Volume 40, Issue 3 (May 2012)
Dissolving Behavior of Carbohydrate Ingredients During Pre-Extraction Process of Alkaline Hydrogen Peroxide of Bamboos
In this work, alkaline peroxide mechanical pulp (APMP), with pre-extracted bamboo by alkaline hydrogen peroxide, is prepared and the effects of pre-extraction on APMP in beating, bleaching, and physical properties are discussed. The results show that after pre-extracting, the energy consumption of beating has a significant reduction, the brightness of unbleached and bleached pulp are increased 5.0 % ISO (International Organization for Standardization) and 6.94 % ISO, respectively, the post-color PC number is reduced more than double, and the yield of bleaching pulp is maintained well. However, the tensile index and the folding strength is decreased, the burst index is kept, and the tear index is increased slightly. Furthermore, with the change of maximum temperature and holding time, in extraction liquid the extraction rate of the main sugars (glucose, xylose, arabinose, galactose) are detected with high-performance anion chromatography, and the contents of solids and the pH variation also are investigated. It is found that with the extension and increase of holding time and temperature, the pH decreases constantly, the contents of solids and the dissolution rate of sugar increase continuously to the maximum when the holding time is 1 h, and the temperature is from 80°C to 90°C. The dissolution rate of xylose is less than 1 %, and the highest dissolution rates of arabinose and galactose are 7 % and 12 %, respectively.