NOVEL CATION-EXCHANGE COMPOSITES RESULTING FROM POLYMERIZATION CROSS-LINKING OF ACRYLIC-ACID N-METHYLOLACRYLAMIDE MIXTURES WITH CELLULOSE

Novel cation-exchange composites were prepared by polymerizing/cross-l inking of mixtures of acrylic acid (AA) and N-methylolacrylamide (NMA) in the presence of cellulose pulp using ammonium persulfate in conjun ction with a sodium thiosulfate, sodium metabisulfite, or glucose init iating redox system. The (NH4)2S2O8/Na2S2O3 . 5H2O redox system proved to be efficient for aqueous polymerization / cross-linking reactions and/or interactions of cellulose with highly concentrated mixtures of NMA and AA, used as commercially available, at very low polymerization temperature (30-degrees-C) and for a very short duration of polymeriz ation (90 s) using a liquor-to-cellulose ratio of 6.25 L/kg. Various p arameters that affect the synthesis of these composites, such as react ion temperature, concentration of redox system components, and drying temperature as well as AA and NMA concentrations, were reported. Four kinds of cation-exchange composites of different nitrogen and carboxyl contents were synthesized and characterized by investigating their po tentiometric titrations, water solubilities, and swellabilities as wel l as their durabilities.