Photo-induced synthesis, characterization and swelling behavior of poly(2-hydroxyethyl methacrylate) grafted carboxymethyl chitosan

In the present study, carboxymethyl chitosan was prepared and characterized. Photo-induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto carboxymethyl chitosan (CMCs) was then carried out under nitrogen atmosphere in aqueous solution using 2,2-dimethoxy-2-phenyl acetophenone (PI) as photo-initiator. Grafting process was confirmed and the produced copolymers were characterized with aid of elemental analysis, FTIR, 2D-X ray diffraction, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of HEMA and PI concentrations and the reaction time on the grafting yield were investigated by determining the grafting percentage and grafting efficiency. Under the applied experimental conditions, the optimum grafting conditions were obtained at: CMCs = 0.2 g. HEMA = 0.615 mol/L, PI = 0.0078 mol/L and reaction time = 90 min. The synthesized copolymers revealed a self-ability to form physically crosslinked hydrogels. The hydrogel nature of the copolymers was investigated by studying the solubility profiles and the cyclic swelling-deswelling behavior of copolymers with different grafting extents. These investigations of the photo-synthesized graft copolymers showed that they can be tailored and exploited as promising carriers for drug delivery purposes. (C) 2010 Elsevier Ltd. All rights reserved.