PREPARATION OF DEAE COTTON-G-POLY(METHACRYLIC ACID) FOR USE AS ION-EXCHANGER

Diethylaminoethyl (DEAE) cottons having different % N were prepared by reacting cotton cellulose in the fabric form with diethylamine hydroc hloride at different concentrations in the presence of sodium hydroxid e. The modified samples so obtained were subjected to the graft polyme rization reaction using methacrylic acid (MAA) as the vinyl monomer an d potassium permanganate-citric acid system as the initiator. The perc entage of grafting (PG) was found to increase by increasing the % N, i ndicating that the presence of the DEAE groups in the molecular struct ure of the cellulose enhances the susceptibility of the latter to graf ting. DEAE groups seem to act as additional sites for grafting; and/or , by virtue of their basicity, they interact with the citric acid, the reby creating primary free radicals in the vicinity of the cellulose. As a result, grafting increases, increasing the initiator and monomer concentration, as well as the polymerization time and temperature func tions in favor of the PG. It was also disclosed that DEAE cotton-g-pol y (methacrylic acid) serves as cationic and anionic ion exchanger by v irtue of the presence of both DEAE and carboxylic groups. This was evi denced by the results of a detailed investigation on the ability of th e exchanger to adsorb direct and basic dyes as well as Cu2+ ions. (C) 1998 John Wiley & Sons, Inc.