GENERATION OF GLUCURONIC ACID DURING ALKALINE PEROXIDE BLEACHING OF ASPEN CTMP
Dissolved and colloidal substances (DCS) could be released into the process water during the bleaching of pulp, and the main component of anionic material in DCS was uronic acid, including galacturonic acid and glucuronic acid (GlcA). The aim of this paper is to investigate the origin of GlcA during alkaline peroxide bleaching of CTMP. Aspen CTMP and whatman No.l filter paper, which have been extracted with acetone, were bleached with alkaline hydrogen peroxide. The content of carbohydrate component was analyzed according the procedure of methanolysis, silylation and GC/MS. The results showed that large amount of GlcA existed in the fibres of bleached aspen CTMP and bleached filter paper. And GlcA in DCS of bleached CTMP is much more than that of unbleached CTMP. The increase of GlcA in bleached CTMP fibres may be due to the following reasons: the glucose units in the long chains of carbohydrates were oxidized to GlcA, the aldehyde-ester bond between xylan and lignin in the LCC may cleave to form GlcA, and Some of GlcA dissolved into the process water may re-polymerized and adsorbed on the fibre surface. The increase of GlcA in DCS of bleached aspen CTMP mainly attribute to the degradation and release of 4-Omethylglucuronic acid in hemicelluloses. The glucose in DCS can not further be oxidized into GlcA during alkaline peroxide bleaching.
aspen CTMP glucuronic acid alkaline peroxide bleaching GC-MS
Dan Huo Menghua Qin Yingjuan Fu Na Liu
Key Laboratory of Paper Science and Technology of Ministry of Education, Shandong Polytechnic University,Jinan, 250353, 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
1196-1201
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）