Chitosan-Clay Based (CS-NaBNT) Biodegradable Nanocomposite Films for Potential Utility in Food and Environment

The aim of this work is to design newer material for food packaging applications and to valorize the Moroccan marine wastes using chitosan (CS) prepared from exoskeletons of shrimps. Biodegradable and uniform nanocomposite films developed from sodium bentonite nanoparticles dispersed in chitosan matrix were carefully studied. The montmorillonite is used as nanofiller, and aqueous acetic acid solution is employed as a medium for dissolving and dispersing chitosan and montmorillonite. The existence of dialdehyde chitosan as cross-linking agent was examined. Morphology, thermal behavior, and mechanical properties of the nanocomposite films have been studied using FTIR, TGA, FEGSEM, TEM, XRD, and a tensile test. The XRD results indicate the formation of an intercalated and exfoliated nanostructure at low bentonite content and an intercalated and flocculated nanostructure at high bentonite content. Plastic deformation of the chitosan film is carried out using a thermomechanical treatment in the presence of a solvent and a plasticizer. The nanocomposite films obtained show a good tensile strength due to the reinforcement of chitosan intercalation in the silicate, which is an interesting mechanical property needed for food packaging applications. These nanocomposite films made from naturally occurring materials might play an important role in advanced research in food and environmental science