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 1H NMR and FT-IR spectroscopy, elemental analyses and GPC. Estimates of the degree of grafting were quantitatively found from integration of the 1H 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.