an additional pathway to the classical mechanism proposed in the literature. The influence of a pulp pre-treatment with sodium borohydride was studied, and the origin of its protective effect during oxygen bleaching was demonstrated.