Development of New Functional Polyelectrolytes From Lignins.

点击翻译按钮获取中文摘要

It is quite essential to develop new and characteristic ligno-chemicals for the economically feasible total- utilization of wood. In this research, the developments of new ligno-polyelectrolytes which can be utilized as dispersing agents and soil additives, were aimed. For that purpose, the radical-sulfonation and alkali-oxygen treatments of several isolated lignins were accomplished under the various conditions. Here, the radical-sulfonation treatment was developed by the author, by which a sulfonic acid group is introduced into an aromatic nucleus at the ortho-position to a free phenolic hydroxyl group. This is why a radical-sulfonated lignin has been expected to show some characteristic and different nature from a normal lignosulfonate, in which a sulfonic acid group is located at the side chain of lignin.At the first stage of this project, we succeeded to establish the optimum treatment conditions for the radical-sulfonation treatment. At the second stage, the reactivities of various lignins were examined form the standpoints of their structural characteristics. It is very interesting to note that even highly condensed Klason lignin showed a comparable reactivity to kraft lignin. At the third stage, we studied the behaviors of water soluble lignins in aqueous solutions. It was found that these lignins do not exist as single molecules, but exist as aggregates presumably because of the hydrophobic interaction. At the final stage, the effect of these lignins to the growth of young white birch trees. It is too early to conclude at this noment, but a fully radical-sulfonated kraft lignin may have an acceleration effect for the growth of trees.