UPGRADING CHEMICAL PULPS FROM EGYPTIAN BAGASSE BY ALKALINE BORAX EXTRACTION DURING CEH BLEACHING

The addition of borax during the second step in the bleaching of bagasse dissolving pulp solubilized part of the carbohydrates by chelation with the hydroxyl groups or the lower molecular weight cellulose and hemicellulose. Borax, also, stabilized the long chain cellulose macromolecules against degradation and dissolution in the alkaline medium. Chelation with the hydroxyl groups belonging to two neighbouring cellulose macromolecules increased the intermolecular distances and hence increased the degree of swelling in water and aqueous alkali. This was affected in better reactivity towards xanthation.