Sulfuric acid bleaching of kraft pulp III: reactivity of kraft pulping-resistant structures under acidic conditions |
| |
| Authors: | Tsutomu Ikeda Yoichi Tomimura Kengo Magara Mitsuro Ishihara Shuji Hosoya |
| |
| Institution: | (1) Institute of Agricultural and Forest Engineering, The University of Tsukuba, 1-1-1 Tennoudai, 305-0006 Ibaraki, Japan;(2) Wood Chemistry Division, Forestry and Forest Products Research Institute, PO Box 16, 305-8687 Tsukuba Norin Kenkyu Danchi-nai, Ibaraki, Japan |
| |
| Abstract: | To investigate the bleaching mechanism, a lignincarbohydrate complex (LCC) model compound, a vinyl ether-type lignin model dimer, and a hexeneuronic acid model compound were treated with dilute sulfuric acid of different pHs. Beech kraft pulp and red pine kraft pulp were also treated with dilute sulfuric acid and then extracted with aqueous alkali. The amount of hexeneuronic acid degradation products in acid effluents and lignin dissolved in alkali effluents were determined. It was found that the benzyl ether-type LCC bond and the vinyl ether bond in lignin were effectively cleaved under the pH where sulfuric acid bleaching of kraft pulp was effective. Hexeneuronic acid group was also effectively degraded during sulfuric acid bleaching. In beech kraft pulp bleaching, both lignin removal and hexeneuronic acid removal contributed to the kappa number reduction. In red pine bleaching, the contribution of hexeneuronic acid removal was negligible, and most of the kappa number reduction was achieved by the lignin removal.Part of this report was presented at the 9th International Symposium on Wood and Pulping Chemistry, Montreal, July 1997 |
| |
| Keywords: | Kraft pulp Sulfuric acid Lignin-carbohydrate complex Vinyl ether Hexeneuronic acid |
| 本文献已被 SpringerLink 等数据库收录！ |
|
