Development and characterization of a novel biodegradable laboratory-made pullulan blended films

Abstract

Aim: To develop and characterize laboratory-made pullulan blended film using pullulan obtained from yeast-like fungus Aureobasidium pullulans mixed with gelatin and sodium alginate. Methodology: The laboratory-made pullulan blended (LPB) and standard pullulan blend (SPB) films were prepared by the solution casting method. Physical and mechanical properties were performed to examine the moisture content, film thickness, film solubility, tensile strength and elongation at break. Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscope techniques were performed to analyze the interaction between the polymeric blends. Results: The polymeric blends had excellent miscibility and compatibility with the pullulan. The addition of glycerol to pullulan blended films improved the solubilization time in water at 125 sec. The blending ratio of pullulan, sodium alginate and gelatin led to lower rates of thickness, moisture content and higher elongation at break. Field Emission-SEM and FTIR analyses revealed that both sodium alginate and gelatin were compatible with pullulan. XRD results confirmed that pullulan blended films possess an amorphous structure that readily absorbs the moisture content. The biodegradability test confirmed the potential use of pullulan blended films as biodegradable plastic film. Interpretation: The laboratory-made pullulan blended films exhibited improved mechanical and water barrier properties due to strong interaction between the plasticizer and polymer matrixes which enhances the flexibility of pullulan blended films for the fabrication of biodegradable plastic film. Key words: Aureobasidium pullulans, Biodegradable plastic film, Microscopic techniques, Pullulan blended films