Enhanced performances of polyvinyl alcohol films by introducing tannic acid and pineapple peel-derived cellulose nanocrystals

The applications of polyvinyl alcohol (PVA) films are still hampered due to great affinity to water, poor mechanical strength and lack of biological properties. To overcome these shortcomings, this study presented a successful development of PVA films by the introductions of tannic acid (TA) and pineapple peel-derived cellulose nanocrystals (PPNc). The structure, morphology, light transmittance, water adsorption and solubility, and mechanical properties of the prepared films were studied and compared. The uniform dispersions of PPNc and TA in PVA matric were observed by the SEM and XRD results. The introductions of TA and PPNc effectively enhanced thermal stability and tensile strength, but slightly reduced the light transmittance of the films. The water adsorption ability and solubility of the films were corresponded to the contents of TA and PPNc. Especially, the introduction of TA endowed the films with a strong anti-ultraviolet ability and antibacterial activity against Staphylococcus aureus. Based on the overall results, the prepared films can be used as green and active packaging materials. [GRAPHICS]