Preparation and characterization of chitosan - clay biocomposites

Chitosan-clay biocomposites have been prepared in which montmorillonite (MMT) is used as nanofiller and diluted acetic acid is used as solvent for dissolving and dispersing chitosan and montmorillonite respectively. The effect of MMT loadings in biocomposites has been investigated. The characterization with different methods (FTIR, DSC, TGA, and SEM) on chitosan/MMT biocomposites systems was examined. Morphology and properties of chitosan biocomposites have been studied compared with those of pure chitosan. The FTIR and SEM results indicated the formation of an intercalated-and-exfoliated structure at low MMT content and an intercalated-and-flocculated structure at high MMT content. The thermal stability and the mechanical properties of the composites were also examined by DSC, TGA/DTG and tensile strength measurements, respectively. The dispersed clay improves the thermal stability of the matrix systematically with the increase of clay loading. Tensile strength of a chitosan film was enhanced and elongation-at break decreased with addition of clay into the chitosan matrix. Key words: Chitosan, biocomposite, montmorillonite, thermal properties