Gellan gum-g-N-vinyl-2-pyrrolidone: synthesis, swelling, metal ion uptake and flocculation behavior.

The synthesis of graft copolymer (gellan gum-g-N-vinyl-2-pyrrolidone) is carried out in nitrogen atmosphere using potassium bromate and silver as redox system. The reaction conditions for maximum grafting have been optimized by varying the reaction variables, including the concentration of N-vinyl-2-pyrrolidone (12.0 × 10(--2) to 28 × 10(--2) mol dm(-3)), potassium bromate (6 × 10(-3) to 22 × 10(-3) mol dm(-3)), silver (2.4 × 10(-3)to 5.6 × 10(-3) mol dm(-3)), sulphuric acid (2.0 × 10(-3) to 10 × 10(-3) mol dm(-3)), gellan gum (0.6-1.4 g dm(-3)) along with time duration (60 to 180 min) and temperature (30-50 °C).Water swelling capacity, metal ion sorption and flocculation studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.