Two pulping methods were used on fibers and pith of sugar cane bagasse: soda/anthraquinone and ethanol/water. These pulps were submitted to carboxymethylation in a slurry of isopropanol/water (8/1 m/m) at 80ºC for 4 hours using a molar relation 8,8/5,4/1 of monochloroacetic acid/sodium hydroxyde/cellulose. The average degrees of substitution of the carboxymethylated products, determined by ¹H N.M.R. spectroscopy, were between 0.44 and 1.27, depending on the pulp employed for derivatization. The more substituted pulps were the more absorbent products, suggesting that the water retention capacity of these products is closely associated to their degrees of substitution.
Sugar cane bagasse; ethanol/water pulping; soda/anthraquinone pulping; absorbent; carboxymethylcellulose
