Poly(vinyl alcohol) - Chitosan blends: Preparation, mechanical and physical properties

Poly (vinyl alcohol)-chitosan blend films were prepared by casting the respective polymer solutions. The glutaraldehyde was used as a cross-linking agent. A series of PVA-chitosan blends were prepared by varying the ratio of the constituents. Mechanical and physical properties of blended films such as tensile properties in the dry and wet states, water uptake, surface tension and contact angle were characterized. Blending PVA and chitosan improved strength and flexibility of the films in the dry and wet states. Cross-linking with glutaraldehyde improves tensile strength and decreases elongation of the films. PVA Content in the blends increases water uptake while cross-linking the films with glutaraldehyde causes less hydrophilicity. Water uptake in PVA-chitosan blends can be controlled by variation of their contents, cross-linking agent and the pH of solution. Blending of PVA and chitosan improves bulk and surface hydrophilicity of blended films.