CHANGES OF LIGNIN STRUCTURE DURING ALKALINE PEROXIDE BLEACHING OF ASPEN CTMP
CTMP from aspen was bleached with alkaline peroxide. The residual lignins were isolated from both control and alkaline peroxide bleached pulps, and their structures were characterized by GPC, 31P-NMR and 2D HSQC NMR techniques. The results showed that guaiacyl unit was easier to be oxidized by peroxide than syringyl unit. Double bond groups in lignin side chain and β-O-4 type sub-structure with α-carbonyl or a-ether linkage were degraded, while β-β and β-5 type sub-structure were stable to peroxide bleaching. The contents of both aliphatic OH and COOH groups in residual lignin increased, whilst total phenolic OHs decreased obviously after alkaline peroxide bleaching. Mn, Mwand Mw√Mn of residual lignin obtained from bleached pulp were lower than those of the control pulp, approving farther that lignin has been somewhat oxidized and degraded during alkaline peroxide bleaching.
alkaline peroxide bleaching aspen CTMP lignin structure 31P-NMR, 2D HSQC NMR
Yingjuan Fu Yanzhu Guo Menghua Qin Fengshan Zhang Jianhua Li
Shandong Polytechnic University, Jinan, Shandong 250353, China Huatai Group Corp. Ltd., Dongying, Sh Shandong Polytechnic University, Jinan, Shandong 250353, China Huatai Group Corp. Ltd., Dongying, Shandong 257335, China
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
208-211
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）