Synthesis, Characterization, and Enzymatic Degradation of Chitosan/PEG Hydrogel Films

Poly(ethyleneglycol) (PEG)/tartaric acid (TA)-crosslinked chitosan hydrogel (CPT) films were prepared, and the formation of the PEG/TA-crosslinked structure was confirmed by Fourier transformed infrared (FTIR), nuclear magnetic resonance (NMR), and scanning electron microscope (SEM) measurements. The thermal properties of the crosslinked films were also determined with thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) analysis. The swelling properties of the films were investigated at different temperature and pH values. It was found that the swelling ratio increased with the decrease of pH value of the surrounding buffer solutions, amount of PEG, and with the increase of temperature. Swelling behavior of the PEG/TA-crosslinked chitosan hydrogel films depended on pH and reversible with the temperature. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1556-1563, 2011