Optimization of reaction conditions for chitosan-g-methacrylic acid graft copolymers

The present paper deals with the synthesis of chitosan-g-methacrylic acid by free radical polymerization using potassium peroxymonosulphate/cyclohexanone as a redox pair in an inert atmosphere. The reaction conditions have been optimized by varying the reaction variables, including the concentration of methacrylic acid from (12 x 10^-2 to 36 x 10^-2) mol dm^-3, peroxymonosulphate (0.6 x 10^-2 to 1.2 x 10^-2) mol dm^-3, cyclohexanone (0.8 x 10^-2 to 1.6 x 10^-2) mol dm^-3, sulphuric acid (2 x 10^-3 to 6 x 10^-3) mol dm^-3, chitosan (0.6 to 1.4) g dm^-3 along with time duration and temperature. It has been observed that the maximum grafting ratio has been obtained at time 120 min, temperature 35 °C and at 2.2 x 10^-2 mol dm^-3 concentration of peroxymonosulphate. Metal ion sorption, and flocculation properties have been studied along with swelling property or graft copolymer. It has been found that graft copolymer shows enhancement in these properties and is thermally more stable than parent polymer The graft copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis.