Synthesis and characterisation of chemically modified chitosan microspheres

Chemically modified chitosan was synthesised by graft copolymerisation of poly(ethylene glycol) diacrylate macromonomer onto chitosan backbone. The polymerisation was initiated by ceric ammonium nitrate. Graft copolymers were prepared by varying the concentration of chitosan and the macromonomer. These graft copolymers were characterised by FT-IR, H-1-NMR and DSC techniques. Microspheres based on chitosan and polymer grafted chitosan were prepared by a polymer dispersion technique. Microspheres were characterised by scanning electron microscopy, (SEM) particle size distribution analysis and DSC methods. A comparative study in relation to the structural deviation among chitosan and modified chitosan microspheres is discussed. These chemially modified chitosans appeared to be hydrophilic and form aggregates during microsphere preparation. (C) 2002 Elsevier Science Ltd. All fights reserved.