Physical properties of PVOH/chitosan-blended films cast from different solvents

Homopolymer films of chitosan and polyvinyl alcohol (PVOH) and blended films consisting of PVOH and chitosan were cast from different organic acid solvents: acetic acid (AA), citric acid (CA), lactic acid (LA) and malic acid (MA) and characterized for mechanical and barrier properties. Intermolecular interactions were investigated with FTIR. Cross-linking and interactions with the solvent system resulted in a wide range of properties. Also, the effect of blends and acid solvent on the mechanical properties [tensile strength (TS), % breaking elongation (%BE)] and barrier properties [water vapor permeability (WVP)] was investigated. The organic acid used as a solvent affected mechanical properties and the WVP of PVOH/chitosan films blends. TS and %BE of PVOH/chitosan films were 13.5-221.9 Mpa and 5.2-451.8%, respectively. The WVP ranged from 0.19 to 0.62 ng m/m(2) s Pa. The range of properties, both intermediate from the component polymers and extending beyond either individual component suggests molecular interactions and cross-linking within the blends. Elucidation of these interactions continues. (C) 2001 Elsevier Science Ltd. All rights reserved.