Synthesis and characterisation of chitosan-graft-poly(OEGMA) copolymers prepared by ATRP

Two synthetic routes, grafting-from and grafting-to the chitosan backbone, were investigated to prepare chitosan-graft-poly(OEGMA) copolymers by ATRP. The copolymers were characterised by (1)H NMR and FT-IR spectroscopy, elemental analyses and GPC. Estimates of the degree of grafting were quantitatively found from integration of the (1)H NMR spectra. The GPC data indicated that the hydrodynamic volumes of the polymers were significantly altered by the incorporation of poly(OEGMA). A comparison of the two synthetic methods showed differences in the ratio of synthetic and natural polymers present in the resulting combs. The grafting-to synthetic route was preferable as the polymers were of higher purity and more defined. (C) 2009 Elsevier Ltd. All rights reserved.