The Research On Using Surfactant In E.urophylla Grandis AS-AQ Pulp And TCF Bleaching

We chose the surfactant for the cocking in the first part of this paper, which can give the AS-AQ pulp a good result. And then we did a lot of research at LAS effect mechanism, which can make us understand the LAS action better. We screened the surfactant for bleaching in the second part of the paper. And we achieved a lot of conclusions, which will give us a guidance to choose surfactant for bleaching. The main conclusions:(1) The best arts and crafts of UG AS-AQ was sodium hydrate (12-13)%, sodium sulfite (16-18)%, AQ(0.06-0.1)%, LAS(0.2-0.3)%, the last heat preservation time (120-140)min. From the orthogonal test result, we got a good result of cooking. LAS gave a good effect which made the screen yield enhance 2.3%, whiteness increase 2.4%ISO, viscosity increased and rosin rundown, the fiber was easier to bleach.(2) LAS can not make the AQ to become small in cooking liquor. The diameter less than 0.45μm of AQ decreased 35% in the normal temperature because of LAS adding. And in the 90℃the consistence of the AQ diameter less than 0.45μm became fewer. LAS added in the cooking liquor which made AQ consistence increase 56% in the first one centimeter of chip, 73% in the second one centimeter chip, 27% in the third one centimeter chip. LAS added in cooking liquor which made sulfonic acid group consistence increase 12% and 19% in 100℃and 120℃, the sulfonic acid groups almost same in the 140℃.(3) Added surfactant in the oxygen bleaching can make the whiteness increased (2.6-3.8)%ISO, kappa number decreased, especially LAS made the kappa number decrease mostly. But viscosity will decreased by adding surfactant, especially the LAS. The composite surfactants (0.25%LAS and 0.25%AEO9) kept the viscosity to decrease 36mg/mL and the whiteness to increase 3.6%, Kappa number to decrease 1.3.(4) When Tween80 dosage was 20mg/mL added in the xylanase bleaching, the enzyme lives increased 27%; When Tween80 overrun 20mg/mL The enzyme lives will decrease. The whiteness of the xylanase bleaching increased when Tween80 increased; When Tween80 dosage less than 20mg/mL the whiteness increased quickly, the viscosity increased quickly, the Kappa number decreased quickly; When Tween80 dosage more than 20mg/mL the white ness increase slowly, the viscosity and the Kappa number kept same.(5) When the same series surfactant used in the aquae hydrogenii dioxide bleach, the bleach result is decided by the HLB number, which can give a direction for choosing the surfactant added in the bleaching. NP series is the best additive, 16.1 was the best HLB number, which consisted NP10 0.25%, NP40 0.75%.(6) Added different surfactants in the O-X-Q-P bleaching can make the whiteness increase 5.1%ISO, that mean a lot of resin was removed and more lignin was removed in the bleaching. And at same time the strength was increased which means the surfactant can protect the cellulose and hemicellulose avoiding hurt.