Graft copolymerization and characterization of styrene with chitosan via radical polymerization

In this study, styrene was successfully grafted onto chitosan by conventional free radical polymerization technique, using potassium persulphate (KPS) as the initiator. The effect of various reaction conditions including chitosan:monomer weight ratio, polymerization temperature, reaction time and concentration of initiator were studied. The highest percentage grafting (G %) 180% was found at 1:4 chitosan:styrene weight ratio, 0.4 g KPS and 70oC reaction temperature. Fourier transform infrared spectroscopy (FTIR) results showed the presence of polystyrene peaks, indicating the success of the grafting procedure. Thermogravimetric analyses (TGA) revealed that the thermal stability of the prepared copolymer is higher than that of chitosan alone. Mw and Mn of the isolated polystyrene from the graft copolymer were found to be 9.5249 × 104 g/mol and 3.0755 × 104 g/mol, respectively, with a polydispersity index of 3.1Keywords: Biomaterials, Chitosan, Grafting, Polymers, Polystyrene, Potassium persulphat