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 bagas se dissolving pulp solubilized part of the carbohydrates by chelation with the hydroxyl groups or the lower molecular weight cellulose and h emicellulose. Borax, also, stabilized the long chain cellulose macromo lecules against degradation and dissolution in the alkaline medium. Ch elation with the hydroxyl groups belonging to two neighbouring cellulo se macromolecules increased the intermolecular distances and hence inc reased the degree of swelling in water and aqueous alkali. This was af fected in better reactivity towards xanthation.