New Insights into Lignin Modification During Chlorine Dioxide Bleaching Sequences (II): Modifications in Extraction (E) and Chlorine Dioxide Bleaching (D 1 ) # Brian N. Brogdon, 1, * Douglas G. Mancosky, 2 and Lucian A. Lucia 2 1 Kemira Chemicals, Inc., Marietta, Georgia, USA 2 Institute of Paper Science and Technology at Georgia Tech, Atlanta, Georgia, USA ABSTRACT Previously, it was shown that chlorine dioxide delignification (D 0 ) modifies kraft residual lignin by oxidizing phenolic groups to both quinonoid and muconic structures in 2-to-1 ratio (1.7 mmol/g lignin vs. 0.8 mmol/g lignin), respectively. Alkali extraction (E), in addition 221 DOI: 10.1081/WCT-200038087 0277-3813 (Print); 1532-2319 (Online) Copyright # 2004 by Marcel Dekker, Inc. www.dekker.com # Dedicated to Drs. Donald R. Dimmel and Thomas J. McDonough on their retirement from the Institute of Paper Science and Technology. *Correspondence: Dr. Brian N. Brogdon, Technical Department, Kemira Chemicals, Inc., 1525 Church St. Ext., Marietta, GA 30060-1023, USA; E-mail: brian. brogdon@kemira.com. JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY Vol. 24, No. 3, pp. 221–237, 2004