On the Origin of Cellulose Depolymerization During Ozone Treatment of Hardwood Kraft Pulp

摘要: An oxygen-delignified eucalypt pulp (Eucalyptus grandis x Eucalyptus urophylla hybrid) was provided by a Brazilian mill. It treated with chlorite to remove lignin, or long acidolysis stage most of the hexenuronic acid groups (HexA) followed treatment lignin. Three samples were increasing ozone charges (up 2% on pulp) at high consistency and room temperature. The containing no lignin but all HexA appeared be affected treatment. This indicated that reaction generates radicals, which then react cellulose, leading depolymerization. also captures some these radicals. ESR spectroscopy confirmed hydroxyl radicals are formed when reacts maleic acid, can considered model compound. These findings open way improvement chlorine-free bleaching sequences stages.