Preparation and spectroscopic characterization of methoxy poly(ethylene glycol)-grafted water-soluble chitosan

摘要

The object of this study was to test the solubility of a methoxy poly(ethylene glycol) (MPEG)-grafted chitosan copolymer in organic solvents and aqueous solution. Water-soluble chitosan with low molecular weight (LMWSC) was used in a PEG-graft copolymerization. The MPEG was conjugated to chitosan using 4-dicyclohexylcarbodimide (DCC), and N-hydroxysuccimide (NHS). Introduction of PEG was confirmed by H-1 and C-13 NMR spectroscopy and FT-IR spectroscopy. The degree of substitution (DS) of MPEG into chitosan was calculated from H-1 NMR data and also by estimating the molecular weight (MW) using gel permeation chromatography (GPC). The DS values obtained from H-1 NMR spectroscopy and GPC were similar, indicating that MPEG-grafted LMWSC was synthesized and properly characterized. Furthermore, the introduction of PEG into chitosan increases the solubility in aqueous solutions over a range of pH values (4.0-11.0) and organic solvents such as DMF, DMSO, ethanol, and acetone. (c) 2007 Elsevier Ltd. All rights reserved.