Abstract:
The cross-linking of chitosan in homogeneous solution by using glutaraldehyde as a crosslinking agent was carried out at room temperature. The effect of pH of chitosan solution on the crosslinking was examined in the range of pH 2 to pH 6 and amount of glutaraldehyde was examined in the range of 3.0x10 -7 mole to 12.0x10 -4 mole per 1 gram of chitosan. It was found that the condition at pH 4 and glutaraldehyde 3.0x10 -6 mole was suitable for preparing crosslinked chitosan film. Chitosan and crosslinked chitosan films were prepared from a solvent-casting technique and characterized their chemical and mechanical properties and degradation test. Crosslinking chitosan with glutaraldehyde produced a membrane with lower crystallinity and solubility and less water absorption, but better mechanical properties, especially at amount of glutaraldehyde 3.0x10 -6 mole per 1 gram chitosan. When amount of glutaraldehyde increase beyond this point, chitosan films become brittle ; and tensile strength and elongation decrease. The degradation test of chitosan and crosslinked chitosan films in physiological buffer solution were carried out at 37 ํC, pH 7.3 for 13 weeks. From weight loss and the retention of tensile strength, it was found that crosslinked chitosan films can be degraded faster than chitosan films