Free radical graft copolymerization of methacrylamide onto agar

Graft copolymerization of methacrylamide (MAM) onto agar was studied in an aqueous solution using eerie ammonium nitrate, as an initiator. The graftin g reaction was influenced by the reaction time, concentrations of monomer a nd initiator and material-to-liquor ratio. The grafting reaction has also b een studied in the presence of solvents. The maximum percentage add-on (17. 28) has been observed at 30 degrees C for the concentration of monomer (0.6 9 mol/L), initiator (20 mmol/L), for the reaction time of 3 h. Acid hydroly sis and infrared (IR) spectroscopy were used for confirmation of the graft copolymer formation. Further, thermogravimetric analyses (TGA) of agar and a typical graft copolymer were studied. The solubility/swellability and the gelatinization characteristics are reported. (C) 1999 Published by Elsevie r Science Ltd. All rights reserved.