Ponente
Descripción
Cuban natural bentonite (Bent) clay's distinctive properties—including its exfoliation into nanolayers in aqueous dispersions, high chemical stability, cation exchange capacity and swelling capacity—make it a promising reinforcing agent for polymer-based food packaging. In this work the incorporation of Bent into various biodegradable polymer matrices is evaluated in order to prepare hybrid nanocomposites with enhanced properties for food packaging. The casting method was used to prepare these nanocomposites by dispersing Bent into carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and their binary blends (PVA/CMC and PVA/PVP). The resulting films were characterized using scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). Evaluation of physical properties, such as thickness, opacity, and water resistance, revealed significant improvements with the addition of Bent. SEM images showed a homogeneous dispersion of the clay within the polymer matrices. Ultraviolet-visible spectroscopy (UV-Vis) confirmed increased opacity, particularly in Bent/HPMC films, suggesting their suitability for packaging light-sensitive foods. Bent/HPMC and Bent/PVA/CMC films exhibited notable water stability, remaining intact for up to 20 days in water immersion, while Bent/PVA/PVP films dissolved after 24 hours. Bent/CMC films required calcium chloride pre-treatment to enhance water resistance. The results highlight the potential of natural bentonite-based nanocomposites for developing sustainable and high-performance food packaging solutions.
Keywords: Bentonite, Films, Biodegradable polymers, Nanocomposites and Food packaging.
